皖南双季稻区长期施肥效应研究

在安徽休屯盆地进行的10年肥料定位试验结果表明，土壤对水稻产量的贡献率明显大于肥料，施肥的增产幅度随施肥年限有逐年降低趋势。氮磷钾肥增产效应依次为K＞N＞P。长期施用有机肥可保持水稻稳定增产，但在等养分条件下，紫云英与氮磷钾化肥配施（MNP），早稻平均产量明显低于等养分的化服单施（NPK），说明有机肥应提早施人，并增加氮肥作基肥的比例，以满足水稻幼苗对养分的需求。施用化肥或有机肥除有效钾外，土壤养分均有增加。因此从增产增收和养分平衡的意义上讲，必须重视稻田施用钾肥，适当控制磷肥用量。

STUDY ON THE EFFECT OF LONG-TERM FERTILIZATION IN DOUBLE RICE CROPPING SYSTEM OF SOUTHERN ANHUI

A ten years fertilizer experiment was conducted in double rice field in Xiutun Basin of Anhui Province. The results showed that the rice plants absorption of nutrients from soil was more than that from fertilizers. Response of rice to fertilizers was in order K>N >P, and the effect of long-term application chemical fertilizer was gradually reduced with extending years of fertilization. Long-term application of organic manure can keep steadily increasing yield of rice, however,organic manure combined with fetrtilizer(MNPK) the total yield of double rice was lower than that application of inorganic fertilizer(NPK) under the same rate of nutrients condition, indicating organic manure should be applied earlier and raised the ratio of N as basal to meet the needs on nitrogen nutrient of rice seedling growth. Long-term application of chemical fertilizers or organic manures the nutrient contents in soil was increased, except available potassium. Therefore, the emphasise should be given to supply potash in paddy soil and reduce the P rate so as to increase rice yield and income, and maintain the balance of nutrients.