BACKGROUND : Estimation of soil nitrogen supply is essential to manage nitrogen fertilization in arable land. In Korea, nitrogen fertilizer is recommended according to range of soil organic matter because it is difficult to assess nitrogen mineralization of upland soils. The objective of this study was to confirm the relation of soil organic matter content and nitrogen mineralization.
METHODS AND RESULTS : Soil samples from the 0 to 10 cm depth were collected from 18 individual pepper cultivated fields in Tae-an and Chung-yang province before fertilization. Nitrogen mineralization in the soils was quantified using incubation for 70 days at 30℃. The mineralizable soil nitrogen(MSN) was positively correlated with soil organic matter(SOM), and the relation equation betweeen MSN and SOM was‘MSN(kg 10a-1) = 0.2933*SOM(g kg-1) + 0.7475 (r2=0.6224)’. However, the differences of nitrogen mineralization among the soils belong to the same range of soil organic matter were about 3 to 4.6 times.
CONCLUSION : We concluded that soil organic matter could not reflect soil nitrogen supply to recommend nitrogen fertilization. Therefore, soil properties and labile organic matter should be considered to improve the nitrogen fertilization in arable land for sustainable agriculture.