氮添加对科尔沁沙地羊草产量及氮肥利用效率的影响

Effects of nitrogen application on yield and nitrogenuse efficiency of Leymus chinensis in Horqin sandy land

摘要:

为了探讨不同施氮水平对沙地羊草草产量、土壤全氮变化及羊草对氮肥利用率的影响,设置了0(CK)、100、200、300、400 kg/hm²的施氮(纯氮)量。结果表明:随着施氮水平的提高,羊草产量呈先增加后平稳的趋势,309.66 kg/hm²施氮量草产量最高,羊草干草产量与施氮量的回归方程为y=-0.073x²+45.21x+3 808;羊草植株粗蛋白含量随着施氮水平的增加呈增加趋势,300 kg/hm²处理水平氮肥利用率最高;羊草生育期内土壤全氮含量、氮肥贡献率、氮肥吸收利用率与其产量呈显著正相关。施氮肥会提高羊草干草粗蛋白水平,施氮水平的高低决定土壤残留氮素的多少。施入309.66 kg/hm²氮时羊草干草产量最高,可以作为科尔沁沙地人工羊草草地的最佳施肥量。

Abstract:

This study aimed to explore the effects of different nitrogen levels on the yield and nitrogen use efficiency of Leymus chinensis (Trin.) grown in artificial sandy grassland,together with the change in soil total nitrogen.Four different N levels (100,200,300 and 400 kg/hm²) were applied with nil-N as the control (CK).The result showed that along with the increased nitrogen levels,the yield of Leymus chinensis (Trin.) initially increased then became steady,with the highest yield observed at a nitrogen rate of 309.66 kg/hm².The regression equation of hay yield against nitrogen application was y=-0.073x²+45.21x+3 808.The crude protein content of Leymus chinensis (Trin.) plants increased along with the increased nitrogen levels.The highest nitrogen use efficiency was found at N3.Total soil nitrogen content,the contribution rate of nitrogen,nitrogen absorption rate were significantly positively correlated with the yield of Leymus chinensis (Trin.).Nitrogen application could improve the crude protein level of Leymus chinensis hay,and the level of nitrogen application affected the amount of residual nitrogen in soil.In this experiment,the optimum yield of Leymus chinensis hay was observed at 309.66 kg/hm²,which can be used as the best fertilization amount for artificial Leymus chinensis grassland in Horqin sandy land.