Effects Of Irrigation Amount On Yield,Quality And Soil Nutrient Movement Of Alfalfa Artificial Grassland In Horqin Sandy Land

In order to ensure the scientific and stable development of alfalfa industry in China and alleviate the contradiction between water shortage and grass industry development in Horqin area,this experiment is based on the Penman-Monteith method recommended by the Food and Agriculture Organization.The main conclusions of yield,quality and soil available nutrient leaching are as follows:1.In the Horqin area,three crops of alfalfa were castrated.The water demand of the three crops decreased gradually,and the water demand in the whole growing season was 830.87mm.The average daily water intensity fluctuated within the range of 1-11mm/d.Water consumption and water intensity increase with the increase of irrigation volume.It is suggested that the first crop should be replenished according to the meteorological conditions such as temperature after the alfalfa growth status,and the third crop should be paid attention to the rainfall forecast in time during the third crop and combined with the meteorological conditions.2.The yield of alfalfa showed a trend of first increase and then decrease with the increase of irrigation amount.The first crop,the second crop,and the third crop all reached the maximum under 100%ETc treatment,and the first crop and the third crop were treated with W3.It was significantly higher than other treatments(P<0.05);compared with 100%ETc,irrigation increased by 20%,yield decreased by 15%,irrigation decreased by 20%,yield decreased by 20%,and water reduction decreased by 30%under 40%treatment.The regression equation was used to fit the relationship between irrigation volume and yield with a one-dimensional quadratic equation,and the fitting equation y=-0.2027X2+270.04X-76312 was obtained.The partial derivative of the equation can be obtained to yield up to 13635.83kg/hm2 The highest irrigation amount was 666.11mm.3.The crude protein content of alfalfa increased by stubble,and the effect of irrigation amount on the crude protein content of alfalfa was basically not significant;the relative feed value,neutral washing fiber,and acid washing fiber content decreased by stubble,and the impact of irrigation amount on it was not significant.4.The amount of leaching of alkaline nitrogen,available phosphorus and available potassium increased with the increase of irrigation amount.There was no significant difference in the amount of leaching of alkaline nitrogen under the treatment of W3 and W4.There was no significant difference under the treatment of W3 and W3;there was no significant difference in the amount of available potassium leaching between the treatments of W2,W3,and W4.5.Considering the water demand,water consumption,yield,quality and nutrient leaching of alfalfa,it is recommended to irrigate according to the irrigation amount of 100%ETc during the growing period.