Study On The Optimal Irrigation Schedule Of Tobacoo In The Different Ecotype Tobacoo Area Of Hubei Province

As a kind of mainl economic crop which consumes amount of water, tobacco needs a lot of irrigation water, and its production meets great challenge because of water resource scare and durative drought. There is great inconsistency between traditional irrigation method and water resource scare. The region of planting tobacco is abroad in china.It is impossible to make optimal irrigation pattern for every tobacco planting zone. Therefore, it is important to partition area of planting tobacco where the weather is similar and optimize water resource distribution reasonably in order to make it realization that limit water can be distributed with reasonably at the different growth stage of tobacco to get maximum economic benefit. After analyzing tobacco agricultural climate region partition and optimal irrigation schedule, researches below are carried out:(1) According to theory of similar climate in a range of region, 13 kinds of climate material for 40 year from 1961 to 2000 in Hubei province are analyzed in the cluster analysis method with SPSS. 27 tobacco planting zone in Hubei province are divided into 6 different ecotype tobacco planting region, and their characteristics of climate are analyzed.(2) Water requirement at different growth stages in different ecotype tobacco planting region are calculated with formula of Penman-Monteith and crop coefficient(Kc) . The result shows that the precision is fine to calculate with the formula of Penman-Monteith and outcome could be used to tobacco production. By analyzing frequency of net irrigation water supply, water requirement and effect rainfall of tobacco growth stage in moderate year (50%) , medium dry year (75%) and dry year (95%) were confirmed.(3) Combined with material of tobacco water-saving irrigation experiment in Hubei Enshi County, the variable rule about sensitive index of tobacco water product function and expression of crop water product function are researched, and tobacco irrigation schedule optimization mode is made up with method of successive approximation. Optimal irrigation schedule in different typical year of tobacco for different ecostyle region in Hubei are calculated with computer program. The results suggest that optimal irrigation schedule can do well in solving the problem of water-supplying short in tobacco growth and water resource distribution in tobacco growth stage, improving the production of tobacco and increasing economic efficient.