Of Soils and Nutrients

Phosphate, among other things, is a catalyst, and as such it recycles. It has a function that is special, for it guides all elements into the plant except nitrogen. In other words, all elements go into the plant in phosphate form except nitrogen. Somewhere along the line there has to be a union of the phosphate atom with necessary nutrient elements for healthy plant growth. If there is a phosphate insufficiency, the plant can still uptake nutrients, but they will not be incorporated into the cell. The consequence is shrinkage. When the crop is hay, shrinkage can make the crop almost vanish. A third of the corn crop can disappear because of shrinkage. The alfalfa crop is literally annihilated when there is a phosphate shortfall. Stems will be hollow, and the difference between half a yield and a full yield.

The last cutting on a farm I worked with had 80% solid stemmed alfalfa when we foliar fed after each harvest. The yield was greatest on the fourth cutting even though it wasn't taller – but there was no shrink.

A thinner stem may permit a larger population, but if the soil has insufficient nutrients there will not be enough energy to support the plants. If corn is healthy, tubules will be packed together all the way to the center. The center or pith of the stalk should be pearly white, not the dirty gray called gummosis.

Excess nitrogen will reveal a black layer node when the stalk is cut and put under a microscope. Such tubules often are completely blocked, much like a water pipe that is completely clogged. This is always an indication that there is not enough phosphate and calcium in relation to nitrogen.

Peppermint and spearmint do not have hollow stems if correct mineralization has been part of the fertility program. Even oats have solid stems if phosphate levels are maintained correctly to permit cell nourishment and growth. Properly nourished and nurtured, such oat stems will be more like a sturdy willow than a fragile soda fountain straw.

The research station at Bethesda, Maryland fed phosphate through the leaf in order to measure the effect on rootlets. Workers found that phosphate will travel to the roots at the rate of three feet per second. When it reaches the rootlet it forms an organic acid and solubilizes fertility elements for plant uptake. But once phosphate reaches a basic level in the soil, its need is greatly reduced. 

Nitrogen can carry all essential nutrients into the plant, potassium included. That is why much of agriculture grows crops with a combination of nitrogen, potassium and lots of water. This approach paints the field deep green, but at harvest the shrink is fantastic. It reminds one of grocery store hamburger made to look superb by blending the meat with crushed ice. That same hamburger melts away in a hot skillet. 

The same thing applies to livestock. It is possible to simulate growth and weight by feeding more nitrogen and potassium and keeping the phosphate level down. The gain is simply water in the cells. In a skillet or roaster, such meat shrinks and at the table it tastes like cardboard because minerals and nutrients for really good quality meat simply weren't there. 

The environment around you will tell most of the story if you see what you look at. If you go through an area where all the trees have branches bushed out at the top but there are no branches down the tree, that is an indication of a phosphate deficiency or a lack of availability to the plant. If a tree is branched out all the way to the ground, that indicates a good phosphate level in the area, or perhaps that there was one… 

Photo credit: AgFax

…carbon in the molecular structure of the seed brings water into the soil…one part carbon will hold four parts water. There are two million pounds of soil in the top six inches of an acre. A 1% organic matter soil will thus contain 20,000 pounds of carbon, and 20,000 pounds of carbon will absorb 80,000 pounds of water – or 10,000 gallons. It takes 28,000 gallons of water to cover an acre one inch deep. The problem of a three inch rain on a 1% organic matter soil is at once apparent. Even a 5% organic matter soil – which is difficult to achieve under row crop conditions – would have only 100,000 pounds of carbon, and therefore a potential for holding 400,000 pounds of water, approximately 50,000 gallons, only enough capacity to absorb a two inch rain. Once a saturation point is reached, the rest of the water will run off. The soil management problem is further complicated by hardpan, which prevents water from moving down into a water dome or aquifer and forces it to run off. 

With good biologically active carbon in the soil, there will still be a complement of soil air…Carbon attracts moisture from the air, especially at night. If there is high humidity in the air and enough carbon in the soil, plants can get enough moisture from the air to fix a crop if there is at least 20 to 25% humidity. 

Southern California was essentially desert in the early 1900s. The hills had no grass or trees. The Soil Conservation Service presided over the seeding of mountain areas with a variety of grasses. When the water wash ran off in the spring, a green layer developed and worked its way into the valley. Now when they get rain in that area, there is a basic climate change. In fact, it is possible to so manage carbon that is will change the climate of an area. It is also possible to so mismanage carbon that droughts are created. In Iowa - where they plow every possible acre from border to border – they have created droughts in areas where this phenomenon has never been heard of before. 

It is difficult to get carbon in the soil to go down. Magnetism must first be created, meaning phosphate molecules must be utilized to create a condition supportive of bacteria. This means aeration – and incorporation of carbon dioxide into the soil. When air can no longer enter soil, carbon goes out as CO₂ gas. Bacteria that run into salt-rich plow pan areas die off, much as if they were cast into a salt brine tank. 

The chemical symbol "C" means pure elemental carbon, a product that is difficult to achieve. We use the term carbon, but this expression requires a modifier. Carbon does not go in the soil as pure carbon. Generally speaking carbon is bonded with water and nitrogen to form organic acids in the soil which contain carbon. To really make soil magnetic, carbons have to be in residence to provide food for bacteria in the form of sugars. 

A cornstalk has cellulose, a form of carbon. If you break it down, the breakdown products will include sugars. Bacteria can work on this cornstalk if they have a suitable environment. A mandatory component of that environment is oxygen. Another is moisture.

It is not uncommon to see cornbelt farmers put in soybeans after one corn season, then return the third year to plow up corn stalks that have been neatly embalmed. Dead soils form formaldehyde, the same stuff that's used to preserve cadavers until after the funeral. Formaldehydes are an anaerobic breakdown product. In some cases aerobes work from the top down and dilute and break out the preserved biomass. But aerobes cannot survive in formaldehyde. The remedy, again, is carbon.

Carbon, we have noted, keeps the soil from blowing, not because it is some foo-foo dust, but because it serves up amino acids and nitrogen – the key to stickiness, in that order, and in that order of importance. This is the soil's method of storing nitrogen from one year to the next. The conventional wisdom has farmers using a modified hydroponic system. In this view soil has little function except to prop up the crop, and maintenance of a microsystem is a luxury too costly to justify. Such a soil on injectable nitrogen is much like a drug addict. It becomes dependent on the needle arrangement. 

No-till is to a large extent needle-till, forever dependent on hard chemistry. There is also a negative aspect to no-till, an inability to get the carbon to go down without air. No-till works best if the crop residue is incorporated into at least the top two inches of soil – a sort of contradiction. There has to be soil contact for microbial breakdown. There is usually as much biomass under as above the soil. 

Minimum tillage, in the beginning, is better than most management systems in keeping topsoil from blowing. With residue incorporated in the top inch or two of soil, it permits enough contact for meaningful activity. Basically, organic matter is some form of plant or animal life. Mixed with the life and work of microorganisms, organic matter delivers a most valuable constituent, carbon. Carbon can also come into an active soil through the air via the agency of bacteria. 

Another source is photosynthesis. The leaf takes in CO2 from the atmosphere through its stomata. Organic matter in the soil decomposes under proper conditions, releasing carbon dioxide for plant use. Decomposing bacteria break down into humus – a point at which parent material can no longer be recognized – organic material such as corn stover. The efficiency of this process is governed by the ratio of carbon to nitrogen in the soil, which at its optimum level should be twelve parts of carbon to one part of nitrogen. 

…bottom line seems to be that poor soils with less than 1% organic matter are not uncommon. Midwest prairie soils were running 10 to 12% in organic matter before the arrival of the moldboard plow. Today most of them have organic matter in the 2 to 3% range. Only a few well managed soils have a 5 to 6% index. Only rarely will 8% become an entry on a soil audit. Once intensified farming is started, most excellent soils have a tendency to back down to 5 or 6%.

…When such soils have a high carbon content, the roots will travel through the soil rapidly.

 

- Excepted from Mainline Farming for Century 21 - Dr. Dan Skow and Charles Walters