共 2 条
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Effect of grazing and cultivation on some chemical properties of soils in the mixed prairie. Dormaar J F,Willms W D. Journal of Range Management . 1990
[2]
Estimation of ammonia losses after application of liquid cattle manure on grassland. Braschkat J,Mannheim T,Marschner H. Zeitschrift fur Pflanzenernahrung und Bodenkunde . 1997