Study On Climatic Regionalization OfAlfalfa Based On Fall Dormancy In China

Alfalfa (Medicago sativa L.) has a developed root system, with the abilities of regeneration, drought and cold-tolerance, salinity, strong resistance and other characteristics. The suitable temperature for the growth of alfalfa is about25℃, and it performed well within the range of15-21℃. alfalfa can grow well in many different types of soil. It has a2,000years period of alfalfa planting history in China. In the traditional sense that the main growing areas are located in the Northwest, Northern China, the western mountainous areas of the Northeast, Shanxi, Shaanxi, Gansu, Xinjiang provinces and other regions.Experimental study found that alfalfa fall dormancy is closely related to its cold hardiness. This study aimed to explore the effect of meteorological factors on fall dormancy rating alfalfa autumn regeneration performance study area planted in Beijing meteorological factors in the relationship between fall dormancy rating of alfalfa varieties in autumn after cutting through the calculation of direct and indirect path coefficients, and residual effects come to the conclusion, accumulated temperature, Illumination time and precipitation three meteorological elements is are the three important factors for alfalfa fall dormancy, its degree of influence was in the order of in order to accumulated temperature> light precipitation volume.Based on the experimental results, on the basis of previous research results, combined with expert opinion, using the analytic hierarchy process (APP) to select the9climate factors were weight calculation, the annual precipitation, annual average temperature, sunshine duration, maximum temperature, minimum temperature, average relative humidity, is more than ODEG C. the average temperature, the hottest, the coldest month on average9Different Fall Dormancy Alfalfa regionalization climatic factors index weight values were:0.1659,0.1144,0.1659.0.0418,0.0768,0.0418,0.2748,0.0418,0.0768. In order to climate similarity theory as the basis, the use of fuzzy similarity priority ratio in the Hamming distance similarity priority ratio method, on the nationwide194site samples, different Fall Dormancy Alfalfa fall dormancy climatic division, followed by the basis can be guidance in different regions of China of Different Fall Dormancy Alfalfa introduction.The results showed that:in Northeast China, Inner Mongolia, northeastern and northern Xinjiang provinces, suitable for planting alfalfa fall dormancy rating of1-2; southwest of Inner Mongolia, northern Xinjiang, Gansu, Ningxia and Sichuan provinces in some areas suitable for planting alfalfa fall dormancy rating of4;,Tianjin, Hebei and northern Henan provinces and other areas suitable for planting fall dormancy rating of five varieties of alfalfa; China’s Shaanxi, Shanxi, Ningxia provinces and other parts of the most suitable for planting varieties of alfalfa fall dormancy rating of6-7; fall dormancy rating of8alfalfa varieties suitable for most of Henan, Shanxi, Shaanxi parts of planting; fall dormancy rating of9varieties of alfalfa planting of suitable areas in parts of Henan, Hubei, Shaanxi and Sichuan provinces.