Meta-analysis Based Comparative Evaluation Of Crop Water Use Efficiency In Minqin County,Gansu Province

Agriculture plays a leading role in the desert-oasis region of Minqin county,Gansu province.Water is a key factor for the sustainable development of local agricultural production and environment.Based on the household survey,collection and analysis of literature,this study focused on the current water use situation of major crops in Minqin as well as the agricultural input and output.Meta-regression analysis was utilized to explored the relationship between crop water use efficiency(WUE)and micro irrigation,crop management,soil management and water management,etc.Suggestions were proposed regarding sustainable development of agricultural production,water use and household profits.The main results were presented as follows.1.For most of the crops in Minqin,their irrigation water use exceeded the irrigation quota from 2011 Minqin Water Resources Allocation Scheme.Specifically,the irrigation water use for onion(Allium cepa),melons(Cucumis melo)and hot pepper(Capsicum annuum)exceeded the quota by 56.79%,46.35%and 35.58%;wheat(Tritcum aestivum),maize(Zea mays)and sunflower seed(Helianthus annuus)by 11%-26%.The WUE for wheat,maize,onion,cotton(Gossypium hirsutum),hot pepper,sunflower seed,melons and fennel(Foeniculum vulgare)were 0.87 kg m-3,1.17 kg m-3,8.71 kg m-3,0.56 kg m-3,2.68 kg m-3,0.78 kg m-3,3.27 kg m-3 and 0.51 kg m-3,respectively.The total water use for each crop in Minqin was remarkably greater than that from literature,and large proportions of water use could be saved to realize fewer amounts of water use and higher WUE,49%,46%,28%,27%,55%,45%,55%and 35%,for wheat,maize,onion,cotton,hot pepper,sunflower seed,melons and fennel,respectively.2.The WUE for different crops were variously influenced by irrigation methods and management ways.Based on the data from empirical studies,the application of micro irrigation could increase cotton yield by 12.76%with 5.63%less water compared with furrow irrigation,while both furrow and micro irrigation didn’t make much change for wheat and maize regarding water use and yield.Meta-regression analysis revealed that micro irrigation and water management could significantly increase the WUE of wheat;soil management could significantly increase the WUE of maize;and micro irrigation,crop management,soil management and water management could significantly increase the WUE of cotton.3.In Minqin county,agricultural production gave relatively lower income compared with other income resources.The average agricultural net profit was 5651 yuan per household;the average income for families with migrant workers was 9609 yuan per household;the average income for families of livestock breeding was 5386 yuan per household.The maximum household net profit,17395 yuan,could be achieved through reducing crop production of low price onion and increasing the migrant workers.4.Based on the study,the agricultural production structure should be adjusted through reducing the planting area of high water consuming and low WUE crops,like onion,wheat and maize.Micro irrigation methods,such as drip irrigation,pipe irrigation and impervious channel irrigation,should be applied to improve crop WUE.Grassland agro-ecosystems should be developed to maintain the sustainability of Minqin oasis.