Effect Of Processing With Sand Adding And Transplanting Stage On Soil Ecological Characters Of Tobacco-growing Area In Ankang City

In order to explore the rational soil improvement measures and tobacco transplantingprogram of tobacco-growing areas, to maximize the use of natural soil conditions of thetobacco-growing areas, In this study, Yunyan97was used as the test species, A randomizedblock experiment was carried out in the tobacco growing areas of Ankang City, ShaanxiProvince. We design the mixed sand treatment respectively (Not mixed with sand, sand mixedwith10%,20%,30%,40%) and transplanting period of treatment (On April30, May5,10,15,20), biological indicators, physical index and chemical index of soil were measured after theharvest, and the Soil micro ecological characteristics, physical properties and nutrient changecharacteristic under different mixed sand treatment and transplanting stage treatment wereanalyzed. The results show that:1）The total number of soil microorganisms in the non-sand processing area is the largest.Under the same sand treatment, the number of bacteria is the largest, following actinomycetes,fungi at least. The number change tendency of the bacteria, actinomycetes and fungi underdifferent mixed sand treatment is different. But the number remained the largest undernon-sand treatment. The soil respiration intensity of sand mixed with20%is the highest. Andthe difference reached significant levels. The soil invertase, urease and catalase activity ofsand mixed with10%were the highest, as well as the soil phosphatase activity.2）The performance of Soil water retention under mixed sand treatment is: Sand mixedwith sand20%>10%> not mixed with sand> sand mixed by30%>40%. The waterretention capacity of soil is the best under sand mixed with20%treatment. After more than20%with the increase of mixed sediment soil water retention ability become weak gradually.The soil bulk density is between1.499and1.674g/cm3under different mixing sandprocessing. Soil bulk density is a bit on the high side. But the soil bulk density is minimummixed sand20%minimum treatment.3）The soil pH value mainly concentrated between7.32and7.62under different mixingsand processing. It is belong to the neuter slightly alkaline. The effect of different mixed sandtreatment on tobacco-growing zone soil nutrient characteristics is: Sand mixed with sand20%or10%under the treatment of various nutrient contents were higher. Non mix with sandfollowed, Sand mixed with30%and40%treatment is lower. And under the sand mixed withsand and30%to40%processing soil nutrient content are showing a sharp decline. Thisillustrates the mixed sand amount must not exceed30%. From the test results, sand mixed with20%or10%has practical reference value for soil improvement. Consideringcomprehensively,20%mixed sand has more advantages.4）The total number of soil microorganisms under transplanting treatment on May10isthe largest. And under the same transplanting treatment, the number of bacteria is the highest,and actinomycetes followed, the number of fungi is the lowest. The number of soil bacteriaunder different transplanting process is the highest on May10. The respiration intensity ofsoil under different transplanting process on May10is the strongest, which is6.80μg/(g·h),extremely significant difference between with other processing, is higher as a whole undertransplanting process on May10, soil respiration intensity is also stronger. The processingfollowed on May15, May5. The soil enzyme activity on April30, on May20is the weakest.5） Water retention capacity of soil under different transplanting processing istransplanting on May10> May15>May5>April30>May20, soil water retention ability oftransplanting process on May10is stronger. It became weaker on May15and May5, andweakest on April30and May20. That too early or too late transplanting has large effects onsoil water retention. The soil bulk density under different tobacco transplanting period isbetween1.38and1.46. It belongs to the good soil structure as a whole. But it is slightly highviscosity, soil texture under the influence of the different transplanting stage are all loamyclay.6）Tobacco soil pH is mainly between7.37and7.53under the influence of the differenttransplanting periods. It basically belongs to the neutral soil and is suitable for tobacco growth.Tobacco’s maximum utilization value of soil nitrogen, phosphorus and potassium nutrientappears in the May15or May10transplanting. The utilization rate of soil organic matter invarious transplanting period is relatively similar. As the delay of transplanting period,Tobacco’s use of soil total nitrogen, total phosphorus, total potassium, available nitrogen,available phosphorus and available potassium utilization first increased and then decreased.The use peak occurred on May10, or May.15.Analyzing on a comprehensive basic, Ankang tobacco-growing areas of soil improvedsolution is mixed sand with20%, the biological activity of soil is the strongest under mix sandwith20%treatment. The physical structure is suitable for the growth of tobacco and nutrientholding capacity. The biological activity is strong when transplanting between May10andMay15. Physical properties such as soil moisture, bulk density achieves the best. Tobacco’ssoil nutrient utilization ability is also strong. This is a relatively appropriate transplantingperiod in this area.