长期(13年)定位试验表明:3种类型有机肥(厩肥、绿肥和秸秆)都能增加红壤旱地有机质的积累,但速度不同。在当地习惯用量的条件下,有机质的年增长量以厩肥最快、其次是绿肥、再次是秸秆。土壤有机质的积累和肥料用量间的关系服从规律:Y(有机质的积累量)=Ae^bX (X为有机肥用量)。影响土壤有机质积累速度的主要因素是有机肥用量和它们的C/N。而有机肥的C/N则影响不同有机肥的有机质积累系数(单位肥料用量的有机质积累量)。
在生产实践上通过施用有机肥提高红壤(特别是红壤丘陵区)有机质水平要解决两个问题:肥源和运输,否则难以实行。本试验结果表明:本田秸秆就地还田也能增加红壤有机质的积累,但是速度较慢。秸秆就地还田不仅使作物吸收的大部分(>60%)K素重新还回土壤,而且解决了红壤旱地有机肥施用的肥源和运输问题,从而使这一措施在生产上实际可行。在生产实践上通过施用有机肥提高红壤（特别是红壤丘陵区）有机质水平要解决两个问题：肥源和运输，否则难以实行。本试验结果表明：本田秸秆就地还田也能增加红壤有机质的积累，但是速度较慢。秸秆就地还田不仅使作物吸收的大部分（>60%）K素重新还回土壤，而且解决了红壤旱地有机肥施用的肥源和运输问题，从而使这一措施在生产上实际可行

A long-term experiment (13 years) indicates that three type of organic manure can increase the content of soil organic matter in upland of red soil, but the rates vary. With the local traditional rate of manure application, the annual growth rate of soil organic matter is the highest in the farmyard manure treatment, followed by the green manure treatment and the straw treatment. The relation between accumulation of organic matter and quantity of organic manure applied is Y=Ae^bx, where Y stands for content of organic matter in the soil and X for quantity of organic manure applied. The primary factors affecting the accumulation rate are quantity and C/N of the organic matter applied. C/N of the organic matter has a major effect on the accumulation coefficient of organic matter of different organic manure source(kg OM/kg fertilizer).
The most important problems affecting increasing content of organic matter in red soil through application of organic manure are sources and transportation of organic manure, especially in hilly red soil areas. The results of the experiment indicate recycling straw as manure in the plots yet slightly increases organic matter content in the red soil, and also brings back most part of the potassium (>60 percent) absorbed by the crop to the soil, but at a low rate. Thereby, this measure can be taken as solution to the above-mentioned problems in farming practice.

中国科学院知识创新项目(KZCX2-407和KZCX2-413-4)的资助。