Phosphorous fertilization

Solid phosphoric fertilizers are available as mono-ammonium phosphate, di-ammonium phosphate, triple superphosphate and single superphosphate additionally, high-grade liquid phosphoric acid is available. 

Young, Ronald D., D. G. Westfall, and Gary W. Colliver. (1985). production, marketing, and use of phosphorous fertilizers. In Fertilizer technology and use. Third Edition. O. P. Englestad. Madison, WI Soil Science Society of America. 

Ammonium polyphosphate is one of the most often used phosphoric fertilizers (Corbridge, 1980). It was found to be equally effective when compared with single superphosphate and diammonium phosphate for increasing the yields of wheat and maize and for increasing the available phosphorus content in soil during field experiments (Sharma and Singh, 1998). 

Arkhipov, N.P., Fedorova, T.A., Fedorov, E.A., Fevraleva, L.T. and Tyumentseva L.M., Natural radionuclide content alteration in soils by regular phosphoric fertilization (in Russian). Prochvovedenie 12 (1981)52-61. 

P4O10 H3PO4 Phosphoric Fertilizer, chemical synthesis... 

At the same time the increase of mobile phosphorus content in soils is but one effect of phosphorous fertilizer intensive application. A considerable portion of the phosphorus above its carry-over with crop yields transformed into not mobile forms creating the reserve of phosphorus plant nutrition [2-4], According to Ref [5] during 25 years about 300 kg/ha of phosphorus were applied above its carry-over the entire amount was stayed in soil. The amount was sufficient to harvest 2 t/ha of grain yield during 25-30 years imless the phosphorous fertilizer application. 

Experimental technique was based on the materials of prolonged trials and our proper studies. We analyzed the effect of systematic organic and mineral (including phosphorous) fertilizer application in increased rates on change of mobile phosphoms content. Different soils were studied the soddy gle5dc heavy textured loamy soil (Lithuania), the sod-podzol heavy textured loamy soil (Moscow Region), the soddy-podzolic easy-loamy soil (Smolensk Region), the sod-podzol loamy sandy soil (Belams) and ordinary chernozem (Stavropol). 

We calculated the economic balance of phosphoms by principal variants of field experiments taking into account the applied phosphoms content with rotation of field rotations. We detected the influence of systematic long-termed phosphorous fertilizer application on mobile phosphoms content in soils. 

Hence, for the last two rotations of the field crop rotation, the application of609 kg/ha of phosphorous fertilizers not only has not increased the content of mobile phosphorus in soil, but also even had lowered the content by 6 mg/kg as compared to the end of the third rotation. 

Inasmuch as soil is bio inert system which has formed under the influence of biological factors it is inherent the function of conservation and transformation of substances [12, 13] and it reacts to soluble phosphorous fertilizer application according to Le Chatelier principle If a system at equilibrium experiences a change then the equilibrium shifts to partially counter-act the imposed change [14]. In different soils these functions are manifested in accordance with root natural causes. In soddy-podzolic soils with increased iron and aluminum compounds content applied phosphorous fertilizers transform in phosphate sesquioxides while in carbonate-enriched chernozems and chestnut soils the function of phosphoms conservation manifests itself in emergence of phosphates with different basicity including sparing soluble compounds, for example, apatite. Obviously the specific reasons determined a small increase or... 

Frank and Hirano (1990) survey the potential for the production and consumption of alternative, usable, commercial byproducts in conjunction with a major reduction in national emissions of SO2 and NO,. Hiey conclude that the potential byproduct yields from the U.S. acid rain control program greatly exceed available markets for the chemical products. Byproducts evaluated in the study include gypsum, sulfuric acid, ammonium sulfate, ammonium sulfate/nitrate, and nitrogen/phosphorous fertilizer. Henzel and Ellison (1990) present a review of past, present, and potential future disposal practices and commercial FGD byproduct utilization. Hiey indicate that the only discemable trend is the production of usable gypsum by wet FGD systems. The 1990 Clean Air Act Amendments may create a need for disposal sites, which tend to be expensive and scarce and which could in themselves be environmental problems. Systems that produce usable byproducts are expected to become more important in the future as the disposal option becomes less viable. 

Energy requirements for producing phosphorous fertilizers add up to as little as 15 GJ/t P for phosphate rock and as much as nearly 30 GJ/t for complex P-containing compounds. Mining, crushing, and beneficiation of potash (KCl) usually does not cost more than 10 GJ/t of the nutrient. As we will see in the next chapter, only a small part of synthesized ammonia is used directly as a fertilizer conversion of NHj to liquid and solid nitrogen fertilizers that dominate the field applications requires a considerable amount of additional energy. ... 

---