유기질 비료 급원이 배 과원의 토양 물리화학성 및 미생물성에 미치는 영향

Abstract

본 연구는 유기농 배 과원에서 2년간 시용한 여러 종류의 유기질 퇴비와 화학비료에 따른 시기별 토양 물리화학성 및 미생물성에 미치는 영향을 구명하고자 수행하였다. 대조구는 NPK 화학비료를 시용한 처리구를 선정하였고 유기질 비료는 유박과 휴믹산 그리고 키틴퇴비를 포함하였다. 모든 처리구는 질소성분량 200 g/나무 양으로 동일시해서 2008년부터 2009년까지 2년간 매해 3월 30일에 수관주위에 산포 처리하였다. 토양 물리성은 처리구간에 별다른 영향이 없었다. 5월과 8월에 조사된 토양 유기물과 전질소 그리고 칼륨, 칼슘, 마그네슘 농도는 유기질 비료 처리구에서 일반적으로 대조구보다 높게 나타났고 유기질 비료간에 일관성 있는 효과가 나타나지 않았다. <TEX>${\beta}$</TEX>-glucosidase를 제외하고 미생물 생체량 탄소와 질소, dehydrogenase, acid-phosphatase, 그리고 chitinase활성은 시기별로 증가하는 경향을 보였다. 8월 조사에서 유기질 비료인 유박과 키틴퇴비는 대조구보다 높은 미생물 활성이 나타났다. BACKGROUND: This study was conducted to investigate the effects of different organic treatments and a chemical fertilizer on the soil chemical, physical, and microbial properties in an organic pear orchard. METHODS AND RESULTS: Control was referred as a NPK chemical fertilizer (15N-9P-10K) and organic treatments included compost containing with oil cake, compost containing with humic acid, and compost containing with chitin substance. All treatments applied at rates equivalent to 200 g N per tree per year under the tree canopy in March 30 of 2008 and 2009. Soil bulk density, solid phase, liquid phase, and penetration resistance were not significantly different among the treatments. Organic treatment plots had greater organic matter, total nitrogen, potassium, and magnesium concentrations compared to control, and the nutrient concentrations were not consistently affected by the organic treatments. Microbial biomass nitrogen and carbon, dehydrogenase, acid-phosphatase, and chitinase activities overall increased from March to August. Organic treatments, especially compost containing with oil cake or chitin aicd, increased the microbial variables compared to control. CONCLUSION(s): All the organic treatments consistently stimulated soil biological activity. The consistent treatment effect, however, did not occur on the soil mineral nutrition as the trees actively taken up the nutrients during a growing season, which would have diminished treatment effects. Long-term study required for evaluating soil physical properties in a pear orchard.