Effect Of Oyster Shell Powder On Adjusting Soil PH And Controlling Tobacco Bacterial Wilt

Soil is the basic condition for the survival of crops,and its quality directly affects the growth and development of crops and the formation of yield and quality.According to statistics,China’s acidified soil area reaches 200 million hectares,accounting for about 23%of the country’s total area.The pH of most acidified soil is mostly below 5.5,and the serious pH is even less than 4.5,and the degree and area of such acidification are still increasing.Soil acidification has caused continuous deterioration of land quality,which has become a major problem facing China’s intensive agricultural production.Soil acidification not only promotes the loss of nutrients in the soil,but also increases the solubility of various metals and heavy metal compounds in the soil.The harm of elements to the environment.Soil acidification breeds pathogenic bacteria,making rhizosphere diseases more difficult and difficult to control,especially cruciferous root swollen diseases and solanaceous vegetable bacterial wilt and verticillium wilt.The study found that the soil pH range of tobacco bacterial wilt disease is 4.5⁵.5,and Ralstonia solanacearum still grows well under the rich medium condition of pH 4.5⁵.5.The soil pH has an effect on the occurrence of tobacco bacterial wilt important influence,through the application of soil amendments to adjust the pH of the soil can effectively regulate the occurrence of bacterial wilt.In this paper,by studying the effects of oyster shell powder and other four materials on soil physical and chemical properties and tobacco growth and development,from the perspective of soil pH and other soil physical and chemical properties,the feasibility of oyster shell powder as a soil acidification modifier was confirmed;From the perspective of soil pH,the control effect of oyster shell powder on tobacco bacterial wilt was studied,and the characteristics of oyster shell powder as a new soil acidification improved material were clarified.Continue to carry out in-depth research on oyster shell powder,clarify the effect of different amounts of oyster shell powder on soil pH,tobacco growth and development,and control of tobacco bacterial wilt disease.Rhizosphere micro-ecological mechanism,and finally systematically evaluated the demonstration application effect of oyster shell powder in the field.The main findings are as follows:1.Clarified the effect of soil acidification modifiers such as oyster shell powder on soil pH and its effect as an acidification modifier.Through indoor and field soil cultivation experiments,the evaluation of four soil acidification modifiers of silicon fertilizer,potassium fulvic acid,oyster shell powder and quicklime showed that oyster shell powder had the best improvement effect on acidified soil.Compared with the control treatment,the oyster shell powder treatment（1 g/kg）increased the soil pH value by 0.72 and 0.69units on the 35th day and the 95th day respectively.;under field soil culture,the soil pH value under the treatment of 1500 kg·hm^-2 oyster shell powder on the 20th and 65th days of cultivation was higher than that of the control treatment.1.15 and 0.93 units,cultivated to the 80th day,compared with the control treatment,the content of exchangeable hydrogen ions and aluminum ions in the soil were reduced by 0.21 cmol/kg,3.05 cmol/kg,soil exchangeable calcium ions and exchangeability Magnesium ion content increased by 322.49 mg/kg and 15.40 mg/kg,soil total potassium,total phosphorus and available potassium increased by 0.79 g/kg,0.17 g/kg and 113.17 mg/kg,available copper and available boron content respectively Increased 1.95 mg/kg and 1.07 mg/kg,respectively.2.Clarified the effect of soil acidification modifiers such as oyster shell powder on soil pH and its effect as an acidification modifier.Through indoor and field improvement of acidified soil and tobacco cultivation experiments,it was found that oyster shell powder can not only increase soil pH and improve soil acidification,but also have a certain impact on the growth of tobacco and the occurrence of tobacco bacterial wilt;As the application rate increases,the acid-adjusting effect on the soil gradually increases.Laboratory experiments show that the addition of 0.1%oyster shell powder can significantly increase the fresh weight of tobacco above ground by 1.933 g,increase the soil pH value by 0.85 units（cultivation to32 d）,and reduce the soil exchangeable acid content by 0.42 cmol/kg（cultivated to 32 days）,effective control of tobacco bacterial wilt（relative control effect up to 53.25%）;field trials in Chongqing and Sichuan show that applying 1500 kg/hm² oyster shell powder treatment can not only increase soil pH（It has increased by 0.67 and 0.68 units,respectively）.It can also improve tobacco agronomic traits and have a better control effect on tobacco bacterial wilt（relative control effects are53.97%and 57.38%,respectively）.3.The effects of different amounts of oyster shell powder on the microbial metabolic activity of tobacco rhizosphere soil and community composition were analyzed.After clarifying the effect of oyster shell powder improved acidification on tobacco bacterial wilt,Biolog ECO and 16S rRNA high-throughput sequencing technology were used to analyze the metabolic activity of oyster shell powder application on tobacco microbial soil carbon source metabolism and Influence of the diversity of soil microbial structure.Biolog ECO plate observation showed that the application of oyster shell powder to acidic soil can increase the metabolic activity of soil microorganisms,but with the increase of the application amount,the carbon source metabolic capacity of soil microorganisms will gradually decrease;16S rRNA high-throughput sequencing found that the oyster shell powder treatment can significantly increase the relative abundance of Nitrospira in the soil,the treatment of 1500 kg/hm² oyster shell powder significantly increased the abundance and diversity of bacteria in the rhizosphere soil of tobacco,and Significantly increased the relative abundance of rhizobacteria Pseudomonas.The relative abundance of fungi（Ralstonia solanacearum）has no significant effect;it indicates that the improved acidified soil of oyster shell powder can improve the metabolic activity of tobacco rhizosphere soil microorganisms and the richness and diversity of bacteria,so that the soil environment and tobacco growth remain healthy,so as to achieve Prevention and control of tobacco bacterial wilt.In summary,oyster shell powder can be used as an improved material for soil acidification.The recommended concentration in the field is 1500 kg/hm².4.Demonstration application of using oyster shell powder to adjust soil pH to control tobacco bacterial wilt has achieved obvious results.Demonstration application of 100 acres of tobacco area in the Pengshui Runxi base unit by using oyster shell powder to improve acid soil technology.The results showed that oyster shell powder acidification improvement combined with soil microecological regulation can promote tobacco growth and development,the growth period is about one week earlier;effectively increase the soil pH value by 1.0 unit,and alleviate the impact of soil acidification during tobacco growth period;delay tobacco bacterial wilt The onset time was more than 10 days,reducing the incidence of tobacco bacterial wilt,and the relative control effect in the mid-harvest period was 67.55%;the yield value of tobacco leaves was significantly increased,and the yield of tobacco leaves in the control area was 143.38 kg/667 m²,which was higher than the control area of 12.26 kg/667 m²,the output value is 3623.21 yuan/667 m²,higher than the control area 417.70 yuan/667 m²,and the comprehensive results show that the technology has application value and promotion value.