Effects Of Nitrogen Application Time And Rate On Forage And Seed Yield Of Leymus Chinensis

Leymus chinensis,also known as alkali grass,and also the dominant species and species of grassland in the songnen plain of northeast China.L.chinensis not only has strong resistance ecological characteristics of cold,drought and salinity,and plays an important role in soil and water conservation and ecological construction.L.chinensis as an important high-quality grass forage,plant leaves large,high nutritional value,palatability,known as "grass in the fine grain," cattle and sheep are eating,in the harvest should be as much as possible of the nutrient branch and as little as possible to enhance the nutritional quality and palatability of forage.On the other hand,in order to restore serious degraded grassland,ecological construction requires the production of seeds,but it needs to have as little vegetative branches as possible and as much as possible to increase seed yield.Therefore,different production purposes need different production technology control measures.In this study,random sampling was carried out twice a month(0kg/ha,45kg/ha,90kg/ha,135kg/ha,180kg/ha)in the spring(May,June)and summer and autumn(July,ugust and September),the effects of different nitrogen application time and level on the forage and seed yield of L.chinensis were studied.Results are as follows:1.The different nitrogen application rates had a significant effect on the yield of forage grass per hectare in spring,and the forage yield increased with the increase of nitrogen application rate.The plant weight,stem weight,leaf weight and plant height per unit area of L.chinensis were significantly increased with the increase of nitrogen application rate due to the enhanced photosynthetic capacity of L.Chinensis.The tiller number of L.chinensis increased,so the density of L.chinensis increased significantly with the increase of nitrogen application.Therefore,the application of 180 kg / ha of pure nitrogen on May 15 to improve the yield of L.Chinensis forage the most obvious effect.2.The application of nitrogen fertilizer in autumn had a significant effect on the yield of L.chinensis for the following year,with the increase of nitrogen application rate.The plant weight,leaf weight and plant height per unit area increased significantly with the increase of fertilizer application.As the L.chinensis community to produce buds and sub-strains of the asexual reproduction of the main,so the density of L.chinensis in the second year of experimental treatment began to have a significant response to fertilization,with the increase in fertilizer increased.The input of L.chinensis was limited,so fertilization had no significant effect on the weight of L.chinensis.So the July 30 application of 180 kg / ha pure nitrogen to improve the yield of L.chinensis forage the best.3.The time and level of nitrogen application in spring were the most significant effects on the seed yield per unit area of L.chinensis.The seed yield,the seed setting rate and the 1000 grain weight per panicle increased significantly with the increase of nitrogen application rate with the increase of nitrogen application rate.There was no significant effect of nitrogen application on heading number and heading rate per unit area of L.Chinensis.Therefore,when applying 180 kg / ha of pure nitrogen on May 15,the effect of improving the yield of L.chinensis was the best.4.The time and level of nitrogen application in autumn had a significant effect on the seed yield per unit area of L.chinensis in the following year.With the increase of nitrogen application rate,the yield of L.chinensis was increased.The number of heading,heading rate,seed setting rate and thousand grain weight of L.chinensis were significantly increased with the increase of nitrogen application rate.The effect of nitrogen application on grain number per panicle was not significant.Therefore,when the application of 180 kg / ha pure nitrogen on July 30,the yield per unit area of L.chinensis was the highest.5.For the two consecutive spring treatments,the marginal yield of L.chinensis forage was the largest at 90 kg / ha on May 15.In the autumn treatment,the marginal yield of L.chinensis was the largest in the following year when the amount of nitrogen applied was 135 kg / ha on July 15.For the two consecutive spring treatments,the marginal yield per unit area of L.chinensis seeds was the highest at 135 kg / ha of nitrogen on May 15.In the autumn treatment,the marginal yield of L.chinensis was the largest in the following year when the amount of nitrogen applied was 135 kg / ha on July 15.In the agricultural production,the marginal yield of L.chinensis was the highest when the nitrogen level was 90 kg / ha on May 15,and the yield of L.chinensis was the highest when the nitrogen level was 135 kg / ha on July 30 in autumn.