| With the continuous improvement of the economic level,the total demand for agricultural products,such as grain,meat,egg and milk in China has been rapidly increasing in the past few years.On the one hand,China has to adopt the agricultural operation mode of‘high input,high output,high pollution'to meet the food demand,while the method of long-term unreasonable fertilization leads to the decline of soil fertility.On the other hand,due to the improvement of living standards,people's consumption of meat,egg and milk will continue to increase for a long time,which has promoted the rapid development of the breeding industry,resulting in a large amount of agricultural organic solid waste.At present,the main means of dealing with livestock manure in China is to convert it into fertilizer,energy and feed.Among them,converting livestock manure into fertilizer is the most important and most economical means.However,the mineral nutrient content of bio-organic fertilizer is low,which needs to be combined with chemical fertilizer to achieve the best effect.However,problems may appear in the application of bio-organic fertilizer and chemical fertilizer:Inorganic nutrients in fertilizers,especially nitrogen,inhibit microorganisms in the soil during crop growth.The stratification of bio-organic fertilizer and chemical fertilizer during fertilizer application.The mixed storage of bio-organic fertilizer and chemical fertilizer leads to the problem of shortening the effective period.Based on the above problems,a bio-organic-inorganic compound fertilizer with the advantages of bio-organic fertilizer and chemical fertilizer is prepared by using resin coated urea and bio-organic fertilizer as raw materials.In the first part of the experiment,chicken manure and amino acid is used as raw materials,and EM liquid is used as fermentation agent to prepare bio-organic fertilizer.In the second part,bio-organic-inorganic compound fertilizer is prepared by using resin coated urea as carrier,bio-organic fertilizer as coating material and polyvinyl alcohol as binder.The controlled-release performance and storage period of bio-organic-inorganic compound fertilizer are determined by constant temperature extraction at25 C and dilution plate method,respectively.In the third part,the pot experiment of maize is used to preliminarily explore the comprehensive fertilizer effect.The main results are as follows:1.The optimum process conditions for the preparation of bio-organic-inorganic compound fertilizer by roller granulation method are heating temperature of 40°C and the addition ratio of polyvinyl alcohol is 1.5%.Under this process condition,the success rate of coating is 96.1%.2.After the completion of the fertilizer storage test,the number of living bacteria in bio-organic-inorganic compound fertilizer is 0.3723×10~8cfu/g(dry weight)exceeding the national standard of 0.2×10~8cfu/g.It can be initially determined that the production of bio-organic-inorganic compound fertilizer is feasible.3.The nitrogen release characteristics of bio-organic-inorganic compound fertilizer are studied by 25°C constant temperature extraction method and Kjeldahl method.The results show that the slow-release performance of bio-organic-inorganic compound fertilizer is lower than that of resin coated urea.Its fertilizer effective period is 21 days,which is 2 days shorter than that of resin coated urea.4.The fertilizer efficiency of bio-organic-inorganic compound fertilizer is studied by pot experiment of maize.Bio-organic-inorganic compound fertilizer treatment has better yield components than common urea treatment,and its yield is 15.41%higher than that of common urea treatment.Under the same yield conditions,the nitrogen input can be reduced by 20%. |
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