A Study On The Main Physical-chemical Characters Of Tobacco Soil And Fertilization Effects In Tobacco Farming Regions Of Nanping

By means of large size sampling(1067samples)and field experiments,this research present the evaluation of the nutrient statu and the obstructive factors against tobacco growing in tobacco farming regions of Nanping.Based on the data of experiments,the fertilization skill is put forward to overcome of those obstructive factors.The main results are as following:1.The average soil pH value of soil is 5.28±0.45 with Coefficient of variance(CV)of 8.52%.The soil area with suitable pH with value of 5.5～6.5 accounts for 29.09%,and 69.97%of soil pH value is less than 5.5.Therefore,pH value of most of the soil is lower than the basic requirement of producing the high quality tobacco.The average percentage of soil clay particles is situated in 38.15±8.00%with CV of 20.97%.There distributes most kinds of soil with exception of sandy soil in Nanping tobacco region,among them,.silt and light silt soil account for 55.55%and most of them have a medium quality meeting the needs of tobacco growing.2.The content of soil Organic Matter(OM)is quite plentiful for the whole area.The average OM content equals to 28.77±10.39 g/kg with CV of 36.11%,among which,32.22%with OM content of 20～30 g/kg and 44.22%with OM content over 30g/kg.While average soil nitrogen(N)content is 1.60±0.66g/kg with CV of 41.25%,48.96%of soil is be affluent in N content above 1.5g/kg for growing tobacco.Meanwhile,Average alkali-nitrogen content distributes 156.43±40.12 mg/kg with CV of 25.65%.Among them,52.43%of soil with alkali-nitrogen content more than 150 mg/kg,implying that the alkali-nitrogen content of Nanping area ranks in suitable to affluent level.3.Average phosphor(P)content of soil distributes 0.48±0.25 g/kg with CV of 52.08%,this figure is significant higher than that by the second soil investigation, however,there is still 61.95%of soil N content less than medium level,implying low level of the overall P pool in soil While,the fast efficient P content averages to 26.19±19.35 mg/kg with CV of 73.88%,such value is statistically over broad,but the fast efficient P content above＞20mg/kg is up to 48.96%,indicating the comparatively affluent P level in the area.4.The average total Potassium(K)content of soil comes up to 0.48±0.25g/kg with CV of 52.08%and 40.41%of soil with K content is less than 20 g/kg.The average tardo K content is situated 314.86±200.44mg/kg with with CV of 63.66%。Nearly 54.24%of soil tardo K content is less than 300mg/kg.The results above suggests that soil of whole region is lack of K for tobacco growing.The average efficient K content is up to 86.75±55.85 mg/kg with CV of 64.38%,and with nearly 86.23%of soil distributed with less than 150 mg/kg available K content,implying that low supply of K level has been one of main barrier factors for tobacco farming in Nanping.5.Most of soil is abound with exchangeable calcium(Ca).The average exchangeable Ca content of soil distributes 497.81±194.44 mg/kg with CV of 39.06% and 92.86%of soil with exchangeable Ca content comes up to over 400mg/kg.The average exchangeable Mg content of soil distributes 37.71±16.39 mg/kg with CV of 43.46%and 81.77%of soil with exchangeable Mg content is less than 50mg/kg.The lack of Mg content is quite normal in Nanping region.The average efficient S content of soil distributes 29.68±30.86 mg/kg with CV of 103.98%,showing that it has highly various S content with soil types,and fortunately,there is only 12.43%of soil within potential S deficient threshold,suggesting that S is not a deficient nutrient in the area The efficient Fe,Mn,Cu,Zn content amount to 51.86±32.34 mg/kg,13.37±11.96mg/kg,3.61±2.55mg/kg,3.09±1.86mg/kg,all are above the desired standard.Meanwhile,the average exchangeable B content of soil amounts to 0.20±0.14 mg/kg with CV of 70.00%and 90%of soil with efficient B content is less than standard level.The situation of B deficiency is serious in whole region.While, the average water-solubility Cl content of soil is up to 19.37±14.67 mg/kg with CV of 75.74%and 70.53%of soil with water-solubility Cl content is less than 20 mg/kg。6.The results from the experiment of pH regulation show that there is remarkable significant effects on tobacco yield per capita between using 100kg/667m² of Dolomite lime(DL)and its blank control with net production and economic value increase by 47.9kg and 394 Yuan per 667 m²,respectively.It also indicate that DL input can decrease N,P₂O₅,K₂O fertilizer by 2.5,2.5,5kg per 667m².7.The results from the experiment of N fertilizer utilization show that using 8.5 kg per 667m² tends to increase the yield and economic value with balance chemical composition in quality in medium fertile soil; meanwhile,nicotine and total N in leaf increase and both total and reductive sugar content decrease with amount of N used,it indicates that 10.5kg per 667m² of N fertilizer makes nicotine content of 3.5%in upper leaves of tobacco plant.8.The results from the experiment of N fertilizer utilization show that non and less P fertilizer utilization makes plant grow slow and growing period postponed delay,on the contrary,P fertilizer utilization can promote the plant and root grow and normalize the growing period.It suggests the highest economic outcome can be gained when the ratio of N:P₂O₅ of fertilization attains to 1:0.6～0.8.9.The results from the experiment of K fertilizer utilization show that increasing span of leaf K content expands with amount and percentage of K fertilizer used.It suggests the yield,economic value and tobacco quality attains to the highest degree when the ratio of N:K₂O of fertilization is 1:2.5～2.8.10.The results from the experiment of organic N(ON)percentage utilization show that the optimal organic N percentage in fertilization is 20%～30%,and the highest yield,economic value can be attained when treated with 20%ON in soil with lower efficient K content,both 20%and 30%ON used can harvest more tobacco leaves with the medium nicotine and balanced chemical content,but 30%ON used can also harvest higher percentage of tobacco leaves in good class.11.The results from the experiment of types and amount of Mg fertilizer utilization show that both MgO and Mg(OH)₂ used can attain better results than MgSO₄,in soil with lower Mg content(usually with Mg of 16.92mg/kg), among the treatments,the best plant growing can be attained when using 15kg per 667m² of Mg(OH)₂,moreover,economic value,percentage of tobacco leaves in good class and Mg content in leaves tend to increase with use of amount of Mg(OH)₂12.The results from the experiment of amount of B fertilizer utilization show that nicotine,total sugar and reductive sugar content decrease and leaves quality increases when using 1 kg per 667m² of B compared with its blank control13.The results from the experiment of amount of Cl fertilizer utilizat ion show that using 3 kg per 667m² of KCl can meet the physiological need of Cl for growing tobacco plant,improve the situation of low Cl content and balance the chemical composition,and in leaf,and thus increase the economic benefit of tobacco farming.