Effects Of Climate And Cultivated Land Change On Cultivated Land Productivity In Aksu River Basin

Cultivated land area as a special type of land use,change in which has a certain impact on the crop productivity of the land,and it is one of the important issue of land productivity research.Therefore,under context of the global warming and the continuous expansion of cultivated land area,the relationship between climate and cultivated land change on both of agricultural production conditions and agricultural yield has attracted extensive attention.Considering the reality of regional agriculture sustainable development,the pressure of cultivated land use and crop quality assurance,the many prvious researches has focused on the trend analysis of cultivated land area changes to single crop yield change etc.,actually,in the context of globall warming and the cultivated land area changes,it is difficult to achieve scientific guidance for crop yield assurance,and correct understanding of agricultural green development strategy.Therefore,the meteorological factors and the spatial-temporal evolution characteristics of cultivated land,furtherly,the relationship of them between the main crop yield is taken as the main research tagert,studied the comprehensive impact of climate and cultivated land change on cultivated land productivity by systematic analyzing of changing trend of cultivated land productivity.which has certain reference significance for the agricultural practice expectation in the research area.Aksu River Basin is a cotton production base and an important area of grain production in Xinjiang.It is very sensitive to climate change and one of the regions with fragile ecological environment.Therefore,under the circumstance of climate and cultivated land change in Aksu River Basin,the main crop yield and cultivated land productivity have changed significantly.This work using various kinds of data which including temperature and sunshine duration measurements of Aksu station and Keping Station in Aksu River Basin from 1970 to 2020,remote sensing data of cultivated land use from 1980 to 2018,and agricultural statistical data related to grain and cotton production;applying diverse methods such as trend analysis method of climate elements,moving average method,cumulative anomaly method,M-K test(Mann-Kendall test)mutation analysis method,trend yield and meteorological yield simulation,cultivated land grain productivity evaluation model,the aim is to to carry out detailed analysis on the relationship between climate change,cultivated land area change and crop meteorological yield,cultivated land productivity in Aksu River Basin.The main results of this study are as follows:(1)The interannual variation trend of air temperature and sunshine duration in Aksu river basin is obvious,that is,air temperature increases,sunshine duration decreases,and the seasonal and interdecadal climate change trend is consistent with the interannual variation trend;(2)The cultivated area,total grain and cotton yield and yield per unit area in the study area increased significantly.The total area of cultivated land increased by 3882.3 km~2from 1980 to 2018;The total output of grain and cotton from 1970 to 2019 increased from 14.93×10~4t and 3.48×10~3t to 75.96×10~4t and3.30×10~4t,respectively.The yield per unit increased from 1113.63 kg/hm~2and 502.5kg/hm~2to 8092.08 kg/hm~2and 1710.05 kg/hm~2respectively.In addition,the meteorological yield of grain and cotton fluctuated from-1319.45 to 1386.37 kg/hm~2,and the meteorological yield of cotton fluctuated from-446.19 kg/hm~2to 478.59kg/hm~2.(3)Climate change has significant influence on agricultural climate resources and production conditions,10?or higher accumulated temperature and continuous days showed obvious increasing trend,light resources decreased significantly,but little effect on crop yield,fertilizer seems obvious increase trend,grain crops and cotton seeding time in advance,multiple crop index,the growth period shorten;(4)Climate change and cultivated land area change have significant impacts on cultivated land productivity.There is a positive correlation between the change of meteorological elements and the grain meteorological yield in the study area,while there is a negative correlation between the change of meteorological elements and the cotton meteorological yield,but the correlation is not significant,and the grain and cotton meteorological yield will be decreased in the next 20 years.From the changing trend of cultivated land grain productivity and the impact of cultivated land area on it,it can be seen that the cultivated land grain productivity increased from 419.19 kg/hm2 to806.43 kg/hm~2from 1980 to 2019,showing an obvious increase trend,and the change rate of cultivated land area was slow,grain productivity slightly decreased.It is necessary to improve the ecological quality of cultivated land resources and the cultivated land environment.Therefore,in the development process of agricultural production,to further deepen the understanding of crop production trend under the background of climate change and land use type change,and which induced changes in cultivated land productivity and crop quality process and thier dynamic characteristics,this study analysed effects of change in cultivated land area changes and climate to meteorological yield and the cultivated land productivity.On the premise of this,measures should be taken according to local conditions,and countermeasures should be found to develop the cultivated land utilization mode which is beneficial to the cultivated land production capacity and agricultural green production in the study area.