Distribution Of Water And The Indexes Of Precise Irrigation On Pear Under Different Drip Irrigation

In order to save the irrigation water,it's stressfully to improve the water use efficiency in agriculture.The precision irrigation is effective way to avoid wasting water caused by extensive irrigation method.It transports water according to the requirement of fruit to root zone in moderation and timely.The precision irrigation realizes high water use efficiency meanwhile insures the best quality and high yield.Moreover,it's convenient for achieving irrigation control and automation.Drop irrigation test was set in a pear orchard and different condition of drip irrigation was studied.There were six treatments which were T1(irrigation low limit is 80%and double surface drip pipes),T2(70%and double surface drip pipes),T3(60%and double surface drip pipes),T4(60%and double underground drip pipes),T5(60%and surround drip pipes)and CK(irrigation depend experience and single surface drip pipes).The effects of different irrigation low limit and drip pipe layout on the growth and development of pear and the distribution of water in orchard were observed.The index system of precision irrigation will be set up according by the water requirement of pear.The results show that:(1)Irrigation low limit promoted the gro.Arth of shoots and improved the content of soluble solids of pear but restrained the enlargement of single fruit volume.The length of shoots under T3 was 5.44%and 14.07%longer than T1 and T2,however,the single fruit volume was 5.32%and 7.70%smaller than them.In the same condition of irrigation amount,the length of shoot and single fruit volume were increase which treatments irrigated by the double underground drip pipes and the surround drip pipes.In addition,the yield improved 32.6%and 6.28%by the double surficial drip pipes.(2)The irrigation uniformity of the surround drip pipes was the best among all the treatment.Exorbitant irrigation amount made great leakage which water content of surface soil was low and deep soil water was high.The wettest soil layer among irrigation were 10,30,20 cm in tlie treatments of double surficial drip pipes,double underground drip pipes and surround drip pipes.The wettest soil layer after 5 days were 70,30,20 cm in the three treatments.(3)The water consumption of the treatment irrigated by single surficial drip pipes were the highest.and the water consumption of the treatment irrigated by surround drip pipes is higher than other treatments which were same irrigation amount.The water use eff-iciency of the treatment irrigated by surround drip pipes were the highest.It was 45.83%higher than the treatment irrigated by single surficial drip pipes.And the consumption of water on July and August were biggest,on May was lowest.(4)The time stability of soil water between plants was higher than liners during the growth period.Meanwhile,the time stability of soil water of less irrigation amount was lower than the high irrigation amount.And the time stability of soil water of treatment irrigated by double surround drip pipes was higher than others.The C/C0+C of the soil water between plants was higher than liners,which mean the influence of random factors between plants was higher than it between liners.Monitoring points should be set up concentrated when irrigation uniformity was high,such as setting between plants and int the treatments having a high irrigation amount.Therefore,the treatment which irrigation low limit is 60%can improve the quality and water use efficiency.Meanwhile,the double underground drip pipes could improve the yield under the same irrigation low limit.