Research On Nutrient Status Of Tobacco-planting Soil And New Fertilizer Application Technology In Luliang

Fertilizer management was of great significance in the flue-cured tobacco production, Wood peat and sophora alopecuroides L liquid fertilizer were tested for easing obstruction factor of tobacco-planting on the basis of investigating and analyzing the nutrient status of tobacco-planting soil in Luliang county. Their influence on tobacco growth and quality were researched to make a comprehensive evaluation of field application and provid scientific basis for local flue-cured tobacco fertilizer management. The results were as follow:(1) Soil nutrition of Luliang tobacco-growing area had low variation in space. The pH, alkali-hydrolyzable N were at an appropriate level, available P, available K, available Zn and available B content were low, organic matter and available Mg content were high coparetivaly, while water-soluble Cl content were at a high level.The pH of tobacco-growing soil in Xiaobaihu was low, Longhai was high in alkali-hydrolyzable N content.The SFI (soil fertility suitability index) in different towns was:Xiaobaihu> Huoshui> Zhongshu> Damogu> Fanghua> Majie> Banqiao> Longhai> Zhaokua.It varied from 0.547 to 0.623 with mean of 0.592. The proportion of soil fertility grades Ⅰ-Ⅳ in Luliang were 15%,57.06%,24.12%,3.82% respectively and there was no soil graded V. Huoshui had the highest percentage of grade I (35.14%) while Zhaokua had the lowest (4.00%)(2) Woody peat could improve physicochemical characters of tobacco-planting soil, and the woody peat treatment had a higher increase at the content of organic matter, available N, available P and available K than single fertilizer treatment. In addition, woody peat was advantageous to the growth of tobacco at early time, but high amount of fertilizer was disadvantageous to the yellowing and maturity of tobacco leaves. Woody peat could improve the agronomic trait of tobacco and had a significant effect to plant height, stem girth and leaf area. Woody peat increased the weight and density of tobacco leaves, while decreased stem content markedly, it increased the availability of tobacco leaves to a certain degree, but the equilibrium moisture content of leaves was lower than that of the single fertilizer treatment. The woody peat treatment could increase the production of tobacco and the proportion of superior tobacco, the production of tobacco of low amount treatment (300kg/hm2),middle amount treatment (600kg/hm2) and large amount treatment (900kg/hm2) increased 5.58%,9.19% and 10.35% than single fertilizer treatment respectively. But the large amount treatment had a lower proportion of superior tobacco compared with the middle amount treatment. Woody peat could increase the total sugar, reducing sugar and total nitrogen content of tobacco leaves, but decreased the content of nicotine and chlorine, and the potassium content of tobacco increased with the increase of fertilizer amount. The grey relational grade of tobacco chemical composition suitability were middle amount> low amount> contrast> high amount treatment, it indicated that woody peat treatment could enhance the availability of tobacco leaves to a certain degree, but excess woody peat will be against the improvement of tobacco quality. Taken together, the tobacco of middle amount fertilizer treatment had better chemical and physical characters than others,the appropriate amount of woody peat was 400kg/hm2.(3) Sophora alopecuroides L liquid fertilizer is advantageous to the growth of tobacco plant, root fertilizer could promote the growth of tobacco at early time,while leaf fertilizer had an obvious effect on the growth of tobacco in middle and later period. Sophora alopecuroides L liquid fertilizer could decrease the occurrence rate of insect diseases and increase the SPAD of tobacco leaves at early time significantly, while SPAD of liquid fertilizer treatment were lower than the contrast,which was good for leaves’yellowing. The physical properties of tobacco leaves of liquid fertilizer treatment was better than single fertilizer treatment, the weight of leaf was heavier, the density was bigger and the stem ratio was lower, but the moisture content was lower compared to the contrast. The production of tobacco dealed with leaf fertilizer, root fertilizer and the combined treatment increased 4.88%,6.70% and 8.42% than CK respectively, and the proportion of superior tobacco increased 4.63%,2.01% and 5.41% respectively. Liquid fertilizer could increase the total sugar, reducing sugar, potassium content of tobacco leaves significantly, while decrease the content of total nitrogen, nicotine and chlorine. In addition, sophora alopecuroides L liquid fertilizer could increase the polyphenols and pigment content of tobacco leaves significantly. The tobacco leaves fertilized with liquid fertilizer had better maturity and color compared with the contrast and the grey relational grade of tobacco chemical composition suitability were combined fertilizer treatment> leaf fertilizer treatment> root fertilizer treatment> CK,thereinto the combined fertilizer treatment had best characters,while leaf treatment had better performance than root fertilizer treatment,it indicated that sophora alopecuroides L liquid fertilizer could improve the quality and enhanced the availability of tobacco to a certain degree.