| Because intercropping is benefical to increasing the yield and water use efficiency,it is a fact that intercropping plastic mulching widely used in arid areas.With the shortage of water resources and the aggravation of soil environment pollution,it is urgent to study the water use efficiency(WUE)of mulch reduction and the single plastic mulching for 2 years.Then,collaborative efforts of intercropping soil moisture in time and space is the key internal cause to efficient water use of intercropping.Therefore,it is vital to study the key period and driving factors of moisture compensation in the single plastic mulching for 2 years of intercropping.The maize/pea intercropping system(MP)was used as the research object in Hexi Corridor Oasis Irrigation Area.With the single plastic mulching for 2 years(R),conventional mulching(C)and three irrigation level(I1: low,450 mm;I2: medium,495 mm;I3: high,540 mm),it explored the water consumption characteristics,the influence factors of water utilization,the relationship between the water utilization efficiency and the influence factors.The aim was to reveal the driving mechanism of high water use efficiency in R.It also provided theoretical basis for improving water use efficiency in the same arid area.The main results were as follows:1.Mulching maize/pea intercropping with the single plastic mulching for 2 years(RMP)increased the soil water content before sowing and during the the important growing period,reduced the evaporation,evapotranspiration ratio(E/ET),the invalid loss of moisture and had no significance to water consumption.The maize strip of RMP increased the 0-60 cm soil water content by 4.5% than that of convential maize/pea intercropping(CMP).In maize/pea intercropping symbiosis period,soil water content was higher 15.1% than that in sole pea and RMP also increased amplitude.After peas harvested,soil water content of intercropping was higher 2.8% than that of monoculture maize and R increased soil water effective than that in C.In two mulching methods,improving irrigation amount significantly incresed soil water content.Water consumption of RMP were higher 14.0% to 14.5% than weighted average of those of monoculture maize and pea monoculture,respectively.From the pea seedling to pod stage in RMP,daily evaporation decreased by 24.3%,8.7% than those in monocropping pea and corn and total evaporation decreased by 22.3%,5.5% than those in monocropping pea and corn.The average soil temperature decreased in R before mulching,which was beneficial to decreasing evaporation,increasing irrigation amount.It is obvious to degrade temperature in R by improving irrigation amount.Water consumption in RMP decreased by 27.6%,11.7% than those in monocropping pea and corn,which indicated that RPM reduced ineffective water consumption ratio.2.Different water moisture of two crop contributed to the water migration between two strips.RMP increased soil water potential from the pea seedling to pod stage by improving irrigation and enhanced the water migration amount between two strips.During the symbiosis period of pea intercropping maize,the soil water content of maize strip increased by 32.1% than that in pea strip.After peas harvested,the soil water content of maize strip decreased by 34.5% than that in pea strip.Compared with the CMP,soil water potential of maize from seedling to flowering stage in the RMP increased by 14.5%.During the symbiosis period of pea intercropping maize,in RMP intercropping,the water volume migrated 14.5 to 21.3 mm from maize strip to pea strip.The water volume in RMP were higher 4.1% to 8% compared with the CMP.After peas were harvested,the water volume in RMP migrated 20.4 to 23.0 mm compared with the CMP.Transfer volume in the RMP increased by 4.4%,and 5.2% compared with the CMP.The water transport between intercropping crops reduced the competition of water between strips,and increased the complementary use of water between pea and maize.3.The RMP improved dry matter by increasing the leaf daily gain and enhanced trecovery effect after peas were harvested.RMP and high irrigation incerased the yield index of intercropping maize,the transformation of dry matter to grain yield,grain yield.Total leaf area in RMP increased by 27.5% and 7.3% compared with monocropping pea and maize,respectively.While the irrigation level increased the leaf area,and medium and high irrigation have no difference in the leaf area.Before maize flowering,recovery effect of RMP compared with the traditional film lowed 9.2% and recovery effect under high irrigation was better;Recovery effect of RMP in maize filling was 21% higher compared with CMP and recovery effect under high irrigation was better.The grain yield of RMP was highest under medium and high irrigation level,and reached 13822.9 kg/hm2 and 4106.0 kg/hm2,respectively.The difference between two irrigation treatments was not significant.The correlation between grain yield and leaf daily yield showed that grain yield was significantly correlated with LAI-D,and leaf daily attributed to increasing the yield.4.As traditional monoculture maize and pea monoculture mulching RMP significantly increased water use efficiency(WUE)compared with CM and CP treatments,WUE of the lower irrigation level is higher.The WUE of RMP was 4.1%,5.2% and 4.4% higher than that of the CMP under the low,medium and high irrigation levels,and WUE was the highest in the medium irrigation treatment level.The WUE of RMP were 4.1% higher than that of CMP,and 9.4% higher than that of CM under low irrigation level.On the basis of correlation of factors affecting water use and water use efficiency,the water use efficiency and soil water content had significantly positive correlation,the water use efficiency and evaporation was negatively correlated,and the water use efficiency and evapotranspiration ratio was negatively correlated,analysis of soil water content,inter tree evaporation and evapotranspiration ratio were performed.These results indicated that high water use efficiency of pea was related to the evaporation decrease,plant evapotranspiration decrease,the small evapotranspiration ratio,which contributed to high water use efficiency.The RMP increased soil water content,reduced soil evaporation and evapotranspiration ratio,invalid water loss,improved WUE in the low irrigation.Therefore,the potential of increasing WUE in RMP with low irrigation can make it an ideal intercropping model in arid areas a film for two years under low irrigation treatment to improve water use efficiency makes it an ideal intercropping model in Arid Areas?... |
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