冬种紫云英对水稻产量及其养分吸收的影响

Effect of Chinese milk vetch in winter on rice yield and its nutrient uptake

通过始于2008年冬季的定位试验研究了不同施肥处理下冬种紫云英对水稻产量及养分吸收的影响。结果表明:相同施肥措施下,冬种紫云英后能够提高水稻产量和地上部全氮吸收量,紫云英翻压后,减少化学氮肥用量20%～40%,不会降低稻谷和稻草产量。紫云英翻压后,N、P、K化肥100%施用的处理其水稻地上部对全N、全P、全K的吸收总量最高,分别为228.6、48.6、305.6 kg/hm2,若氮肥用量减少20%,不会对水稻地上部氮素的吸收累积产生明显影响,但当水稻季化学氮肥用量减少40%,将会明显降低水稻地上部氮素的吸收总量。紫云英翻压后,水稻不施K肥处理,其稻谷产量分别较NPK(冬种紫云英)处理和NPK(冬闲)处理降低了13.0%和3.4%;没有外源钾肥的投入,使得其水稻地上部全氮、全钾吸收总量明显下降,钾素生理效率提高,说明冬种紫云英不能完全替代化学钾肥作用。

A field experiment that started the winter of 2008 was carried out to study the effect of Chinese milk vetch in winter on rice yield and its nutrient uptake under the condition of different inorganic fertilizer application rate. The results indicated that the rice yield and total N uptake of rice shoot increased after Chinese milk vetch grown under the same fertilization. The yield of rice and straw did not decrease when chemical nitrogen fertilizer reduced 20% -40% after ploughing the Chinese milk vetch back. The rice shoot of treatment which application the chemical N, P, K fertilizer 100% after ploughing the Chinese milk vetch back had the highest absorption about total N, total P and total K, and the total absorption were 228.6, 48.6 and 305.6 kg/hm~ respectively. When nitrogen decreased by 20%, the nitrogen uptake of rice shoot had no significant effect. But when nitrogen decreased by 40% , the effect of the nitrogen uptake of rice shoot was significantly. The rice yield of no potassi- um application after ploughing the Chinese milk vetch back was decreased by 13.0% and 3.4% compared with the treatments of NPK （grew Chinese milk vetch in winter） and NPK （fallow in winter） respectively. Because of no potassium application, the total absorption of nitrogen and potassium of rice shoot decreased significantly, the physiological efficiency of potassium was increased. Therefore the Chinese milk vetch was planted in winter could not substitute the role of chemical potassium fertilizer completely.