Fertilizer phosphorus

Commercial name Chemical formula Apparent Bulk Phosphorus Market 

Calcium phosphate monobasic (calcium dihydrogen phosphate) Ca(HjPO,)j 2220 n.a. 60.68 n.a. 

Concentrated superphosphate (calcium di hydrogen phosphate monohydrate) Ca(HjPO,)j.HjO 2220 n.a. 56.34 1275-1320 

Calcium phosphate dibasic anhydrous (calcium hydrogen phosphate) CaHPO, 2310 960 48.97 250 

Triple superphosphate (mixture of calcium dihydrogen phosphate, hydrogen phosphate and gypsum) 30 wt.% Ca(HjPO,)j.HjO 10 wt.% CaHPO, 45 wt.% CaS0,.2H,0 10 wt.% impurities 5 wt.% water n.a. 800-890 43-50 n.a. 

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Biochar from dairy manure also has pofenfial for environmenfal remediation or for creating slow release phosphorus fertilizers (Cau and Harris, 2010). Dairy manure was converted by heating at temperatures below pyrolysis temperatures (< 500 °C) and in the presence of air. The potential benefit for lowering GHGs was nof defermined but the products have the potential of creating new markets for manure. 

ICRAF (1996) Replenishing soil fertility through improved sesbania fallows and phosphorus fertilization, International Centre for Research in Agroforestry, ICRAF Annual Report, 147-152... 

The toxic impurities of phosphorus ores are conserved in phosphorus fertilizers produced from these ores, and finally they are accumulated in the agroecosystems (see Chapter 13). These pollutants can enter into biogeochemical food webs and increase the ecological risk especially under acid soils distributed in many regions of the World (Europe, Asia and North and South America). 

Chand K, Dixit ML, Arora SK. 1992. Yield and quality of forage sorghum as affected by phosphorus fertilization. J Indian Soc Soil Sci 40(2) 302-306. 

All phosphorus fertilizers come from wet process phosphoric acid or directly from phosphate rock. Normal superphosphate, triple or concentrated superphosphate, and ammonium phosphate are the three common types used. Normal or ordinary superphosphate (NSP or OSP) is mostly monocalcium phosphate and calcium sulfate. It is made from phosphate rock and sulfuric acid and is equated to a 20% P2O5 content. It led the market until 1964. The production of normal superphosphate is similar to that for the manufacture of wet process phosphoric acid (Chapter 2, Section 3) except that there is only partial neutralization. Normal superphosphate is no longer used to any great extent. The following reaction is one example of an equation that represents this process. 

Ninety five percent of the phosphorus on Earth belongs to the minerals of the apatite group. Apatites are inorganic constituents of bones and teeth of vertebrate and man, as well as a basis of many pathologic sohd formations. Minerals of the apatite group are the main raw materials in the production of phosphorus fertilizers, fodder and technical phosphates, elementary phosphorus, and phosphor-organic compounds. The mineral is sometimes substantially enriched in rare-earth elements (REE) making their extraction possible (Altshuller 1980). 

Plant nutrient sulfur has been growing in importance worldwide as food production trends increase while overall incidental sulfur inputs diminish. Increasing crop production, reduced sulfur dioxide emissions, and shifts in fertilizer sources have led to a global increase of crop nutritional sulfur deficiencies. Despite the vital role of sulfur in crop nutrition, most of the growth in wodd fertilizer consumption has been in sulfur-free nitrogen and phosphorus fertilizers (see Fertilizers). 

Kanobo, I.A.K. and Gilkes, R.J. 1988. The effect of particle size in North Carolina phosphate rock on it dissolution in soil and on levels of bicarbonate-soluble phosphorus. Fertilizer Research 15 137-145. 

Cereals and meats are the major sources of phosphorus in human diets. Phosphorus deficiencies in most regions have not been a serious problem in human nutrition. Insofar as food is concerned, the primary value of phosphorus fertilizers is that they generally increase the total food production not die content of phosphorus in the food per se,... 

When phosphorus fertilizers are added to soils deficient in available forms of the element, increased crop and pasture yields ordinarily follow. Sometimes the phosphorus concentration in the crop is increased, and this increase may help to prevent phosphorus deficiency in the animals consuming the crop, but this is not always so. Some soils convert phosphorus added in fertilizers to forms that are not available to plants. On these soils, very heavy applications of phosphorus fertilizer may be required. Some plants always contain low concentrations of phosphorus even though phosphorus availability from the soil may be good. See also Fertilizer. 

Fig. 1. Historical use of nitrogen and phosphorus fertilizer in the United States. Data from the Fertilizer Institute, Washington, DC.

Phosphorus rates have ranged between 14 and 100 kg ha and potassium between 52 and 100 kg-ha Phosphorus fertilization can have a significant effect on tuber sugar content, although the requirements depend heavily on soil type and other agronomic factors (Bachmann, 1964 Kosaric et al., 1984). 

Akbarinia, A., Sefidkon, F., Chalavand, A., Sarvestani, Z.T. and Ashorabadi, E.S. (2005) Effect of nitrogen phosphorus fertilizer and manure on content and chemical composition of Trachyspermum ammi L. journal of Essential Oil Bearing Plants 8(1), 82-86. 

Sullivan, M., and Daiber, F. (1974). Response in production of cord grass, Spartina alternijlora, to inorganic nitrogen and phosphorus fertilizer. Ches. Sd. 15, 121—123. 

Mortvedt, J.J. and Sikora, F., Heavy metals, radionuclides and fluorides in phosphorus fertilizers. In Sikora, F. (ed.). Future Directions for Agricultural Phosphorus Research, pp. 69-73. TVA Bulletin Y.224. National Fertilizer and Environmental Research Center, Muscle Shoals, AL, 1992. 

The manufacture of this type of phosphorus fertilizer (also known as NPK- or NP-fertilizers) is largely restricted to Europe. The worldwide capacity in 1985 was estimated to be 4.4 10 t/a P2O5, Western Europe accounting for 2-10 t/a P2O5 and Eastern Europe for 1.1 10 t/a P2O5. 

Calcium phosphate (phosphate rock) is not applied directly as a phosphorus fertilizer. Why ... 

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