论文部分内容阅读
Fried 和 Deau 认为,植物从土壤和肥料中吸收的营养物质与其相应的有效率成正比。当施入土壤的标记肥料为标准肥料(已知量)时,则可求出土壤有效营养物质的数量(“A”值)。如用一种非固 N 植物与豆科植物一起种植于使用~(15)N 标记肥料的同种土壤上,则豆科植物中的 N 可来源于大气固定的 N、土壤 N 和标记肥料~(15)N;而非固 N 植物中的 N 只来自土壤 N 和标记肥料~(15)N。如种植的非固 N 植物是固 N 植物的一种合适的参照作物,则可利用“A”值法来区分豆科植物的三种 N 源。豆科植物测得的土壤加固定的有效 N 量(“A”值_(土壤+固定))
According to Fried and Deau, nutrients that plants absorb from soil and fertilizer are directly proportional to their relative effectiveness. When the labeled fertilizer applied to the soil is a standard fertilizer (a known amount), then the amount of soil available nutrients (“A”) can be found. If a non-fixed N plant is planted with the leguminous plant on the same soil using a ~ (15) N-labeled fertilizer, N in the leguminous plant may originate from atmospheric fixed N, soil N and labeled fertilizer ~ (15) N; whereas N in non-fixed N plants only comes from soil N and labeled fertilizer ~ (15) N. If planted non-immobilized N plants are a suitable reference crop of solid N plants, the “A” value method may be used to distinguish the three N sources of legumes. Measured soil legumes applied a fixed effective N amount (“A” value _ (soil + fixed))