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Friday, November 9, 2018

Greenland melting and Latent Heat

Possible effects of Latent Heat with regard to the melting of Greenland are interesting.  As usual, this is speculation but based on old established physics.  So what is Latent Heat.

When you add heat to an object it gets warmer.  We will use the old imperial measurement since in this instance it is easier to understand.

A calorie (with a small 'c') was defined as the amount of heat needed to raise one gram of water by one degree centigrade.  This is not Latent Heat. The term used is Sensible Heat - possibly because we can sense when something gets warmer.  And, of course,  it will take 100 calories to raise one gram of water, from zero degrees to the boiling point.

There are two types of latent heat.  Lets start with the phase change from ice at zero degrees to water at zero degrees.  For this transformation, it takes 80 calories to melt one gram.  That is to say, the amount of heat to melt a gram of ice is the same as is needed to raise a gram of water from 00to 80 degrees Centigrade.  This is the latent heat of the phase change between ice and water.

Importantly, when water becomes ice, exactly this amount of heat is given out.  You might be tempted to say - "but won't this heat up the water".  No.  But it will keep the temperature at zero degrees centigrade until the water is all frozen.  When ice is melting (say in a styrofoam cup) it will remain at zero degrees until all the ice is melted at which time the added heat from the environment will cause the water to warm.

The second  latent heat is the phase change from water to water gas (water vapor).  To convert a gram of water to water vapor takes 540 calories.  This is 6.75 times as great as the phase change between ice and water.  This will be important below.

Let's see what the importance may be of latent heat with respect to the great big ice cube which is Greenland  or the even larger ice cube, Antarctica.

At some time in the not too distant future, all the ice will be gone on the Arctic ocean.  Initially it will only occur in mid September when the ice minimum occurs but the period of no-ice will widen in subsequent years.  Without ice, the heat absorbed by the open water will go into warming the water*.  Here is our first effect of Latent heat, in this case the Ice-Water Latent heat.  The ice will keep the water cold until it is all gone. When the ice is gone, the water begins to warm up.
Actually this is a bit of an exaggeration.  If you draw a cross section of the Arctic ocean to scale, it is a very shallow body of water in comparison to it's width.  Already, for a considerable portion of the melt season, large areas are ice free.  These are warming already since the ice that could keep them cool is far away across the ocean, but you get the idea.

As more and more of the water is ice free, we have ever warmer water on the surface of the Arctic ocean, heating the air from below and evaporating water vapor into the air.  Since the solar radiation penetrates into the water, the warming occurs over one or two tens of meters of the surface, depending on the clarity of the water.  It takes a lot of heat to warm water so the temperature only gradually increases but a very large amount of heat is stored in this surface water.  It heats and humidifies the air blowing across the ocean.  What happens when this air blows across Greenland.

First we must define The Lapse Rate.  The Lapse Rate is the change in temperature if you take a body of air and increase it's altitude without the addition or removal of heat.  For reasons, I won't go into, as air expands, it cools.  Conversely as it is compressed, it warms.  You can feel the practical effect of this if you pump up your tire with one of those cylindrical hand operated air pumps that you hold near the flexible tube that connects with the tire and pump with the other hand.  The hand holding the tube gets hot.  

Lapse rate is 9.8 degrees per km of altitude.  That is to say, if I took a perfectly insulated balloon full of air and raised it up a kilometer, it would be 9.80C cooler at the top than when I started up.

 Little boy inflatingf bicycle tires : Stock Photo

It gets a tad more complicated when there is water vapor in the air (as there always is) but we will leave that for now.

Now, for the sake of the argument let's assume that we have fully saturated air at 100C blowing onshore in Greenland.  The air hits the ice.  Look at the following table.  That 10 to the minus 3 kg/m cubed in the third column is their way of saying grams so a cubic meter of saturated air at 100c contains 9.39 grams of water in the form of water vapor.

Water Content
(oC)(oF)(10-3 kg/m3)(10-3 lb/ft3)
-25 -13 0.64 0.040
-20 -4 1.05 0.066
-15 5 1.58 0.099
-10 14 2.31 0.14
-5 23 3.37 0.21
0 32 4.89 0.31
5 41 6.82 0.43
10 50 9.39 0.59
15 59 12.8 0.8
20 68 17.3 1.07
30 86 30.4 1.9
40 104 51.1 3.2
50 122 83.0 5.2
60 140 130 8.1

This saturated air contacts the ice at 00C and the ice cools the air and causes water to condense out of the air.  Remember that as water vapor changes into water, it gives out 540 calories per gram of water.  Each gram of water condensed from the air gives out enough heat to melt six and three quarter grams of ice*.

*Incidentally if you want to read a dramatic account of a warm wind blowing across ice, read the book Plains of Passage by Jean Auel.  True it is a novel but Jean did her homework and reports what generations of glaciologist have observed.  It is somewhere around chapter 42 or 44.  I can't find my copy of the book.   

Let's back up a step. Where did this heat actually come from.  The wind blowing across the open water is picking up the water vapor from above the ocean.  Each gram of water that evaporates from the ocean takes this 540 calories from the ocean.  So the air is cooling the ocean and the heat is being contained in the air as latent heat.  If you have a wind that is blowing for some time from the water to the ice, a considerable amount of heat can be transferred.

You remember, I said that the top ten or twenty meters of water are heated by the sun.  As the surface water is cooled by the wind, it sinks and warm water comes to the surface.  If the water has been open for a good portion of the summer, there is a lot of heat available.

Note that sun shining on snow isn't very good at melting it.  Most of the radiation is reflected back to space without warming the snow.  Clear ice or ice with a pool of water on its surface is a little different.  The radiation penetrates but has to heat a considerable layer of ice up to zero degrees C before melting starts.  

A warm wind or a wind with lots of water vapor is something else again.  The heat is applied on the very surface of the ice and is constantly replenished from the sea.  If there is considerable water vapor in the wind, latent heat of condensing water vapor is added to the sensible heat of the wind. 
 Sea ice reflects as much as 85% of solar radiation hitting the surface, hence absorbing only 15%. Ocean water, by contrast, reflects only about 7% of solar radiation, absorbing 93%.

If this was dry wind blowing across  Greenland, it would only contribute sensible heat to the ice.  The air would cool both by contact with the ice and the expansion of air as it rose up the slope.  However with a high water vapor content, some of the latent heat of the condensing water vapor stays in the air.  

You remember, in our example we started with 10 degrees C, fully saturated air.  At a little over a km in altitude, it would have cooled to zero degrees and would stop melting the ice.  However some of the latent heat which is released as water vapor condenses into droplets (fog), the air will remain above zero degrees to a higher altitude, all the while melting the ice.

Of course the situation get's rapidly worse as the air becomes warmer than the 100 C we took as our example and the water vapor content of the air increases.  Have a look back at the table. 

While we are at it, there is another scenario that may be relevant to the story of a melting Greenland.  

Suppose there isn't much wind but Greenland is bathed in war moist air right to the top.  This air is light (relatively) due both to it's temperature and it's water vapor content.  That's right.  Humid air is lighter than dry air.  The reason is interesting and explained below.  It is in contact with the ice.  The ice cools this air and condenses out some of the water vapor making it heavier.  If the droplets of water stay in the air as fog, this exacerbates the effect.  This air now begins to flow down the slope as a density current.

You remember the lapse rate.  It works in the other direction too.  For every km that this air flows down the slope (vertical kilometer), it warms by 9.8 degrees C.  by compression.  Of course, it doesn't actually warm.  It transfers this heat to the ice, melting it.  These are the the famous Piteraqs that are seen around the shores of Greenland.   

A body of air flowing from the very top of Greenland to the sea would warm almost 30 degrees if it didn't gain or loose heat.  This heat plus the latent heat of water vapor condensing on the ice is available to melt the ice.  We should see some rather extreme melting events in the future.

Relative density of gases  
Gases have some interesting properties.  The volume of a gas is inversely related to pressure (if you keep temperature constant).  That is to say, if you double the pressure, you half the volume.  The volume of a gas is directly related to temperature.  Not Centigrade but Kelvin temperature otherwise known as absolute temperature.  This is temperature measured from absolute zero.  If you increase the temperature of a liter of a gas, for instance, from zero degrees centigrade (2730K) to 100 degrees centigrade (3730K) then the volume will increase by 373/273 =  1.37liters.

Leaving all this aside, let's get on to the really interesting aspect of gases.  It turns out that a given volume of any gas at the same temperature and pressure contains the same number of particles.  I say particles rather than atoms since many gases exist as molecules of two atoms such as N2, O2 and H2.  This has an interesting implication.  If you know what gas you have, you can work out it's relative density to, for instance, air.

Now air is a combination of mainly Nitrogen and Oxygen.  An atom of Nitrogen has an atomic weight of 14 so each N2 atom is 28.  Oxygen, similarly has an molecular weight of 32.  So air is approximately 30 (I should have done a weighted average but we are just illustrating the principle).  Water vapor consists of two hydrogen atoms and one oxygen atom so has a relative weight of 18.  Water vapor is only 18/30 = 3/5ths or 60% as dense as air.  Now we need one more property of gases.

When you put sugar into water it dissolves and  to some extent the sugar fits between the water molecules.  The volume of the sugar and the water is somewhat less than the volume of the water and the sugar added together.  Gases are not like this.  Each molecule occupies the same volume as any other molecule.  So if you add a tenth of a liter of water vapor to a liter of air (with no condensation, of course) you end up with 1.1 liter of gas.

You can see, therefore, that humid air which is a mix of water vapor (relative density 18) and air (relative density 30) is lighter than dry air.

All bets are off, of course, if the water vapor condenses into fog.  Now you have a suspension of water droplets in air and it is heavier than dry air.

So we have a couple of mechanisms that could cause a rather striking acceleration in the melting of the surface of Greenland.


Thursday, October 25, 2018

The End of the Ice Age

Sorry to rain on your parade but it ain't over.  We are still in the middle of an Ice Age.  It has been going on for about 2.8million years and is not over.  It is actually, if named  correctly, an epoch.  Namely the Pleistocene Epoch.  This Epoch is colloquially called the Ice Age.

During the Pleistocene Epoch (Ice Age)  there have been many icy periods (Glacials or glacial periods) and relatively ice free periods (Interglacials or Interglacial periods).  We are at present in the Holocene Interglacial and the previous one around 125,000 years ago was the Eemian Interglacial.  You could say that the Holocene Interglacial started 20,000 years ago since that was the peak of the previous Glaciation but melting really got underway a little less than 12,000 years ago so that is usually taken as the beginning of the Holocene Interglacial.

We should already be beginning our slide into the next Glacial period (not Ice Age - remember, we are still in an ice age) but the plow, rice paddies and the destruction of forests slowed our slide into the next galcial just long enough for the Industrial revolution to kick in and send us into a warming phase.  Read Plows, Plagues and Petroleum by Ruddiman for chapter and verse on the plow, plagues and rice paddies.  Despite early (from about 8000 years ago) human influence delaying our slide into the next glaciation, we apparently were just starting into the next glacial period when the industrial revolution reversed the trend.

The final straw in our slide into the next Glacial was the demise of the population of North America due to European diseases and the black death in the 'Old world'  Both resulted in forests regrowing and the suck down of Carbon dioxide just enough to start the accumulation of snow way up on the high lands of Baffin Island.  Apparently there is still a halo of dead lichens around this area where the expanding permanent ice and snow killed the lichen.  Green house gases then increased enough to reverse the accumulation of snow.

Some scientists are predicting that we are going into a sort of Maunder Minimum in which sun activity decreases.  No way, though, that this will reverse our warming.  We have put way too much Carbon dioxide into the atmosphere.

Our output of green house gases, by the by, long before the industrial revolution, is the explanation of why this interglacial has been so much more stable, weather wise, than previous interglacials.

With our output of Green House Gases and especially Carbon dioxide, we have put off the next glacial and with a little luck we may put it off until the next Interglacial.

However, we now have too much of a good thing and it is time to put carbon back into the soil, into trees and to stop adding more to our atmosphere.  We have the technology.  Any reasonably bright year 12 student could tell the politicians exactly what they should be doing but the politician won't listen.  They want to be elected next time and need the money from the vested interests to succeed.  Until we make it illegal for anyone to contribute anything to any politician for any reason whatsoever, we will be pushing the brown stuff uphill with a spoon.  Never was the old adage, Who Pays the Piper Calls the Tune more true.

One of the barriers to the use of renewable energy is it's unpredictability.  In the long term, you know more or less how much wind and sunshine you will get at any location but it comes in unpredictable booms and busts.  There are may fixes including notably,  demand balancing of our grids (electricity priced to reflect the extent of availability over  demand and devices that use electricity selectively when it is most available and hence least expensive).  However, a really good battery for stationary applications would go a long way to help.  Fortunately there is a technology in the wings, which could fill in the gaps left by other methods and systems.  It is the Vanadium flow Battery. Another one recently developed is the Zinc bromide flow battery.

You might ask yourself, why I get so up tight over terminology - namely the misuse of the term Ice Age.    You will see in the popular literature and even in scientific papers, the use of the term Ice age to mean the glacial period between the present Holocene interglacial and the previous Eemian interglacial.  Why is this important.  We as humans are prone to lie to ourselves.  For instance, we note that the megafauna of North America disappeared when the Ice Age ended.  And we admit that man might have had something to do with it but it was probably climate change.  Nonsense.

First, as I said, we are still in an Ice age.   (The Pleistocene Epoch to be totally correct) so it hasn't ended.  But that is the least of the deception.  The Mega Fauna survived repeated cycles of glacials and interglacial and depending on how you define them, there have been between 30 and 50 such cycles within the present ice age (Pleistocene epoch).

No, the NA mega fauna disappeared at the end of the most recent Glacial period.  They survived quite happily the end of many previous Glacials and the subsequent interglacial and only the recent one caused their demise.  The only difference was the arrival of the first people who ate their way through these animals from one end of the Americas to the other.  If you don't think that primitive hunters could wipe out the mega fauna of the Americas, just look at the extinctions in Australia (50,000 years ago) and New Zealand (700 years ago) or in  any other  area when man first arrived.   Now we are finishing the job with habitat destruction.  Soon we will be alone in the world and then pooooof.   We are Gone Burgers. Evolution can begin again from whatever remnants remain.

ps.  Note that there are indications that around 12,000 years ago, there was a major meteorite hit on North America which left a layer of sediment recording it's existance.  This could have had an effect on the fauna of North America but there would only have to be a few 'refugia' left for the animals to make a come back.  Future work may shed more light on this possibility.

The Anthropocene actually started at different times in different locations with the arrival of man.  So much for first people being the guardians of nature.  In actual fact, they eliminated any animal that they could hunt faster than it could reproduce. Now modern man is finishing the job.

Tuesday, September 11, 2018

The story of wheat

I have just purchases a grain mill to make my own flour and hence the interest in this fascinating story.

                 The Story of Wheat

In the 'old days' you would take your wheat to a miller, he would grind it and you would take it home to bake delicious nutritious bread. But there was a problem.  Wheat berries would last till the next harvest and beyond, but once you ground the flour you had to use it or refrigerate it.  The oil in the germ was spread through the flour, the wheat was no longer alive and over time, it went rancid..... so, in the summer, you ground only enough wheat at one time for at the most a month.
 Image result for image grist mills

Wheat  was full of essential minerals, vitamins and oils that mainly came from the germ* (80%) plus some nutrients and valuable bulk from the bran. In a minute you will see why I said "was".

*The germ is the little embryonic plant inside the grain.  It is only about 20% of the weight of the wheat seed (berry) but contains 80% of the nutrients.  It is most easily seen in a dicot like a bean.  Soak a bean in water overnight and then dissect it.  You will see the little embryonic plant between the two sides of the bean.

Since wheat was harvested in the fall with winter coming on, ground flour would last for quite a while before going rancid as long as you kept it cold.

The short slelf life of flour didn't please the business men who saw a great chance to make a profit.  They wanted to be able to buy large quantities of wheat from the farmers, mill it into flour and ship it far and wide.  Fortunately for them along came the roller mill.  This allowed the  germ to be sieved out of the flour and presto chango, you had a commercial commodity that would last without refrigeration for a very long time.
 Image result for image modern flour mill

This was the beginning of the end for wheat as the 'staff of life',

For some unfathomable reason, white flour was considered a great luxury so the millers also sieved out the bran.  Was this possibly promoted by them??.  Out went  the little nutritional value left in flour and to add insult to injury, they worked out a way to bleach the flour.  All that was left was the bleached endosperm.  The bran and the germ was fed to animals who were better fed than us.

In the third world, many folks once ground their own flour and some still do so wheat was still a vital part of their diet but we in the west have found a way to even muck that up.

In the 1960's along came Norman Borlaug.  He was a plant breeder and got the Nobel prize for his work in the 70's.  He realized that you could increase the yield of the wheat plant considerably by conventional breeding but that the stalk of the wheat plant would have to be shorter so that wind would not flatten the more heavily laden wheat plant.  He bred not only wheat but rice and other grains to produce vastly greater yields.  In some cases he tripled the yield of these vital food sources.  So what was the down side.

Yields per wheat plant were greatly increased but the nutrient content didn't keep pace.  In fact it stayed the same per wheat plant as before.  Because of this wheat and other grain contained as little as a third of the essential nutrients per kilogram as previous varieties.  Starvation was fended off (at least for a while) but people suffered from nutrient deficiency. 

As a side effect, it is estimated that with the cessation of famine in a number of third world countries, there are now 700m more people in the world than would have been the case without this agricultural revolution.

As Richard Dawkins said in  his book The Greatest Show on Earth,  "If there is ever a time of plenty, this very fact will automatically lead to an increase in population until the natural state of starvation and misery is restored."

There is a get out of jail card and if you want to see what it is, click here.  It is not relevant to this discussion.

Come forward to today.  Wheat berries last a very long time.  The wheat is alive (as you can see by sprouting some) and under good conditions will last for decades.  The farmer can use this to maximize his profit.  If he has a silo, he can augur his wheat into the silo and sell,  either when the price is right, or when the grain merchant or miller has space in his silo to take his wheat.  But there is a problem. 

Along with the wheat he can be putting insects and insect eggs attached to the grain into his silo.  So what does he do.  He dribbles a little organophosphate into the grain as it is augured into the silo.  The Active compound is Pirimiphos-methyl, often going under the brand name Actellic.  (There are many other products with the same active ingredient).

As one farmer told me, the grain merchant, not trusting the farmer, puts in a little more and the miller ditto.  This might have been tongue in cheek or perhaps not.

If you read the rap sheet on Pirimiphos-methyl, it talks about full body protection when using the product and one rap sheet suggested that if you have any choice, use something else.  That is how toxic this product is and it is put regularly into our wheat; a product that is not only the main ingredient of our bread but is in a vast array of other prepared products.  Do you ever get the impression that you know an awful lot of people with cancers.

Info on organophosphates says that besides being carcinogenic, they cause dizziness, nausia, loss of memory, nuralgia (whatever that is) and a raft of other symptoms.

What is sad is that the use of Actellic is completely unnecessary.  Enlightened farmers, and there are precious few of them, pump Carbon dioxide into their silos from the bottom.  It does the same thing.  Carbon dioxide is one and a half times as dense as air so by introducing it into the bottom of the silo, it pushes out the air.  Any aerobic organism dies.

It gets worse.  Many farmers roundup their grain fields shortly before harvest.  This has two purposes.  First it brings the grain to ripeness all at the same time.  The grain is not killed, only the plant. The second reason is to stop his harvester from plugging up with weeds.  Of course, if it is roundup-ready wheat, it is also rounduped during its growing phase.  (Does New Zealand import roundup ready wheat for milling??).

We now have two carcinogens in our wheat and hence in our food chain.  Note that roundup has not been proven to be carcinogenic to humans.  No ethics committee would agree to the necessary experiment!!! However it has been shown to be carcinogenic in animals.  As the lawyers say, I rest my case.

So wheat has  been bred to reduce nutrients, machined to further take out what was left, bleached (in the case of white flour) and now poisoned, all in the name of profits for the industrialists.  I wonder how many other products that we eat day in and day out have a similar story.  How many of these additives
work synergistically to cause cancers.  For that matter are people really gluten intolerant or are some of them simply showing a reaction to the poisons they are ingesting.

Friday, August 24, 2018

Grinding your own flour, Making your own bread

I'm away from home just now but when I return at the end of the month (7/18) there should be a flour grinder waiting for me.  I suspect I will be making updates to this blog for years as I discover the joys of producing and using my own flour.  What have I discovered so far.

Apparently threshed and winnowed wheat berries (grain) will last for decades if kept, even at room temperature, as long as they are kept dry.  I remember something I read many years ago.  Somewhere, I can't remember where, there are some people that make grain storage bins from ferro-cement, buried in the ground with the removed soil making a berm around the entrance.  The bins are conical in shape getting wider toward the bottom.  Grain is alive.  It uses Oxygen and produces Carbon dioxide.  Apparently when the grain is stored this way, any insects, mice and anything that needs oxygen to survive dies.  The grain is preserved this way for very long periods.

Some "modern" folks apparently use a plastic liner for the grain.  Critical is to have the grain below 14% moisture for long preservation.  

In contrast, when grain is ground, it's shelf life is very short unless refrigerated and even then should be used in a week or so.  This is why the flour you buy at the store, even the brown flour, doesn't hold a patch on real whole meal flour for nutrition.  When you used to take your wheat for grinding to the mill, bread really was the staff of life.  However, in order to turn flour into a marketable commodity that would last, the germ had to be removed.

 This is the little wheat plant that is tucked into the grain and while it is about 20% of the weight of the wheat berry, it contains some 80% of the nutrients.  Using roller mills it was possible to remove the germ and make a flour that would last for a very long time and could be shipped long distances.  However, as with so much of our food, we lost a huge amount by having this convenience.

By the way, if you want to see the germ (the little plant in a seed), it is most easily seen in  a bean seed.  A bean is a dicot which means that the endosperm is stored in two halves and they can be split to expose the germ.  Soak a bean seed in water over night.  In  the morning, carefully remove the outer coat and split the two halves apart.  You will see the little plant inbetween.  You can even leave the bean in water that only partially covers it and let it sprout.  The little plant grows and can be more easily seen as can the cotyledons.  It is harder to do this with wheat but the principle is the same.

I have my grinder but before I get into it's use, I must tell you some more I have discovered about our wheat supply.  It is not pretty.

I have checked with a number of farmers and a grain merchant and the story remained the same with all of them.  Apparently when grain is augured into the silos, a little Pirimiphosmethyl is added against insect pests.  This can be added by the farmer, especially if he is going to store his wheat in his own silos for any length of time, by the grain merchant and/or the miller.  If you look up the rap sheet on this chemical, you find a recommendation that if you have any other choice of pesticide, use it.  This stuff is nasty. Besides being highly poisonous (you guessed it) it is a carcinogen. It gets worse.

If the weeds have got away from the farmer toward harvest time and even earlier if the farmer is using 'roundup ready' wheat.  he will roundup his field.  Apparently the weeds will plug up his combine so he lets the roundup do its work and then harvests.

So, not only do we have a known carcinogen pesticide in our wheat but a known carcinogenic herbicide.  Roundup has not been proven to be a carcinogen to humans.  After all, you can't feed Roundup to a hundred humans and not to a control group.  But it has been proven to be carcinogenic to animals. I rest my case.

What is particularly annoying is that the use of the pesticide is so unnecessary.  Enlightened farmers (and there are precious few of these) use Carbon dioxide.  They have a connection at the bottom of their silo where they can attach a hose from a Carbon dioxide cylinder and fill the silo with this completely harmless gas.  Problem solved.  Any insect or their eggs that have come in with the grain dies.

Sunday, June 10, 2018

Our white skin

We "whites" seem inordinately proud of our white skins.  We have always considered it to be a sign that we are superior to the darker variety of homo sapian.  So I thought it would be fun to consider where our white skin came from.

We all know that people living in sunny climates which includes much of Africa, where we originated, have dark skins.  Undoubtedly, this included all the species of the genus Homo that preceded us.  Look at our nearest relatives, the Chimpanzies and great apes.  All with black skins despite the fact that they live, for the most part, in jungles.  Early hominids must have spent many hours in the sun and often, due to warm temperatures,  went with limited body covering.  They had to spend considerable time in the open finding their daily crust of bread and they developed dark skins to protect their skin from too much sunshine.
 Image result for image chimpanzees

Note that the babies have white faces while the adult is black.  Why do you think this might be.

Sunshine of course, provides us with vitamin D which is essential for the calcification of strong bones.  A hominid with weak fragile bones hasn't got much of a show in an environment in which his speed agility and strength will often make the difference between eating or being eaten.

But, vitamin D is important for so much more and we keep finding additional functions  of this important vitamin.  Some functions which have so far being discovered include:

*Strengthened immune system
*Enhanced muscle function.
*Improved lung health
*Anti-inflamatory properties
*Reduced blood pressure
*Reduced hardening of the arteries
*Protection from kidney disease
*Suppression of a pathogenic appetite
*Protection agianst Alzheimer

So there is a strong selective pressure for anything that ensures you obtain enough vitamin D

Sunshine is not the only source of vitamin D either.  Other sources include:
*Fresh fatty fish
*Oysters and some other 'shell fish'
*Some livers
*Egg yokes
*Raw milk
*Some mushrooms
*Some fish eggs.

Think of the dilemma of the first hominids that left sunny Africa.  Those that migrated along the coast toward India had little selective pressure to evolve a light colored skin.  Not only did they migrate through sunny climates but if they were able to fish, they would have got their vitamin D that way.

However for those that left the beach and migrated northward it was a different story.  There was a double whammy against them.  First, if they migrated into northern climates, it was more cloudy giving them less exposure to sun.  In addition in these colder climates, they would have had to dress in skins or clothes made of wool which was shed annually by various woolly animals.  They probably had only their face and hands exposed to the sun so there was a strong selective pressure to loose their protective melanin so that they could obtain their vitamin D.

For the males, there was another factor.  We had beards, possibly for the same reason that a male peacock has beautiful feathers so even less of our skin was exposed to the sun.

The interior of continents are very warm in the summer so they probably also evolved the ability to sun tan, if they didn't have this already.

According  to our present archaeological knowledge, Homo erectus  arrived in Eurasia at least 1.6million years ago.  For those that challenged the northern interior of the continent, there would have been a strong selective pressure for the evolution of a white skin.  Erectus sites from 1.6m years ago contain  flint tools including  retouched flakes so he was no dummy and it is not unreasonable to assume he fashioned some sort of covering.

Homo erectus likely evolved into  Homo heidelbergensis and then into
Homo neanderthalensis.  It is unlikely that this was a new migration from Africa since neanderthal genes are found in European people of today but not in modern Africans.  Incidentally another species which may have developed from Homo erectus is Homo sapiens denisova  further East in Asia.  Presumably, Denisovians who lived in northern climates characterized by cold cloudy conditions, they also had pale skins.

But there is something curious.  Bones of Homo sapien have been found in Africa from 315,000 years ago but only appeared in the fossil record in Europe 45,000 years ago.  How come.  Of the various theories presented, my favorite is armament.  It is likely that Neanderthals and our species came into contact much earlier than 45,000 years ago in the bridge from Africa to Europe, namely in the middle East. Think what a conflict that would have been.  The gracile Homo sapien comes up against the powerful, robust Homo neanderthalensis who makes his living stabbing large and small animals at close quarters with his spear.  No prizes for working out who would win that contra-ton.

I suspect the critial development which allowed our species to make inroads into Eurasia was the development of throwing weapons.  This could have included the lance, atyl atyl*, sling and even the bow and arrow

*Trowing stick which allowed a spear of a size between a lance and an arrow to be thrown with much more force that with the hand alone.

Our whole history is one of killing at greater and greater distances*.  It has culminated now with cowardly soldiers sitting safely in America, killing people with gattling guns and hell fire missils from their drones in other peoples countries as if they were in some sort of video game.

*In more modern times, the Battle of Agincourt

Neanderthals were at two disadvantages.  Their culture was one of killing prey close up and with humans the way we are, there was probably a strong sexual selection for the man that did this most effectively.  You bring home the bacon and the girls want you for their mate. So their whole culture favored the man who was a real man and could kill a deer at close quarters. But they had a second disadvantage.

You would think that they would rapidly adapt throwing weapons once they saw how effective they were.  Unfortunately, through evolution, they had evolved a shoulder joint that while it was very powerful, it was not adapted for throwing.  Even if they wanted to adopt the new weapons, they would have been very clumsy at it. Neanderthals lacked a throwing arm.

An effective throwing weapon would have completely changed the balance of power. And again, the way we are, when a tribe of Sapiens defeated a tribe of Neanderthals, they probably killed all the males and took the females for themselves.  Here a little diversion into genetics.

With the difficulty of travel when all you could call upon were your legs, and considering how territorial humans are, the two tribes were what we might consider pure breeds.  In other words, they would have had a high degree of homozygosity* at many more sites on their chromosomes than modern humans who breed with other humans who are distant both in geographical terms and in their genetics.

*Each cell of our bodies has two copies of each chromosome.  The genes on each chromosome at the same locus can be the same (homozygose) or different (hetrozygose).  When closer related individuals mate, this increases homozygosity and of course when a recessive lethal gene or even a disadvantagous gene comes together in an individual, he is either dead or disabled.  Inbreeding over time, to some extent, weeds out deleterious recessive genes from the population.  When two inbred individuals from different genetic lines breed, their offspring are likely to be particularly robust

 We keep chickens for the production of eggs.  We start with a variety called brown shafers who are great layers.  They are a hybrid of at least 4 so called pure breed varieties and express hybrid vigor. However we allow them to breed freely and you should see the varieties of chickens produced.  They not only revert to the original varieties but produce all sorts of assorted mixes.

Imagine the offspring of this first mating of male Sapien with female Neanderthals.  The two populations had been isolated and inbreeding for thousands of years.  The result would have been the equivalent of our Brown Shafers.  They would have all looked very similar and likely would have been very strong with a somewhat better throwing arm than Neanderthals but not a good as Sapien and with an intermediate skin colour.

In order not to make the whole story too complicated, I will assume that a throwing shoulder is determined by one gene and likewise skin color.  Any genetisist will tell you that many genes are involved in the determination of these characteristics and most others.  Mendel lucked on to some characteristics of peas that indeed were determined by one gene and so laid the basis of genetics.  I will also assume that both genes have equal influence.  That is neither is dominant over the other.  We will use W for a white skin and w for a dark skin.  Also T for a throwing shoulder and t for a non throwing shoulder.  This is a huge simplification but will make the situation easier to understand.

In what the genetisists call the F1 generation we have a cross between two quite homozygous populations (pure bred) The offspring will have half their genes from the mom  and half from the dad and those from all the dads will be quite similar to each other and likewise all those from the moms, similar to other moms.  Then the fun starts.

When the children start to reproduce, their offspring will have all sorts of mixes of these genes.  We will have:
WWTT - a white skin and a throwing shoulder
WwTT - a dusky skin and a throwing shoulder
wwTT - a dark skin and a throwing shoulder
and so forth.  Use a Mendelian square to work out all the variations.  On one axis you put WT, Wt, wT and wt and the same on the other axis.  These are the genes in the gametes (eggs and sperm).  Now selection begins.  Since humans are nasty and of great danger to each other, a throwing shoulder will be selected for as will a lighter skin, especially as these hybrid humans move away from the coast into more northern areas.

We have all heard by now that we have a small percent of Neanderthal genes.  This begs the question of what is a species.  The old definition was that two individuals are of the same species if they can produce a viable offspring that itself can breed and produce viable offspring.  Of course the situation on the ground is more complicated than this.  Apparently the various species of hominin in Africa bred back and forth in all sorts of combinations and clearly we bred with Neanderthals.  Otherwise we wouldn't have their genes.  Over the thousands of years since we started to breed with Neanderthals, individuals would be selected with characteristics from both strains of human that had the best survival.  Here we have only considered two.

I suppose we we were lucky to breed with a species that had already adapted to northern climates.  It would have speeded up considerably our rate of adaptation as we kept those characteristics that benefited us rather than having to start with favorable mutations - a much slower process.

We can thank the Neanderthals for our white skin.

Post scriptum
Facts are such a bitch when it comes to a great theory.  It was great fun poking fun at the white supremicists but it turns out that it probably is not true.  Have a look at the youtube videos from this chap.   Apparently it is true that at least some neanderthals were white and interestingly they had red hair.  The whatsit in the woodpile is that the genes that make present day whites, white are different from the ones that made Neanderthals white.  We seem to have evolved out own genes to turn our skin white and hence give us our daily dose of Vitamin D.

Now, of course, this doesn't mean necessarily that all Neanderthals were white.  If there was a population that lived in sunny parts of the world or on the sea shore where they got enough vitamin D from the sea, they could well have been black or brown, just as present populations of humans display all color variations.  Anyway, so much for a fun theory.

Monday, April 23, 2018

Brown flour

Brown flour just ain't what is is cracked up to be.  Let me quote a paragraph or two from The Third Plate by Dan Barber (incidentally, highly recommended)

"The roller mill appeared in the late 1800's just in time to expand the divide between the wheat field and the table.  It was a technological breakthrough that revolutionized the wheat industry just as the cotton gin had done for the cotton industry a century earlier.  Until its widespread use, people used stone mills.  Stone mills like the one we use at Blue Hill work like molars, crushing the kernels between two large stones.  They are effective, but slow and tedious, and they do little to separate the kernel into its component parts, a key development in the drive to industrialize flour.
 Image result for image a water powered flour mill

A few years ago, Klaas's wife, Mary-Howell showed me a picture of a wheat kernel in cross section.  It looked like an ultrasound image of a six-or seven week old human gestational sac, which isnt a bad comparison; a wheat kernel is a seed, after all.  The grain's embryo or 'germ' is surrounded by the starchy endosperm, - the stuff of refined white flour - which stores food for the germ.  Surrounding the endosperm is the seed coat or bran, which protects the germ until moisture and heat levels indicate it's time to germinate. 
 Image result for image wheat kernel

Whereas stone mills had crushed the tiny germ, releasing oils that would turn the flour rancid within days, roller mills separated the germ and the bran from the endosperm.  This new ability to isolate the endosperm allowed for the production of self-stable white flour, able to be stored and transported long distances.  Overnight, flour became a commodity. 
 Related image

It's hard to fathom that merely removing a temperamental little germ could revolutionize a staple grain, but that's just what happened.  The settling of the Great Plains and the advent of roller-mill technology meant that white flour was suddenly cheaper and more readily available.  Small wheat farms, including those in the former grain belt of New York, couldn't compete. Gristmills dotting the landscape became the stuff of folklore.  The homogenization of the US wheat industry had begun

The whiter flour became, the greater the demand.  To be fair, that's been the history of wheat for thousands of years.  But for all its efficiency, steel couldn't match the old-school grindstone in two key respects.  In fully removing the germ - that vital, living element of wheat - and the bran, the roller mill not only killed wheat but also sacrificed nearly all of its nutrition.  While the bran and the germ represent less than 20% of a wheat kernel's total weight, together they comprise 80% of it's fiber and other nutrients.  And studies show that the nutritional benefits of whole grains can be gained only when all the edible parts of the grain - bran, germ and endosperm - are consumed together*.  But that's exactly what was lost in the new milling process.

*this probably relates to the fact that you need to consume all the amino acids in protein at the same time.  The digestive system takes up amino acids as balanced proteins.  If there is an excess of one amino acid, the excess is rejected. Presumably there are different amino acids in the various components of the wheat seed and only by consuming the whole seed do you get the full nutrition.

There was another cost as well, just as devastating. Stone-milled flour retained a golden hue from the crushed germ's oil and was fragrant with bits of nutty bran.  The roller mills might have finally achieved a truly white flour, but the dead chalky powder no longer tasted of wheat - or really of anything at all.  We didn't just kill wheat,  We killed the flavor.

The Chinese Dilema

You may have wondered why there are so many Chinese in the world today.  The answer is surprisingly simple.  Many many years ago some Chinese genius worked out that in order to have sustainable soils, you have to return every bit of organic material you can to the soil.  This includes animal waste, human waste and all the inedible parts of your crops.  You can also supplement this with material from the sea since you are sending huge amounts of nutrients down your rivers from the land.  It has worked a treat and despite  mongol hoards, palace revolutions and wars, the Chinese have grown and prospered.'

It helped that they had rich deep loes soils gratis of the continental glaciers that ground rock into fine powder to be carried and deposited by the wind but so did America and they have gone through meters of this 'god given' bounty in a few centuries.

In the mean time other empires have prospered and declined as they mined their soils and the area they occupied had to wait for the slow process of building new soils from the bottom up before significant numbers of people could once more occupy the areas where empires once existed.

Back to the Chinese, they are now coming into the 'modern world' and it doesn't auger well for them.  On the nutrient front, they now have flush toilets and will be sending massive amounts of nutrients to sewage plants to be detoxified, denitrified and what is left, sent down to the sea.

It doesn't have to be this way.  For instance, in Seattle, they now have a sewage plant that is turning their 'feed stock' into valuable fertilizer, the sale of which covers half their running costs.  If this becomes the norm instead of the exception, perhaps us westerners can also have a sustainable future.

The Chinese are sinning against sustainability in another way now.  In their rush to industrialize. they are polluting their air to an extreme extent. It is so bad that they are negatively affecting their agriculture.  Never mind. there is light on the horizon.  At the same time they are working as hard as they can to replace coal energy with wind and solar energy and petrol vehicles with electrics.  With their command economy, they will most likely succeed and rather rapidly at that.

In the mean time the Chinese are buying up land all over the world to be able to feed their people.  If they adopt the western model of flushing nutrients down to the sea, they will have to buy up a lot more.

Monday, April 2, 2018

historical sea level

Time                         Level
 22000 years ago      Minus 120m
 15,000                                 -107
 10,000                                 -40
   9,000                                 -25
   8,000                                 -15
   7,000                                 -30cm


Sunday, April 1, 2018

Electrical demand balancing

Electricity generating companies are facing a couple of problems which can be solved by demand balancing but first, what is demand balancing.

At present, most generating companies monitor the use of electricity and as demand goes up, bring on more generators and as demand goes down, reduce the power output of generators and even shed them.  All generators have a certain range of output so as power demand increases, smaller variations in demand can be met by increasing the amount of power produced by a given generator but beyond a certain level, more generators must be brought on line Power companies have a dilemma in that they must have sufficient generating capacity to meet peak loads.  This is expensive.  To build new generation capacity when it will only be used occasionally is a nightmare to their accountants.

There are peak generation periods such as in the morning when everyone is getting ready to go to work or school and more so in the evening when everyone is home, the TV is running, mom is making dinner in the oven, it is winter and all the lights are on.  What the generating companies don't need is that at this peak load time you are also running the dish washer, cloths washer, cloths drier, water heater and so forth.  If these functions could be shifted to late at night when all the evening activity is over and the lights are out, then they could avoid having to build more 'plant' that will only be needed in peak hours.

This is where demand balancing comes on.  The power company has to find a way to induce us to use power whenever possible in trough hours so that we don't need this power in peak hours.  The inducement is simple.  The make power less expensive during trough demand.

They could simply make power less expensive for all uses as demand goes down but what is really the holy grail for them is to be able to switch on and off some of your electrical devices as needed to balance their base generation.

We need some hardware and soft ware to make this happen.  Here is an idea of how it will work.

You have special little units that you plug into your wall socket and then plug your device into the unit.  It 'talks' to your smart meter you have installed.  You can set the unit to come on at different prices for electricity and, of course, the power company, when they have a little excess power, will send a message down their lines that now power is at 24c, 23c, 22c and so forth as they need more demand to balance the base power they are producing.

You are unlikely to put one of these devices on your TV or stand up lamp.  If you do, the TV and/or the lamp will go off if the price for power goes above what you have selected. All these functions that are on demand.  ie that you can switch on and off as you want, you still pay the full power price of, let's say, 25c/kWh.  The only equipment you are likely to use these special plug in units for are your chothes and dish washer, any batteries you are charbing (such as your car or wall unit), your hot water cylinder and so forth.  On the front of the device will be a dial that you turn to the price you are willing to pay for the function in question.  But all devices are not equal.

With your car battery or hot water cylinder, the power can go off and on as the power company adjusts the price to use their base generation.  Your washing machine is something else.  Once the cycle starts, you want it to finish.  Otherwise you may have food baked on to your dishes or a wet mess in your clothes washer.  So we have another wee switch on the device which you can put in 'continue to the end' or intermitent.  Now we have one more problem.  For your dish washer, you will set the 'continue' function so once it starts it will finish.

A battery or water heater is something else again.  You may have set your car battery charging unit to, say 10c since past experience shows that you are likely to get some power at this price during the night but here we have a different problem. You want to be able to get to work in the morning.  so we need one more function in our wall plug device..

We have a timer on the device which you set so that full power comes on, say, an hour before you go to work.  If the battery is fully charged, it will not take any more power but if the battery is only partially charged, it will fill up your battery at the full cost.  Not to worry.  Even at the full day time rate, it costs about a third as much in fuel to drive a km than with fossil fuel.

Despite what you hear, power companies are more worried at present by the decrease in power demand.  People are putting in LED lights, factories are becoming more efficient and the power companies are seeing decreasing revenue.  The Electric car is a god send to them.  But they don't want to have to build generating plants that only work to take care of peak demand.  By shifting demand to off periods, they solve this problem and make existing generators much more revenue efficient.  For instance, when there is lot's of water, they can send more of the water through the generator rather than over the spill way.

This is also a great way to help solve the problem of intermitent generation of renewable energy.  Say that during the day, the generation of wind energy is unusually good.  They can lower the price for these special functions such as heating the water in your cylinder even during the day.  You get cheaper power, they sell the excess instead of wasting it and over all, less fossil fuel is used.  Win win all around.

Monday, January 29, 2018

Wasted Effort

We are wasting our effort, dissipating our effectiveness, peeing against the wind and farting at thunder.  We are ensuring our failure.  I refer to our various  campaigns.  Save the flowers, save the bees, save the snails, save the trees.

i could go on and on with  mitigating climate change, re-wilding, stopping all sorts of pollution, getting control of trade agreements that shaft us, stopping subsidies to fossil fuel companies, saving our corals, preserving our fisheries resources, stopping getting into war after war that 'the west' looses and on and on it goes.  There is one ring that controls them all.

Nowhere is that old adage "Who Pays the Piper Calls the Tune" more true than in politics.  We, the peasants,  think we are gaining some advantage by others paying for the election campaigns of our elected officials and then, we wonder why the elected officials do the bidding of the vested interests.  What a great investment for them.

They pay pennies and get back dollars, pay millions and get back billions.  For big business and the uber rich, this has to be one of the best investments they will ever make.  They support politicians, often on both sides, just to hedge their bets and the politicians make sure that the legislation is in favor of big business and uber rich individuals and ensure that they get tax breaks, favorable legislation and subsidies.  Do you realize how many countries still give financial concessions to coal companies!!!

Because of the system, many countries and especially America and Australia have socialism for big business and the rich and capitalism* for the poor.

*Incidentally there is nothing wrong in theory with Capitalism or any other 'ism'.  The problem is with uncontrolled capitalism;  what used to be called Laisse faire and now is called the New Liberalism.  As an individual, I am not allowed to kill by commission or omission, throw my garbage on the commons or the property of my neighbour, bear false witness, lie to the authorities with no consequences and so forth and so on.  Big business and the uber rich get away with all of these in both overt and subtle ways.  We espouse everyone being equal before the law but it is just lip service.  Similar to how various regimes have used religion to keep the peasants under control.

The politicians don't do the bidding of their financiers because they were supported in the last election.  They do their bidding because they know if they don't, they won't be supported in the next election.

The ultimate argument of politicians to explain their failure to fulfill their election promises is that if they aren't in office they can't do anything.  Nonsense.  Far better a one term MP that does what is necessary, sets an example and begins to steer the ship of state in the necessary direction than a 5 term MP that continually compromises to the point of total betrayal of the people who elected him.

This is costing us hugely in our day to day life and it is now clear that this system could bring down our civilization.

Even if some of the milder scenarios from the scientists are correct with respect to the effects of climate change, we could  knock ourselves back into the dark ages or even the stone age.  The fringe scientists suggest we could trigger a run away green house effect that would turn us into a new Venus.  Just look at Australia.  As of the beginning of 2020 it is disappearing in a cloud of smoke the ning nong of a PM still denies climate change is real and promotes the massive sale of coal*

*Australia sell three times as much coal as she uses in Australia and in Australia, coal is the main source of electricity; this, in a country with, arguably the greatest renewable energy sources in the world.

If some of the predicted tipping points are reached, climate will change faster than our very precariously balanced agriculture can cope with.  Even a single year of crop failure in the grain belts of the Northern Hemisphere and Australia will be disastrous.  This grain is shipped to countries all over the world.  Imagine a decade of such crop failure until we work out how to grow crops  under the new climate regime.

Or even more disastrous, it is a real possibility that our climate will flick-flack back and forth between the existing and the new climate regime before it settles down.  This would be even more serious than a sudden change to a new climate. You would have no idea what crops would succeed from year to year.

At least by the end of the process, the world population would probably be down to the Lovelock Number*

*James Lovelock, the man who articulated the Gaia Hypothesis, suggested that within this century the population of the earth will have fallen to 1b (it is at present at 7b and predicted to go to 9b)

We have seen, in the 1930's and again, even more so, in 2008, how interconnected the world  is.  Back many centuries ago, if Europe crashed, America didn't even know Europe existed.  Now one country going down economically brings all down.  How much more disastrous would it be if our food supply suddenly crashed.  America, Canada, Russia and Australia provide most of the grain to a wide range of third world countries.

And consider this.  The higher you are the harder you fall. All the predictions say that the poor will suffer most under climate change and this could well be so.  But most cities in the so called civilized world have only enough food to feed their residents for three days.  Most large cities would take far longer than that to evacuate (and where would they go).  At some point in the future we may see some internal migration in the so called first world to the rural areas with really nasty consequences.

Some commentators suggest that the Arab Spring was triggered (not caused)  by the rise in food priced caused by a poor grain harvest in Russia.  If so, that was just a wee warning shot across our bow.

Consider, as well, the refugee problem, mainly in Europe at present.  It is just a tiny fore-taste of what will face us when climate change begins to get really serious.  Consider the social disruption this mini migration is causing in many European countries.  Then multiply it by 10 and 10 again.

So what is the bottom line.  If we want politicians to do what is best for "we, the people", we must be the ones that pay for their election campaigns and the first order of business after this is achieved is to pass legislation that anyone who pays money to any politicians for any reason what-so-ever gets mandatory jail time.  This, of course, includes any non monetary bribes.  Campaign money must come from the exchequer.

And......It doesn't have to cost the ridiculous amounts that it costs now.  Politicians can be given a legislated amount of money and a legislated time on national radio and television.  They would get a legislated space on news papers.  Venues would be rented for them to hold town meetings where each candidate answers questions from each other, from the moderator and from the audience.  These would be put in their entirety on Youtube and shown on Television channels.

We should also set up a standard web site for each of them
On their individual, standardized web site, they can express themselves as they please.   But there will also be a section, inaccessible to them, in which past promises are compared with their voting record and a second section comparing their voting record with any other politician one is interested in.    Of course, they can use the Internet to their hearts content.  It costs nothing.

If we want to call the tune, we have to pay the piper.  We should stop all our campaigns for various causes and concentrate a huge ground swell on this one alone.  Then we can return to our other vital campaigns with a much better chance of success.  We are so smart individually but so dumb in the collective.  How hard is it to understand.
Who Pays the Piper Calls the Tune

Saturday, January 20, 2018

Kao-pectin and the pharm industry

When I was a young fellow, some 60 years ago, there was a sovereign cure for the trots (diarrhea).  It was called Kao-pectin.  As the name suggests it was a suspension of fine clay in a solution of pectin.  It was mildly distasteful to swallow but, man, did it work.  After a few one table spoon doses taken about an hour apart, you could once more trust a fart.  I can only speculate how it works.

Clay is made of fine platelates and a small amount of clay has a huge surface area.  It apparently adsorbed the nasties in the GI* track and firmed up the contents so that peristalsis could move them down stream to be eliminated.

Also, I only have a sample of one.  Myself.  The stuff was a miracle.  Can I buy it now in my local pharmacy. Not on your nelly.  At least in New Zealand, the UK or Canada, the pharmacies I have tried don't stock it.    Why not.  It is still produced in some other countries so it is available.

I suspect that there is not enough profit in it.  After all, how much can you charge for a suspension of clay in a solution of Pectin.  When I was young, I watched the evolution of this product.

First they made the new improved Kao.  They added a bit of flavoring and some colour.  Judging by the color, it was probably Tartrazine, not something you want in a medicine.  Whatever was added, the Pharm industry could now charge more.  It still worked so not too much harm done except perhaps for someone at the bottom of the earning ladder with sick kids.

Next they added some sort of medicine to it.  I seem to remember that it was an anti-biotic of some sort.  It wasn't needed.   The original formulation worked a treat but now they could charge even more.

Finally, the product was discontinued.  Still not enough profit??

There is no denying that we get valuable, effective cures for various conditions from the pharmacies but they have the morals of a cigarette salesman.  If their isn't enough profit or if it will detract us from buying a more expensive product, they ain't going to carry it.

I'd like to see some double blind testing done on simple Kao-pectin against other products to see just how effective it is and then, if it proves to be as good as I say it is, to publicize it widely.  Can't be done in a university.  They can't endanger their funding from the Pharm industry.  It would have to be an independent research outfit that isn't in thral to the pharm industry.  What we need is a government research branch for research that can't be funded by vested interests.

Mitigating the harm dairy causes to the environment

We are having a debate in New Zealand for and against irrigation.  It really boils down to a debate on our national dairy herd.  With irrigation, you can put cows on land that otherwise would not support them.  Our dairy herd can then increases and with it the pollution of our environment.

True, there are some concerns about the irrigation itself but the main concern is that it allows the increase in our national dairy herd and with it increased pollution.

To come out for or against irrigation  may be good for radio sound bites but as with most cases in the affairs of man, the devil is in the details.Clearly we need irrigation for our farmers to fill in the gaps left by nature. Even in the best areas, there are periods without rain.  A farmer needs reliable inputs to be able to run his business.

On the other hand, equally clearly, if we can not find ways of farming that preserve our environment then the crude sledge hammer method of reducing herds and restricting where they can graze must be taken.  The question is;

 Can we have dairy herds and not pollute.

The answer may be yes for some areas and no for others and will depend, to quite a large extent, on the details of how we farm.

The core of the problem is to be able to apply the waste output of the cows back on to the  land a) in a way, b) in a concentration and c) at the right time such that it constitutes a valuable fertilizer, is taken up by the pasture plants, and hence is not an environmental pollutant. If this can be done, dairying is no longer a source of pollution.

As a bonus and possibly the most important consideration, applying organic material such as the manure of cattle to our soils preserves the soil organisms on which we depend for fertile soils.

Throughout history, societies that trashed their soils, declined and disappeared.  One factor in trashing soils is not returning nutrients to the soil that are extracted. so far  as is possible, nutrients must be returned in an organic form that benefits the soil organisms.  Quite clearly, the urine, manure and spilt milk from a dairy herd constitutes a valuable resource for the enhancement of the soil.

That is not to say that chemical fertilizer should not be used but as you will see, much less of them can be used if farming methods are tweaked.

If farming remains a process of plow, add chemical nutrients, sow the seeds and irrigate then our soils will degrade, wash to the sea, pollution will be rampant and we will go the way of many previous societies that mined their soils  instead of farming them.

It takes a lot more 'smarts' to farm in a way that improves the soil, reduces  inputs, increased water infiltration,  and leaves you with a much better farm to pass on to your children or to sell at retirement than when you started.  What is not generally realized is that you can do this while improving your bottom line and your resilience to weather and  price fluctuations.

Let's look at some of the tools we have available.

Riparian Zones
Fencing off streams and encouraging the growth of trees, shrubs and grasses between the fence and the stream is a great help.  Not only does it stop the cows from entering the stream and urinating and defecating into it but the roots of the vegetation of the riparian zone take nutrients from the water table which is slowly flowing toward the stream.

However, it has been reported that 70% of the nutrients entering the streams comes from the very small feeder streams and ditches.  It is simply not possible to fence off every little feeder stream. We need some other measures in the pasture.

Composting Barns
Composting barns use deep layers of wood shavings or coarse saw dust as bedding and the cows are allowed (not forced)  to bed down there at night.  They also have free access to the barn to escape inclement weather.  The bedding is stirred mechanically every day, keeping it aerobic.  It has been found that cows prefer such an environment to bed down in, even choosing it ahead of a straw-lined byre.  The composting process produces heat which reduces the feed needed by  the cows and a rich compost eats up pathogens.  The compost captures all the nutrients from the waste of the cows including N and S which in an anaerobic system  go off as the gases NH3 and H2S.

The bedding can be applied to the fields at the correct concentration and correct time which most benefits the soil and the pasture plants and hence causes no pollution.  Some research needs to be done on what portion of the effluent of a cow is released while in such a barn compared to what proportion is released out on the pasture*.  Do they mainly urinate and defecate at night or in the day,,,, while they are grazing or when they are chewing their cud.  this would give an indication of how much of the nutrient stream can be captured by a composting barn.

*Great job for some long suffering masters student

Bio-Gas Generators.
At long last a farm in Southern New Zealand is using the waste produced in the milking shed* to generate bio-gas.  The biogas is use  to produce electricity. The waste heat from the motor which drives the generator is used to heat the water used in the milking shed.  This combination, utilizing the waste heat from the motor that powers the generator, makes for a very efficient system, energy wise.  The effluent from the biogas generator contains almost all the nutrients in the waste stream since mainly C and H have been taken off as biogas (and some of the S).   As with compost-bedding the effluent remaining after extracting the biogas, can be applied to the fields when and in what concentrations most benefits the pasture and hence least pollutes the environment. Excess electricity is sent to the grid for an added income stream and/or excess biogas can be used in the house and farm.

*More work for that long suffering student.

Managing the Pasture
We have now removed a portion of the waste stream with a)Riparian zones, b) compositing barns and c)biogas generators.  Let's see what we can do out on the pasture.  There is a fantastic book by David R Montgomery called Growing A Revolution; Bringing back our soils.  In it he describes visiting farmers all over the world who have independently come up with a way of farming.  The methods they use would be familiar to any farmer before the advent of cheap chemical fertilizers but each method is updated in light of modern knowledge. Farming this way results in an improved bottom line, slashed pollution to the environment, reduced farming costs, increased infiltration of rain, continually improving soils  and as a bonus sequesters significant amounts of carbon in the soils.

It has become to be known as Conservation Agriculture.

It also, due to the greatly increased organic content of the soil, results in the capture of much of the Nitrogen when a cow urinates. The urine is soaked up by the organic material giving the soil organisms time to scavenge the nitrogen.

Of course, it also results in the sequestration of considerable carbon in the soil.

Before we go off half cocked and reduce one of our most valuable industries, we must pay attention to the details.  Farming can not be allowed to degrade our environment but there are farming methods which address this problem.  What is great is that these methods can improve the bottom line of the farmer and his resilience to weather and fluctuating prices for his products while at the same time making him the darling of the greens.  The devil is in the detail.

Wednesday, January 17, 2018

Conservation agriculture

There is a 'new' sort of agriculture practiced by a handful of farmers in diverse locations around the world.  Conservation Agriculture is not a descriptor although the words describe to some extent what it is.  It is, rather, a name given to a suit of farming methods which taken together are called Conservation Agriculture.

This so called Conservation Agriculture involves a) not ploughing the soil, (and hence, direct drilling) b) rotating crops in a random fashion, with longer periods between growing the same crop, c) leaving all the unused parts (stems, leaves and, of course roots) of the past crop on the land as a mulch and d) the planting of cover crops between commercial crops.  It is not absolutely against using chemical fertilizers but results in great reduction or even  elimination of the use of such chemicals.  In addition it may involve grazing down the standing crop residue and/or cover crops, and thus converting them into dung and urine. If grazing is used, it is very intense, very infrequently.  It may also involve,  the incorporation of char into the soil.  To find more detail on the methods go to this site or to get a historical perspective on the fate of societies that didn't preserve their soils, to this site.  What I would like to explore in this blog is the logic behind the methods.

Let's take a corn plant as an example.  The seed grows into a plant and the plant uses water, carbon dioxide and various minerals to build it's roots, stems, leaves, and seeds (the corn we eat).  The energy to transform these simple, low energy substances into complex, high energy compounds comes from the sun and this captured energy is now in the form of chemical energy.  The resulting chemicals (largely cellulose along with many other  compounds in lesser amounts) can be burnt as a fuel but can also be 'burnt' by soil organisms just as we 'burn' the corn in our bodies for energy.  The soil organisms  incorporate some of this stover into the substance of their bodies, especially proteins and vitamins just as we do with the corn seeds.

Saprophytes (funguses) are specialist in using dead plant material for their sustenance.  Think of the fungus growing on dead wood in moist conditions.  But these are the fruiting bodies of the fungus.  Most of the fungus consists of thin filaments (mycelia) that extend through the media and collect nutrients.  Of particular importance in-so-far as we are talking about soil health for crop production is that the funguses not only use dead organic material for energy but can also mobilise minerals in the soil that are in insoluble, mineral form and make them available to plants.  Many of the funguses grow their mycellia inside or around root hairs and exchange the nutrients they have mobilized  for energy rich compounds that the plant provides. Anything to encourage the growth of these funguses and to avoid disrupting the mycellia that extend throughout the soil is good for the crop.  Therefore we put lots of organic material on the soil where the fungus can access it and we do not plough

 The obvious question is why don't we mix this material into the soil.  Firstly, this would involve ploughing and hence the disruption of the mycellia of the funguses but there is another reason.  If there is a large amount of reduced carbon (cellulose and other compounds) in the soil, the micro-organisms that produce cellulase* and hence can access this source of carbon and energy, will scavenge all the available soluable nutrients from the soil to build their bodies.  The funguses are not the only organisms that can utilise cellulose.  Many single cell soil organisms have the same ability.  If a considerable amount of cellulose is incorporated into the soil, there will be nothing available for the growth of the crop you have planted.  Put the organic material on the surface and it is gradually incorporated into the soil and nutrients are still available for the crop.  But the surface layer of mulch has other benefits.

* The enzyme that can break down cellulose.

The surface mulch shades the soil and keeps it from heating up so much.  The soil looses less water by evaporation, leaving more for the crop.  The mulch softens the blow of the rain and slows the flow across the ground and hence avoids sealing the surface of the soil and increases infiltration.  Again more water for the crop.

A word here about trophic levels.  As a first approximation, only ten percent of the material consumed is fixed into the next trophic level.  10 tons of algae will make one ton of krill and one ton of krill will make a tenth of a ton of whale.  Sounds good since the 90% excreted is mineralized. Some of it is in a form that can be taken up by plants, but here is the rub.  If there is lots of cellulose around, the micro-organisms which can break down cellulose will use the cellulose as energy and scavenge all the mineralised material, which has been released by other organisms, leaving none for the plants.  Of course as the quantity of remaining cellulose decreases, more and more of the mineralised nutrients will be available for the plants.

So, the next thing is why do we plant a cover crop when the main crop has been harvested.  First we capture more sun energy in the form of the chemical energy of the cover crop and hence produce more organic carbon for the soil organisms.  Secondly we scavenge any left over soluble nutrients from the soil and turn them into a slow release fertilizer (the bodies of the plants).  As this organic material breaks down it releases its nutrients into the soil over time.

If we include a deep and a shallow rooter, we scavenge nutrients throughout the depth of the soil as well as spreading roots through the soil which will not only disintegrate over time but will provide passages for water and air to penetrate the soil.

If we include a legume that is either inoculated with the appropriate rhyzobium bacteria or finds the correct bacteria in the ground, atmospheric nitrogen will be taken from the air and turned into a nitrogen compound that can be used by the next cash crop.  Since most of the nitrogen compounds produced will be incorporated into the leaves, stems and seeds of the legume, it is important that this material be left in the field to enrich the soil.

If we include a root crop such as a radish or turnip, as they later disintegrate, in addition to releasing their nutrients, they create tunnels for water to infiltrate.  They also often are deep rooted which will help to scavenge nutrients from lower levels.

It is important to cut down the cover crop or trample or roll it into the surface of the soil before it sets ripe seeds.  You don't want the plants of the cover crop to themselves become weeds.

If you decide to graze the cover crop, it is grazed very heavily for only a day or two.  This tramples some of the crop into the surface of the soil, ensures that all plants are utilized and not only the favorites, including weeds that you have not planted, and turns the cover crop into urine and manure.  This short sharp grazing leaves lots of time for the soil organisms to  sort out any surface damage and to incorporate the animal excretement into organic material.

When the cash crop is then planted by direct drilling, it has all the best of the soil structure and soil organisms to support it.