Trials Of Biochar Based Fertilizer Production And Evaluation

The problem with ordinary fertilizer is leaching loss of nutrient and low usage rate of fertilizer,while the application of biochar as slow release material has adopted special physicochemical properties of biochar,such as high porosity and large specific surface area,which prepares the biochar slow release fertilizer by combining biochar with common fertilizer via fertilizer preparation processes,such as extrusion molding,coating and granulation,reducing leaching loss of nutrient and improving usage rate of fertilizer.Meanwhile,as for the soil acidification in hot-zone mentioned above,the addition of biochar in fertilizer plays a very positive role in increasing the pH of soil and enhancing the capacity of soil to absorb nutriments.In the present study,char fertilizers with different biochar contents are prepared by means of a variety of fertilizer preparation processes,and the slow release effect and soil reclamation effect thereof are evaluated through soil column leaching method and soil constant-temperature cultivation.1.In soil column leaching tests,the fertilizer sticks was added 0,10%,20%,and 30%of the biochar treatment,nitrogen and potassium cumulative leaching rates were:53.19%,59.95%,58.70%,57.92%and 52.38%,59.06%,60.74%,60.49%after the end of the 12 times leaching,the gap is not obvious among the treatments,but with the increase in the compressive strength of the fertilizer rod raw material and the amount of biochar reduced,and the correlation was significant,the sustained-release fertilizer with the rod and increase the compressive strength enhancement,it is added to the release effect biochar fertilizer nutrients will be reduced due to the compressive strength of the fertilizer rod caused by the effect of accelerated release overshadowed.2.The use of biochar as a coated material can efficiently reduce the leaching loss of Nitrogen in urea,and throughout the leaching period,in comparison with controlled treatments,treatments with the amount of the biochar used of 10%,20%,30%decrease by 13.68%,21.75%,36.5%of the cumulative elution rate for nutrient,respectively,which shows that the slow release effects are enhanced with the increase of the amount of the biomass used,and the optimal slow release effects occur when said amount is 30%.3.The addition of biochar can efficiently reduce the leaching loss of Nitrogen and Potassium in a compound fertilizer.In the leaching test,in comparison with controlled treatments,treatments with the amount of the biochar used of 10%,20%,30%decrease by 3.40%?9.19%?30.42%of the cumulative elution rate for nitrogen;and decreasing by 5.15%?5.29%?10.40%of the cumulative elution rate for potassium.the slow release effects are enhanced with the increase of the amount of the biochar used,and the compound fertilizer has the optimal slow release effect and the most stable release rate when the amount of the biochar used is 30%.4.After the addition of biochar,the alkaline fertilizer has a significant effect on improving pH and CEC of soil which is vitally different from controlled experiments.After applying an alkaline fertilizer and cultivating the soil under constant temperature,the pH of the soil is increased with the extending of cultivation time in the first five samples and tends to stabilize afterwards,and the CEC of the soil is increased with the extending of cultivation time in the first three samples and tends to stabilize afterwards.After the cultivation is finished,in comparison with controlled experiments,treatments with the amount of the biochar used of 10%,20%,30%increase by 0.51,0.99,1.49 in the pH of the soil,respectively,and increase by 0.77 cmol/kg,1.67 cmol/kg,2.38 cmol/kg in the CEC of the soil,respectively,which indicates that the improvement effect of biochar on soil is enhanced with the increase of the amount of the biochar used,and said effect is optimal when said amount is 30%.