Study On The Coupling Relationship Of Grain Production And Soil And Water Resource Allocation In Sanjiang Plain

Agriculture is the foundation of the national economy.Grain production has a bearing on the national economy and the people's livelihood,and is the cornerstone of maintaining social stability and the long-term stability of the country.China is a populous country,but the per capita arable land and water resources are less than half of the world's average level.With the rapid development of urbanization and industrialization in China,the shortage of agricultural soil and water resources and unreasonable allocation are becoming more and more prominent,which will directly affect the improvement of regional grain production capacity and become a fundamental and long-term problem in the process of restricting the agricultural development of our country.Sanjiang plain is an important commercial grain production base in China and one of the first modern agricultural demonstration bases.During the period from 2003 to 2015,the grain output in Sanjiang plain increase for the 12 th time,which playe an important role in ensuring national food security.In 2016,food production declined as a result of the adjustment of planting structure,such as corn reduction.In view of the lagging construction of water conservancy facilities in the Sanjiang Plain area in recent years,the utilization efficiency of surface water is extremely low and the groundwater exploitation is serious,resulting in the unreasonable allocation of water and soil resources.Under the above background,this paper studies the coupling effect of grain yield and its allocation of soil and water resources at county scale from the perspective of increasing grain yield,and gives some suggestions to improve the utilization efficiency of agricultural soil and water resources and promote the high and stable yield of regional grain,so as to provide scientific decision basis for the sustainable development of regional agriculture.The main contents of this paper include:(1)Explain the related research on food production and the allocation of soil and water resources at home and abroad,and introduce related theoretical foundations and concepts,research areas and data sources.(2)Based on the perspective of grain yield increase,LMDI model is used to analyze the temporal and spatial variation of grain yield pattern and its influencing factors in Sanjiang Plain area from 2003 to 2015.The results show : the "twelve consecutive increase" of grain production in the study area is an epitaxial increase based on the expansion of sowing area.From the perspective of yield increase pattern,the yield increase of rice is the most significant,followed by maize,and the yield of soybean showe a downward trend.The yield increase in the eastern counties is better than that in the west,and the north is better than the south.From the perspective of the total effect of yield increase,the planting area and yield of grain have positive effects,but the contribution value of grain yield is less than one-third of the contribution of planting area effect.From the perspective of different effects on different crops,the contribution of planting area effect and yielding effect is rice > corn > soybean,and the cumulative effect of soybean planting area is negative.(3)DEA model is used to calculate the efficiency of the allocation of agricultural soil and water resources in each county area of Sanjiang Plain,and the reasons for the difference in the allocation efficiency of agricultural soil and water resources are analyzed.The results show: During the research period,the comprehensive efficiency of agricultural soil and water resources allocation in the Sanjiang plain is in a good grade on the whole,and the allocation effect is better in the east than in the west,north over the south,and margin over the hinterland.In the northeast of the research area,the pure technical efficiency is higher but the scale efficiency is lower,and there exists the phenomenon of input redundancy,while the pure technical efficiency is lower but the scale efficiency is higher in the central and southwest counties,mainly because they are close to the cities with good economic development and convenient transportation,which are characterized by more non-agricultural employment and less traditional agricultural input.Judging from different crops,the utilization effect of soil and water resources in paddy fields is obviously better than that in dry crops,and the proportion of soil and water resources redundancy of soybean is the highest,which is manifested in rice > corn > soybean.(4)Based on the coupling coordination model,the relationship between the grain yield and the allocation of soil and water resources in each county is analyzed from the perspective of time and space.From the change of time series of coupling coordination relations,the coupling degree and coupling coordination degree of the whole Sanjiang Plain area show a rising trend of fluctuation,from the moderate coordinated running-in stage to the highly coordinated coupling stage.During the study period,although the coupling coordination level between agricultural soil and water resource allocation efficiency and grain yield are improved,the coupling results between counties are not ideal and there are significant regional differences between counties.It mainly shows that the coupling coordination level of northeast county is higher than that of southwest,and the edge is better than the distribution law of hinterland county.(5)Finally,corresponding suggestions are given for the above research results:the government should improve water conservancy facilities and strengthen scientific guidance and management;stabilize the planting area of crops,develop precision agriculture,and realize the improvement of grain yield per unit;implement the urbanization strategy of ensuring food security.