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(一) 充分用地、积极养地,是农业生产上的一个关鍵間題,也是农业科学研究工作中的一个重要課題。养地是用地的基础,用地是养地的目的。土地的用和养,是一个问题的两个方面,它們之間有着一种相互依存、相互促进的辯証关系。单純强調养地,过多地休閑和反对复种、間种,結果就要影响人民的生产和生活,而且往往会反过求影响养地的效果。相反的,只用不养或多用少养,必然会带来地力减退,甚至土壤盐化、碱化等現象,使土地生产力降低。农作物生长发育所需要的营养成分很多,而氮、磷、鉀则是土壤中較缺的三种营养成分,特别是氮素,对土壤肥力的关系最密切。氮素营养在农作物生长发育过程中,具有特别重要的作用。氮在蛋白质中含量很
(A) Full use of land and active raising of land are a key issue in agricultural production and an important issue in agricultural scientific research. Land is the basis for land use, land is the purpose of raising land. The use and maintenance of land are two aspects of a problem. There is an interdependent and mutually reinforcing dialectical relationship between them. Simply emphasizing the cultivation of land, excessive leisure and opposition to multiple cropping and inter-species planting will have an impact on people’s production and livelihood, and will often reverse the effect of raising their own land. On the contrary, it is inevitable to bring about a decline in soil fertility and even soil salinization and alkalization, so that land productivity will be reduced. The nutrients required for crop growth and development are many, while nitrogen, phosphorus and potassium are the three nutrients missing in the soil, especially nitrogen, and are most closely related to soil fertility. Nitrogen nutrition in crop growth and development process, has a particularly important role. Nitrogen content in the protein is very high