Effects of co-incorporation of Chinese milk vetch and rice straw with ni-trogen fertilizer reduction on rice yield and nitrogen nutrition balance
The combined returning of Chinese milk vetch and rice straw is an important measure to reduce fertilizer and increase efficiency.The effects of combined application of Chinese milk vetch and rice straw with nitrogen fertilizer re-duction on rice yield and nitrogen nutrition balance were studied to provide theoretical basis for rational utilization of Chinese milk vetch and rice straw in the south of Henan province.Nitrogen fertilizer was applied at two levels of 60%nitrogen(N0.6)and 100%nitrogen(N).Rice straw was returned to the field with high stubble(St)and not returned to the field.Two modes of green manure were adopted:planting and rolling Chinese milk vetch(Mv,22 500 kg/hm2)and winter fallow.The treatment of winter fallow,no straw returning and no fertilization was used as a blank con-trol(CK).In this study,a total of 10 treatments were used to study the effects of co-incorporation of Chinese milk vetch and rice straw with nitrogen fertilizer reduction on rice yield,rice aboveground nitrogen accumulation,soil nitrogen content,nitrogen use efficiency and soil nitrogen apparent profit and loss.The results showed that the rice yield in the treatment of Chinese milk vetch and rice straw combined with 60%nitrogen fertilizer(MvStN0.6)was significantly increased by 4.77%,6.49%and 23.48%,respectively,compared with that in the treatments of winter fallow+rice straw not returning+100%nitrogen fertilizer(N),Chinese milk vetch or rice straw returning with the same amount of nitrogen fer-tilizer(MvN0.6,StN0.6).The aboveground nitrogen accumulation of rice in Chinese milk vetch returning treatments was significantly higher than that in other equal nitrogen fertilizer treatments.Compared with the treatment of winter fallow+rice straw not returning+100%nitrogen fertilizer,the treatment of Chinese milk vetch returning+100%nitrogen fertilizer significantly increased the content of alkali-hydrolyzable nitrogen in paddy soil.In the nitrogen reduction treatments,only the MvStN0.6 treatment significantly increased the soil total nitrogen content.The apparent nitrogen use efficiency in the treatment of co-incorporation of Chinese milk vetch and rice straw with nitrogen fertilizer was significantly higher than that in the treatment of winter fallow+rice straw not returning+equal nitrogen fertilizer,and the actual nitrogen use efficiency in MvStN0.6 treatment was significantly higher than that in N0.6 treatment.The apparent profit and loss of soil nitrogen under different treatments varied greatly,ranging from-67 kg/hm2 to 69 kg/hm2.In summary,the co-incorporation of Chinese milk vetch and rice straw with 60%nitrogen fertilizer can effectively increase the accumulation of nitrogen in the aboveground part of rice,improve the harvest index of rice and the actual utilization rate of nitrogen fertilizer,thereby in-creasing rice yield and reducing nitrogen fertilizer non-point source pollution.
Chinese milk vetchrice strawyieldnitrogen accumulationapparent profit and loss of nitrogen
NETL
NSTL
万方数据
