By Gary Wilson – The late soil scientist, William A. Albrecht, PhD, has left us a large volume of scientific evidence in published papers he wrote during his lifetime. Many of these papers are published in a series of volumes called, “The Albrecht Papers”. Albrecht was a Professor of Soils and Chairman of the Department of Soils at the University of Missouri College of Agriculture.
This example is taken from a series of twelve articles all titled, “It’s the Soil That Feeds Us”, published in 1960 by Natural Food Associates. The subtitle for this example is, “more fertility means more cover, stable soil structure and less erosion”. This is published in Volume I of “The Albrecht Papers”.
Two adjacent plots were planted with corn every year starting in 1888. The complete crop, corn and fodder, was removed. The two plots were treated the same except for one plot only received six tons of barnyard manure. Albrecht reports the results after 62 years of this ongoing comparison.
Both fields are plowed each year prior to planting the corn. After 62 years, one rain is sufficient to flatten the plowed condition of the plot not receiving the annual manure application. In addition, it seals over the surface of the soil reducing the infiltration of water. Albrecht points out that, without the border of sod protecting this plot, its soil would drain onward to the Gulf of Mexico. In comparison, the plot receiving the annual application of manure experienced different results from the same rain falling on both plots. The plowed condition of this field was not altered by the rain. Rainwater penetrated the soil creating a reserve of water in the soil.
During the summer the surface soil is cooler by ten degrees Fahrenheit than its companion plot. Rills formed by running water on the untreated plot are absent on the treated plot. The corn yield is twice as large on this plot as on the untreated plot. The soil granulation on the manured plot under laboratory testing showed that water was going into the soil three times as rapidly compared to its companion plot. This soil granulation did not plug itself up so quickly resulting about four times as much water entering the soil as its companion plot.
The results of this experiment suggest that perhaps global warming or climate change is not totally responsible for increased damage from floods, increased damage from droughts, increased damage from fires and increased erosion of the soil. In fact, the major cause of these events may be declining soil fertility with global warming or climate change having a much smaller role to play in the causation of these events.
While these events may shown to be occurring at the same time as the climate is changing, correlation does not prove causation.
Floods are caused by excessive water running off the land in the entire drainage basin of the river system. This experiment demonstrates that the lower the level of soil fertility increases the amount of water running off and a higher level reduces the amount of water running off regardless of the total rainfall. Thus higher soil fertility at least mitigates any flood damage done in periods of high rainfalls. In addition, droughts are caused by a shortage of water. As Albrecht points out, water provides its service to plants when it is in the soil, not when it is falling from the sky. Thus increasing the soil fertility to increase the amount of water stored in the soil would at least mitigate damage done by droughts. When there is water in the soil, plants are able to transpire water keeping themselves cooler and they avoid becoming dried out and more susceptible to fire. Needless to say, this experiment demonstrates that declining soil fertility increases erosion of the soil itself.
Does anyone in California look at declining soil fertility?
When you harvest a crop, whether corn or trees, you remove some of the ability of the soil to produce protein. The ability of the soil to produce protein is determined by the presence of some dozen or so minerals. If these minerals are not replaced in the soil, the soil fertility declines. The experiment cited here demonstrates this over a long period of time. Minerals in the soil can be replaced if there is parent rock containing these minerals, if silt created by glaciers grinding rock is deposited in the annual river flooding in the spring melt, if wind blown dust is deposited on the soil or if organic matter containing the minerals is returned to the soil. Rainfall is made slightly acidic by carbon dioxide in the air that is dissolved in the falling rain. This rain will break minerals out of parent rock as long as the parent rock is in the soil thereby replacing minerals removed by the crop. The same rain, however, is also dissolving these same minerals in the water and carrying them to the sea. You can see it yourself, its the scale in your kettle. Over a much longer period of time than the 62 years in this experiment, soil fertility at first created by the rainfall can be then removed from the soil by continued rainfall. Human action only increases the speed of declining soil fertility.