Potential Nitrogen Mineralization and Availability in Upland Soil Amended with Various Organic Materials

Abstract

In this study, we evaluated the nitrogen (N) mineralization potential and Nitrogen use efficiency (NUE) ofoil-cake, compost, hairy vetch and barley, which are the most widely used organic amendments in South Korea. The N mineralization potential (No) for organic fertilizers treated soil was highest for the hairy vetch treatmentwith a value of 18.9 mg N 100 g-1, followed by oil-cake, barley and compost. The amount of pure Nmineralization potentials in hairy vetch, oil-cake, barley and compost treatments were 8.42, 7.62, 3.82 and 3.60mg N 100 g-1, respectively. The half-life (t1/2) of organic N in soil amended with oil-cake fertilizer mineralizedquickly in 17 days. While, t1/2 values of organic N for the compost and barley treatments accounted to 44.4 and44.1 days, respectively. Oil-cake was good in supplying nutrients to plants. Compost and barley inhibited plantgrowth in the beginning growth stage and this is attributed to N immobilization effect. The results of this studyhighlight that compost and barley could be used as potential slow release fertilizers in conventional agriculture.