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

Received: February 1, 2017 Revised: February 22, 2017 Accepted: February 28, 2017 In this study, we evaluated the nitrogen (N) mineralization potential and Nitrogen use efficiency (NUE) of oil-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 treatment with a value of 18.9 mg N 100 g -1 , followed by oil-cake, barley and compost. The amount of pure N mineralization potentials in hairy vetch, oil-cake, barley and compost treatments were 8.42, 7.62, 3.82 and 3.60 mg N 100 g -1 , respectively. The half-life (t1/2) of organic N in soil amended with oil-cake fertilizer mineralized quickly in 17 days. While, t1/2 values of organic N for the compost and barley treatments accounted to 44.4 and 44.1 days, respectively. Oil-cake was good in supplying nutrients to plants. Compost and barley inhibited plant growth in the beginning growth stage and this is attributed to N immobilization effect. The results of this study highlight that compost and barley could be used as potential slow release fertilizers in conventional agriculture.