Effects Of Nitrogen Application Quantity And Seeding Amount On Yield And Quality Of Rapeseed After Wheat Multiple Cropping As Feed And Green Manure

For using light,heat,soil and soil nutrient of time from wheat harvest to winter,and solving the shortage of silage in winter and spring and soil fertilizer,Hua Youza62 was used as the test variety,to set field experiments on different rates and nitrogen application rates.By measuring the growth indexs,nutrient uptake,quality,fresh grass yield and soil physical and chemical properties of Rapeseed under different treatments,the experiment explored the effects of different sowing rates and nitrogen application rates on the biological properties of rapeseed and the soil improvement by rapeseed overturning pressure,so as to determine the optimum sowing rate and nitrogen application rate.The main conclusions were as follows:1.Sowing amount on 15.0-22.5 kg/hm2 and nitrogen application amount on 225-300 kg/hm2 were conducive to the accumulation of fresh weight and dry matter in the upper part of the rape field;medium and high seeding amount and nitrogen application amount were helpful to improve the accumulation total amount and accumulation rate of nitrogen(N),phosphorus(P2O5)and potassium(K2O)in rapeseed.2.The sowing amount was 17.5-18.2 kg/hm2,and the fresh grass yield of rape as feed and green manure can reach 117.6-155.5t/hm2;the amount of nitrogen application was 225-300 kg/hm2.and the fresh grass yield was 86.5-104.5t/hm2.3.The content of neutral washing fiber and acid washing fiber in the stem of fape as feed and green manure was higher than that in the leaf,and the content of crude protein,crude fat and ash in the leaf was higher than that in the stem.The acid washing fiber content of leaves decreased gradually with the increase of sowing amount,and the crude protein content of leaves and stems increased with the increase of nitrogen application.The content of neutral washing fiber in leaf and stem of rapeseed increased with longer harvest time,but the content of crude protein,crude fat,ash and acid washing fiber decreased.4.For 0-20 cm topsoil,the organic matter content of 8 100 kg/hm2 topped rape roots was 1.67%higher than that of other treatments.With the increase of root turnover,the content of organic matter in soil increased,and alkali-hydrolyzed nitrogen and available potassium decreased.To sum up,the biological yield of rape as feed and green manure could be increased by appropriately increasing the sowing amount and nitrogen fertilizer amount and extending the harvest period in the yellow diversion irrigation area of ningxia.Seeding rate on 17.5-18.2 kg/hm2 and nitrogen application rate on 225-300 kg/hm2 were more helpful to increase the yield of rape as feed and green manure.The quality of rapeseed was the best after 54th day of seedling emergence..