旱区压砂地甜瓜水分生产函数试验研究

Experimental Research on Water Production Function for Melon in Gravel-mulched Field of Arid Area

针对压砂地甜瓜的最优补灌问题,通过盆栽试验,对甜瓜需水规律、产量及水分生产函数模型进行了研究。结果表明:甜瓜产量与需水量之间呈二次抛物线趋势变化,随着需水量的增加,产量随之增加;当增加到一定程度时,产量反而逐渐下降,呈报酬递减规律;同时建立了压砂地甜瓜生育阶段水分生产函数模型,计算得出各生育阶段水分敏感指数按开花坐果期、伸蔓前期、膨大前期、伸蔓后期、膨大中期、膨大后期依次降低,其变化规律与甜瓜的需水规律相一致,在开花坐果期、伸蔓前期和膨大前期需保证水分需要,其他阶段可适当减少补水量。

This paper studies water-saving irrigation system,yield and water production function to solve the problem of optimal irrigation system for melon planting.The findings indicate that the curve between melon yield and water demand changes with the trend of second degree parabolic.With the increase of water demand,production increases.However,when the water demand increases to a certain degree,the yield will decrease gradually with the law of diminishing returns.According to the calculation result of the established water production function model of gravel-mulched melon,the moisture sensitive index of each growth stage decreases progressively with the order of blossom and fruit period,tendril elongation prophase,enlargement prophase,tendril elongation anaphase,enlargement metaphase and enlargement anaphase.So,irrigation amount should be guaranteed in blossom and fruit period,tendril elongation prophase and enlargement prophase while reduced at other stages.