Spatial-Temporal Variations Of Climatic Potential Productivity Of Rice In Liaoning Province In Recent 30 Years

Rice is an important food crop in Liao Ning Province.It is of great significance to study the temporal and spatial variation characteristics of climatic potential productivity for improving grain yield and ensuring grain security in the future.This study was based on meteorological data from 24 meteorological stations in Liao Ning Province from 1987 to 2016,using step by step correction method to estimate the photosynthetic potential productivity,light and temperature potential productivity and climatic potential productivity of rice in Liao Ning Province during the growing period from May to September,analysis of the temporal and spatial variation and interannual variation,respectively.The effects of different regional climate factors affecting rice potential productivity,and according to the analysis of resource utilization and the climate of Liaoning Province rice yield potential future yield change reality.The main results are as follows:(1)Climate change during rice growing period in Liaoning Province in recent 30 years: The surface solar radiation showed decreasing trend in time,and the decreasing rate was 4MJ?m-2?10a-1,spatially,it gradually decreases from west to east.Temperature showed a marked upward trend in time,with a rising rate of 0.2??10a-1.spatially,the temperature in Western Liaoning is higher than that in eastern Liaoning.The precipitation showed downward trend in time,and the downward rate was 10.19 mm?10a-1,spatially,the precipitation in Western Liaoning is less than that in southeastern Liaoning.(2)Changes of rice photosynthetic productivity potential in Liaoning Province during growth period in recent 30 years: The average photosynthetic potential of rice in Liaoning Province was 25168 kg·hm-2,which showed a downward trend with time,and the downward rate was 39.25 kgkg·hm-2·(10a)-1.The spatial distribution of solar radiation tends to be consistent with the surface solar radiation,showing the characteristics of high in the northwest and low in the southeast.The average utilization rate of rice photosynthetic resources in Liaoning Province was 28.57%,which showed a significant upward trend with time,and the upward rate was 1.88%.(10a)-1.In spatial distribution,the central part of Liaodong Peninsula is the area with high utilization rate of photosynthetic resources,and western Liaoning and southeastern Liaoning have great potential to increase production.(3)Changes of rice light and temperature productivity potential in Liaoning Province during growth period in recent 30 years: The average light and temperature productivity potential was 22616 kg·hm-2,which showed an upward trend with time,with an increase of 258.25 kg·hm-2·(10a)-1.The spatial distribution shows a strip shape from the high value area in Western Liaoning Province to the low value area in eastern Liaoning Province.The average utilization rate of light and temperature resources of rice in Liaoning Province was 31.69%,which showed a significant upward trend with a rising rate of 1.77%.(10a)-1.Spatially,the utilization rate of high light and temperature resources is in the Liaodong Peninsula,while the low value areas are in the arid and semi-arid areas of western Liaoning and parts of northeastern Liaoning.(4)Changes of rice climate potential productivity in Liaoning Province during growth period in recent 30 years: The mean climatic potential productivity is 14499kg·hm-2,which shows a downward trend with time,and the rate of decline is 212.34 kg·hm-2·(10a)-1.Spatially,the trend is increasing from northwest to southeast.The high value area is located in the lower reaches of Yalu River in southeastern Liaoning Province,and the low value area is located in the arid and semi-arid area in Northwest China.The spatial variation is significant.The average utilization rate of rice climatic resources in Liaoning Province is 52.24%,which shows an upward trend with the change of time.The rate of increase is 2.73%.(10a)-1.In spatial distribution,the utilization rate of climate resources in eastern Liaoning is higher than that in Western Liaoning and southeastern Liaoning.The correlation analysis between climatic factors and potential productivity of each station shows that,temperature is positively correlated with radiation,while both are negatively correlated with precipitation.and precipitation is the main driving factor affecting the growth and development of rice.In some areas of Liaoning Province,there is still a great potential for increasing production.It is necessary to strengthen the level of agricultural management technology,increase agricultural investment,rationally utilize water resources,increase the input of pesticides and fertilizers,optimize soil fertility and promote the rapid development of rice in Liaoning Province.