The Effects of Organic Materials on Yield and N Use Efficiency of Organic Rice Grown under Frequent Heavy Rains

Abstract

BACKGROUND:This study was conducted to investigate growth and yield of organically grown rice under a typhoon during a fall. The treatments included NPK chemical fertilizer, compost, oilcake, oilcake 2X, hairyvetch, and vetch+rye. METHODS AND RESULTS: Nutrient applications were made at rates equivalent to approximately 0.9 kg of actual N per acre. Oilcake and hairyvetch treatments had the lowest C:N ratio, but compost had the highest C:N ratio of 34:1. Rice treated by organic nutrient sources had great growth and development at the beginning of the growing season but had depressed growth and yield at the harvest. Oilcake 2X-treated rice in early growing season, especially, showed better growth and development than rice treated by other nutrient sources but was severely lodged at the harvest season due to the typhoon. Compost treatment with high C:N ratio slowly released inorganic N and produced poor rice growth and yield; however, it recued rice lodging. N uptake was the greatest for the oilcake 2X and vetch+rye treatments but the lowest for the compost, which was the similar pattern to the N use efficiency; the greatest and lowest N use efficiency was observed for the oilcake 2X

Effects of Continuous Use of Organic Materials on Watermelon (Citrullus vulgaris Schrad.) Yield and Soil Chemistry in Plastic Film House

“…유기농업은 무기질비료와 화학농약 등을 사용하지 않고 유기농업자재를 사용하여 작물을 재배하는 농업이고, 우 리나라는 1990년대 후반 이후 활발한 연구가 수행되었다 (Kim et al, 1998;Lee et al, 1999;Jeon et al, 2003;Cho et al, 2011). 유기농업은 관행농업에 비해 병해충방제와 제초작업 등 많은 노동력과 값비싼 유기농업자재가 투입되기 때문에 농가는 영농비용 증가로 어려움을 겪고 있다 (Sung and Jung, 2015).…”