The Dynamic Change Of Tobacco Rhizosphere Soil Nutrients And Microbial In Tobacco Growing Period

In this paper the Yellow soil (dryland tobacco) and Paddy soil (paddy tobacco) were for the study,there were planted Yunyan 97, Yunyan 105, NC71. Yunyan 99 and K326 five varieties of tobacco. Researched the dynamic variation of tobacco rhizosphere soil nutrients and microbial under different soil conditions, and between different tobacco varieties the differences of nutrient uptake, to grasp the ecological adaptability of tobacco varieties under the different soil conditions, provided scientific basis for tobacco planting. After transplanting tobacco collected rhizosphere soil five times, Rhizosphere soil macronutrients, in the amount of elements, trace elements and microorganisms were determined. The main conclusions were as follows:(1) Under different soil conditions, pH took on decreasing after taking on increasing trends, Organic matter and nitrogen to increase after the first drop, Phosphorus and potassium as "down-up-down". pH after transplanting 60d appears valley. The organic matter, nitrogen, phosphorus and potassium peaked at 60d, two kinds of soil rhizosphere soil organic matter, nitrogen and available phosphorus content less, Yellow soil pH was higher than the Paddy soil. Growth period Yunyan 105 rhizosphere soil pH, organic matter, nitrogen and potassium were high, K326 rhizosphere soil phosphorus was significantly (p<0.05) lower than the other four varieties.(2) Under different soil conditions rhizosphere soil exchangeable Ca, exchangeable Mg and available S, were tested effective "down-up-down" trend, and they got to peak value after transplanting in 60d. Yellow soil exchangeable Ca content than Paddy soil, the exchangeable Mg and available S. lower than paddy soil. K326 high rhizosphere soil exchangeable Ca content, Yunyan 99 low exchangeable Ca content, NC71. higher rhizosphere soil exchangeable Mg, Yunyan 99, high rhizosphere soil available S. In Yellow soil the Ca/Mg is 27, in Paddy the Ca/Mg is 19, Yellow soil more prone to the phenomenon of Mg deficiency.(3) Under different soil conditions, the tobacco rhizosphere available Fe took on "up-down-up" trends, in Paddy soil after transplanting in 60d reached the valley, in Yellow soil after transplanting in 60d reached a peak value. The available Mn, it took on "down- up -down" trend, and got to peak value after transplanting in 60d. The available Cu and Zn in paddy soil took on "up-down-up". In the Yellow soil they took on increasing trend at first, and after transplanting they got to peak value. Paddy soil available Fe, Mn, Cu content is higher than the Yellow soil, the available Fe high content of Yellow soil is 2.13 times. K326 rhizosphere soil trace elements were lower than other varieties, having a strong resistance of fertilizer. NC71 and Yunyan 99 rhizosphere effective higher available Mn content, Yunyan 97 hizosphere effective higher available Cu content, Yunyan 99 and NC71 hizosphere effective higher available Zn content.(4) In two soils showed the number of microorganisms were Bacteria> Actinomycetes> Fungi.Under different soil conditions the tested tobacco rhizosphere microbes took on increasing trend and then decreasing trend, and the number of Bacteria of rhizosphere soil increased great after transplanting in 20-40d.While Fungi and Actinomycetes in the sharp rise 40-60d after transplanting, after transplanting got to peak in 60d. There were different number of microorganisms in two soils, the number of Bacteria in Paddy soil> Yellow soil, the number of Fungi in Paddy soil> Yellow soil, the number of actinomycetes in Yellow soil> Paddy soil. The number of Bacteria in K326 and NC71 in rhizosphere soil more, the same as Yunyan 99. The number of Fungi Yunyan 105 less, the number of Actinomycetes in K326 and NC71 more.In summary, different soil nutrients with the growth performance of different tobacco law, and under different soil conditions are different manifestations, however, different varieties of tobacco absorption rule for the same elements are substantially identical. Yellow soil contains more actinomycetes than Paddy soil, the available Fe content in Paddy soil iron ultrahigh appears stressed. By comparing different tobacco varieties soil nutrient content and microbial quantity variation, the test considered growing tobacco in Paddy soil is superior to Luzhou yellow soil for, K326 and NC71 rhizosphere nutrient more appropriate than the Yunyan 97, and the more number of Bacteria and Bctinomycetes microbiological composition, it can be considered as an alternative to tobacco variety Yunyan 97.