Abstract:

The effects of different amount chemical fertilizer usage under ploughing down milk vetch on nutrients status in rice filed and the accumulated absorption of N, P, K in rice was studied. The influence of rice yield was analyzed too. The results showed that different chemical fertilizer amount under ploughing down milk vetch could increase the content of available N and K of soil after the peak of tillering season, and offer more N, K nutrients for rice growth and development than those of the treatment only applying chemical fertilizer during the late growing season. At the maturing stage, the accumulated absorption of N, K was higher in rice with different chemical fertilizer amount under ploughing down milk vetch than that of the treatment only applying chemical fertilizer. Ploughing down milk vetch was benefit to the formation of rice seed. Ploughing down 22500 kg/hm2 milk vetch with N 132 kg/hm2、P2O5 90 kg/hm2、K2O 90 kg/hm2 (80% of conventional dosage) was the best for rice yield. The yield could reach to 9424.5 kg/hm2, remarkably increased by 5.19% compared to the treatment just applying chemical fertilizer. Ploughing down milk vetch could reduce the amount of chemical fertilizer by 20% without the rice yield loss. Milk vetch as a kind of green manure crops of rice filed could increase the rice yield, reduce input, save energy and reduce emissions.