Ground Phosphate Rock

a type of phosphorus fertilizer. Finely ground phosphate rock is gray or brown; insoluble in water, it does not cake, and it is readily dispersed. This fertilizer contains 19–30 percent P₂O₅ in the form of Ca₃(PO₄)₂, which is all but inaccessible to plants, with impurities of CaCO₃ and CaF₂. The types of rock that are ground to produce the fertilizer include nodular, granular, and certain karstic phosphorites. Ground phosphate rock is used as a base fertilizer on acid podzolic, gray wooded, and bog soils and on leached chernozems and red soils. It is applied in the autumn before plowing. In an acid medium, the phosphorus in ground phosphate rock is gradually converted into Ca(H₂PO₄)₂·H₂O, a form that can be used by plants. Ground phosphate rock is most effective on loamy and clay soils for lupine, mustard, buckwheat, peas, and other crops whose roots acidify the soil. The fertilizer is not used on soils that are well limed and heavily manured. The rate of application varies from 40 to 90 kg of P₂O₅ per hectare. Ground phosphate rock is also used in preparing composts.

Production of ground phosphate rock in the USSR has grown from 90,000 tons of P₂O₅ in 1940 and 1950 to 265,000 tons in 1960, 973,000 tons in 1970, and 1,059,000 tons in 1975. Outside the Soviet Union, ground phosphate rock is used primarily in the United States and Canada.

单词	ground phosphate rock
释义	Ground Phosphate Rock Ground Phosphate Rock a type of phosphorus fertilizer. Finely ground phosphate rock is gray or brown; insoluble in water, it does not cake, and it is readily dispersed. This fertilizer contains 19–30 percent P₂O₅ in the form of Ca₃(PO₄)₂, which is all but inaccessible to plants, with impurities of CaCO₃ and CaF₂. The types of rock that are ground to produce the fertilizer include nodular, granular, and certain karstic phosphorites. Ground phosphate rock is used as a base fertilizer on acid podzolic, gray wooded, and bog soils and on leached chernozems and red soils. It is applied in the autumn before plowing. In an acid medium, the phosphorus in ground phosphate rock is gradually converted into Ca(H₂PO₄)₂·H₂O, a form that can be used by plants. Ground phosphate rock is most effective on loamy and clay soils for lupine, mustard, buckwheat, peas, and other crops whose roots acidify the soil. The fertilizer is not used on soils that are well limed and heavily manured. The rate of application varies from 40 to 90 kg of P₂O₅ per hectare. Ground phosphate rock is also used in preparing composts. Production of ground phosphate rock in the USSR has grown from 90,000 tons of P₂O₅ in 1940 and 1950 to 265,000 tons in 1960, 973,000 tons in 1970, and 1,059,000 tons in 1975. Outside the Soviet Union, ground phosphate rock is used primarily in the United States and Canada.
随便看	first national bank in quanah first national bank of anchorage first national bank of arizona first national bank of arvada first national bank of bellevue first national bank of botswana first national bank of broken arrow first national bank of brookfield first national bank of central florida first national bank of chicago first national bank of crossett first national bank of eastern arkansas first national bank of florida first national bank of fort smith first national bank of gwinnett first national bank of houma first national bank of hughes springs first national bank of ipswich first national bank of litchfield first national bank of marin first national bank of morton grove first national bank of mount dora first national bank of northern california directed recursive labelnode hypergraphs directed retry