肥料增产贡献率及其对土壤有机质的影响

CONTRIBUTION OF FERTILIZERS TO YIELD INCREASE AND ITS EFFECT ON SOIL ORGANIC MATTER

本文通过十年定位监测,研究了不同施肥结构肥料的效应特点及肥料各组分的增产贡献率,同时也分析了施肥结构与水稻产量和土壤有机质的关系。结果表明不同施肥结构对水稻产量的影响是明显的,共产量总趋势是:MNPK>NPK>MNP,MN>NP,M、N>CK。肥料的增产贡献率为35.4％。施用化肥仍是主要的增产途径,其增产占总增产的70％左右,而有机肥仅占30％。有机肥的增产主要是由于有机肥携入的钾所致,约占80％。氮钾的增产效果相当,氮为44％,且主要是化肥氮的贡献;钾为50％,化肥钾与有机肥钾的功效相当。有机肥氮磷钾一定程度上可代替化肥氮磷钾的增产作用,共代替率分别为N12％,P29％,K53％。因此在有机肥与化肥氮配合施用情况下便可满足总增产中90％以上的增产需求。磷肥的增产效果颇低,甚至造成可能是诱发了某种微量元素(如Zn)紧缺而减产。因此氮磷钾的增产效果是K、N>P。长期施用化肥对土壤有机质的影响不大,主要是增加谷物产出。然而在化肥与有机肥配施情况下,在获得更高的谷物产出的同时,土壤的有机质含量也会有较大的提高,为作物的进一步增产提供土壤的肥力基础。

This paper deals with the contribution of fertilizers to yield and the effect of different fertilization system on rice yield through a ten-year field experiment. Results indicated that fertilization system greatly affected rice yield. The general trend was MNPK>NPK>MNP, MN>NP; M,N>CK. Using chemical fertilizer was a major measure for higher output and its contribution accounted for 70% of all the output increased, and other 30% attributed to organic fertilizer. Yield increase from organic fertilizer was mostly attributed to K (80%) carried by organic material. About 44% of yield increase was attributed to N applied, mainly inorganic form. Potassium fertilization contributed to 50% of yield increase, with similar effect from organic and inorganic sources. So the use of organic fertilizer in combination with chemical one might fulfil 90% requirement for higher output. Effect of P fertilizer was rather poor, even it might cause a decrease in yield owing to the stress of some microelement which may be induced by overuse of P fertilizer. Long-term application of chemical fertilizer had little effect on soil organic matter content, but signiticantly increased output of grains. However when organic fertilizer was used with chemical one, not only a good output might be attained, but an increase in soil organic matter might become possible so as to establish a better foundation for further more output.