不同施肥处理对退化高寒草甸植被群落特征及牧草营养价值的影响

Effects of different fertilization treatments on vegetation community characteristics and nutritional value of degraded alpine meadows

摘要:

【目的】 明确氮磷肥配施微生物菌肥对退化高寒草甸的修复效果以及施用菌肥后化肥减量的可行性，筛选祁连山高寒草甸恢复的适宜施肥方案。【方法】 在东祁连山典型中度退化高寒草甸设置不施肥（CK）、施氮磷复合肥600 kg/hm2（PM）、施菌肥75 kg/hm2（BM）、氮磷复合肥600 kg/hm2+菌肥 75 kg/hm2（PⅠBM）、氮磷复合肥450 kg/hm2+菌肥75 kg/hm2（PⅡBM）、氮磷复合肥300 kg/hm2+菌肥75 kg/hm2（PⅢBM）6个施肥处理。采用田间小区试验方法，对不同施肥处理的植被群落特征及植物种生产性能进行研究。【结果】 相比不施肥，施用氮磷肥以及氮磷肥配施菌肥可以有效提高退化高寒草甸植物群落平均高度及地上生物量，其中PⅠBM、PⅡBM处理的地上生物量分别较CK提高了1.37 和1.35倍。同时氮磷肥以及氮磷肥配施菌肥提高了植物群落结构的多样性和稳定性，提升群落中禾本科（Poaceae）、豆科（Fabaceae）等可食性牧草优势度。本研究条件下，氮磷肥配施菌肥明显降低了植物中性洗涤纤维和酸性洗涤纤维的含量，并有效提升了扁蓿豆（Medicago ruthenica）、麻花艽（Gentiana straminea）的粗蛋白含量。【结论】 氮磷复合肥450 kg/hm2+菌肥75 kg/hm2对退化高寒草地植被群落特征改善及营养价值的提高有明显作用。

Abstract:

【Objective】 Fertilization is an important measure for the prevention and restorationof degraded alpine grassland.【Method】 There are six fertilization treatments were set up，including no fertilization （CK），nitrogen and phosphorus compound fertilizer 600 kg/hm2（PM），microbial fertilizer 75 kg/hm2（BM），nitrogen and phosphorus compound fertilizer 600 kg/hm2+microbial fertilizer 75 kg/hm2（PIBM），nitrogen and phosphorus compound fertil izer 450 kg/hm2+microbial fertilizer 75 kg/hm2（PIIBM），nitrogen and phosphorus compound fertilizer 300 kg/hm2+ microbial fertilizer75 kg/hm2（PIIIBM），in order to clarify the restoration effect of nitrogen and phosphorus fertilizer combined with microbial fertilizer on degraded alpine meadows，and feasibility of fertilizer reduction after the applica tion of microbial fertilizer，to screen the suitable fertilization scheme for the restoration of alpine meadows in the Qil ian Mountains，and plant community characteristics and nutritional value of different fertilization treatment on by field community fertilization experimental method were studied.【Result】 The characteristics of vegetation communities and the production performance of plant species under different fertilization treatments were studied by field commu nity experimental method，and the following conclusions were obtained：Compared with no fertilization，the applica tion of nitrogen and phosphorus fertilizer and nitrogen and phosphorus fertilizer combined with microbial fertilizer can effectively increase the average height and aboveground biomass of plant communities in degraded alpine meadows， and PIBM、PIIBM treated aboveground biomass increased by 1. 37 and 1. 35 times compared with CK. It also can im prove the diversity and stability of plant community structure，and improve the dominance of edible forages such as grasses and legumes in the community. Under the conditions of this study，the content of NDF and ADF in plants was significantly reduced by nitrogen and phosphorus fertilizer and microbial fertilizer，and the CP content of Medicago ru thenicaandGentiana stramineawas effectively increased.【Conclusion】 Nitrogen and phosphorus compound fertilizer 450 kg/hm2+microbial fertilizer 75 kg/hm2 had a significant effect on the improvement of vegetation community char acteristics and nutritional value in degraded alpine grassland.