Hydrolysis of Urea and Its Reaction Rate Constants in Sandy Clay Loam Soils

An incubation experiment was conducted at Water Technology Centre, Tamil Nadu Agricultural University, Coimbatore during 2011, to study the hydrolysis and reaction rate constants of urea in sandy clay loam soil. The different concentration of urea was used with constant moisture and temperature. The values for K_HU, (hydrolysis rate constant) observed were 0.014, 0.0134, 0.0139, and 0.0140 h⁻¹ for 1.582, 3.71, 37.04, and 55.55 (mg N/cm³), respectively. The K_D, (distribution rate coefficient) values observed were 0.0138, 0.03465, 0.03386, and 0.0139 h⁻¹ for 1.582, 3.71, 37.04, and 55.55 (mg N/cm³), respectively. K_V, volatilization coefficient values observed were 0.0070, 0.0078, 0.0083 and 0.0071 hr⁻¹for the ureaN concentrations of 1.582, 3.71, 37.04, and 55.55 (mg N/cm³), respectively. And the K_N, nitrification rate constant values were 0.0076, 0.0074, 0.0074 and 0.0077 h⁻¹ for 1.582, 3.71, 37.04, and 55.55(mg N/cm³), of ureadoses respectively