红壤有机无机复合状况及氮素形态分布与肥力的关系

不同肥力红壤有机无机复合状况及氮素形态分布的研究结果表明，土壤肥力水平提高，有机无机复合量增大．复合量与土壤有机质、全氮、碱解氮、速效磷和ＣＥＣ呈显著或极显著正相关，与速效钾、缓效钾的相关性不显著；复合度与上述肥力性状的相关性均不显著．因此，可以用复合量来评价肥力状况．红壤酸解性氮占全氮７７％－８６％；在酸解性氮中，各组分氮所占比例为氨基酸态氮＞酸解氨态氮＞酸解未鉴别态氮＞氨基糖态氮．氨基酸态氮占酸解性氮的比率为高肥力红壤大于低肥力红壤，且与土壤有机质、全氮、碱解氮、速效磷里显著正相关，也可作为衡量土壤肥力状况的指标之一．

Relationship between Organo-Mineral Complexation Status, N Forms Distribution of Red Soil and Its Fertility

The organo-mineral complexation status and N forms distribution of red soils with different fertility were studied in the paper. The results were presented as follows:the amount of complexed carbon increased with the rising of soil fertility, and was significantly correlated with soil organic matter, total N, alkali-hydrolyzable N, available P and CEC, whereas was insignificantly correlated with available K and slowly available K;there was no significant relationship between the complexation degree and soil properties mentioned above. Therefore, the amount of complexed carbon could be used to evaluate soil fertility.In red soil, acid soluble N accounted for 77%-86% of total N, and the proportion of N fractions of acid soluble N was amino acid - N >ammonia - N > acid soluble unknown N > amino sugar N. The ratio of amino acid - N to acid soluble N was larger in high fertility soils than in low fertility soils, and significantly correlated with soil organic matter total N, alkali-hydrolyzable N and available P. So it could ie used as soil. fertility evaluation indes.