关键词: 施氮量, 根茬还田, 大麦, 产量, 品质, 土壤养分

Abstract: 【Objective】To investigate the effects of different nitrogen application rates and stubble returning on barley yield,quality,and soil nutrients.【Methods】Using the barley variety Neinongke Forage Barley No. 1 as the experimental material,three nitrogen application levels were set：0 kg/hm²（N0）,75 kg/hm²（N1）,and 150 kg/hm²（N2）. For each nitrogen level,two treatments were designed：stubble returning（S） and no stubble returning（N）. The effects of the treatments on subsequent barley yield,quality,and soil nutrients were analyzed.【Results】 Under stubble returning,the fresh grass yield of the N2 treatment increased significantly by 32.60% compared with the N0 treatment（P<0.05）. For both stubble returning and no stubble returning treatments,the dry hay yield followed the order N2>N0>N1,with no significant differences（P>0.05）. After stubble returning,the crude protein content of the N2 and N1 treatments increased significantly by 1.10 and 0.95 percentage points respectively,compared with the N0 treatment（P<0.05）;the relative feed value（RFV）of the N2 treatment was 4.67 and 13.50 percentage points higher than that of the N1 and N0 treatments,respectively;differences in crude protein content,crude fat content,and RFV between the N1 and N2 treatments were not significant（P>0.05）. After stubble returning,the soil total nitrogen content of the N1 treatment was significantly higher than that of the N0 treatment by 23.78%（P<0.05）,while the alkali-hydrolyzable nitrogen content of the N1 and N2 treatments increased significantly by 22.69% and 26.53%,respectively,compared with the N0 treatment（P<0.05）,with no significant difference between the N1 and N2 treatments（P>0.05）;the soil total phosphorus content of the N2 treatment increased significantly by 30.38% and 53.78% compared with the N1 and N0 treatments,respectively（P<0.05）;the soil available phosphorus content followed the order N2>N1>N0,with no significant differences（P>0.05）;the soil total potassium content followed the order N2>N1>N0,with the N2 treatment significantly higher than the N0 treatment by 37.28%（P<0.05）,but no significant difference between the N2 and N1 treatments（P>0.05）;the available potassium content in the N1 treatment was significantly higher than in the N0 and N2 treatments（P<0.05）;the soil organic matter content in the N1 and N2 treatments increased significantly by 20.05% and 23.04%,respectively,compared with the N0 treatment（P<0.05）. Fresh grass yield was significantly and positively correlated with soil total phosphorus content and total potassium content（P<0.05）,while dry hay yield was significantly and positively correlated with soil total nitrogen content and total phosphorus content（P<0.05）.【Conclusion】Considering the cost of nitrogen fertilizer,stubble returning with a nitrogen application rate of 75 kg/hm² effectively enhanced barley yield and quality and improved soil physicochemical properties.

Key words: Nitrogen application rate, Stubble returning, Barley, Yield, Quality, Soil nutrients