Flue-cured Tobacco In The Rotation Cycle Of The Nutrient Cycles And Integrated Technology Of Fertilizer

This research focuses on the four cropping systems of flue-cured tobacco-free, flue-cured tobacco-rape, flue-cured tobacco-wheat and flue-cured tobacco-ryegrass as the object of study. By studying the different influence of previous crops before transplanting soil nutrient contents of flue-cured tobacco. And the spatio-temporal dynamic change of soil nutrient under different rotations. And tobacco plant of different rotation handles on the law of absorption and distribution of nitrogen, phosphorus and potassium nutrients. Further master the flue-cured tobacco under different rotations in the life cycle of nutrient cycles. On this basis, combined with the climatic conditions, soil fertility in Guiyang tobacco-growing areas, such as, for flue-cured tobacco in different rotations put forward reasonable fertilization programme.1.Growth of different previous crops on soil nutrient content in flue-cured tobacco before transplanting to produce certain effects. In addition to flue-cured tobacco-free processing of organic matter and available nitrogen contents in the soil did not change, but the other three deals have increased and added 47.13 g.kg-1、38.81 g.kg-1、40.24 g.kg-1and 19.8mg.kg-1、25.2mg.kg-1、4.2 mg.kg-1. Four processing of soil available phosphorus and available potassium contents did not change significantly.2.Throughout the growing period of tobacco, different crop rotation will produce different effects on soil nutrients of shape and number. With the advance of flue-cured tobacco growth period, four kinds of crop rotation on soil nitrate- nitrogen and ammonium-nitrogen, available phosphorus and potassium with fertilization time showing a variation of the first increases and then decreases, but available phosphorus and potassium content basically unchanged in flue-cured tobacco transplant before and after harvest. There are differences of soil inorganic nitrogen in four deals and processing performance is flue-cured tobacco-free ﹥ flue-cured tobacco-wheat ﹥ flue-cured tobacco-rape﹥ flue-cured tobacco-ryegrass, and available phosphorus and available potassium contents is not obvious. At different depths in the soil, nitrate-nitrogen and ammonium-nitrogen, phosphorus and potassium contents has the same pattern. With the soil depth increasing(0-80cm), the content gradually decreased. Content of topsoil have certain differences, but 20-80 cm of the soil content have no difference.3.Four rotations in flue-cured tobacco throughout the growing cycle, because of different previous crops, the nitrogen cycle is showed different patterns. In terms of nitrogen input, due to the influence of previous crops, under the same fertilizer, there are certain differences of soil nitrogen mineralization and initial nitrogen content in four kinds of crop rotation. The deal of flue-cured tobacco-free has the highest initial nitrogen content. In the whole growth period of flue-cured tobacco, flue-cured tobacco-ryegrass handles has the largest number of the total amount of nitrogen mineralization, followed by flue-cured tobacco-free and flue-cured tobacco-wheat, flue-cured tobacco-rape at least. Due to the different previous crops, the input of the total nitrogen have the different contents. Then causes the differences of the absorption of nitrogen content, amount of ammonia volatilization, leaching of soil volume and residues, and other losses. In terms of nitrogen output, flue-cured tobacco-rape treatment of tobacco plants has absorbed the highest nitrogen, followed by flue-cured tobacco-free and flue-cured tobacco-ryegrass, and no significant difference between the two, flue-cured tobacco-wheat processing at least, only 76.07kg·hm-2.In terms of total ammonia volatilization and leaching, in addition to treatment of flue-cured tobacco-ryegrass, the other three deals have the less difference, and also have a more volatile and less leaching patterns. On the amount of residual nitrogen, flue-cured tobacco-rape has the residue at least. Other three deals than it does and flue-cured tobacco-free treatment 14.07kg·hm-2.more tobacco than flue-cured tobacco-rape. Four rotations in other ways on the losses and volatile ammonia losses makes little difference, and has input of nitrogen 3.34%-4.85%. Processing performance is flue-cured tobacco-free > flue-cured tobacco-ryegrass > flue-cured tobacco and wheat > flue-cured tobacco-rape. Phosphorus and potassium cycle of flue-cured tobacco throughout the growing cycle in four rotations is basically the same. Phosphorus and potassium in soil have large surpluses and lead to them are relatively stable in the soil.4.Four rotations absorb nitrogen and potassium mainly in seeding period and vigorous period. Phosphorus uptake throughout the whole growth period. In the whole growth period, tobacco plants absorbed nitrogen mainly from the soil. The percent of soil nitrogen in total nitrogen content with the increase of growth stages and the promote of leaf position increased significantly. On the distribution of nitrogen, phosphorus and potassium, the distribution of three elements all is leaf﹥stem﹥root. After removing the top of tobacco, there are certain shifts of nitrogen and potassium, and cause redistribution of them. At budding period, flue-cured tobacco leaf nitrogen accumulation in the various parts are as follows: middle leaf > lower leaf > upper leaf and the mature period are as follows: upper leaf > Middle leaf > lower leaf. After removing the top of tobacco, its potassium content of leaf and whole plant is reduced and the potassium content in the stem and root is increase. Most evident change especially in the upper leaves, reduced proportion of entire plant potassium respectively is 1.35%, 6.64%, 6.03%and 4.22% at mature period of the four rotation handles. Due to the less percent of phosphorus in the plant, it does not change significantly.5.Considering the appearance of plant growth, dry matter accumulation and the chemical content of tobacco leaves and their coordination on the indicator and the production value, flue-cured tobacco-free rotation and flue-cured tobacco-rape rotation choose k fertilization program first, and A fertilization plan is the preferred choice for flue-cured tobacco-wheat rotation and flue-cured tobacco-ryegrass rotation prefer B fertilization scheme.