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通过一系列的田间试验研究了长期施肥的牧地土壤中磷的特性和可利用性,这些试验包括施用石灰、氮肥、耕作,以及自1982—83年两年中监测植物对磷的吸收和表层土(0—7.5厘米)磷组分的变化情况。施用石灰增加了土壤有机磷的矿化,这可由施石灰土壤中可提取态有机磷明显降低,同时微生物生物量磷增加加以证实,尽管土壤磷的这些变化对牧草产量和磷的吸收量无显著影响;另一方面,氮肥增加了牧草产量和磷的吸收量,但对土壤各种磷组分中的磷量几乎没有影响;在耕作土壤中,植物可利用的无机态磷量的增加是由于植物残茬分解过程中释放出磷,而休闲降低了这些土壤中的微生物态磷量。
The characteristics and availability of phosphorus in long-term fertilized grazing land were studied through a series of field trials involving the application of lime, nitrogen fertilizers, tillage and the monitoring of plant uptake of phosphorus and surface layers over the two-year period 1982-83 Soil (0-7.5 cm) phosphorus composition changes. Application of lime increased the mineralization of soil organic phosphorus, which was confirmed by the significant decrease of extractable organic phosphorus in lime soils and the increase of microbial biomass phosphorus, although these changes in soil phosphorus had no significant effect on pasture production and P uptake ; On the other hand, nitrogen fertilizer increased pasture production and phosphorus uptake, but had little effect on the amount of phosphorus in various phosphorus fractions of the soil; in cultivated soils, the increase in available inorganic phosphorus content of plants was due to Phosphorus was released during the decomposition of plant stubble, while recreation reduced the amount of microbial phosphorus in these soils.