Publisher's Synopsis
Organic fertilizers are an essential source for plant nutrients and a soil conditioner in agriculture. Due to its sources and the composition of the organic inputs as well as the type, functionality and failures of the applied treatment process, the organic fertilizer may contain various amounts of infectious agents and toxic chemicals, especially the antibiotics that can be introduced to the subsequent food chain. A range of human and animal pathogens of bacterial, viral and parasitic origin have been the cause of food-borne epidemics due to unintended contamination from organic fertilizers. The use of antibiotics by humans and in animal feeds will also end up in the organic fertilizers. These antibiotics and other chemicals, depending on the sources of the organics, will enhance the likelihood of occurrence of resistant and multi-resistant strains of microorganisms in society and have been reported to cause ecotoxicological environmental effects and disruption of the ecological balance. Exposure of microorganisms to sublethal concentration of antibiotics in the organic products induces antibiotic resistance. Shifting from conventional farming to organic farming has many benefits to the human's well-being, protecting the environment (soil, water, and air), rebuilding soil fertility through improving its physical, chemical, and biological characteristics, and improving the quality of produced crops. However, producing crops organically may come with higher production costs (i.e., lower yield and higher labor costs). Recycling, composting, and using local inputs may decrease the production cost. In general, soils rarely have sufficient nutrients available for crops to reach their potential yield. Therefore, farmers tend to apply soil amendments (synthetic or organic amendments) that are rich in nutrient, i.e., N, P, and K to enhance soil fertility and increase crop productivity. However, most growers apply fertilizers based on the general recommendations for each crop, without prior knowledge of the soil fertility status and nutrient mineralization and release pattern from the fertilizers. Organic Fertilizers Potentialities and Problems comprehends chapters of review articles and case studies and provides information in field of organic farming and fertilizers. Organic farmers are limited to "natural" fertilizers which for non-legume, large acreage, crops boils down to manure or composted manure (Organic growers are not the only ones that use manure, but the problems occur for all). Some of the nitrogen molecules in an "organic" fertilizer are exactly the same chemicals as in "synthetic" fertilizers - urea and ammonia. Some of it is in more complex biologically formed molecules like amino acids, nucleic acids and a variety of intermediate metabolites and structural molecules. That is why organic fertilizers are "slow release" forms of nitrogen. Over time, soil microbes convert those more complex forms into exactly the same nitrate ion that comes from a synthetic fertilizer - the nitrate that plants can use (and which can become a pollutant of the water or atmosphere). The problem is that the conversion process does not match the crop demand. To achieve good yields, Organic growers need to apply very high amounts of total nitrogen so that enough is available when the crop needs it. Much of this nitrogen continues to be turned into nitrate well after the crop is using it and so it is well documented that this form of fertilization leads to water pollution issues. This is why farmers are being payed to truck manure far away from the waterways that drain into the bay. Slow-release nitrogen sounds a lot better than it is. Organic fertilizers also have the problem that they contain more phosphorus than is needed if they are used at the rates that make sense from a nitrogen point of view. Growers using manure or compost pick rates based on nitrogen, but that means that phosphorus is over-supplied. This too leads to water pollution. Organic fertilizers are an essential source for plant nutrients and a soil conditioner in agriculture. Due to its sources and the composition of the organic inputs as well as the type, functionality and failures of the applied treatment process, the organic fertilizer may contain various amounts of infectious agents and toxic chemicals, especially the antibiotics that can be introduced to the subsequent food chain. A range of human and animal pathogens of bacterial, viral and parasitic origin have been the cause of food-borne epidemics due to unintended contamination from organic fertilizers. The use of antibiotics by humans and in animal feeds will also end up in the organic fertilizers. These antibiotics and other chemicals, depending on the sources of the organics, will enhance the likelihood of occurrence of resistant and multi-resistant strains of microorganisms in society and have been reported to cause ecotoxicological environmental effects and disruption of the ecological balance. Exposure of microorganisms to sublethal concentration of antibiotics in the organic products induces antibiotic resistance. Shifting from conventional farming to organic farming has many benefits to the human's well-being, protecting the environment (soil, water, and air), rebuilding soil fertility through improving its physical, chemical, and biological characteristics, and improving the quality of produced crops. However, producing crops organically may come with higher production costs (i.e., lower yield and higher labor costs). Recycling, composting, and using local inputs may decrease the production cost. In general, soils rarely have sufficient nutrients available for crops to reach their potential yield. Therefore, farmers tend to apply soil amendments (synthetic or organic amendments) that are rich in nutrient, i.e., N, P, and K to enhance soil fertility and increase crop productivity. However, most growers apply fertilizers based on the general recommendations for each crop, without prior knowledge of the soil fertility status and nutrient mineralization and release pattern from the fertilizers. Organic Fertilizers Potentialities and Problems comprehends chapters of review articles and case studies and provides information in field of organic farming and fertilizers. Organic farmers are limited to "natural" fertilizers which for non-legume, large acreage, crops boils down to manure or composted manure (Organic growers are not the only ones that use manure, but the problems occur for all). Some of the nitrogen molecules in an "organic" fertilizer are exactly the same chemicals as in "synthetic" fertilizers - urea and ammonia. Some of it is in more complex biologically formed molecules like amino acids, nucleic acids and a variety of intermediate metabolites and structural molecules. That is why organic fertilizers are "slow release" forms of nitrogen. Over time, soil microbes convert those more complex forms into exactly the same nitrate ion that comes from a synthetic fertilizer - the nitrate that plants can use (and which can become a pollutant of the water or atmosphere). The problem is that the conversion process does not match the crop demand. To achieve good yields, Organic growers need to apply very high amounts of total nitrogen so that enough is available when the crop needs it. Much of this nitrogen continues to be turned into nitrate well after the crop is using it and so it is well documented that this form of fertilization leads to water pollution issues. This is why farmers are being payed to truck manure far away from the waterways that drain into the bay. Slow-release nitrogen sounds a lot better than it is. Organic fertilizers also have the problem that they contain more phosphorus than is needed if they are used at the rates that make sense from a nitrogen point of view. Growers using manure or compost pick rates based on nitrogen, but that means that phosphorus is over-supplied. This too leads to water pollution.
