The Impact Of Climate Change On Maize Production Efficiency

In recent years,the issue of climate change characterized by climate warming has become the focus of global attention.The fifth assessment report of the United Nations Intergovernmental Panel on climate change pointed out that the average global temperature warming was 0.85 ℃ from 1880 to 2012,and agriculture sensitive to climate change was impacted to a certain extent.In the "Special Report on Climate Change and Land"(2019),the IPCC pointed out that on a global scale,maize is a crop that is susceptible to climate variability and leads to poor harvests.In the past 50 years,Hebei’s temperature has risen by an average of 1.2°C,which is twice the rate of the global average temperature rise.The annual precipitation has decreased by 45 millimeters,and the climate change trend is obvious.Hebei is located at the intersection of the two major maize-producing regions of East China North and Huang-huai-hai.It is a major food province dominated by maize cultivation.The impact of changes in Hebei’s maize output and its production layout on domestic food supply security cannot be ignored.Starting in 2015,the Ministry of Agriculture proposed to adjust the structure of maize planting,reducing the maize planting area in some non-dominant planting areas in maize-growing provinces,including some areas in Hebei Province.The adjustment of agricultural structure does not mean the reduction of grain production.In the 21 st century,China’s consumption structure has been upgraded rapidly,but the demand for grain quantity is increasing(Mingzhe Pu et al.,2019).The reduction of maize planting area has put forward higher requirements for the maize production capacity of Hebei Province.Under the current technical level and land resource constraints,to achieve stable maize production,it is necessary to seek room for growth from the perspective of productivity.Facing the severe trend of climate change,in recent years,research on the impact of climate change on agricultural production has gradually increased the research results of the impact of climate change on agricultural productivity.Some studies have confirmed that climate change has a significant impact on technical efficiency and total factor productivity.However,there are few documents on the impact of specific food crops,especially maize production efficiency.Therefore,this article has certain theoretical and practical significance from the research on the impact of climate change on the efficiency of maize production technology in specific regions.Taking Hebei maize production as an example,this paper uses meteorological data during the maize growing period from 1978 to 2018 to construct a standardized precipitation evapotranspiration index(SPEI)and related indicators to characterize the temporal and spatial characteristics of climate change in Hebei Province in the past 40 years.Then use the maize production data of Hebei Province from 1993 to 2018 and the meteorological data of the corresponding years to construct a stochastic frontier production function model and an efficiency loss model to analyze the distribution characteristics of the technical efficiency of maize production in Hebei Province in the past 26 years,and further explore the impact of climate change on maize The impact of production technology efficiency.Based on the above research,the main conclusions are as follows:(1)From 1978 to 2018,the SPEI value of the maize growing period in Hebei Province decreased at a rate of 0.048/10 a.During the study period,the overall climate tended to become arid.The inter-annual change is characterized by increasing frequency of fluctuations and obvious phase characteristics.The spatial distribution characteristics are that the frequency of climate aridification in the central and northern regions is higher than that in the eastern and southern regions,the humidification frequency is higher in the central and northeastern regions,and the humidification frequency is lower in the southeast.(2)The parameter results of production function show that the input of labor,machinery and land has a positive impact on maize output,while the increase of pesticide and chemical fertilizer will lead to the decline of maize output.There is a significant non-linear relationship between the average temperature and precipitation during the growing period and maize yield.(3)The technical efficiency of maize production in Hebei Province fluctuated greatly from 1993 to 2016,the growth rate was small,the overall situation was not stable,and the decline rate was large in some years.The overall average technical efficiency of Hebei Province is 0.8950,and the order of efficiency value is: Southern,Central,Eastern and Northern Hebei.(4)In the results of the efficiency loss model,the increase in the effective irrigation rate and the conservative rate of drought and flood have a positive impact on technical efficiency,and the increase in the proportion of corn planting is not conducive to the improvement of efficiency.Among the climate variables classified according to SPEI,mild to moderate drought and extreme drought hinder the improvement of technical efficiency;mild to moderate humidity and extreme humidity promote the improvement of technical efficiency.(5)The results of grouping analysis based on different planting ratios show that the impact of climate change on areas with different planting ratios is different.Mild and moderate droughts have a greater negative impact on areas with a low corn planting ratio,and extreme droughts have a more significant negative impact on areas with a low corn planting ratio.The effect of mild to moderate humidity is better in areas with a higher corn planting ratio than areas with a lower corn planting ratio,while the improvement effect of extremely humid climates is opposite.The results of grouping analysis based on different periods show that the impact of climate variables on the technical efficiency of corn production was greater during 1993-2002,and less during2003-2012.In 2013-2018,as the drought trend increased,The degree of influence has increased compared with the previous stage.