| ?Direction?Water is one of the key limiting factors influence on maize growth and yield.However,due to lacking of the theory and technical support of combining crop water requirement and precision,irrigation time and frequency were determined by experience and response to water morphology in the growth stage of maize during actual planting process of agricultural production.This study was conducted with optimizing irrigation volume and frequency and its distribution in maize growth stage to establish optimum irrigation system for water and nutrition use efficiency and high yield of drip-irrigated maize in northern Xinjiang.?Method?The study was conducted during the year 2013-2014 using a split plot design with three irrigation volume treatments(W4500?4500 m3/hm2?,W6750?6750 m3/hm2?and W9000?9000 m3/hm2?)and two irrigation frequency treatments(8 times?T4?and 10 times(W6750))with three replication,respectively.Maize dry matter accumulation,nitrogen and phosphorus uptake and its use efficiency and yield was investigated,soil profile water content was monitored with the PR2/6 soil profile moisture meter.?Results?1.Maize Dry matter accumulation was significantly increased by increasing of irrigation volume,the response of irrigation volume to maize dry matter accumulation was:W4500?28357 kg/hm2?<W6750?37289 kg/hm2?<W9000?39541 kg/hm2?,irrigation frequency to maize dry matter was:10 times(W6750,37289 kg/hm2)<8 times?T4,39031kg/hm2?.2)Maize nitrogen uptake rate increased as irrigation volume increased,The largest value of PEP was 193.1196.8 kg/kg when the irrigation volume was W6750?6750 m3/hm2?,the largest nitrogen uptake value was 374.5 kg/hm2(W9000).The NUE,NAE and PFPN increased as irrigation volume increased,and NUE reached the maximum value at W9000?37.1%-38.6%?,irrigation frequency had no significant influence on it.3)Maize phosphorus accumulation was increased by increasing of irrigation volume,irrigation frequency had no significant influence on it.Maize PAE,PPFP increased with the irrigation volume increased.Maize PEP increased as irrigation frequency increased.The largest value of PEP was 193.1196.8 kg/kg when the irrigation volume was W6750?6750m3/hm2?.4)Soil water content at different soil profile was significantly affected by irrigation volume,soil moisture content of 0-40cm decreased rapidly and the value was the lowest at W4500,soil moisture content of 0-40cm was higher with W6750 and W9000,which was helpful to the effective utilization of maize.5)Maize Yield and its components under drip irrigation system were increased along with irrigation volume,irrigation frequency to maize dry matter was:10 times(W6750)<8 times?T4?.The W4500?1158711941kg/hm2?significantly reduced maize yield,the largest maize yield value was 1637519022 kg/hm2 at T4.6)Irrigation volume was significantly decrease along with irrigation volume increased.The highest WUE?yield?was obtained in the W4500?2.73.1 kg/m3?,by contrast,the lowest WUE was recorded for an irrigation volume at 9000 m3/hm2?1.81.9 kg/m3?.The effect of irrigation frequency on maize WUE was ten times treatment(W6750,2.41 kg/m3)<eight times irrigation frequency?T4,2.43 kg/m3?.?Conclusions?1)The estimating model for irrigation volume recommendation on basis of maize dry matter accumulation were fulfilled in 2-yrs field trials.Wa=8354-0.22Y,Wa=12180-0.54Y,Wa=13386-0.38Y and Wa=30451-0.81Y estimating models were achieved during maize growth stage of jointing,silking,filling and milk stage,respectively.Through estimating model,the best economic irrigation volume was 6798 m3/hm2.The critical dry matter accumulation were 1109 m3/hm2,2252 m3/hm2,4553 m3/hm2 and 7741 m3/hm2 were presented correspondingly.2)Maize growth and yield were significantly restricted in under the condition of high density cultivation?more than 105000 plants/hm2?in W4500,irrigation volume at 6750 m3/hm2,eight times is optimize irrigation strategy of drip-irrigated maize in Northern Xinjiang. |
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