The Effect Of Low Pressure Sprinkler Irrigation On Water-fertilizer Saving And Yield Increasing Mechanism Of Winter Wheat

In order to establish an efficient irrigation model to save water andfertilizer, field experiments with different water applications were conducted forwinter wheat (Triticum aestivum L.) to evaluate the effects of low pressure sprinklerirrigation on chlorophyll content, chlorophyll fluorescence, photosyntheticcharacteristic, the final grain yield and the spatial-temporal distributions of nitrogenusing the traditional surface irrigation (flooding irrigation) as a control. The results asfollows:Compared with the traditional flooding irrigation, low pressure sprinklerirrigation not only significantly saved the farmland water-consumption, but also theunique form of moisture infiltration can reduced soil compaction, increased soilpermeability, improved the soil hardening significantly caused by the flooding,the soilcompaction date is CK>T3>T2>T1in all treatments. Low pressure sprinkler irrigationincreased soil urease activity after flowering period and made more NO3--N andNH4+-N concentrated in0-60cm root zone, preventing further leakage of the waterand nitrogen. Compared with the flooding irrigation method, the peak of the ammoniavolatilization rate and the total amount of ammonia volatilized were significantlydecreased, the total amount of T3ammonia volatilization was least. while the totalnitrogen content and nitrogen transport rate of leaves, sheaths and stems of the plantwere considerably increased.Low pressure sprinkler irrigation improved the content of chlorophyll,Especially in the late growing period, all treatments chlorophyll content was T3＞T2＞T1＞CK.the senescence of flag leaf that aging speed significantly delayed. For thechlorophyll fluorescence, low pressure sprinkler irrigation increased the chlorophyllfluorescence Fv/Fm and Qp, improved the light energy conversion and the open scaleof PS Ⅱ, enhancedthe photosynthetic electron transport. Shown as on photosynthesis,significantly improved photosynthetic rate, reduced the intercellular CO2concentration, decreased transpiration rate and stomatal conductance. The dry matter accumulation significantly higher than the flooding irrigation,the T3obtain highestphotosynthetic rate and dry matter accumulation.Eventually the production of winter wheat, the low pressure sprinkler irrigationsignificantly improve the winter wheat tousand kernel weight,the the size is T3＞T2＞T1＞CK, low pressure sprinkler irrigation obtained the higher grain yield than thesurface irrigation. Both water and nitrogen use efficiency was enhanced to differentextent under low pressure sprinkler irrigation treatments, among which the treatmentwith15%reduction in water amount obtained the highest grain yield, and the highestwater and nitrogen use efficiency, but the least losses of water and nitrogen.