太湖地区油菜生长的养分效应

研究了在苏南太湖地区油菜和水稻轮作的种植条件下,不同施肥量对油菜生长发育的影响.结果表明:N肥和P肥施用皆显著增加油菜产量;N肥用量较当地施肥量减少25% 时,并没有造成油菜产量的明显降低;施肥量N 200 kg/hm2、P2O5 110 kg/hm2处理其干物质、N和P的积累量以及油菜籽产量都是各处理中最高的,其N肥利用率为60%,P肥利用率为42%;各处理N肥利用率最高达68%,P肥利用率最高为45%.产量和干物质之间具有良好的相关性,相关系数R2都在0.95以上.在营养生长阶段,产量和干物质之间呈现二次曲线相关;生殖生长阶段,则表现为明显的直线相关.此外,施加P肥能提高土壤中速效P含量.这些结果可为当地合理施肥提供理论指导.

Nutrient Effects of Rape Growth in Taihu Lake Region

Field experiments were carried out to investigate the effects of nitrogen and phosphorus application rate on rape growth in Taihu Lake region. The results showed that nitrogen and phosphate fertilization could increase rapeseed yield and there was no significant reduction when the conventional nitrogen fertilizer application rate were reduced by 25%. The optimal treatment was N 200 kg/hm2 and P2O5 110 kg/hm2 with N efficiency 60% and P efficiency 42%. The maximal fertilizer efficiency was 68% for nitrogen and 45% for phosphorus. The correlation coefficient was above 0.95 between the yield and biomass with significant quadratic curve correlation in nutritional growth stage but linear correlation in reproductive stage. Phosphate fertilization could increase the content of P-Olsen in soil. These results can provide theoretic instruction for practical field management in rape cultivation.