Charcoal-base polyaspartic acid slow-release urea as well as preparation method and application thereof

The invention provides charcoal-base polyaspartic acid slow-release urea. The preparation method comprises the steps of 1) charring agricultural waste which is taken as a biomass raw material at 400-600 DEG C to obtain porous charcoal particles; 2) carrying out a reaction between urea and formaldehyde to obtain a modified urea solution; 3) adding polyaspartic acid and derivative thereof to the modified urea solution; 4) soaking the charcoal particles in the mixing solution obtained from the step 3) for 3-10 hours, and drying the soaked charcoal particles; 5) implementing a reaction between starch and a sodium hypochlorite solution to obtain an oxidized starch solution which serves as a binder; and 6) adding the dried charcoal particles to the binder, pelleting and drying to obtain the charcoal-base polyaspartic acid slow-release urea. The preparation method disclosed by the invention is low in cost, and can relieve conversion from NH4+-N to NO3--N, inhibit rapid decomposition and loss of the urea, prolong fertilizer efficiency, improve nitrogen use efficiency and relieve non-point source pollution; results of field experiments show that the slow-release urea product disclosed by the invention can effectively increase both production and income, and can achieve a yield-increasing effect under a circumstance of reducing application of fertilizer.