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机构地区:[1]陕西省政府农业办公室,西北农业大学农化系,陕西省铜川市效区农技站
出 处:《西北农业大学学报》1995年第1期93-97,共5页Journal of Northwest Sci-Tech University of Agriculture and Forestry(Natural Science Edition)
摘 要:地球上98%的氮素存在于原生岩(火成岩)中,但其对氮素循环贡献甚微;大气圈中的气态氮仅是地球中总氮素质量的1.9%,但实际上是供应所有生命需要的唯一氮源;生物圈中的氮量很小,然而全球植物初级净产物中90%~97%的氮在生物圈内循环。氮素在生物圈中的循环主要包括增加、损失和转化3个途径,这种循环因生态系统而不同。The primary (igneous)rocks of the earth’s crust hold approximately 97.8%ofthe global N. However ,these rocks contribute very little to the cycling of N. Al-though gaseous N in the atmosphere represents only 19% of the earth’s total N mass,ithas apparently contributed virtually the sole source of N for nutrition of all forms oflife. In comparison with N contained in the atmosphere and lithosphere , the quantitiespresent in the biosphere are very small. However,on a global scale ,90~97% N contentof the net primary production of plant is derived from recycling of N within the bio-sphere. The N cycling in the biosphere include 3 ways in the main;additions ,losses andtransformations ,and the cycling varies with different ecosystems.
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