tailieunhanh - Effect of the change of climate indicators on agricultural yields in Son La province

Due to climate change, the agro-climatic indicators in Son La province has changed in the following trends: (i) the total heat in the Winter - Spring crop and the Summer crop as well as the total annual heat have increased; (ii) The amount of time in a year with temperature below 20 degrees has shortened; the amount of time in a year with temperatures above 25 degrees has lengthened; (iii) the absolute minimum temperature tends to increase rapidly; (iv) the rainfall in Winter - Spring crop has increased slightly whereas the season rainfall and total annual rainfall tend to decrease. | Vietnam Journal of Science and Technology 55 (6) (2017) 756-766 DOI: EFFECT OF THE CHANGE OF CLIMATE INDICATORS ON AGRICULTURAL YIELDS IN SON LA PROVINCE Nguyen The Hung1, *, Nguyen Huu Quyen2, * 1 Climate change department – Hanoi University of Natural Resources and Environment, No 41 A, PhuDien Road, North-Tu Liem district, Ha Noi Viet Nam 2 Vietnam Institute of Meteorology, Hydrology and Environment, , Nguyen Chi Thanh Road, Dong Da District, Ha Noi, Viet Nam * Email: ; nhquyen13@ Received: 13 October 2016; Accepted for publication: 30 September 2017 Abstract. Due to climate change, the agro-climatic indicators in Son La province has changed in the following trends: (i) the total heat in the Winter - Spring crop and the Summer crop as well as the total annual heat have increased; (ii) The amount of time in a year with temperature below 20 degrees has shortened; the amount of time in a year with temperatures above 25 degrees has lengthened; (iii) the absolute minimum temperature tends to increase rapidly; (iv) the rainfall in Winter - Spring crop has increased slightly whereas the season rainfall and total annual rainfall tend to decrease. The climatic factors in Son La province obviously affect rice yield in the Winter - Spring crop, the Summer crop as well as corn and soybeans. However, compared with other crops, soybean yield is less related to climatic factors. There are major differences in climate characteristics between the high and the low crops yield year. However, these differences depend on the type of the crop and the harvest season. Keywords: climate change, climate indicator, crop yields, Son La. 1. INTRODUCTION Along with agricultural land loss due to sea level rise, climate change also greatly affects the farming sector through many impacts (rising temperatures, precipitation change and the occurrence of extreme weather phenomenon, etc.) [1, 2, 3]. this change not only .