盐渍地人工苜蓿草地生产力与土壤改良研究

目的]为改进和利用河西走廊盐渍化土地提供依据。方法]在临泽县盐渍地种植苜蓿,测定1～5年生人工苜蓿草地的生产力,并研究苜蓿对盐渍化土地的改良效果。结果]在盐渍地种植苜蓿后,苜蓿的主根长、主根直径和侧根数随着生长年限的增加而增加。从种植到第5年,盐渍地苜蓿的鲜草产量呈逐年增加的趋势。盐渍地种植苜蓿后,土壤有机质含量不断增加,而土壤盐离子含量不断下降。有机质含量的增加速度和盐离子含量的下降速度均在苜蓿种植后的生长前期较慢而生长后期较快。结论]苜蓿的生产力与灌水量、灌水次数有关。一个生育周期应至少灌水4次,种植苜蓿的适宜灌水量为4275m3/hm2。

Study on the Productivity of the Artificial Alfalfa Grassland in the Salinized Land and the Soil Improvement

Objective] The research aimed to provide the basis for improving and utilizing the salinized land in the Gansu Corridor.Method] Alfalfa was planted in the salinized land in Linze county to determined the productivity of 1～5-year-old alfalfa artificial grassland.And the improvement effects of alfalfa on the salinized land were studied.Result] After planting alfalfa in the salinized land,the length and diameter of main roots,lateral root number in alfalfa were increased with the increase of the growth years.The fresh forage yield of alfalfa in the salinized land showed an increasing trend year by year from planting to the 5th year.After planting alfalfa in the salinized,the content of organic matter in the soil were continuously increased,while the content of salt ions in the soil were continuously decreased.Both the increase rate of organic matter content and the decrease rate of salt ions content were slower in the early stage and faster in the late stage after planting alfalfa.Conclusion] The productivity of alfalfa was related with the irrigation amount and irrigation times.There were at least 4 times of irrigation in one growth cycle and the suitable irrigation amount for planting alfalfa was 4 275 m3/hm2 .