Effect Of RDI On Physiological Performance And Yield Of Sugar Beet With Drip Irrigation

In order to study the water-saving,high-yield,high-efficiency irrigation physiological basis and evaluation indexes of sugar beet,this experiment used artificial shelter and artificial irrigation to control soil moisture in 2015 and 2016,under the condition of drip irrigation,the different irrigation lower limit was set up the water requirement of sugar beet's two biggest growth period-the vegetative development period and root swelling period:the water holding capacity was 60%?70%,50%?60%and 40%?50%.In this experiment,the effects of Regulated Deficit Irrigation on the physiological characteristics,yield and water use efficiency of sugar beet were studied,In order to providing the theoretical basis for water-saving irrigation for sugar beet high quality.The following findings were obtained:1.During the vegetative development period,regulated deficit irrigation had significantly reduced the plant height and leaf area index of sugar beet,the moderate water deficit had a compensatory effect on leaf area,root dry matter weight and root/shoot ratio after rewatering.Severe water deficit had an inhibitory effect on plant height,leaf area index and dry matter quality of sugar beet.The effect of regulated deficit irrigation on root swelling period less than that in vegetative development period of sugar beet.The moderate water deficit had a compensatory effect on the dry matter quality after rewatering,and severe water deficit was resumed growth after rewatering.2.Although the photosynthetic rate decreased after mild and moderate water deficit in the vegetative development period,but they are mainly caused by stomatal conductance decreased,the photosynthetic performance was restored after rewatering,the photosynthetic performance of moderate deficit was improved,and the compensation effect was obtained.The photosynthetic efficiency of severe water deficit can't be recovered after rewatering.After rewatering of moderate water deficit in root swelling period,the photosynthesis has a compensatory effect.Sugar beet in severe water deficit state can also resume growth after rewatering.3.The water consumption of sugar beet in growth stage increased with the irrigation amount,when the water consumption of vegetative development period and root swelling period were 235.78mm and 130.55mm,the yield and sugar production is higher,and the water use efficiency is also higher.4.In vegetative development period and root swelling period,the water saving of moderate water deficit were 33.56%and 36.82%higher than that of control respectively;Production were 7.34%and 0.79%higher than that of control respectively,water use efficiency increased by 28.46%and 13.45%respectively compared with the control.In vegetative development period and root swelling period,the water supply were 1147.78 m3·hm-2 and 635.54 m3·hm-2of sugar beet with drip Irrigation,the yield could reach 92009kg·hm-2 and 86399kg·hm-2,and the water use efficiency were reached 149.93kg·mm-1·hm-2 and 132.41kg·mm-1·hm-2 respectively.