不同滴灌管埋深对紫花苜蓿水分利用效率和草地覆盖率的影响

A Study on Water Use Efficiency and Grassland Coverage of Alfalfa under Different Drip Pipes Buried Depth

为研究不同滴灌管埋深对紫花苜蓿水分利用效率和草地覆盖率的影响,在甘肃省肃南裕固族自治县进行试验。结果表明,地埋式滴灌条件下,苜蓿首茬干草产量占全年总产量的40%左右,且占比随滴灌管埋深增加而略呈下降趋势;滴灌管埋深0.20 m时,苜蓿产量和水分利用效率均达最高,为该区苜蓿地埋式滴灌生产中滴灌管的最优埋深;不同滴灌管埋深在苜蓿不同生育周期对草地覆盖率的影响不同,滴灌管埋深0.10 m以内更有利于苜蓿首茬及第二茬返青,而埋深0.30 m则不利于首茬苜蓿的出苗。

In order to study the influences of different drip pipes buried depth on water use efficiency and grassland coverage of alfalfa,the experiment was carried out in Sunan Yugu autonomous county of Gansu Province.The results show that the first hay yield of alfalfa accounts for about 40% of the total annual output under underground drip irrigation conditions.At the same time,the proportion will be reduced with the increase of drip irrigation pipe buried depth.The yield and water use efficiency can reach the highest level when the drip irrigation pipe buried depth is 0.20 m,which is the optimal depth for alfalfa under underground drip irrigation in this area.The influences on water use efficiency and grassland coverage will be different in distinct growth period of alfalfa under different drip irrigation pipe buried depth.It will be advantageous for the first and second alfalfa turning green when the drip irrigation pipe is buried within 0.1 m depth,while the 0.3 m buried depth is not conducive to the first emergence of alfalfa.