| Biogas slurry is the residual liquid methane fermentation, not only rich in a large number of water-soluble nitrogen, phosphorus and potassium available nutrients, but also contains amino acids, trace elements, vitamins and other nutrients. Biogas slurry application in agricultural production more widely, will be applied to improve soil fertility for production, regulating plant growth and improve the quality of agricultural products has played a positive role. With growing concern for the quality of agricultural products and to attach great importance to environmental pollution, slurry of heavy metals are toxic heavy metals in particular will be important to evaluate the quality and safety indicators, the same time, by the stench of anaerobic fermentation slurry Pungent odor such as use of biogas slurry as a fertilizer to promote the use of the drawbacks to be solved. Therefore, as the scale of rural biogas project the continuous development of biogas in the safe handling and use of resources of concern.This paper aims to study the effect of adding waste molasses and different microbial agents in slurry to get rid of stench pungent odor and ameliorate available nutrients of the soil on livestock farm, the action of adding gray Streptomyces waste mycelium in slurry for adsorption of cadmium Cd。Reasearch of the influence of slurry mixed with bacteria to five crop yield such as cotton, cabbage, soybeans, beans and potato, in order to provide a theoretical basis for its application in agricultural production.The main results as follows:1. The contents of organic matter, total nitrogen, total phosphorus, total potassium in original slurry were 1270mg/L,971.1mg/L,69.3mg/L,293.2mg/L, indicating that the content of nutrients was low. The content of copper, lead and cadmium in original slurry were 0.324 mg/L,0.304 mg/L,0.108 mg/L, and, Nemerow index of integrated pollution was 0.287<1, illustrating the test slurry was not contaminated, single factor analysis for heavy metal pollutants shows that the other two heavy metals exceeded the standards of irrigation water quality except copper.2. Optimal adsorption conditions of waste streptomyces mycelium were determined: 2.5g adsorption material/100mL slurry; pH value 5; adsorption time 24h; adsorption temperature 28℃.3. The slurry supplemented with one of the bacteria such as Bacillus subtilis, Bacillus licheniformis, Bacillus pumilus can weaken its pungent odor; moreover, adding waste molasses with mass volume ratio of 1% to 10% along with Bacillus can effectively remove its pungent odor.4. Study on the influence of microbial slurry to available nutrients of the soil showed that:employing microbial slurry and blank slurry is superior to bacteria liqid for improving available nutrients (nitrogen, phosphorus), and, applying microbial slurry is better than applying blank slurry to improve available nutrients (Nitrogen, phosphorus and potassium). With the increasing time, the content of available nutrients in the soil was increasing gradually. Application of microbial slurry and blank slurry for improving the extent of each available nutrients in the soil were:nitrogen> potassium> phosphorus, and 20 times dilution> 50 times dilution. The effect of 5 different microbial slurry were: Photosynthetic bacteria slurry> Bacillus licheniformis slurry> Bacillus pumilus slurry> Bacillus subtilis slurry> Lactobacillus slurry> blank slurry. Optimal conditions for the application:the test slurry was fermented by photosynthetic bacteria, then diluted to 20 times and applied to loam, the fourth week (28d), available N, P and K were individually increased by 38.89%,32.4% and 18.3%.5. Application of microbial slurry mixed with photosynthetic bacteria and Bacillus licheniformis can increase the crop yields of cotton, beans, potatoes, cabbage, and, different dilution ratio can increase more than 5%, and 40-fold dilution is the best, in which potatoes, cabbage, soybean production increased up to 28.21%,20.61%,22.81%. |
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