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在豆科植物的栽培中,正常情况下是不必施用N肥的。因为在适宜的条件下,它们能够在具有N素的及通过共生固氮而得到N素的土壤里生长良好。然而,在某些情况下,恰当施用N肥能保证作物高产。在植株生长前期,根瘤未完全发育时,幼苗是依靠土壤里的N以及贮存在子叶里的N而正常生长的。当土壤的N供应不足时,豆科植物的幼苗就生长缓慢。由于这个原因,已经发现,施用小剂量的N不仅能促进豆科植物的生长,而且也能促进固氮。但据文献报道,大量的N肥对共生固N_2有抑制作用。因此,应当切实估计,要施什么水平的N肥才能既使固N_2效率高,又确保作物高产。本研究的主要目的是比较不同的大豆栽培种在施用低水平和高水平N肥时固N_2的能力。
In the cultivation of legumes, under normal circumstances do not have to apply N fertilizer. Because under the right conditions they can grow well in soils that have N-rich and get N-rich through symbiotic nitrogen fixation. However, in some cases, the proper application of N fertilizer can ensure high crop yield. In the early stages of plant growth, when the nodule is not fully developed, the seedling relies on N in the soil and the N stored in the cotyledons to grow normally. When soil N is under-supplied, legumes grow slowly. For this reason, it has been found that the application of small doses of N not only promotes the growth of legumes but also promotes nitrogen fixation. However, according to the literature, a large amount of N fertilizer inhibits symbiotic solid N_2. Therefore, we should actually estimate that we should apply what level of N fertilizer in order to make N_3 solid efficiently and ensure the high yield of crops. The main purpose of this study was to compare the ability of different soybean cultivars to immobilize N_2 when applying low and high N fertilizers.