【摘要】 通过施用不同浓度铵态氮肥和钾肥,对18种水稻土在淹水条件下对NH₄⁺的固定能力、K⁺存在时对NH₄⁺固定的影响以及土壤对K⁺和NH₄⁺固定的比例等方面进行了研究。结果表明。淹水条件下土壤对施人的NH₄⁺-N肥具有较高的固定能力。在施氮量达200mg Nkg^-1时,2天内可固定施人氮量的32％～63％;其固定速度很快,2h固定量可达48h固定量的56％～95％;一般情况下,NH₄⁺、K⁺同时施用对NH₄⁺的固定没有影响,但先施K⁺后施NH₄⁺时,除K⁺本身的固定明显增加外,对NH₄⁺的固定有减少趋势;在给予同样数目的NH₄⁺和K⁺时,其固定比例约为1.7～3.3。更多还原

【Abstract】 The present research was conducted to study the effects of NH₄⁺ and K⁺ of various concentrations on the fixation of NH₄⁺ and K⁺ and their interrelations in 18 paddy soils under submerged conditions. Results showed that these soils when submerged had considerably large capability of fixing NH₄⁺ applied as N fertilizer. When application rate amounted to 200mgNkg^-, 32％～63％ were fixed within 2 days. When NH₄⁺ and K⁺ were applied simulteniously, K⁺ had no effect in general on NH₄⁺ fixation. However, if the application of K⁺ was prior to NH₄⁺, amount of fixed NH₄⁺ seemed to be decreased and more K⁺ was fixed as compared to that when NH₄⁺ and K⁺ were simultaneously applied. The ratio of fixed NH₄⁺ to K⁺ was 1.7～3.3 in terms of equivelant cations of NH₄⁺ and K⁺ used.更多还原