不同灌水量和灌水频率对田间黄瓜耗水特性及产量的影响

Effects of Irrigation Amount and Frequency on Water Consumption and Yield of Field Cucumber

【目的】确定大田黄瓜最适宜的灌溉频率和灌水量。【方法】试验于2018年在华北水利水电大学农业高效用水试验场进行,以20cm标准蒸发皿的累积蒸发量(E20)作为灌水依据,灌溉处理分为2个灌溉间隔(I1:3d;I2:6d)和3种水面蒸发系数(K1:0.5;K2:0.7;K3:0.9),共6个处理,对黄瓜耗水特性、产量构成和水分利用效率进行了分析。【结果】黄瓜整个生育期耗水量在380~570mm之间波动,黄瓜的产量在18.2~46.1t/hm2之间波动。从不同灌水频率组合来看,I2K3处理的产量最高,其中,K3处理的早期产量最高,而I1与I2处理的水分利用效率无明显差异。果实数与灌水量之间、耗水量与产量之间均呈正线性相关关系。【结论】建议对于田间黄瓜栽培,灌溉间隔设置为6d,蒸发皿系数选择0.9为宜。

【Background】Optimal irrigation scheduling not only provides a suitable soil environment for plants to grow but can also reduce agrichemical leaching caused by excessive irrigation.Irrigation scheduling in modern agriculture is normally calculated based on the water a crop requires during different growth stages.In addition to determining water consumption by the crop and irrigation interval,knowing the sensitivity of the crop to soil moisture at different growth stages is also essential.【Objective】The areas of field-cultivated cucumber have seen an increase over the past few years agricultural high efficiency water use test site of North China University of water resources and hydropower,but there is a lack of understanding of a suitable irrigation scheduling for it.The purpose of this paper to fill this knowledge gap.【Method】The experiment was conducted in 2018 in a rainproof shelter;it consisted of two irrigation intervals:3 days(I1)and 6 days(I2).Added to these were three irrigation amounts with each determined from evaporation measured from a 20cm pan multiplied by an evaporation coefficient-0.5(K1),0.7(K2)or 0.9(K3).Overall,there were six treatments.In each treatment we measured the change in soil water content,yield traits including diameter,weight and length of the fruits,water consumption,water use efficiency and irrigation water compensation rate.【Result】Prolonging irrigation frequency as in I2 made soil moisture approach the wilting point prior to next irrigation which topped up the soil moisture approximately to the field capacity.Water consumption by the cucumber over its whole growth season was between 380 and 570 mm,with its associated yield varying between 18.2 and 46.1 t/hm2.I2K3was most effective for improving yield;when other conditions were the same,K3 increased the yield most.The irrigation frequency did not have a noticeable effect on water use efficiency.The yield traits varied with both irrigation amount and frequency,with the yield increasing with the irrigation amount.It was found that,similar as the linear increase in yield with water consumption,the fruit numbers were also positively proportional to irrigation amount.There was a linear positive correlation between the water consumption and the pan-evaporation in all treatments,indicating that the evaporation measured from the 20 cm pan is adequate to be used to determine the irrigation scheduling of the field cucumber.【Conclusion】Combing irrigation interval of 6 days with the evaporation measured from the 20cm pan multiplied a pan coefficient 0.9 as the irrigation amount in each irrigation was most effective to improve cucumber yield and its water use efficiency.