干热河谷坡地果园灌溉覆盖方式的抗旱节水效应分析

Analysis of effects of different modes of irrigation and mulching on water-saving and drought-resistance in sloping orchards of dry-hot valley

在金沙江干热河谷坡地青枣果园设置裸地漫灌,直沟和目字沟埋草沟灌,地面秸秆、生物覆盖漫灌以及直沟埋草沟灌加地面秸秆覆盖等6种灌水覆盖实验,研究干热河谷坡地果园覆盖灌水方式的抗旱节水效应,筛选适宜的节水抗旱灌溉技术。结果表明:土壤保水、蓄水能力表现为覆盖漫灌高于开沟埋草沟灌,显著高于裸地漫灌。灌溉水利用率和经济效益则表现为:目字沟、直沟埋草沟灌>地面秸秆、生物覆盖漫灌>裸地漫灌。直沟埋草沟灌加地面秸秆覆盖处理的灌水次数最少,灌水量不到裸地漫灌对照的28.6%,灌溉水利用率是对照的6.7倍。节水效果依此表现为:直沟埋草沟灌+地面秸秆覆盖目字沟埋草沟灌≥地面秸秆覆盖漫灌>直沟埋草沟灌≥地面生物覆盖漫灌裸地漫灌(CK)。经济效益最好的是直沟埋草沟灌+地面秸秆覆盖处理,其次是目字沟埋草沟灌,纯效益分别是裸地漫灌的2.36倍和2.16倍,产投比是对照的1.9倍和1.8倍。结果说明,在干热河谷燥红土果园,开沟埋草沟灌,地面覆盖,使灌溉水渗透土壤,减少地表径流和蒸散损失,提高土壤的保蓄水能力,能有效提高灌溉水的利用率和果园经济效益。

In jujube orchards of the slope area in the dry-hot valley of Jinsha River,six modes of irrigation and mulching were set in the experiment,namely flood irrigation in bare land（CK）,furrow irrigation with straw buried in straight ditches,furrow irrigation with straw buried in mesh ditches,flood irrigation with plants covering,flood irrigation with soil surface straw mulching,and furrow irrigation with straw buried in straight ditch ＋ soil surface straw mulching.The results show that,for soil conservation and water storage capacity,flood irrigation with soil surface straw mulching is better than furrow irrigation with straw buried in straight ditches,and much better than CK.As for rrigation water use efficiency and economic benefit,furrow irrigation with straw buried in straight ditches and furrow irrigation with straw buried in mesh ditchesflood irrigation with straw or plants coveringflood irrigation in bare land.The frequency of furrow irrigation with straw buried in straight ditch ＋ soil surface straw mulching is the lowest,less than 28.6% of that of ck,while its water use efficiency is 6.7 times of the ck.The order of water-saving efficiency is furrow irrigation with straw buried in straight ditch ＋ soil surface straw mulchingfurrow irrigation with straw buried in mesh ditches≥flood irrigation with soil surface straw mulchingfurrow irrigation with straw buried in straight ditches≥flood irrigation with plants coveringCK.Furrow irrigation with straw buried in straight ditch ＋ soil surface straw mulching has the best economic benefit,then followed by furrow irrigation with straw buried in mesh ditches,and they are 2.36 and 2.16 times of that of ck,while their output/input ratio are 1.9 and 1.8 times of that of ck.All these indicate that furrow irrigation with straw buried in straight ditch plus soil surface straw mulching can make irrigation water fully infiltrate into soil,reduce surface runoff and evaporation,improve soil water storage capacity,so as to improve irrigation water use efficiency and orchard economic benefits.