MAJOR ORGANIC SOURCES AND TRANSFORMATIONS
Carbon present in soil is in the form of organic matter. The organic materials most commonly used to improve soil conditions and fertility include farm yard manure (FYM), animal wastes, crop residues, urban organic wastes (either as such or composted), green manures, bio-gas spent slurry, microbial preparations, vermicompost and biodynamic preparations. Sewage sludge and some of the industrial wastes also find application in agriculture. For all organic matter, atmospheric carbon dioxide serves as the main source of carbon. Carbon dioxide is converted to organic carbon largely by the action of photoautotrophic organisms; the higher green plants on land and algae in aquatic habitats. Carbon is being contentiously fixed into organic form through the process of photosynthesis and once bound; the carbon becomes unavailable for use in the generation of new plant life. Carbon fixation involves a reduction of carbon dioxide by hydrogen donor NADPH (reduced form of the co-enzyme nicotinamide adenine dinucleotide phosphate, NADP) and the synthesis of carbohydrate from reduced carbon through complex cyclic mechanism called the
Calvin cycle. Carbon dioxide constitutes only 0.03 percent by volume of the earths atmosphere. It has been estimated that the vegetation of the earth's surface consumes some 90 billion kg carbon dioxide per annum, about one twenty - fifth of the total supply of the atmosphere and that the total supply of carbon dioxide would be completely exhausted in twenty years at the present rate of photosynthesis , if not replenished by decomposition of organic materials. As the availability of carbon dioxide on the earth's surface is very limited, it must be recycled. Upon the death of the plants and animals, microbiological metabolism assumes the dominant role in cyclic sequence. The dead tissues added to soil undergo decay and are transformed into microbial cells and a vast heterogeneous body of carbonaceous compounds. According to the different stages of decomposition, the soil organic matter becomes available in distinct fractions. Farm yard manure made from cattle dung, excreta of other animals, animal tissues and excretory products, and compost from rural and urban wastes, crop residues and green-manure are collectively designated as bulky organic manures because of their low contents of major nutrients, while materials like oil cakes, fish meal, animal meal, poultry manures, slaughter house wastes containing comparatively higher contents of plant nutrients are grouped under concentrated organic manures. In general organic manures containing upto two percent nitrogen are included in bulky category and those with more than two percent nitrogen are treated as concentrated. Irrespective of source and composition, organic matter when added into the soil undergoes microbial decay and becomes the food for micro flora and fauna. Even the microbial cells serve as a source of carbon for succeeding generations of microscopic populations. A great variety of microorganisms live in soil which include bacteria, actinomycetes, fungi, algae and protozoa. In general the number per gram of soil is bacteria > actinomycetes > fungi > algae > protozoa. The average nutrient content of bulky manures.
Manure Percentage content
N P2O5 K2O Animal refuse 0.3-0.4 0.1-0.2 0.1-0.3 Cattle dung,fresh 0.4-0.5 0.3-0.4 0.3-0.4 Horse dung ,fresh 0.5 -0.5 0.4-0.6 0.3-1.0 Poultry manure,fresh 1.0-1.8 1.4-1.8 0.8-0.9 Sewage sludge,dry 2.0-3.5 1.0-5.0 0.2-0.5 Sewage sludge, 4.0-7.0 2.1-4.2 0.5-0.7 Cattle urine 0.9-1.2 trace 0.5-1.0 Horse urine 1.2-1.5 trace 1.3-1.5 Human urine 0.6-1.0 0.1-0.2 0.2-0.3 Sheep urine 1.5-1.7 trace 1.8-2.0 Ash, coal 0.73 0.45 0.53
Ash,household 0.5-1.9 1.6-4.2 2.3-12.0
Ash,wood 0.1-0.2 0.8-5.9 1.5-36.0
Rural compost,dry 0.5-1.0 0.4-0.8 0.8-1.2 Urban compost,dry 0.7-2.0 0.9-3.0 1.0-2.0
Farmyard manure,dry 0.4-1.5 0.3-0.9 0.3-1.9
Filter-press cake 1.0-1.5 4.0-5.0 2.0-7.0
Rice hulls 0.3-0.5 0.2-0.5 0.3-0.5
Groundnut husks 1.6-1.8 0.3-0.5 1.1-1.7
Banana,dry 0.61 0.12 1.00
Cotton 0.44 0.10 0.66
Source:Organic Farming for Sustainable Agriculture by A.K.Dhama ,1996 Agro Benificial Publishers (India)
Carbon present in soil is in the form of organic matter. The organic materials most commonly used to improve soil conditions and fertility include farm yard manure (FYM), animal wastes, crop residues, urban organic wastes (either as such or composted), green manures, bio-gas spent slurry, microbial preparations, vermicompost and biodynamic preparations. Sewage sludge and some of the industrial wastes also find application in agriculture. For all organic matter, atmospheric carbon dioxide serves as the main source of carbon. Carbon dioxide is converted to organic carbon largely by the action of photoautotrophic organisms; the higher green plants on land and algae in aquatic habitats. Carbon is being contentiously fixed into organic form through the process of photosynthesis and once bound; the carbon becomes unavailable for use in the generation of new plant life. Carbon fixation involves a reduction of carbon dioxide by hydrogen donor NADPH (reduced form of the co-enzyme nicotinamide adenine dinucleotide phosphate, NADP) and the synthesis of carbohydrate from reduced carbon through complex cyclic mechanism called the
Calvin cycle. Carbon dioxide constitutes only 0.03 percent by volume of the earths atmosphere. It has been estimated that the vegetation of the earth's surface consumes some 90 billion kg carbon dioxide per annum, about one twenty - fifth of the total supply of the atmosphere and that the total supply of carbon dioxide would be completely exhausted in twenty years at the present rate of photosynthesis , if not replenished by decomposition of organic materials. As the availability of carbon dioxide on the earth's surface is very limited, it must be recycled. Upon the death of the plants and animals, microbiological metabolism assumes the dominant role in cyclic sequence. The dead tissues added to soil undergo decay and are transformed into microbial cells and a vast heterogeneous body of carbonaceous compounds. According to the different stages of decomposition, the soil organic matter becomes available in distinct fractions. Farm yard manure made from cattle dung, excreta of other animals, animal tissues and excretory products, and compost from rural and urban wastes, crop residues and green-manure are collectively designated as bulky organic manures because of their low contents of major nutrients, while materials like oil cakes, fish meal, animal meal, poultry manures, slaughter house wastes containing comparatively higher contents of plant nutrients are grouped under concentrated organic manures. In general organic manures containing upto two percent nitrogen are included in bulky category and those with more than two percent nitrogen are treated as concentrated. Irrespective of source and composition, organic matter when added into the soil undergoes microbial decay and becomes the food for micro flora and fauna. Even the microbial cells serve as a source of carbon for succeeding generations of microscopic populations. A great variety of microorganisms live in soil which include bacteria, actinomycetes, fungi, algae and protozoa. In general the number per gram of soil is bacteria > actinomycetes > fungi > algae > protozoa. The average nutrient content of bulky manures.
Manure Percentage content
N P2O5 K2O Animal refuse 0.3-0.4 0.1-0.2 0.1-0.3 Cattle dung,fresh 0.4-0.5 0.3-0.4 0.3-0.4 Horse dung ,fresh 0.5 -0.5 0.4-0.6 0.3-1.0 Poultry manure,fresh 1.0-1.8 1.4-1.8 0.8-0.9 Sewage sludge,dry 2.0-3.5 1.0-5.0 0.2-0.5 Sewage sludge, 4.0-7.0 2.1-4.2 0.5-0.7 Cattle urine 0.9-1.2 trace 0.5-1.0 Horse urine 1.2-1.5 trace 1.3-1.5 Human urine 0.6-1.0 0.1-0.2 0.2-0.3 Sheep urine 1.5-1.7 trace 1.8-2.0 Ash, coal 0.73 0.45 0.53
Ash,household 0.5-1.9 1.6-4.2 2.3-12.0
Ash,wood 0.1-0.2 0.8-5.9 1.5-36.0
Rural compost,dry 0.5-1.0 0.4-0.8 0.8-1.2 Urban compost,dry 0.7-2.0 0.9-3.0 1.0-2.0
Farmyard manure,dry 0.4-1.5 0.3-0.9 0.3-1.9
Filter-press cake 1.0-1.5 4.0-5.0 2.0-7.0
Rice hulls 0.3-0.5 0.2-0.5 0.3-0.5
Groundnut husks 1.6-1.8 0.3-0.5 1.1-1.7
Banana,dry 0.61 0.12 1.00
Cotton 0.44 0.10 0.66
Source:Organic Farming for Sustainable Agriculture by A.K.Dhama ,1996 Agro Benificial Publishers (India)
