When the first fertilizer was manufactured in the 19th century, scientific community was euphoric that it would be the panacea for all the ills plaguing agriculture in the world. Undoubtedly, synthetic nutrient sources have led to huge increase in production of crops particularly on low fertile soils with high yielding varieties and hybrids. Fertilizers result in rapid growth and development of plants when applied particularly under irrigated conditions.
The euphoria was short lived. Soon, we could notice the grave dangers of synthetic fertilizers on the health of the soil, quality of underground water, microbial ecology, tolerance of crops to pests and diseases, etc. Over the years, synthetic fertilizers make the soil biologically inert resulting in poor soil structure and dominance of soil borne pathogens. Fertilized soils degrade in water holding capacity due to depletion of beneficial soil microbes and biomass content. Fertilized crops are susceptible to pests and diseases due to lush growth, which necessitates heavy pesticide applications. Synthetic pesticides destroy the dynamic equation between insect pests/pathogens and beneficial insects/microbes. The cost of production increases in the inorganic farming practices due to degradation of ecology. The farming practice heavily dependent on external, synthetic sources and poisonous pesticides is not ecologically sustainable. The food thus produced is unhealthy due to accumulated toxic substances in the food chain. Synthetic fertilizers are the key factor in this vicious cycle of unsustainable farming.
Are there alternatives!
Alternative soil nutrient management could be the turning point in reversing these unhealthy farming systems. Adding organic carbon and biomass is the effective way out. Scientific community world over has accepted the un-sustainability of inorganic sources for soil and crop management. But, it has been pondering over the alternative sources, as the manures and biomass are bulky and low in nutrients. The quantity required to meet the nutrient demand is exorbitantly high compared to concentrated inorganic fertilizers.
The concentrated organic manures such as edible and non-edible oil cakes contain high nutrients but are uneconomical on the farmers’ field. Among the bulky manures, horse manure, pig manure, night soil, sludge and chicken manure are quite high in nutrients. Chicken manure is widely available and most economical also. It contains 3% nitrogen, 2.5% P2O5 and 1.5% K2O besides being rich in secondary and micronutrients.
The comparison between chicken manure and synthetic fertilizers throws some interesting facts. 1000kg chicken manure supplies 30kg N, 25kg P2O5 and 15kg K2O. To supply this through fertilizers, farmer has to apply 52kg DAP, 45kg Urea and 25kg MOP. Under the local conditions, the cost of chicken manure would be RS. 600-700 per 1000kg. The costs of fertilizers would be about Rs. 900-950 for the above quantity. To supply micronutrients corresponding to chicken manure, it would cost much higher with fertilizers as micronutrient fertilizers are to be added separately. In short, a farmer has to spend Rs. 10 per kg of N, P2O5 and K2O together through chicken manure while Rs. 13 through NPK fertilizers. It clearly demonstrates that, there are organic sources, which are cost effective, ecologically sustainable and practical.
Chicken manure is available in the country in large quantities as poultry is a huge meat industry. Other such widely available sources are sludge, pig manure and fishmeal. They are potential sources of nutrients to the soil as alternatives to chemical fertilizers.
Environmental pollution
The utilization of these sources also helps in combating environmental pollution as they are dumped as wastes or diverted as in case of sludge. Based on local conditions, such organic wastes can be recycled for soil nutrient management. In most developing countries, these wastes are the sources of ground water contamination and human diseases.
Policy directions
State policies in this direction can create conducive atmosphere to utilize such organic wastes in sustainable agriculture. Establishing small-scale industries to recycle the wastes and subsidies through departments to promote their applications can be of great impact on the ground situation in farming systems. It is well known that fertilizers are popular more due to government patronage through subsidies and fertilizer industries than due to farmers’ preference as such.
The euphoria was short lived. Soon, we could notice the grave dangers of synthetic fertilizers on the health of the soil, quality of underground water, microbial ecology, tolerance of crops to pests and diseases, etc. Over the years, synthetic fertilizers make the soil biologically inert resulting in poor soil structure and dominance of soil borne pathogens. Fertilized soils degrade in water holding capacity due to depletion of beneficial soil microbes and biomass content. Fertilized crops are susceptible to pests and diseases due to lush growth, which necessitates heavy pesticide applications. Synthetic pesticides destroy the dynamic equation between insect pests/pathogens and beneficial insects/microbes. The cost of production increases in the inorganic farming practices due to degradation of ecology. The farming practice heavily dependent on external, synthetic sources and poisonous pesticides is not ecologically sustainable. The food thus produced is unhealthy due to accumulated toxic substances in the food chain. Synthetic fertilizers are the key factor in this vicious cycle of unsustainable farming.
Are there alternatives!
Alternative soil nutrient management could be the turning point in reversing these unhealthy farming systems. Adding organic carbon and biomass is the effective way out. Scientific community world over has accepted the un-sustainability of inorganic sources for soil and crop management. But, it has been pondering over the alternative sources, as the manures and biomass are bulky and low in nutrients. The quantity required to meet the nutrient demand is exorbitantly high compared to concentrated inorganic fertilizers.
The concentrated organic manures such as edible and non-edible oil cakes contain high nutrients but are uneconomical on the farmers’ field. Among the bulky manures, horse manure, pig manure, night soil, sludge and chicken manure are quite high in nutrients. Chicken manure is widely available and most economical also. It contains 3% nitrogen, 2.5% P2O5 and 1.5% K2O besides being rich in secondary and micronutrients.
The comparison between chicken manure and synthetic fertilizers throws some interesting facts. 1000kg chicken manure supplies 30kg N, 25kg P2O5 and 15kg K2O. To supply this through fertilizers, farmer has to apply 52kg DAP, 45kg Urea and 25kg MOP. Under the local conditions, the cost of chicken manure would be RS. 600-700 per 1000kg. The costs of fertilizers would be about Rs. 900-950 for the above quantity. To supply micronutrients corresponding to chicken manure, it would cost much higher with fertilizers as micronutrient fertilizers are to be added separately. In short, a farmer has to spend Rs. 10 per kg of N, P2O5 and K2O together through chicken manure while Rs. 13 through NPK fertilizers. It clearly demonstrates that, there are organic sources, which are cost effective, ecologically sustainable and practical.
Chicken manure is available in the country in large quantities as poultry is a huge meat industry. Other such widely available sources are sludge, pig manure and fishmeal. They are potential sources of nutrients to the soil as alternatives to chemical fertilizers.
Environmental pollution
The utilization of these sources also helps in combating environmental pollution as they are dumped as wastes or diverted as in case of sludge. Based on local conditions, such organic wastes can be recycled for soil nutrient management. In most developing countries, these wastes are the sources of ground water contamination and human diseases.
Policy directions
State policies in this direction can create conducive atmosphere to utilize such organic wastes in sustainable agriculture. Establishing small-scale industries to recycle the wastes and subsidies through departments to promote their applications can be of great impact on the ground situation in farming systems. It is well known that fertilizers are popular more due to government patronage through subsidies and fertilizer industries than due to farmers’ preference as such.
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