阔叶类草抑制剂和氮素添加对高寒草地垂穗披碱草营养品质的影响

Effects of broad-leaved grass inhibitors and nitrogen addition on nutritional quality of Elymus nutans in alpine grassland

摘要:

【目的】解决甘南州桑科草原高寒草地阔叶类杂类草大量繁殖而产生的草地质量下降等问题。【方法】采用不同浓度阔叶类草抑制剂（0、0. 9、1. 5、2. 1 kg/hm² ）和不同氮素添加水平（0、75、150、 225 kg/hm² ）相结合的方式，研究其对甘南高寒草地优势禾草垂穗披碱草营养品质的影响。【结果】喷洒抑制剂后垂穗披碱草营养品质显著高于对照（P＜0. 05），且在较高喷施浓度（2. l kg/hm² ）时，垂穗披碱草粗蛋白（CP）、钙（Ca）、磷（P）和粗脂肪（EE）含量分别较对照提高了 2. 18%、9. 23%、9. 52% 和 8. 66%，而中性洗涤纤维（NDF）和粗灰分（Ash）含量分别较对照降低了 3. 31%、14. 21%，酸性洗涤纤维（ADF）在 1. 5 kg/hm² 浓度时较对照显著降低 35. 83%；施氮处理下垂穗披碱草品质显著高于对照（P ＜0. 05），且在较高施氮水平（225 kg/hm² ）时 ，其 CP、Ca、P 和 EE 含量较高 ，分别较对照提高了 27. 94%、35. 09%、14. 29% 和 11. 79%，而 NDF 和 ADF 含量显著降低 ，分别较对照降低了 6. 45%、 12. 55%，对 Ash 含量影响不显著；抑制剂和氮素添加存在显著交互关系，在 2. 1 kg/hm² 浓度抑制剂和 225 kg/hm² 施氮水平下，垂穗披碱草 CP、Ca、P 和 EE 含量均高于其他处理组合，NDF 和 Ash 含量低于其他处理组合。【结论】研究结果对高寒草地提质增效及畜牧业可持续发展具有重要意义。

Abstract:

【Objective】 In order to solve the problem of grassland quality degradation caused by the large-scale reproduction of broad-leaved grasses in the alpine grassland of Sangko grassland in Gannan Prefecture.【Method】 This experiment took Elymus nutans as the research object. The effects of different concentrations of broad-leaved grass inhibitors （0，0. 9，1. 5，2. 1 kg/hm² ） and different nitrogen addition levels （0，75，150，225 kg/hm² ） were used to study the nutritional quality of the dominant grass in Gannan alpine grassland.【Result】 The nutritional quality of Elymus nutans after spraying inhibitor was significantly higher than that of the control （P＜0. 05）. The contents of crude protein （CP），calcium （CA），phosphorus （P） and ether extract （EE） increased by 2. 18%，9. 23%，9. 52% and 8. 66% while the contents of neutral detergent fiber （NDF） and crude ash （Ash） decreased by 3. 31% and 14. 21% compared with the control at higher spraying concentration （2. 1 kg/hm² ），respectively. Acid detergent fiber （ADF） at 1. 5 kg/hm² significantly decreased by 5. 83 compared to the control. The quality of Elymus nutans in nitro- gen application treatments was significantly higher than that of the control （P＜0. 05）. The contents of CP，CA，P and EE in Elymus nutans were higher than those in the control at a higher nitrogen application level （225 kg/hm² ）， which increased by 27. 94%，35. 09%，14. 29% and 11. 79%，respectively. However NDF and ADF were signifi- cantly lower than control by 6. 45% and 12. 55%，respectively，and which had no significant effect on the content of Ash. There were significant interactions between inhibitors and nitrogen application. Under the concentration of 2. 1 kg/hm² inhibitors and 225 kg/hm² nitrogen application levels，the contents of CP，CA，P and EE in Elymus nutans were higher while NDF and ash were lower than other treatment combinations.【Conclusion】 The results are of great significance to improve the quality and efficiency of alpine grassland and the sustainable development of animal hus- bandry.