Effects Of Climate Factors On Yield And Planting Layout Of Black Rice In Donglan County

Black rice is a characteristic agricultural products in Donglan County.The yield and quality of black rice are affected by both cultivation management and meteorological conditions.Donglan is located in the western mountainous area of Guangxi,with complex terrain and obvious three-dimensional climate difference.The yield and quality of black rice in different towns and villages are obviously different.It is of great significance to study the influence of spatio-temporal variation of meteorological factors in different regions of Donglan County on the yield of black rice and explore the optimal spatio-temporal layout scheme of black rice industry,which is of great significance to promote the development of black rice industry.In this paper,the trend analysis was used to analyze the temporal variation and spatial distribution characteristics of sunshine duration,annual mean temperature,active accumulated temperature ≥10℃ and annual mean precipitation in the growing season of 10 national meteorological stations in Hechi cityduring 1960-2020 and 14 regional automatic meteorological stations in Donglan County during 2010-2020.The correlation between meteorological factors and black rice yield data was analyzed by SPSS21.0 to find out the influence degree of different meteorological factors on black rice yield.And the spatial and temporal distribution of rice industry in Donglan County was explored by superposition calculation of four meteorological factors using Arc GIS operating system.The results are as follows:(1).Spatial-temporal variation of climate factors in Donglan County: In terms of time distribution,the average temperature,active accumulated temperature ≥10℃ and precipitation of the growing season in Donglan from2010 to 2020 all showed an upward trend,among which the annual average temperature was 23.5℃ and the warming rate was 0.52℃/10 a.≥10℃ active accumulated temperature ranged from 5200 ℃ to 5700℃,and the growth rate was 124.6℃/10a;The annual average precipitation is 1247.6 mm,and the increase rate is 578.18mm/10 a.The annual average sunshine hours was 993.2h,showing a decreasing trend,but the decreasing trend was not obvious.In terms of spatial distribution,the mean temperature and active accumulated temperature≥10℃ in the middle and southern towns of Donglan County were significantly higher than those in the west and the north;Precipitations in all townships were symmetrically distributed from north to south.Among them,the average annual precipitation in Simeng Township,Lanmu Township,Wuzhuan Township and Donglan Township in the southwest exceeded 1300 mm,and the average annual precipitation in other townships ranged from 1000-1200 mm.The annual average sunshine duration of each township is between 850-1100 h,but the overall distribution is neither regular nor uniform.The sunshine duration of Changjiang,Bachou,Aidong and Sannong is the most,while the sunshine duration of Jingu,Qiexue and Huaxiang is the least.(2).The effects of climatic factors on the yield of black rice in Donglan from 2010 to 2020 was positively correlated with annual mean temperature,active accumulated temperature ≥10℃ and sunshine duration in growing season,and negatively correlated with precipitation.Among them,temperature has the most significant effect on the yield of black rice,indicating that in a certain range,the higher the temperature,the higher the yield of black rice.(3).The spatial and temporal distribution of rice planting was carried out according to different climate resource conditions in each township.Divide by time,The suitable planting period in central and southern towns is from late March to August;Most towns in the east and west are suitable for planting from April to September;The suitable planting period for towns with higher elevations in the north,east and west is from mid-April to October.Divide by geographic space,the most suitable area is mainly concentrated in the middle and south of Donglan.The region is rich in heat resources,sufficient sunshine and appropriate precipitation.The secondary suitable areas are mainly concentrated in the southwest and southeast of Donglan,this area is affected by heavy rainfall in summer,there are relatively few hours of sunshine,but the light and heat conditions are favorable to the production of black rice.The suitable area is mainly the northern alpine mountain area,which has high altitude,relatively low average temperature,large temperature difference between day and night,and less sunshine hours.The unsuitable areas are mainly stone mountains,with less farmland and lack of water resources.