| Contraposing the situation of lacking water seriously in the early growth period of flue-cured tobacco,small leaves,lacking in oil and low output of the flue-cured tobacco in Jinsha River Dry-hot valley area,in Panzhihua city,Sichuan province,an experiment was carried out,which was rain-collecting and water-saving irrigation and postponing transplant time of the flue-cured tobacco in the Panshen tobacco farm in 2006-2007.Through the experiment,we have obtained the following conclusion.1.According to the local planting customs,the flue-cured tobacco was transplanted at the beginning of May,but the rainfall is scarce at that time.Therefore,the experiment of postponing transplant was carried out,which postponed transplant time approached before the rainy season(at the beginning of June).The field experiments indicated that postponing transplanting time to the beginning of June and the plenteous bunch irrigation might promote the growth of tobacco in early period.The growth quantity was bigger and more vigorous obviously,the recovery time only retards about 7 days,at the end of September or the beginning of October,this climatic conditions still conformed to the sound tobacco plucking and roasting request,compared with no postponing transplant,the output in this study achieved 2523.6 kg/hm~2,the value of output achieved 20768 yuan/hm~2.The output and value was 215% and 245%respectively comparing with the convention transplants.2.In order to obtain the system of saving water irrigation,the bunch irrigation experiment was carried out,which supposed 4 treatments,3 iterance,the amount of bunching irrigation in each treatment was 8.25,16.5,24.75,33 m~3/hm~2 respectively.The experiment indicated that this experimental irrigation amount is not remarkable to soil moisture's influence,the field soil moisture is mainly influenced by the rainfall,evaporation as well as the flue-cured tobacco growth.The growth periods were affected a little by bunching irrigation with different water amount.The treatment 2 was biggest in the height and stem encircles of flue-cured tobacco,and treatment 1 was the smallest.In the period of mature,the dry matter of flue-cured tobacco and the dry weight of leaves were displayed as treatment 3＞2＞4＞1.The distribution ratio in root,stem,leaves was1:2:7.The treatment 3 was biggest in the area of leaves.The change tendency of leaf area index of flue-cured tobacco assumed to "S" under different water amount by bunching irrigation.It was remarkably different in output of tobacco,the treatment 3 was biggest and treatment 1 was smallest.By bunching irrigation with 24.75 m~3/hm~2 every time could be the fittest irrigation norm which could get best economic benefit in the flue-cured tobacco production.3.Analyzing the monitor data of soil moisture content and the rainfall evaporation material,the rule of consuming water of the flue-cured tobacco was researched by the water budget method.Daily average water consumption in each treatment was higher in prosperous long-term and the mature period,but the water consumption intensity of the seedling and rosette stage was slightly smaller.Under the different irrigation treatments,the flue-cured tobacco entire period of duration water consumption and the output assumed the conic section line relations.4.The experiment indicated that through constructing the reservoir and collecting the rainfall runoff fully,could solve the problem of lacking water efficiently when flue-cured tobacco transplanted.By bunching irrigation with it,could enhance the survival rate and output of the flue-cured tobacco,and increase the economic efficiency obviously.Caculating as 26 m~3 stored water by each small reservoir, then each reservoir might supply 1.53 hm~2 of flue-cured tobacco to irrigate when transplanted,the ratio of the input and output was 1:5.5;If also bunch irrigatiton twice at the seedling stage,and the amount of irrigation was 24.75 m~3/hm~2 each time,then might irrigate 0.4 hm~2,the ratio of the input and output was 1:2.3.
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