organic farming advantages
organic farming label
intensive farming
organic agriculture
organic agriculture journal
organic food
organic product
Soil Fertility Management and Fertilization In Organic Farming
Soil is A living Natural Body. This is a definition of the soil and life is the main difference between soil & weathering products, which are the sources of soil parent materials. The biological activity of the soil depends on the availability of nutrients and energy supplied by soil organic matter and crop and live stock residues. Most of chemical weathering which takes place in soils is the result of the activity of soil microorganisms, and then the ability of the soil to supply nutrients to the growing crop from its own reserves is going to be diminished by a reduction in soil biological activity. Decline in organic matter levels is of concern in terms of nutrient supply. Artificial fertilizer inputs are presumably able to maintain the productivity levels of the soil. On the other hand we are witnessing a long-term decline in the inherent ability of soil to grow crops without reliance on inputs from outside the system.
The healthy alternative is to create a healthy soil, the concept of soil fertility in the conventional farming and conventional plant nutrition is to provide the crop requirements of NPK, Ca, Mg. etc.., to the end of the required 16 plant nutrients. How to add them in a balanced ratios, at the proper timing. Even if we could do so we can’t guarantee the level of losses in each fertilizer component due to solubility and deep percolation, chemical degradation, and other reactions within the soil complex matrix, The organic concept is feed the soil not the plant, healthy soil healthy plant, same like healthy lady gives healthy baby.
Natural soil fertility provides the current growing crops with nutrients made available by the activity of soil microorganisms. They have developed symbiotic relationships with soil fauna and flora over millions of years. Rhizobia bacteria which live in nodules on the roots of legumes, and fix nitrogen from the atmosphere, mycorhyzae small fungal threads which penetrate plant roots and allow nutrients to be transferred directly from soil to the plant root system.
* Prof. of Soil Science, Faculty of Agriculture, Ain Shams University
The basis of livestock, crops and human beings is a healthy soil. Health soil through its biological activity and inherent fertility can grow high quality crops over long period of time without the need for large inputs from outside the farm.
Creating healthy soil rely on considering soil as a living entity, an ecosystem containing a wide variety of different flora and fauna. The main components of soil ecosystem can thus be categorized as living organisms, minerals, organic matter, water and air, all of which are required for soil efficient function.
The Natural Order :
The soil and the air above it are teeming with life, both visible and microscopic. The existence of every single one of these life forms is essential to the natural order.
These forms of life are dependent upon each other for food, for mutual support and to develop competitive strength. They work together to produce an environment beneficial to their own existence and that of all other life forms, including human life. It can be said that without insects there would be no plants and we would not exist.
So in the natural order, all forms of life (insects, plants, animals and people) co-exist to mutual benefit, in mutual harmony and in prefect balance.
In such a situation insect numbers and types are controlled naturally, soil fertility is at its maximum potential, plant growth is vigorous and we reap the benefit of living in a healthy and supportive environment.
We have grossly under-estimated the importance of maintaining this natural order. Many current agricultural methods, particularly annual ploughing, burning, mono-cropping and the use of agro-chemicals, destroy this harmony.
Be friendly with nature
Probably the most important lesson we have learned this century is that trying to fight nature is foolish, to cooperate is common sense. We have tried fighting with nature and found that not only do the current problems increase but also it becomes more difficult to see what should be done next. When we cooperate with nature the reverse happens. Nature helps us to solve those very same problems and the way forward becomes clear.
Several crops were planted onto the land in the same season, thus ensuring plant diversity, soil protection and soil fertility. In addition, the people had a sound knowledge of the basis of plant breeding for maintaining yield and for resistance to pests and diseases.
Prayers were offered at all important stages and crop loss of some 5-10% (to animals and insects) was accepted as a necessary contribution to maintaining the natural order or ecosystem. Immediately the land began to show signs of exhaustion it was allowed to rest for a lengthy period (about 20 years).
Learning from nature :
Nature has much to teach us. Nature is expert in zero tillage, in providing plant diversity, in recycling energy and nutrients through sunlight, animal wastes and vegetation, and in balancing prey/predator numbers. Our intelligence means we can learn from nature and then forge ahead to enhance natural processes for the benefit of all life forms and to make planet earth itself more fruitful. If, for instance, a plant is infested with insects, we can be sure that nature is teaching us an important lesson. We must examine our methods and determine whether the prey/predator balance has been upset or if the plant itself is less healthy than it should be.
If the plant is less healthy than it should be, examine soil fertility, the watering regime, plant hygiene (diseases), plant suitability or timeliness of planting. Look for clues from the colour and growth pattern of the plant above and below ground.
Experiment with different crop mixtures in the same field to discover which protect each other and which do not. All this information will lead to better selection of crop type or variety, of crop mixtures and rotations and of time of planting. Observe which plants, both wild and cultivated, are and are not attacked by certain insects. The ones that are not attacked may be useful for repelling those insects, whereas the ones, which are attacked, can be used as decoys. Look carefully at the soil. Many and varied insects indicate a soil in good condition. Learn what each insect, bird and animal eats, for that way we begin to understand the extent to which all life is linked and balanced. This knowledge will create within us a respect for nature, which is evidently lacking at the moment. Gradually through such observations made on our own land we develop a detailed knowledge which assists us to re-establish the natural order.
Four Steps to Re-establishing the Natural Order
Ploughing or digging disturbs the balance among soil insects, fungi, viruses, bacteria and other soil life. Soil disturbance breaks up root channels and soil structural units so that the soil can not perform its intended function. Disturbance of the soil also causes a rapid loss of organic matter upon which the crop and many soil organisms feed. Soil is the foundation of agriculture yet on most of our lands it is at its lowest possible fertility level. (Henry El-Well 1995).
1- Re-instate soil fertility :
The first step in reestablishing the natural order is therefore to reinstate the fertility of the soil by minimizing soil disturbance and maximizing soil organic matter. In brief dig less, mulch more and compost always.
2- Provide habitats for predators :
The second step is to provide suitable natural habitats for predators and to preserve existing ones. Here agro-forestry can play an important role; and a diversity of wild plant species should be encouraged on gravelly or rock outcrops and on field edges. There is great scope for using contour ridges for a variety of purposes: for growing fruits, firewood, fodder and trees as windbreaks, all of which will also help to re-establish the pest/ predator balance.
3- Re-introduce plant diversity :
The third step is to re-introduce plant diversity into the cropping system as diversity is nature's most effective way of maintaining the pest/predator balance and of ensuring continued soil fertility. In place of monocropping, farmers should consider ways of increasing plant diversity through the use of rotations, intercropping, mixed cropping, and strip cropping and permaculture designs.
4- Gradually reduce agro-chemicals :
The fourth step is to gradually reduce the amounts of agro-chemicals used as fertilizer, herbicides, insecticides and fungicides. Substitute organic matter and manure in place of mineral fertilizer; use rotations, under planting and mechanical cultivation in place of herbicides.
The value of reinstating the soil's fertility, improving plant diversity and of avoiding the use of agro-chemicals to re-establish the natural order (and thereby increase predator rum- bers) has already been mentioned, as has the importance of providing diverse habitats on contour ridges, rocky outcrops and at field edges.
Soil living organisms which act for improving soil quality and could be negatively affected by adding chemicals such as chemical fertilizers, pesticides and herbicides
The role of legume crops in atmospheric nitrogen fixation.
Table (1)
Soil Organic Matter Properties and Their
Associated Effects on Soil
Property Remarks Effects on soil
Color The typical dark color of many soils is caused by organic matter May facilitate warming
Water retention Organic matter can hold up to 20 times its weight in water Helps prevent drying and shrinking; improves moisture-retaining properties of sandy soils
Combination with clay minerals Cements soil particles into structural units called aggregates Permits exchange of gases; stabilizes structure; increase permeability
Chelation Forms stable complexes with Cu+2, Mn+2, Zn+2 and other polyvalent cations Enhances availability of micro nutrients to higher plants
Solubility in water Insolubility of organic matter is due to its association with clay; also, salts of divalent and trivalent cations with organic matter are insoluble Little organic matter is lost by leaching
Buffer action Exhibits buffering in slightly acid, neutral, and alkaline ranges Helps to maintain a uniform soil pH
Cation exchange Total acidities of isolated organic matter fractions range from 300 to 1400 cmol/kg Increase Cation exchange capacity (CEC) of the soil; from 20 to 70% of the CEC of many soils (e.g., Mollisols) is due to organic matter
Mineralization Decomposition of organic matter yields Co2, NH4+, NO3-, PO43- and SO42- Source of nutrients for plant growth
Combination with xenobiotics Affects bioactivity, persistence, and biodegradability of pesticides Modifies application rates of pesticides for effective control
Table (2)
Estimated Number and Biomass of Soil Animals
and Microorganisms in Surface Horizons
Organisms Abundance Biomass (kg/HFS)
Per meter3 Per gram
Soil animals
Earthworms 200-2,000 <1 110-1,100
Nematodes 107 - 108 104 - 105 11-110
Others 104 - 106 variable 17-170
Microorganisms
Bacteria 1014- 1015 108-109 450-4,500
Actinomycetes 1013-1014 107-108 450-4,500
Fungi 1011-1012 105-106 1,120-11,200
Algae 1010-1011 104-105 56-560
Protozoa 1010-1011 104-105 17-170
Table (3)
Major Legume Crops Used in Agriculture and
Estimates of Annual Nitrogen Fixation
Crop and N-fixing bacteria Annual N2 fixation
Range (kg/ha/year) Typical value (kg/ha/year)
Host plant Rhizobium
Alfalfa R. meliloti 60-500 225
Clovers R. trifolii 60-350 115
Peas, vetch R. leguminosarum 90-180 100
Beans R. phaseoli 20-100 45
Host plant Bradyrhizobium
Lupins B. lupinii 150-170 160
Soybeans B. japonicum 65-200 100
Cowpea B. parasponiae 65-130 100
Note: Rhizobium are fast-growing symbiotic bacteria; Bradyrhizobium are slow growing b. Average values from various sources.Organic wastes as a source of nitrogen.
Table (4)
Representative Values for Nitrogen and Availability
for Selected Organic Wastes.
Organic N source Total N(%) Organic N mineralized a (%)
Beef
Dairy
Poultry
Swine Animal manure
1.3-1.8
2.5-3.0
4.0-6.0
3.5-4.5
25-35
25-40
50-70
30-50
Aerobic digestion
Anaerobic digestion
Composted Biosolids
3.5-5.0
1.8-2.5
0.5-1.5
25-40
10-20
(-10)-10
Fermentation wastes
Poultry processing wastes Other wastes
3.0-8.0
4.0-8.0
20-50
40-60
Note : Average values from various sources.
Table (5)
Nutrient removal estimates for selected crops
Crop (Kg/t fresh weight unless otherwise indicated
Nitrogen phosphate potash CaO MgO
Rye
Wheat
Winter barley
Oats 15
15
20
17 8
8
8
8 5
5
5
5 10
6
10
6 3
3
4
4
Maize (+straw)
Maize (-straw)
Oil seed rape 30
20
55 15
8
30 35
5
50 8
-
60 8
2
10
Potatoes (main crop)
Potatoes (early)
Sugar beet (+tops)
Sugar beet (-tops) 4.5
3
5
2 2
2
2
- 7
5
8
2.5 2
0.5
1.5
0.5 -
0.5
1.5
0.5
Lucerne*
Red clover*
White clover/grass* 30
30
10 8
7
3 20
25
5 25
22
20 4
5
5
Fodder rape
Fodder beet (+tops)
Forage maize
Sunflower
Mustard 5.5
4
3
2.5
4.5 0.5
-
2
-
0.8 5.5
6
4
4
4 3.5
1
1.5
3.5
4 0.5
-
1
0.5
0.5
Carrots
Beer root
Cabbages 2
2
3.5 -
1
1.5 2.5
3
5 N/A
N/A
2 N/A
N/A
0.8
*Per tonne dry matter,Sources:- Various
Table (6)
Approximate composition of materials
suitable for composting
Material Nitrogen
% dry weight basis C:N ratio
15:1
Urine 15-19 0.8
Dried blood 10-14 3
Hoof and horn meal 12 -
Bone meal 4 8
Grass 4 20
Brewers wastes 3 - 5 15
Farmyard manure 2.2 14
Millet, pigeon pea stalks 0.7 70
Wheat, barley, rice straw 0.4 - 0.6 80 - 100
Fallen leaves 0.4 45
Sugar-cane trash 0.3 150
Rotted sawdust 0.2 200
Fresh sawdust 0.1 500
Paper nil Infinity
Source : Gray & Biddlestone (1981)
a Organic N mineralized estimated from laboratory incubation studies. Negative values for composts and papermill sludges indicate that immobilization of N occurred.
Rock Phosphate analysis :
OXIDS: - Heave mineral contents: -
SiO2 – 2.43 % Nicl - Nil
Al2O3 – 1.22 % Vanadium - Nil
Fe2O3 – 4.6 % Lead - 0.03
MgO – 9.5 % Cupper - 0.2
CaO – 41 % Silver - Nil
K2O – 0.5 % Cadmium - Nil
L.O.I –10.44 %
P¬2O5 – 26.7 %
SO¬3 – 4.5 %
---------------------------------------------------------------------------------------
Source, Al –Ahram Co., Egypt.
Approximate composition of materials suitable for composting.
Material H2O % N % P¬2O5 K2O
Cow manure 86 0.6 0.15 0.45
Horse manure 78 0.70 0.25 0.55
Sheep manure 69 0.95 0.35 1.00
Hens manure 55 1.0 0.80 0.40
Wood ash - - 0.10 6.63
Seaweed (Ascophyllum nodosum)
Typical Organic matter
Dry matter 92-98 % Protein 6 - 8 %
Moisture 2 - 8 % Carbohydrates 35 - 50 %
Organic matter 45 - 60 % Alginic acid 10 - 20 %
Inorganic matter 40 - 55 % Mannitol 4 - 7 %
Inorganic matter
Essential major elements: (macro-nutriens)
Micro-Nutrients
N 1.0-1.5% Cu 1-6 ppm
P 0.02-0.05% Fe 20-200 ppm
K 10-12% Mn 5-12 ppm
Ca 0.5-1.0 % Zn 10-100 ppm
S 3-9 % B 20-100 ppm
Mg 0.5-0.9 % Mo 1-5 ppm
Growth stimulants
Adenine (cytokinins) 0.02 %
Betaines 0.04 %
Average composition of farm compost
Farm compost B.D Kg H2O % C/N % N
% OM % P¬2O5 % K2O %
A 584 10.9 20:1 1.2 44.4 - -
B 650 12.0 27.5 0.96 35.0 0.08 0.35
C 690 12.1 31.5 0.68 38.4 0.24 0.71
D 680 12.5 28.3 0.91 36.5 0.025 0.41
E 620 10.0 15.3 0.93 38.0 0.68 0.39
F 700 12.5 30.1 0.72 42.5 0.07 0.35
organic farming label
intensive farming
organic agriculture
organic agriculture journal
organic food
organic product
Soil is A living Natural Body. This is a definition of the soil and life is the main difference between soil & weathering products, which are the sources of soil parent materials. The biological activity of the soil depends on the availability of nutrients and energy supplied by soil organic matter and crop and live stock residues. Most of chemical weathering which takes place in soils is the result of the activity of soil microorganisms, and then the ability of the soil to supply nutrients to the growing crop from its own reserves is going to be diminished by a reduction in soil biological activity. Decline in organic matter levels is of concern in terms of nutrient supply. Artificial fertilizer inputs are presumably able to maintain the productivity levels of the soil. On the other hand we are witnessing a long-term decline in the inherent ability of soil to grow crops without reliance on inputs from outside the system.
The healthy alternative is to create a healthy soil, the concept of soil fertility in the conventional farming and conventional plant nutrition is to provide the crop requirements of NPK, Ca, Mg. etc.., to the end of the required 16 plant nutrients. How to add them in a balanced ratios, at the proper timing. Even if we could do so we can’t guarantee the level of losses in each fertilizer component due to solubility and deep percolation, chemical degradation, and other reactions within the soil complex matrix, The organic concept is feed the soil not the plant, healthy soil healthy plant, same like healthy lady gives healthy baby.
Natural soil fertility provides the current growing crops with nutrients made available by the activity of soil microorganisms. They have developed symbiotic relationships with soil fauna and flora over millions of years. Rhizobia bacteria which live in nodules on the roots of legumes, and fix nitrogen from the atmosphere, mycorhyzae small fungal threads which penetrate plant roots and allow nutrients to be transferred directly from soil to the plant root system.
* Prof. of Soil Science, Faculty of Agriculture, Ain Shams University
The basis of livestock, crops and human beings is a healthy soil. Health soil through its biological activity and inherent fertility can grow high quality crops over long period of time without the need for large inputs from outside the farm.
Creating healthy soil rely on considering soil as a living entity, an ecosystem containing a wide variety of different flora and fauna. The main components of soil ecosystem can thus be categorized as living organisms, minerals, organic matter, water and air, all of which are required for soil efficient function.
The Natural Order :
The soil and the air above it are teeming with life, both visible and microscopic. The existence of every single one of these life forms is essential to the natural order.
These forms of life are dependent upon each other for food, for mutual support and to develop competitive strength. They work together to produce an environment beneficial to their own existence and that of all other life forms, including human life. It can be said that without insects there would be no plants and we would not exist.
So in the natural order, all forms of life (insects, plants, animals and people) co-exist to mutual benefit, in mutual harmony and in prefect balance.
In such a situation insect numbers and types are controlled naturally, soil fertility is at its maximum potential, plant growth is vigorous and we reap the benefit of living in a healthy and supportive environment.
We have grossly under-estimated the importance of maintaining this natural order. Many current agricultural methods, particularly annual ploughing, burning, mono-cropping and the use of agro-chemicals, destroy this harmony.
Be friendly with nature
Probably the most important lesson we have learned this century is that trying to fight nature is foolish, to cooperate is common sense. We have tried fighting with nature and found that not only do the current problems increase but also it becomes more difficult to see what should be done next. When we cooperate with nature the reverse happens. Nature helps us to solve those very same problems and the way forward becomes clear.
Several crops were planted onto the land in the same season, thus ensuring plant diversity, soil protection and soil fertility. In addition, the people had a sound knowledge of the basis of plant breeding for maintaining yield and for resistance to pests and diseases.
Prayers were offered at all important stages and crop loss of some 5-10% (to animals and insects) was accepted as a necessary contribution to maintaining the natural order or ecosystem. Immediately the land began to show signs of exhaustion it was allowed to rest for a lengthy period (about 20 years).
Learning from nature :
Nature has much to teach us. Nature is expert in zero tillage, in providing plant diversity, in recycling energy and nutrients through sunlight, animal wastes and vegetation, and in balancing prey/predator numbers. Our intelligence means we can learn from nature and then forge ahead to enhance natural processes for the benefit of all life forms and to make planet earth itself more fruitful. If, for instance, a plant is infested with insects, we can be sure that nature is teaching us an important lesson. We must examine our methods and determine whether the prey/predator balance has been upset or if the plant itself is less healthy than it should be.
If the plant is less healthy than it should be, examine soil fertility, the watering regime, plant hygiene (diseases), plant suitability or timeliness of planting. Look for clues from the colour and growth pattern of the plant above and below ground.
Experiment with different crop mixtures in the same field to discover which protect each other and which do not. All this information will lead to better selection of crop type or variety, of crop mixtures and rotations and of time of planting. Observe which plants, both wild and cultivated, are and are not attacked by certain insects. The ones that are not attacked may be useful for repelling those insects, whereas the ones, which are attacked, can be used as decoys. Look carefully at the soil. Many and varied insects indicate a soil in good condition. Learn what each insect, bird and animal eats, for that way we begin to understand the extent to which all life is linked and balanced. This knowledge will create within us a respect for nature, which is evidently lacking at the moment. Gradually through such observations made on our own land we develop a detailed knowledge which assists us to re-establish the natural order.
Four Steps to Re-establishing the Natural Order
Ploughing or digging disturbs the balance among soil insects, fungi, viruses, bacteria and other soil life. Soil disturbance breaks up root channels and soil structural units so that the soil can not perform its intended function. Disturbance of the soil also causes a rapid loss of organic matter upon which the crop and many soil organisms feed. Soil is the foundation of agriculture yet on most of our lands it is at its lowest possible fertility level. (Henry El-Well 1995).
1- Re-instate soil fertility :
The first step in reestablishing the natural order is therefore to reinstate the fertility of the soil by minimizing soil disturbance and maximizing soil organic matter. In brief dig less, mulch more and compost always.
2- Provide habitats for predators :
The second step is to provide suitable natural habitats for predators and to preserve existing ones. Here agro-forestry can play an important role; and a diversity of wild plant species should be encouraged on gravelly or rock outcrops and on field edges. There is great scope for using contour ridges for a variety of purposes: for growing fruits, firewood, fodder and trees as windbreaks, all of which will also help to re-establish the pest/ predator balance.
3- Re-introduce plant diversity :
The third step is to re-introduce plant diversity into the cropping system as diversity is nature's most effective way of maintaining the pest/predator balance and of ensuring continued soil fertility. In place of monocropping, farmers should consider ways of increasing plant diversity through the use of rotations, intercropping, mixed cropping, and strip cropping and permaculture designs.
4- Gradually reduce agro-chemicals :
The fourth step is to gradually reduce the amounts of agro-chemicals used as fertilizer, herbicides, insecticides and fungicides. Substitute organic matter and manure in place of mineral fertilizer; use rotations, under planting and mechanical cultivation in place of herbicides.
The value of reinstating the soil's fertility, improving plant diversity and of avoiding the use of agro-chemicals to re-establish the natural order (and thereby increase predator rum- bers) has already been mentioned, as has the importance of providing diverse habitats on contour ridges, rocky outcrops and at field edges.
Soil living organisms which act for improving soil quality and could be negatively affected by adding chemicals such as chemical fertilizers, pesticides and herbicides
The role of legume crops in atmospheric nitrogen fixation.
Table (1)
Soil Organic Matter Properties and Their
Associated Effects on Soil
Property Remarks Effects on soil
Color The typical dark color of many soils is caused by organic matter May facilitate warming
Water retention Organic matter can hold up to 20 times its weight in water Helps prevent drying and shrinking; improves moisture-retaining properties of sandy soils
Combination with clay minerals Cements soil particles into structural units called aggregates Permits exchange of gases; stabilizes structure; increase permeability
Chelation Forms stable complexes with Cu+2, Mn+2, Zn+2 and other polyvalent cations Enhances availability of micro nutrients to higher plants
Solubility in water Insolubility of organic matter is due to its association with clay; also, salts of divalent and trivalent cations with organic matter are insoluble Little organic matter is lost by leaching
Buffer action Exhibits buffering in slightly acid, neutral, and alkaline ranges Helps to maintain a uniform soil pH
Cation exchange Total acidities of isolated organic matter fractions range from 300 to 1400 cmol/kg Increase Cation exchange capacity (CEC) of the soil; from 20 to 70% of the CEC of many soils (e.g., Mollisols) is due to organic matter
Mineralization Decomposition of organic matter yields Co2, NH4+, NO3-, PO43- and SO42- Source of nutrients for plant growth
Combination with xenobiotics Affects bioactivity, persistence, and biodegradability of pesticides Modifies application rates of pesticides for effective control
Table (2)
Estimated Number and Biomass of Soil Animals
and Microorganisms in Surface Horizons
Organisms Abundance Biomass (kg/HFS)
Per meter3 Per gram
Soil animals
Earthworms 200-2,000 <1 110-1,100
Nematodes 107 - 108 104 - 105 11-110
Others 104 - 106 variable 17-170
Microorganisms
Bacteria 1014- 1015 108-109 450-4,500
Actinomycetes 1013-1014 107-108 450-4,500
Fungi 1011-1012 105-106 1,120-11,200
Algae 1010-1011 104-105 56-560
Protozoa 1010-1011 104-105 17-170
Table (3)
Major Legume Crops Used in Agriculture and
Estimates of Annual Nitrogen Fixation
Crop and N-fixing bacteria Annual N2 fixation
Range (kg/ha/year) Typical value (kg/ha/year)
Host plant Rhizobium
Alfalfa R. meliloti 60-500 225
Clovers R. trifolii 60-350 115
Peas, vetch R. leguminosarum 90-180 100
Beans R. phaseoli 20-100 45
Host plant Bradyrhizobium
Lupins B. lupinii 150-170 160
Soybeans B. japonicum 65-200 100
Cowpea B. parasponiae 65-130 100
Note: Rhizobium are fast-growing symbiotic bacteria; Bradyrhizobium are slow growing b. Average values from various sources.Organic wastes as a source of nitrogen.
Table (4)
Representative Values for Nitrogen and Availability
for Selected Organic Wastes.
Organic N source Total N(%) Organic N mineralized a (%)
Beef
Dairy
Poultry
Swine Animal manure
1.3-1.8
2.5-3.0
4.0-6.0
3.5-4.5
25-35
25-40
50-70
30-50
Aerobic digestion
Anaerobic digestion
Composted Biosolids
3.5-5.0
1.8-2.5
0.5-1.5
25-40
10-20
(-10)-10
Fermentation wastes
Poultry processing wastes Other wastes
3.0-8.0
4.0-8.0
20-50
40-60
Note : Average values from various sources.
Table (5)
Nutrient removal estimates for selected crops
Crop (Kg/t fresh weight unless otherwise indicated
Nitrogen phosphate potash CaO MgO
Rye
Wheat
Winter barley
Oats 15
15
20
17 8
8
8
8 5
5
5
5 10
6
10
6 3
3
4
4
Maize (+straw)
Maize (-straw)
Oil seed rape 30
20
55 15
8
30 35
5
50 8
-
60 8
2
10
Potatoes (main crop)
Potatoes (early)
Sugar beet (+tops)
Sugar beet (-tops) 4.5
3
5
2 2
2
2
- 7
5
8
2.5 2
0.5
1.5
0.5 -
0.5
1.5
0.5
Lucerne*
Red clover*
White clover/grass* 30
30
10 8
7
3 20
25
5 25
22
20 4
5
5
Fodder rape
Fodder beet (+tops)
Forage maize
Sunflower
Mustard 5.5
4
3
2.5
4.5 0.5
-
2
-
0.8 5.5
6
4
4
4 3.5
1
1.5
3.5
4 0.5
-
1
0.5
0.5
Carrots
Beer root
Cabbages 2
2
3.5 -
1
1.5 2.5
3
5 N/A
N/A
2 N/A
N/A
0.8
*Per tonne dry matter,Sources:- Various
Table (6)
Approximate composition of materials
suitable for composting
Material Nitrogen
% dry weight basis C:N ratio
15:1
Urine 15-19 0.8
Dried blood 10-14 3
Hoof and horn meal 12 -
Bone meal 4 8
Grass 4 20
Brewers wastes 3 - 5 15
Farmyard manure 2.2 14
Millet, pigeon pea stalks 0.7 70
Wheat, barley, rice straw 0.4 - 0.6 80 - 100
Fallen leaves 0.4 45
Sugar-cane trash 0.3 150
Rotted sawdust 0.2 200
Fresh sawdust 0.1 500
Paper nil Infinity
Source : Gray & Biddlestone (1981)
a Organic N mineralized estimated from laboratory incubation studies. Negative values for composts and papermill sludges indicate that immobilization of N occurred.
Rock Phosphate analysis :
OXIDS: - Heave mineral contents: -
SiO2 – 2.43 % Nicl - Nil
Al2O3 – 1.22 % Vanadium - Nil
Fe2O3 – 4.6 % Lead - 0.03
MgO – 9.5 % Cupper - 0.2
CaO – 41 % Silver - Nil
K2O – 0.5 % Cadmium - Nil
L.O.I –10.44 %
P¬2O5 – 26.7 %
SO¬3 – 4.5 %
---------------------------------------------------------------------------------------
Source, Al –Ahram Co., Egypt.
Approximate composition of materials suitable for composting.
Material H2O % N % P¬2O5 K2O
Cow manure 86 0.6 0.15 0.45
Horse manure 78 0.70 0.25 0.55
Sheep manure 69 0.95 0.35 1.00
Hens manure 55 1.0 0.80 0.40
Wood ash - - 0.10 6.63
Seaweed (Ascophyllum nodosum)
Typical Organic matter
Dry matter 92-98 % Protein 6 - 8 %
Moisture 2 - 8 % Carbohydrates 35 - 50 %
Organic matter 45 - 60 % Alginic acid 10 - 20 %
Inorganic matter 40 - 55 % Mannitol 4 - 7 %
Inorganic matter
Essential major elements: (macro-nutriens)
Micro-Nutrients
N 1.0-1.5% Cu 1-6 ppm
P 0.02-0.05% Fe 20-200 ppm
K 10-12% Mn 5-12 ppm
Ca 0.5-1.0 % Zn 10-100 ppm
S 3-9 % B 20-100 ppm
Mg 0.5-0.9 % Mo 1-5 ppm
Growth stimulants
Adenine (cytokinins) 0.02 %
Betaines 0.04 %
Average composition of farm compost
Farm compost B.D Kg H2O % C/N % N
% OM % P¬2O5 % K2O %
A 584 10.9 20:1 1.2 44.4 - -
B 650 12.0 27.5 0.96 35.0 0.08 0.35
C 690 12.1 31.5 0.68 38.4 0.24 0.71
D 680 12.5 28.3 0.91 36.5 0.025 0.41
E 620 10.0 15.3 0.93 38.0 0.68 0.39
F 700 12.5 30.1 0.72 42.5 0.07 0.35