Effects Of Field Border Length And Supplemental Irrigation By Monitoring Soil Moisture On Soil Water Characteristics And Grain Yield Of Wheat

The experiment was conducted from 2017 to 2018 in Shiwang Village,Yanzhou,Shandong Province.Two levels of target relative soil water content(W1,70% at jointing stage and 70% at anthesis;W2,80% at jointing stage and 80% at anthesis)under five field border length(10 m,15 m,20 m,25 m and 30 m for L1,L2,L3,L4 and L5)were designed for this study.In each treatment,sampling section with 5 m length was set along the irrigation water flowing direction.The experiment was conducted to study the effects of different field border length and target relative soil water content on soil moisture characteristics and grain yield with wheat cultivar Jimai 22.The results as fellow:1 Effects of different treatment on soil moisture characteristics and water characteristics of wheatUnder W1 condition,L1 had highest value of the ration of field border length advancing rate and intake of field border length at jointing and anthesis stage.Under W2 condition,L1 and L2 had the highest value in comparison of other treatments.Under W1 condition,0~40cm soil layer relative soil water content after irrigation at jointing and anthesis stage,the Cv of 0~40 cm soil layer relative soil water content among and total water consumption amounts showed that L1 was lowest than other treatments.Under W2 condition,L1 had the lowest value in comparison of other treatments.2 Effects of different treatment on photosynthetic characteristics and dry matter accumulation of wheatThe average photosynthetic rate,stomatal conductance,transpiration rate,trice water use efficiency and SPAD value of flag leaf at 14,21 and 28 d after anthesis stage in L1 was significantly higher than other treatments,the Cv of photosynthetic rate,stomatal conductance,transpiration rate,trice water use efficiency and SPAD value of flag leaf at 14,21 and 28 d after anthesis stage amount were lowest than other treatments under W1 and W2 condition.Under W2 condition,L2 had higher value in comparison of other treatments.Under W1 and W2 condition,dry matter accumulation amount at anthesis and maturity showed L1 was higher than other treatments,the Cv of dry matter accumulation amount at anthesis and maturity among were lowest than other treatments.L1 obtained the highest current assimilates distributed directly to grain from anthesis to maturity,post-anthesis assimilates allocation to grain and contribution to grain.Under W2 condition,L2 had higher value in comparison of other treatments.3 Effects of different treatment on nitrogen accumulation and transportion of wheat and soil nitrate nitrogen contentUnder W1 condition,L1 obtained the highest nitrogen accumulation amount at anthesis and maturity,nitrogen redistributed amounts from vegetative organs of anthesis to grain and nitrogen distributed directly to grain from anthesis to maturity amount among different treatment,Under W2 condition,the nitrogen accumulation amount at anthesis and maturity,nitrogen redistributed amounts from vegetative organs of anthesis to grain and nitrogen distributed directly to grain from anthesis to maturity amount of L1 and L2 were significantly higher than other treatments.Moreover,the average soil nitrate-nitrogen content at anthesis and maturity of different sampling districts in were significantly lower in L2、L3、L4 and L5 than in L1 under W1 condition,Under W2 condition,0~200 cm soil layer soil nitrogen amount at anthesis and maturity showed L1 and L2 were highest.4 Effect of field border length on flag leaf senescence characteristics of wheatUnder W1 condition,the superoxide dismutase activity and soluble protein content at 14,21 and 28 d after anthesis of L1 was significant higher than L2 、 L3 、 L4 and L5 while malondialdehyde content was inferior to other treatments.L1 and L2 had no significant difference but significant higher than other treatments in superoxide dismutase activity and soluble protein content,L1 and L2 was significant lower than L3 、 L4 and L5 in malondialdehyde content under W2 condition.5 Effect of field border length on grain yield and water use efficiency of wheatUnder W1 condition,grain yield,water use efficiency and irrigation water use efficiency in L1 was significantly higher than others,the Cv of grain yield were lowest than other treatments.Under W2 condition,grain yield and water use efficiency of wheat in L1 and L2 was significantly higher than others,irrigation water use efficiency showed L1>L2>L3 、L4>L5,the Cv of grain yield were lowest than other treatments.These results indicated that the L1 under W1 condition obtained the greatest grain yield,water use efficiency and irrigation water use efficiency among different treatment,which was the best treatment in this experiment.Under each water condition,L1 treatment was the best treatment under W1 condition,L1 and L2 were the beat treatment under W2 condition.