Effcts Of Winter Wheat Photosynthetic Characteristics, Yield And Water Use Efficiency Under Ridge And Furrow Rian Harvesting With Supplemental Irrigation In Guanzhong Irrigation District

This research was conducted in Yangling, Shaanxi province. By setting2different widthof ridge and furrow rain harvesting (RFRH) cultivation under the condition of differentirrigation amount, taking traditional cultivation (CK) as the control, to test the influence ofrain harvesting planting combined with supplementary irrigation on winter wheatphotosynthetic characteristics. Leaf area per plant, the content of photosynthetic pigment, thechange of chlorophyll fluorescence parameters, flag leaf net photosynthetic rate, yield andwater use efficiency according to which to study water saving effect were tested. Results ofthis study could provide theoretical basis and technical guidance for the application of drytechnology in irrigation district. The main conclusions are as follows:1.Leaf area per plant of RFRH in every growth stage was higher than in the traditionalcultivation (CK) and flat planting with irrigation (T7). In RFRH cultivation mode, wide ditch(the width of both ridge and furrow is60cm) irrigated750m3hm-2and no irrigation werehigher than narrow one (the width of both ridge and furrow is40cm), while RFRH irrigated375m3hm-2treatments were on the contrary. Leaf area per plant of RFRH cultivationincreased by44.2%to113.2%significantly than CK (P <0.01). Leaf area per plant of T2, T3and T5, T6(T2:60cm ridge and furrow rain harvesting with375m3hm-2supplementaryirrigation; T3:60cm ridge and furrow rain harvesting with750m3hm-2supplementaryirrigation; T5:40cm ridge and furrow rain harvesting with375m3hm-2supplementaryirrigation; T6:40cm ridge and furrow rain harvesting with750m3hm-2supplementaryirrigation) increased45.1%,72.8%and51.1%,60.9%significantly than T7(flat planting with750m3hm-2supplementary irrigation)(P <0.05).2.The RFRH cultivation increased the chlorophyll a and chlorophyll b, total chlorophylland carotenoid content significantly than CK and T7in heading and filling stage. The RFRHcultivation increased chlorophyll/carotenoids ratio, reduced the chlorophyll a/b ratio,decreased the chorophyll degration speed in middle and late growth stage so as to enhancephotosynthetic rate. The RFRH cultivation with half amount of supplementary irrigation could maintain higher Chl/Car ratio than flat planting with irrigation (T7), and wide ditch wasbetter than narrow one.3.The RFRH cultivation increased flag leaf net photosynthetic rate (Pn), transpiration rate(Tr), stomatal conductance (Gs) and intercellular CO2concentration (Ci) than CK and T7,each index got increase first and then declined along with the advance of the growth stages.Pn increased with the increasing of irrigation amount,60cm RFRH treatments with irrigationof750m3hm-2and no irrigation were higher than40cm RFRH treatments in same irrigationamount.60cm and40cm RFRH cultivation improved Pn than T7by39.3%-50.3%and18.7%-31.6%respectivly. The RFRH cultivation with supplementary irrigation increased Trby41.9%-91.6%significantly than flat planting with irrigation(T7)(P<0.05), there was nosignificant difference between the RFRH treatments, but all of them were significantly higherthan that of the traditional cultivation(CK)(P<0.05). Gs value of RFRH treatmnets reached0.9-2.1times of border irrigation,60cm RFRH treatments were significantly higher than CK(P<0.05). No significant difference between different treatments on Ci. Leaf water useefficiency (WUEL) of RFRH cultivation with supplementary irrigation had no significantdifference with T7during gorwth period.4.The RFRH cultivation increased Fo, Fm, Fv, Fv/Fm, Fv/Fo and qP, reduced the qN thanflat planting. During winter wheat growth period, Fo, Fm, Fv of the RFRH cultivationimproved significantly than that of T7by8.2%-11.9%,3.8%-54.7%,2.4%-122.3%(P <0.05).Fv/Fm, Fv/Fo of the RFRH with supplementary irrigation treatments were higher than that ofT7and CK significantly (P <0.05) in flowering and filling stage. Photochemical quenchingcoefficient(qP) of the RFRH cultivation were higher than flat planting on the whole.Thewinter wheat chorophyll flouresecence parameters of60cm RFRH cultivation were higherthan40cm RFRH cultivation in the same irrigation amount, and these parameters increasedalong with irrigation amount under the same planting pattern. The value of photochemicalquenching coefficient (qN) of each treatment were increased along with the advance ofgrowth stage, all treatments lower significantly than CK in filling stage (P <0.05), qN of theRFRH cultivation decreased with irrigation amount arise.5.The grain yield and biological yield under different planting patterns were increasedwith the increasing of irrigation amount. In the same level of irrigation, the grain yield andbiological yield of60cm RFRH cultivation were higher than that of40cm RFRH cultivation.Irrigation of750m3hm-2treatments were significantly higher than no irrigation and irrigation375m3hm-2treatments (P <0.05) under RFRH cultivation mode. The grain yield of RFRHcultivation increased significantly than CK (P <0.05). T1, T2and T3improved the yield by2.8%,9.6%(P <0.05) and18.9%(P <0.01) respectively than T7. The biological yield of the RFRH cultivation increased significantly by66.3%-105.1%than CK (P <0.05) extremely.T2, T3and T6boosted the biological yield than T7by9.5%,13.0%(P <0.05) and7.2%respectively.6.The RFRH cultivation improved the irrigation water use efficiency (IUE), precipitionuse efficiency (PUE) and total water use efficiency (WUEy) than that of flat planting. PUE of60cm RFRH cultivation was significantly higher than40cm RFRH cultivation under thesame irrigation amount (P <0.05). Treatments which irrigated750m3hm-2were significantlyenhanced than no irrigation and irrigated375m3hm-2treatments under the same plantingpattern. IUE of T2was the highest which reached192.59kg·hm-2·mm-1, significantly andextremely significantly higher than that of other irrigation treatments T5, T3and T6, T7. Theresults showed that the less of irrigation amount, the higher IUE value, and wide ditch ofRFRH cultivation higher than narrow one. The RFRH cultivation significantly improvedwater use efficiency (WUEy) than flat planting (P <0.05), and wide ditch is significantlyhigher than the narrow ditch (P <0.05), there was no significant difference between differentwidth of the RFRH cultivation. WUEy of60cm RFRH cultivation increased significantly by10.3%-15.5%than T7(P <0.05). WUEy of40cm RFRH cultivation significantly lower thanthat of T7, while increased by15.1%-25.4%significantly than CK (P <0.05).