Studies on the Denitrification in the Submerged Paddy Soil -II. The Denitrification Rates Upon Kinds of Applied Organic Matter and Levels of Nitrogen Fertilizer

논토양(土壤)의 탈질작용(脫窒作用)에 관(關)한 연구(硏究) -제(第)II보(報). 유기물(有機物)의 종류(種類) 및 질소시비량차이(窒素施肥量差異)가 탈질(脫窒)에 미치는 영향(影響)

A laboratory experiment was conducted to find out the denitrification rate upon the levels of nitrogen and source of organic matter in submerged sandy and sandy loam soil. The results obtained were sumarized as follows; 1. Evolution of nitrous oxide was increased at 1st and 10 days after incubation. And dinitrogen was increased at 1st and 30 days after incubation. Applications of green manure was enhanced the evolution of nitrous oxide ($N_2O$) and dinitrogen ($N_2$). 2. The cumulative denitrification rates at 50 days was high in Gyuam sandy loam soil (O-M: 1.52%) than that of Hamchang sandy soil (O-M: 3.81%). On the other hand, the cumulative emission of dinitrogen was high in Gyuam sandy loam soil while nitrous oxide was high in Hamchang sandy soil. The total mount of denitrification rate was high in order of green manure > rice straw > compost > control soil. 3. Increases of fertilizer nitrogen was enhanced the rate of emission of dinitrogen and nitrous oxide during the incubation time. 4. According to Michaelis-Menten kinetic equation, denitrification rates and reaction efficiency were remarkably increased by application of readily decomposable organic matter with in higher organic matter content of soil. 5. The negative relationship was observed between the evolution of dinitrogen and carbon ($CO_2+CH_4$) while the nitrous oxide with carbon was positive. 6. Under the this experiment conditions 1 mg of carbon was required for production of 4 mg N as $N_2O$ and 3 mg of N as $N_2$, respectively.

1. 항온기간중(恒溫期間中) $N_2O$의 경시적(徑時的) 발생량(發生量)은 항온(恒溫) 1일(日)과 10일경(日傾) 그리고 $N_2$의 발생량(發生量)은 1일(日)과 30일경(日傾)에 많았다. 2. 토양유기물함량별(土壤有機物含量別) 탈질량(脫窒量)은 현저(顯著)한 차이(差異)를 보이지 않았으며 시용유기물간(施用有機物間)에는 녹비(綠肥)>볏짚>퇴비(堆肥)>무시용(無施用)의 순서(順序)로 높았다. 3. 질소시비량(窒素施肥量)이 증가(增加)할수록 탈질량(脫窒量)은 증가(增加)되었으나 토양간(土壤間)에는 뚜렷한 차이(差異)가 없었음. 4. 탈질반응속도(脫秩反應速度)(계수(係數))는 토양유기물함량(土壤有機物含量)이 많고 역분해성유기물(易分解性有機物)을 시용(施用)할수록 증가(增加)되었음. 5. 토양중(土壤中) 탄소발생량(炭素發生量)과 탈질량(脫窒量)과의 관계(關係)에서 아산화질소(亞酸化窒素)는 정상관(正相關) 그리고 분자상질소(分子狀窒素)는 부상관관계(負相關關係)를 보였음. 6. 탄소(炭素) 1 mg이 소모(消耗)될때 약 4 mg의 $N_2O$와 3 mg의 $N_2$가 생성되었음.