| Guanzhong Plain is an important corn / wheat rotation area in China.In order to improve the grain yield,excessive application of chemical fertilizer is very common,which has a serious impact on Soil and environment.As an important fertilizer,organic fertilizer can improve water and nitrogen utilization efficiency,increase crop yield,improve soil structure and so on.The combination of organic and inorganic fertilizer is an important measure to increase agricultural yield and improve the quality of farmland.However,there are still some problems to be clarified about its optimal application amount and the impact on crop water and nitrogen utilization efficiency under deficit irrigation.In this study,summer maize / winter wheat was selected as the research object,organic fertilizer with high organic matter content and strong water retention performance was selected,and organic fertilizer and inorganic fertilizer were mixed according to different proportions(F1: 100% inorganic fertilizer,F2: 24% organic fertilizer and 76% inorganic fertilizer,F3: 48% organic fertilizer and 52% inorganic fertilizer)according to the principle of equal nitrogen,combined with two levels of irrigation(full irrigation W1 and deficit irrigation W2)The effects of deficit irrigation combined with organic and inorganic fertilizer on the yield and water and nitrogen utilization of summer maize and winter wheat were studied.The results are as follows:(1)Organic fertilizer can increase soil water storage capacity and improve crop water use efficiency.The water storage capacity of summer maize and winter wheat increased by 7.8% and 14.2% respectively,compared with that of jointing stage.The water storage capacity of W2F2 treatment in 0-60 cm soil layer of corn and winter wheat was the most significant,which was 24.6% higher than that of inorganic fertilizer treatment.(2)Combined application of organic and inorganic fertilizer significantly increased nitrogen accumulation,distribution and transport after flowering.Under the same irrigation conditions,compared with F1 treatment,the cumulative amount of nitrogen,the amount of nitrogen transport to the grain and the nitrogen utilization rate of summer maize increased by 2.3%-8.3%,28.1%-36.7%,13.7%-16.7%,and that of winter wheat increased by 12.8%-40.4%,11.9%-36.5%,13.0%-31.6%;under the same organic organic organic organic ratio(F2 and F3),the nitrogen absorption and utilization indexes of summer maize under deficit irrigation W2 treatment were increased by 12.8%-40.4%,11.9%-36.5%,and 13.0%-31.6% W1 treatment was 3.6%-10.1% higher than that of full irrigation,while wheat treatment was 10.0%-28.5%.(3)Organic and inorganic fertilizer can promote the growth of crops.The plant height and leaf area index of summer maize and winter wheat increased with the increase of organic fertilizer under the two irrigation levels,especially under the deficit irrigation,the plant height and leaf area index of summer maize F2 increased fastest than other treatments,while that of winter wheat F3 was the most obvious.The leaf area index and plant height under deficit irrigation were better than that under full irrigation.(4)The combination of organic and inorganic fertilizer increased grain yield significantly.The grain yield of each organic fertilizer treatment was higher than that of single fertilizer treatment.The appropriate deficit irrigation was conducive to the accumulation of dry matter and the increase of crop yield.For summer maize,compared with F1 treatment,the grain yield of F2 and F3 treatment increased by 4.8% ? 6.3% and that of Wheat by 14.8% ? 28.6% under the condition of full irrigation(W1),while that of organic fertilizer treatment increased by 1.8% ? 2.3% and that of Wheat by 13.1% ? 31.8% under the condition of deficient irrigation(W2).The water use efficiency of summer maize and winter wheat treated with W2F2 was the highest,56.1% and 32.7% higher than that of W1F1. |
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