Study On Limited Irrigation Based On Crop Water Production Function

Limited irrigation is a kind of technique of saving water in recent years whichis extensively researched and actively popularized by the domestic and internationalresearchers, its purpose is to make the biggest economical performance with the limitedirrigational water resources. Researching farm crop's evaporation regulation and thefunction of moisture production is the prior condition of making the rule of theinsufficient irrigation. The paper aims at weather, hydrology and soil terms of theregion of Tianjin, through three years' observation, establish the model of farm crop'sevaporation under the condition of insufficient irrigation. To the research of thefunction of farm crop's moisture production, adopting the model of Jensen, combinationof experiment data using the method of multiplex to solve the model parameter, at thesame time, establish the return equation of the relation of production and moisture.Adopting the method of dynamic layout, it researches the irrigational rule'soptimization method of many stages under the condition of lacking water resource. Thearticle gives the method of confirming the insufficient irrigational rule of three mainkinds farm crop which are wheat, corn, cotton of big farmlands, furthermore comparingthe effect of saving water to increase production under different rule of insufficientirrigation. Research result of this text, through expression of small area's experiment,we can attain that it can save 40% irrigational water, under the condition of theproduction reaches the 90% of sufficient irrigation;the efficient of water productionof farm crop can reach 1.9~2.0 kg/ m3. If making further research and popularize, itcan provide powerful technical support to high efficient of using water for farmingin the area of Tianjin where water resources are very wanting.