土壤水分下限控制灌溉对春青稞农田耗水特性及产量的影响

Effects of Controlled Irrigation with Lower Limits of Soil Moisture on Water Consumption Characteristics and Yield of Spring Highland Barley

为探究高原农区春青稞农田耗水规律、干物质积累及产量对土壤水分变化的响应,以“喜马拉22”为试材,于田间设置了75~80θ-f(CF)、65~70θ-f(QK-1)、55~60θ-f(QK-2)和45~50θ-f(QK-3)4个土壤水分下限调控水平和1个旱作处理(CK),分析了不同土壤水分水平调控下的春青稞耗水特性、干物质积累及产量变化。结果表明:春青稞生育期耗水量、耗水强度呈先升高后降低再回升的趋势,且二者随土壤水分调控下限的降低呈直线下降,耗水强度基本在5 mm/d左右浮动。灌水较旱作处理提高了春青稞干物质积累量,平均增幅16.08。QK-1、QK-2、QK-3较CF降低了春青稞干物质积累量及其相对生长率,且生长后期的干物质积累量、相对生长率随土壤水分调控下限的降低而减小。干物质积累与气象因子间的回归分析表明降雨量与干物质积累间线性关系极显著,相关系数r0.9803。灌水较旱作处理提高了春青稞产量,增产幅度介于11.74~53.46之间。当土壤水分调控下限降至55~60θ-f时,春青稞产量达6237.05 kg/hm^2,较CF提高28.30。春青稞产量与生长季降雨量极显著正相关(r0.9945),与气温极显著负相关(r-0.974),二者对产量的综合影响系数达99.23,说明生长季降雨量、气温是影响高原农区春青稞产量的主要气象因子。

In order to explore the response of water consumption law of spring highland barley in plateau,the dry matter accumulation and yield to soil moisture variation,the field plot experiments were carried out with the spring highland barley species“Himala 22”.Four lower soil water limits,including 75%~80%θf(CF),65%~70%θf(QK1),55%~60%θf(QK2)and 45%~50%θf(QK3),and one control treatment(rain-fed irrigation,CK)were applied in the whole growing stages to analyze the water consumption characteristics,dry matter accumulation and yield change under different lower limits level of soil moisture.The results showed that the water consumption amount and water consumption intensity of spring highland barley increased at first and then decreased,then increased again,and decreased linearly with the decrease of the lower soil water limits.The water consumption intensity basically floated around 5 mm per day.Comparing with CK treatment,the irrigation treatments increased the dry matter accumulation of the spring green by 16.08%.Compared with CF,QK1,QK2 and QK3 reduced the dry matter accumulation and relative growth rate of spring highland barley,and the dry matter accumulation and relative growth rate of late growth decreased with the lower limit of soil water control.The regression analysis showed that the linear relationship was extremely significant between dry matter accumulation and meteorological factors,and the correlation coefficient was 0.9803.The irrigation treatments increased the yield of spring highland barley,which increased ranged from 11.74%to 53.46%.When the lower water limit decreased to 55%~60%ofθf,the yield was 6237.05 kg/hm^2,28.3%higher than that of CF treatment.In addition,the rainfall in the growth seasons showed a significant positive correlation(r0.9945)to the yield of spring highland barley,but the temperature had a significant negative correlation(r-0.974)with it.Meanwhile,the comprehensive influence coefficient(99.23%)had a significant effect on the yield of spring highland barely.Therefore,the rainfall and temperature were the major meteorological factors to cause the yield of spring highland barley in plateau.