土壤硝化力主要受土壤ｐＨ值制约，红壤硝化力最强，冲积土次之，滨海盐土最弱．土壤对ＮＨ＋４和Ｋ＋的固定，主要决定于粘粒矿物的类型和含量．红壤固定容量小，保肥稳肥能力弱，Ｎ素损失量高；冲积土和滨海盐土固定容量大，保肥稳肥能力强，Ｎ素损失少．提高供Ｋ水平，将会促进Ｎ素释放，抑制铵固定．而提高土壤Ｎ素水平，由于Ｎ素转化的复杂性，对Ｋ＋的固定与释放的影响没有明显的规律性 Soil nitrification is mainly controlled by soil pH, red soil nitrification is strongest, followed by alluvial soil, coastal weakest saline soil. Soil fixation of NH + 4 and K + mainly depends on the type and content of clay minerals. The fixed capacity of red soil is small, the ability to maintain fertility and stable fertility is weak, and the loss of N is high. The fixed capacity of alluvial soil and coastal saline soil is large, and the capability of fertilizer maintenance and stable fertilization is strong with less N loss. Increased for K level, will promote the release of N, inhibition of ammonium fixation. However, increasing the level of N in soil has no obvious regularity on the effect of K + fixation and release due to the complexity of N transformation