Characteristics of nitrogen mineralization of maize stalk in lime concretion black soil.
The processes and characteristics of nitrogen mineralization in lime concretion black soil in the north of the Huai River of Anhui Province were studied with an interval leached aerial incubation at various temperature(10℃,20℃ and 30℃) and different C/N ratios.The results showed that soil nitrogen net mineralized amount increased as the extension of incubation time under different treatments,while under the same C/N ratios condition it increased with the temperature rising.The result was analyzed with non-linear regression procedure of SPSS software indicated that three models(one-pool model,two-pool model and special model) could significantly fit the experimental data.The soil nitrogen mineralization potential No and nitrogen mineralization rate constant Ko was calculated from one-pool model,and affected by different temperature and C/N ratios.The nitrogen mineralization potential No increased with the increasing of temperature,while under the same condition of incubation temperature,No would be increased with the increasing of C/N ratios.There were close relationships between Ko and C/N ratios,while under the same temperature condition the C/N ratios increased but Ko decreased.Both the two-pool model and special model fitted the the experimental data better than one-pool model suggested that it would be more reasonable and practical to divide the organic nitrogen pool into easily decomposable plant materials Na and resistant plant materials Nr.Nr was deeply affected by temperature,and its value decreased from higher temperature to lower temperature.