不同氮肥与磷肥的互作效应

利用盆栽试验研究了潮土中不同氮肥与磷肥的互作效应，结果表明：不同氮肥与磷肥的配合施用对潮土中油菜的生长和养分吸收有显著的交互作用。生长初期，施氮并不能促进、甚至会抑制油菜的生长，氯化铵较其它氮肥作用突出。随着生长期的延长，氮肥对油荣生长的促进作用逐渐显现，但氯化铵的促进作刚仍低于其它氮肥。植株养分累积受不同氮肥影响的规律与植株干物质累积表现的规律基本一致。土壤有效磷含最受不同氮肥影响较小，而水溶性磷含量因施用不同氮肥表现出显著的差异，特别是在生长初期的土壤中。相关分析结果表明，油菜生长初期的干物质质量与土壤水溶性磷含量达到极显著相关（r=0．727^＊＊）。因此推测，不同氮肥对油菜生长的影响可能因氮肥降低土壤中磷的有效性所致，这些结果对今后的合理施肥提供了重要的参考依据。

Interaction between different nitrogen and phosphorus fertilizer in calcareous soil

The interaction between different nitrogen and phosphorus fertilizer in calcareous soil was investigated in a pot experiment, planting rape. The results indicated that effects of the interaction between different N and P on growth and nutrition uptake of rape were significant. At the initial stages, all N treatments restrained the growth of rape, especially the NH4Cl treatment, but as time went by, the growth finally was increased significantly, so nutrition uptake was. And the interaction had little influence on soil available phosphorus, while influencing water extractable phosphorus greatly, especially in the early days, and the analysis of correlation sug-gested there was a close relationship between s water extractable phosphorus and dry matter production(r=0.727**). Thus, the effects of different N on growth of rape were closely related with soil P availability. Such results were beneficial for fertilizer rec-ommendation.