不同冬灌方式对紫花苜蓿次年生长及土壤水热的影响

Effects of Different Winter Irrigation Methods on Alfalfa Growth and Soil Water and Heat in Next Year

为探寻干旱半干旱地区冬季灌水对土壤水分、温度以及翌年紫花苜蓿返青、生长和产量的影响,进而提出适宜于伊金霍洛旗地区紫花苜蓿高产的灌溉方式,采用大田试验的方法,以未冬灌小区作为对照(CK),设置地下滴灌(DI)和畦灌(BI)2种灌溉方式,灌水定额设置为30 mm,共3个试验处理,每个处理3次重复,共9个试验小区。结果表明冬灌对次年紫花苜蓿返青时各土层土壤含水率和土层温度均有一定影响,地下滴灌和畦灌,均能提高紫花苜蓿返青前的土壤含水率、提高土壤温度、改善紫花苜蓿的越冬环境、提高紫花苜蓿的越冬率。冬灌后次年紫花苜蓿返青率较未冬灌处理小区高13.77%,且滴灌处理条件下返青率最高,有利于后期紫花苜蓿产量的提高。地下滴灌冬灌处理条件下紫花苜蓿第1茬产量最高,鲜草产量为31020 kg/hm^(2),干草产量为6150 kg/hm^(2),相对未冬灌处理分别增产23.32%、21.67%。综合考虑地下滴灌条件下冬灌对次年紫花苜蓿生长及土壤水热的影响,建议伊金霍洛旗地区紫花苜蓿在越冬期进行地下滴灌条件下的冬灌。

To investigate and address the impacts of irrigation in winter on soil moisture,temperature,the greening,growth and yield of alfalfa in the following year in arid and semi-arid areas,a suitable irrigation method suitable for high yield of alfalfa in Yijinhuoluoqi area was proposed.In this study,a field experiment was conducted,and the plots without winter irrigation were serving as the control(CK).Two irrigation methods were set,underground drip irrigation(DI)and border irrigation(BI),and the irrigation quota was set to 30 mm.There were 3 experimental treatments,and each treatment was repeated 3 times,with a total of 9 experimental plots.The results showed that winter irrigation had significant effects on soil moisture content and soil temperature in each soil layer during alfalfa greening in the following year.Both subsurface drip irrigation and border irrigation could increase soil moisture content and soil temperature before alfalfa greening,improve the overwintering environment and increase the overwintering rate of alfalfa.The regreening rate of alfalfa in the following year after winter irrigation was 13.77% higher than that in plots without winter irrigation.The regreening rate under drip irrigation was the highest,which was conducive to the improvement of alfalfa yield in the later period.Under the condition of underground drip irrigation in winter,the first crop yield of alfalfa was the highest,the fresh grass yield was 31020 kg/hm^(2),and the hay yield was 6150 kg/hm^(2),which increased by 23.32% and 21.67% compared with no winter irrigation treatment,respectively.Considering the effects of winter irrigation on alfalfa growth and soil water and heat in the following year under underground drip irrigation,it is suggested that winter irrigation under underground drip irrigation in the overwintering period of alfalfa in Yijinhuoluoqi area can increase the yield of fresh alfalfa grass in the first crop to 31020 kg/hm^(2),which is 23.32% higher than that without winter irrigation treatment,and maximize the utilization of water resources.