| The objective of this paper were to study the change of soil after land leveling,to find out the key factors affecting productivity,and to explore a rapid recovery technology to improve land productivity after land leveling.Changes of nutrient elements and its influence on yield and quality of flue-cured tobacco were studied,with the smooth land soil in Fenggang county as an example.The main results are as follows:(1)On the whole,the content of soil available phosphorus and available potassium in Fenggang modern tobacco agriculture demonstration garden was low.The soil analysis showed that soil nitrogen content of 16.09-187.67mg/kg with an average of 95.93±36.63 mg/kg,22.2% of soil sample with nitrogen content lower than 65mg/kg and 47.3% of soil sample with nitrogen content higher than 100mg/kg.The content of available potassium in soil is 24.32-363.73mg/kg with an average of 97.74mg/kg.Among the all samples,the soil samples with extreme deficiency,deficiency,moderate and abundant available potassium accounted for 45.01%,41.03%,10.55% and 3.42%,respectively.On the whole,the content of available K in soil is low.The content of available phosphorus in soil is 0.00-66.10mg/kg with an average of 14.32mg/kg.Among the all samples,the soil samples with deficiency,moderate and abundant available phosphorus accounted for 48.1%,41.03%,30.2% and 21.7%,respectively.On the whole,the content of available P in soil is relative low.(2)The proportion of demand for three kinds of fertilizers was different for each period of flue-cured tobacco growth,and the dry matter accumulation of different flue-cured tobacco was significant.With the increase of nitrogen application rate,the dry matter accumulation of tobacco plants increased gradually,the amount of dry matter is higher than that of non-applying fertilizer(treatment 6)),The highest accumulation of dry matter was treated with 270 kg of potash fertilizer.The yield of 5(105kgN/hm2)was the highest,and the yield of 5 tobacco leaves was increased by 1137Yuan/hm2 less than that of non-nitrogen treatment(treatment 2).Under different application rates,6(90kgP2O5/(405kgK2O/acre)yield the highest output value,and the output value of treatment 11 was increased by 5148 yuan per mu less than that of applying potassium fertilizer(treatment 7).It can be seen that the effect of potash on the economic traits of flue-cured tobacco is the most significant,and the appropriate increase of potash fertilizer can increase the economic output of flue-cured tobacco.(3)Acidic soils can effectively improve the pH of the soil after adjustment with limestone.The change in soil acidity varies depending on the amount of limestone used.At the beginning of the application of lime,the soil pH increased rapidly,the greater the application rate,the greater the increase;in lime application 2 to 30 days,the soil pH changes slowly and stabilize,the pH of the basic are the first increase the soil pH did not change significantly after 30 days.(4)The amount of lime identification from the agronomic traits,flue-cured tobacco biomass,flue-cured tobacco production to determine the three indicators.Lime directly improves the acidity of the soil,and there is also some change in the improvement while exploring.In terms of agronomic traits,the amount of lime applied was 1500 kg/hm2,and the growth of tobacco was the best in the dome period.When the lime was higher than 1500 kg/hm2,the growth was significantly decreased.When the amount of lime applied is 1500 kg/hm2,the biomass of whole tobacco leaves is the best at maturity,and the output value is the highest.So the new flat tobacco planting soil suitable for the use of lime 1500 kg/hm2.(5)The best proportion of lime and organic fertilizer used together and which method of application is most suitable for the growth of flue-cured tobacco is of great value.Several kinds of common carbon-reinforced organic materials were selected for continuous years,and the dynamic changes of flue-cured tobacco and maize yield,soil organic matter,pH value,soil structure and microbes were monitored.The influence of agronomic traits,the stage and the dome period,the height of the plant height,the leaf length and the leaf width were the best for the agronomic traits of the organic fertilizer.The stem circumference needed the best combination of potassium and lime.The biomass of root and stem of flue-cured tobacco was the least in the blank treatment,but the biomass of flue-cured tobacco was higher.Overall,the treatment without lime is better than lime treatment.On the impact of yield on flue-cured tobacco production,the application of organic fertilizer treatment output value than when not much higher than in the application of potassium acid fertilizer treatment,the total yield of tobacco leaves higher. |
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