44.
Vital Role Of Cattle Manure
In Maintaining Soil’s Organic Matter
by William A. Albrecht, PhD
The use of "fossil" fuels in their various forms, like coal, kerosene, gasoline, and other volatile, readily combustible materials for agricultural power, to replace that of horses and mules, has brought about the highly exploitative attacks on the natural reserve organic matter of our surface soils.
This has resulted for two reasons: (a) more power and speed are applied to the tilling of the soil more deeply and vigorously to hasten the combustion of the reserves of microbial energy materials; (b) less organic matter is returned in the animal feed residues as manure, modified and improved as nutrition for the soil microbes and plants by the addition of the chemically more complex and varied waste products of the animal's physiology.
This has resulted for two reasons: (a) more power and speed are applied to the tilling of the soil more deeply and vigorously to hasten the combustion of the reserves of microbial energy materials; (b) less organic matter is returned in the animal feed residues as manure, modified and improved as nutrition for the soil microbes and plants by the addition of the chemically more complex and varied waste products of the animal's physiology.
Reasons
Striking Results . . . Farm manure (six tons per acre annually — right) demonstrated its effects (July, 1958) in the upkeep of soil productivity under corn continuously (69th successive crop) in contrast to that of the soil under similar cropping but no manure (left). The same noble hybrid seed on both plots didn’t overcome the difference in the soils due to manure and no manure.
The first of these reasons has been widely recognized as an unavoidable result of the high labor costs demanding such speed to raise the output per man.
The second reason has been generally disregarded. Manure handling has always been considered a distasteful sanitary chore incidental to keeping animals housed and penned, more than it has been appreciated as an essential, biochemical contribution to the nutritional quality of feeds and foods grown on manured soil. Also, it simultaneously does much to maintain the organic matter in its fertilizing services.
Chemical studies were made of the soils after 67 years of (a) no cattle manure on one set of plots, and (b) six tons per acre annually on another. Each set in such contrasting pairs had been under cropping to (a) wheat, (b) corn, (c) timothy annually, and also to (d) a four-year rotation of corn, oats, wheat, and clover, and (e) a six-year rotation of corn, oats, wheat, clover and timothy. From these data, it is clearly evident how much the use of barnyard manure (cow dung) has contributed to help in the upkeep of the organic matter supply in those soils. (See the table).
The second reason has been generally disregarded. Manure handling has always been considered a distasteful sanitary chore incidental to keeping animals housed and penned, more than it has been appreciated as an essential, biochemical contribution to the nutritional quality of feeds and foods grown on manured soil. Also, it simultaneously does much to maintain the organic matter in its fertilizing services.
Chemical studies were made of the soils after 67 years of (a) no cattle manure on one set of plots, and (b) six tons per acre annually on another. Each set in such contrasting pairs had been under cropping to (a) wheat, (b) corn, (c) timothy annually, and also to (d) a four-year rotation of corn, oats, wheat, and clover, and (e) a six-year rotation of corn, oats, wheat, clover and timothy. From these data, it is clearly evident how much the use of barnyard manure (cow dung) has contributed to help in the upkeep of the organic matter supply in those soils. (See the table).
Results
Under cropping to wheat continuously, the manured plot of soil had 2.4 percent of organic matter, when the unmanured one had only 2.1 percent. The former was three parts richer over 21 parts, or higher by one-seventh. Under corn continuously, the manure plot was higher in organic matter after the 67 years by four-sevenths. Under timothy sod continuously, the increase figure was nearly one-third; under the four year rotation, it was over one-third; and in the six-year rotation, one-fourth, or next to the lowest, which was the soil under wheat. These were the effects from using manure when in all of these cases the entire crops had been removed and no crop residues were returned.
Help From Cattle Manure
As additional significance, there is the help from barnyard manure in the maintenance of the inorganic part of the soil fertility. This was shown by the ash analysis of the soil for phosphate (phosphoric acid, P2O5) and for some of the cationic essential elements, namely: calcium, Ca; magnesium, Mg; and potassium, K.
It is also significant to note the help from manure in keeping up the soil's exchange--absorption capacity (cation exchange capacity), in which the organic matter is more active than the clay. Also the lowered soil acidity resulting from the use of manure, as measured by the amount of exchangeable hydrogen, in the soil after 67 years, deserves attention as a modified soil condition not commonly appreciated in connection with this soil treatment.
Contrasting values in each of the above cases of the elements cited for manure and no manure (Table) show clearly that manure has fertility values we do not commonly emphasize.
It is also significant to note the help from manure in keeping up the soil's exchange--absorption capacity (cation exchange capacity), in which the organic matter is more active than the clay. Also the lowered soil acidity resulting from the use of manure, as measured by the amount of exchangeable hydrogen, in the soil after 67 years, deserves attention as a modified soil condition not commonly appreciated in connection with this soil treatment.
Contrasting values in each of the above cases of the elements cited for manure and no manure (Table) show clearly that manure has fertility values we do not commonly emphasize.
Demonstration
After nearly three score and ten years of manuring, this treatment demonstrates that, in the matter of soil maintenance, cattle manure has values for:
(a) upkeep of the supply of reserve organic matter;
(b) holding up the soil's content of phosphorus even when manure is relatively low as a fertilizer for this essential element;
(c) preserving the supply of active potassium;
(d) maintaining the exchangeable magnesium;
(e) preserving the supply of active calcium; and
(f) helping to hold down the excessive concentration of acidity as hydrogen.
Manuring the soil has been doing these things for years under merely the belief in it as a good practice, and long before science gave us these few tabulations of what we can prove in favor of cattle manure. In the organic matter of the soil as part of the nutrition of microbes, plants, animals and man there is still much in the realm of good practice and much remains yet for science to prove and to explain.
(a) upkeep of the supply of reserve organic matter;
(b) holding up the soil's content of phosphorus even when manure is relatively low as a fertilizer for this essential element;
(c) preserving the supply of active potassium;
(d) maintaining the exchangeable magnesium;
(e) preserving the supply of active calcium; and
(f) helping to hold down the excessive concentration of acidity as hydrogen.
Manuring the soil has been doing these things for years under merely the belief in it as a good practice, and long before science gave us these few tabulations of what we can prove in favor of cattle manure. In the organic matter of the soil as part of the nutrition of microbes, plants, animals and man there is still much in the realm of good practice and much remains yet for science to prove and to explain.
Respect For Nature
The facts that have been outlined will be observed in nature by those who do not have preconceived ideas about plant growth. Unfortunately the professional agriculturalist often views the effects of soils on the plant’s growth with a distant outlook, as if the only problems were those of industrial manipulation of dead materials, with emphasis on the various technologies for economic advantages only.
People who approach agricultural research in this way have lost sight of agriculture as a biological demonstration by the forces of nature, where man is more spectator than manager in complete control of soil and produce.
Such unrealistic views of agriculture have led to expressions and views by high government officials that soil is but a chemical and physical agent for the production of larger quantities of crops. They seem unaware that the soil of our planet is a complex material developed through many centuries, having the power of creation, not only for plants, but for everything that lives, moves and has its being upon the earth.
(William A. Albrecht, Phd, 1888–1974, was the Chairman of Department of Soils, College of Agriculture, University of Missouri, Columbia.)
People who approach agricultural research in this way have lost sight of agriculture as a biological demonstration by the forces of nature, where man is more spectator than manager in complete control of soil and produce.
Such unrealistic views of agriculture have led to expressions and views by high government officials that soil is but a chemical and physical agent for the production of larger quantities of crops. They seem unaware that the soil of our planet is a complex material developed through many centuries, having the power of creation, not only for plants, but for everything that lives, moves and has its being upon the earth.
(William A. Albrecht, Phd, 1888–1974, was the Chairman of Department of Soils, College of Agriculture, University of Missouri, Columbia.)
