Study On The Application Of Biochar In Organic And Inorganic Compound Fertilizers

Fertilizer is one of the most important factors in grain yield increasing,but the high application rate and low fertilizer use efficiency become the serious problems which limited agricultural development in China.Organic fertilizer can increase soil organic matter content and improve soil physical properties.Therefore,the Chinese Ministry of Agriculture puts forward the application of organic fertilizer to improve soil fertility and increase crop yield.But the production technology of organic fertilizer is backward,as well as the composting cycle is long,the nitrogen loss and the greenhouse gases emission,these become the serious problems in organic fertilizer production.Biochar is produced from agricultural straw waste under relatively low temperature and limitation of oxygen,because of its loosen structure,higher porosity and specific surface area,and the adsorption characteristics for the nutrients,it showed that biochar had been used in many fields in agriculture production.Researchers found that biochar application to livestock and poultry waste composting could adjust the pile structure,promote the composting process,reduce the loss of nitrogen in compost and reduce greenhouse gases emission.But it still lack the effect of biochar on nitrogen transformation during compost.In addition,the biochar based compound fertilizer,which made of biochar and chemical fertilizers,was found can increase the content of organic matter in soil,improve soil physical pore structure,prolong the release time of fertilizer and improve the fertilizer use efficiency,but the field experimental on biochar based fertilizer is rarely reported.Therefore,in this paper we studied the effects of biochar on nitrogen transformation and greenhouse gas emissions in compost,and explored the effects of biochar based fertilizer on crop yield and fertilizer use efficiency.The main results were as follows:(1)the addition of biochar significantly improved the temperature of the stack and shorten the maturity time of compost,in which 15%biochar treatment can reach the high temperature period 3 days ahead of the control.(2)the pH value of swine manure stack will increase significantly with time going on,the addition of biochar can reduce the increase range of pH.With the increase of biochar application rate,the dissolved organic carbon content of the heap was decreased gradually.The addition of biochar significantly decreased the dissolved organic carbon content by 23.3%-52.3%and 16.9%-21.3%before and after composting,but there was no significant difference between different biochar rate.(3)biochar addition significantly increased the content of NH4+-N and NO3--N during compost,and biochar significantly increase the content of NH4+-N and NO3--N during the high temperature period.The 10%and 15%biochar treatment could significantly reduce ammonia volatilization by 68.6%?78.4%,and the percentage of NH3 emission in total nitrogen was reduced by 5.5%-7.4%during composting process.(4)biochar based fertilizer in crop production can ensure crop yield,and at the same time reduce the amount of fertilizer input,which have the potential to reduce fertilizer input in agriculture production.