Response Of Different Artificial Grassland Yield And Quality To Irrigation

The construction of artificial grassland is one of the effective ways to alleviate the grazing pressure of grassland ecosystem in Inner Mongolia Grassland. Water is one of the limited factors for plant growth in Inner Mongolia. Irrigation could increase the yield of forage in the artificial grassland. The study on irrigation is important for over-yield of forage in the artificial grassland. We designed an irrigation experiment on four different forages (zhaodong alfalfa, Medicago varia Martin, AoHan alfalfa and Elymus nutans). Automatic spray irrigation equipment was used in this experiment. The irrigation was begun when the soil water content is met with the wilting coefficient and was stopped when the soil water content was got to the field capacity. The specific leaf area, Leaf stems ratio stem and leaf ratio, tiller numbers, and the quality of the forages (crude fiber, crude protein and crude fat) were measured during the flowering periods of the forages. Our results showed:1. The irrigation treatment significantly increased the height, specific leaf area and tiller numbers of the four forages. Meanwhile, it also significantly increased the Leaf stems ratio of the three alfalfas and had no significant effect on the Leaf stems ratio of Elymus nutans for the first harvest. However, it had no significant effects on the Leaf stems ratio of the three alfalfas and significantly increased the Leaf stems ratio of Elymus nutans during the second harvest.2. The irrigation treatment significantly increased the overall yield of the four forages. The yields of zhaodong alfalfa, Medicago varia Martin, AoHan alfalfa and Elymus nutans were 5111、4752、4676 and 4034 kg·hm-2, respectively. The irrigation treatment increased the yields of zhaodong alfalfa, Medicago varia Martin, AoHan alfalfa and Elymus nutans by 62.3%、6.1%、76.6% and 81.5%, respectively.3. The irrigation treatment significantly reduced the crude fiber content and increased the crude protein content of the three alfalfas. It also increased the crude fiber content of the Elymus nutans for the first harvest, and the crude protein content of the Elymus nutans for the second harvest. However, it had no significant effects on the crude fiber content of the four forages. In conclusion, the irrigation treatment reduced the quality of the Elymus nutans for the first harvest, and increased the quality of the three alfalfas, and Elymus nutans for the second harvest. The quality of Medicago varia Martin is the best among the four forages, which has the higher crude protein content and the lower crude fiber content, while, the quality of Elymus nutans is the worst.4. The irrigation treatment increased the yield of Medicago varia Martin mostly, compared to others. The yield of Medicago varia Martin was 2054 kg·hm-2. According to the market price of alfalfa was 2400-3200yuan/ton, an increase of income of 3330-4973 yuan·hm-2.5. The yield of zhaodong alfalfa is the highest, and the quality of Medicago varia Martin is the best among the four forages. Taken together, zhaodong alfalfa and Medicago varia Martin were the best species for the artificial grassland established under irrigation in Inner Mongolia, Xilinhaote.