Fertilizers natural organic

Fertilizers natural (organic), except compost Nitric acid... 

Albrecht, W.A. (1953) Organic matter balances soil fertility. Natural Food and Farming, February 1953. 

Tiessen, H., Cuevas, E., and Chacon, P. (1994). The role of soil organic matter in sustaining soil fertility. Nature. 371,783-785. 

Vaughan, D., and Ord, B. G. (1985). Soil organic matter—A perspective on its nature, extraction, turnover and role in soil fertility. Soil organic matter and biological activity. Dev. Plant Soil Sci. 16,1-35. 

Historically, attention on soil organic matter (SOM) has focused on the central role that it plays in ecosystem fertility and soil properties, but in the past two decades the role of soil organic carbon in moderating atmospheric C02 concentrations has emerged as a critical research area.This chapter will focus on the storage and turnover of natural organic matter in soil (SOM), in the context of the global carbon cycle. 

Natural organic materials and various chemical byproducts represented a large proportion of the total world fertilizer supply until about the middle of the twentieth century in the later years of the century, however, the dependence shifted almost entirely to synthesized or chemically processed materials. Only by this means has it been possible to keep up with increasing populations,... 

Though many soil amendments are available for organic farming, these materials must be naturally based. In addition to manure-based fertilizers, many organic farmers rely on fish emulsion and seaweed preparations to supply nitrogen and other... 

Numerous synthetic organic and inorganic compounds, organochlorines, dioxins, heavy metals, hydrocarbons, chlorinated phenols, sulfates, sulfides, surfactants, solvents, acids, bases, salts, pharmaceuticals, plastics, resins, explosives, and natural organics Residential and commercial chemicals, pesticides, fertilizers, hydrocarbons, solvents, surfactants, paints, sealants, medicines, volatile organic compounds, resins, plastics, metals, salts, acids, and bases... 

Establishments primarily engaged in manufacturing nitrogenous fertilizer materials or mixed fertilizers from nitrogenous materials produced in the same establishment. Included are ammonia fertilizer compounds and anhydrous ammonia, nitric acid, ammonium nitrate, ammonium sulfate and nitrogen solutions, urea, and natural organic fertilizers (except compost) and mixtures. 

In the year ending June 30, 1991, 77.0 million metric tons of nitrogen fertilizer were used worldwide with 10.1 million metric tons in the United States alone [4], Nitrogen can be added to soil by natural means such as crop rotation, natural organics, mineral nitrogen, or by synthetic nitrogen fertilizers. 

For example, natural organic materials may be acceptable on the basis of total N, P2O5, and K2O content, provided the source of the material is identified and approved. Synthetic organic materials, if sparingly soluble, may require special methods of analysis, particularly if intended for controUed-relcase fertilizers. Likewise, special tests may be required for coated controlled-release fertilizers. 

In some countries, terms such as chemical fertilizer, mineral fertilizer, or inorganic fertilizer are used to distinguish the manufactured product from natural organic materials of plant or animal origin. The latter materials are called.organic fertilizers. 

AAPFCO, in the United States, uses the term natural organic fertilizers and gives the following definition ... 

Natural Organics. Animal and human wastes have long been used as fertilizers, especially... 

Problems associated with excessive levels of nutrients and unwanted nuisance species have already been mentioned. There are cases in which intentional fertilization is used by aquaculturists in order to produce desirable types of natural food for the species under culture. Examples of this approach include inorganic fertilizer appHcations in ponds to promote phytoplankton and zooplankton blooms that provide food for young fish such as channel catfish, the development of algal mats through fertilization of milkfish ponds, and the use of organic fertilizers (from Hvestock and human excrement) in Chinese carp ponds to encourage the growth of phytoplankton, macrophytes, and benthic invertebrates. In the latter instance, various species of carp with different food habits are stocked to ensure that all of the types of natural foods produced as a result of fertilization are consumed. 

Calcium. Calcium is the fifth most abundant element in the earth s cmst. There is no foreseeable lack of this resource as it is virtually unlimited. Primary sources of calcium are lime materials and gypsum, generally classified as soil amendments (see Calcium compounds). Among the more important calcium amendments are blast furnace slag, calcitic limestone, gypsum, hydrated lime, and precipitated lime. Fertilizers that carry calcium are calcium cyanamide, calcium nitrate, phosphate rock, and superphosphates. In addition, there are several organic carriers of calcium. Calcium is widely distributed in nature as calcium carbonate, chalk, marble, gypsum, fluorspar, phosphate rock, and other rocks and minerals. 

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