关键词: 黄河滩地, 牧草, 营养品质, 土壤养分

Abstract: [Objective] This study was conducted to characterize the nutritional value, production performance and soil improvement effects of different varieties of forage grasses planted on floodplain in the Yinchuan section of the Yellow River in Ningxia Hui Autonomous Region. [Method] A total of 11 varieties of forage grasses were included in this study. The nutritional quality and production performance indexes of the forage grasses, as well as the soil nutrient indexes of the forage grass planting plots were determined and statistically compared. In addition, the correlation among these indexes were assessed. [Result] ①There were obvious variations in nutritional quality indexes among the 11 varieties of forage grasses. Zhongmu No.4, Bromus inermis and Festuca arundinacea had the highest contents of crude protein, crude fat and crude ash, respectively. Festuca arundinacea exhibited the lowest contents of crude fiber and ADF, and Zhongmu No.3 exhibited the lowest NDF content. The highest contents of total carbon and total nitrogen were observed in Elymus dahuricus and Zhongmu No.4, respectively, while those of calcium and phosphorus were observed in Ruide and Festuca arundinacea, respectively. ② The plots planted with the 11 varieties of forage grasses had significantly （P<0.05） decreased soil pH value and total salt content compared with those before planting. Except for the soil contents of total phosphorus and available phosphorus in selected forage grass planting plots, most soil nutrient indexes in the forage grass planting plots significantly （P<0.05） increased. The plots planted with Leymus chinensis or Agropyron mongolicum Keng had higher soil contents of total nitrogen, organic matter and alkaline hydrolysis nitrogen. The Leymus chinensis planting plot had the highest soil contents of available phosphorus and available potassium. The highest soil content of total phosphorus was observed in the Agropyron mongolicum Keng planting plot. ③ Except for Elymus dahuricus with a lower plant height, there were no significant （P>0.05） differences in plant height among the other 10 varieties of forage grasses. Elytrigia elongata, Agropyron mongolicum Keng, Zhongmu No.4 and Zhongmu No. 3 had higher grass yield. ④ Correlation analysis demonstrated that grass yield had varying degrees of positive or negative correlation with some indexes of nutritional quality of forage grasses and some soil nutrient indexes of the forage grass planting plots. Principal component analysis showed that the comprehensive evaluation ranking of the 11 varieties of forage grasses was as follows: Leymus chinensis>Agropyron mongolicum Keng>Bromus inermis>Puccinellia distans>Elytrigia elongata>Zhongmu No.4>Elymus dahuricus>Festuca arundinacea>Qishi No.2>Zhongmu No.3>Ruide. [Conclusion] Leymus chinensis, Agropyron mongolicum Keng, Bromus inermis, Puccinellia distans and Elytrigia elongata had better comprehensive performance when planting on floodplain in the Yinchuan section of the Yellow River, and had the potential to be the mainly promoted varieties of forage grasses and used for soil improvement in the Yellow River floodplain.

Key words: the Yellow River floodplain, forage grass, nutritional quality, soil nutrient