Study On The Influence Factors Of N Release Of The Biochar-based Nitrogen Fertilizer

Good pore structure made biochar had the strong ability of adsorption and oxidation resistance.Biochar as slow control material combined with ammonium nitrate, not only could delay the release rate of nitrogen, also could effectively reduced the loss of soil nutrients. It could also provide some nutrient for plants growth after applied into the soil. In this paper, we used maize straw biochar (YJC) and artemisia sphaerocephala krasch biochar (SHC) as the material, and studied the influence of different carbon materials, manufacturing process and conditions and the environment condition on N release through the way of mixed granulation and adsorption granulation.Then to evaluate the effect through immersion experiment, soil column leaching experiment and soil nutrient release experiments. The results are as follows:(1) The properties of the biochar was influenced by material type and carbonization temperature. The microstructure of maize straw biochar and artemisia sphaerocephala krasch biochar were destroyed, C, P, K and ash content increased, N, H content was lower, pH and specific surface area increased, effective NPK content with the increase of carbonization temperature. The content of each element and physical and chemical properties of two kinds of biochar were obvious difference under the same carbonization temperature, the microporous structure of maize straw biochar was damaged by high temperature, and its specific surface area and total entrance and average pore diameter and pH were greater than the artemisia sphaerocephala krasch biochar, while the content of C was less than that the artemisia sphaerocephala krasch biochar.(2) Immersion experiment and soil column leaching experiment showed that, Artemisia sphaerocephala krasch biochar (600℃) adsorption fertilizer cit3 and 50% maize straw biochar (600 ℃) mixed fertilizer were the best. Wallpaper glue for optimum binder, and with the ratio of 1:10 to biochar.(3) Soil nutrient release experiments show that, the nutrient release speed was accelerated along with the increase of soil water content. The effects of environmental temperature on fertilizer nutrient release rate was not that clear and needs further research. Fertilizer nutrient released faster when the soil pH value was 7.