Abstract
Organic fertilizers application has become a popular alternatives to reduce the dependence on chemical fertilizer in Korean farming systems. In this study, we evaluated the nitrogen (N) use efficiency and growth performance of Chinese cabbage grown by black vinyl mulching after application of organic and chemical fertilizers compared with no-mulching. The treatments included chemical fertilizer alone as control (NPK, N-$P_2O_5-K_2O$ : $320-78-198kg\;ha^{-1}$), organic fertilizer alone (OF100), 70% organic fertilizer and 30% chemical fertilizer (OF70+N30), and 30% organic fertilizer and 70% chemical fertilizer (OF30+N70), which were all applied in the no-mulching plots and in plots with black vinyl mulching. Daily means soil temperature was $2^{\circ}C$ higher in the black vinyl mulched treatments throughout the 54 days compared with no-mulched treatments. OF100 with black vinyl mulching gave highest soil inorganic N content. Also, Chines cabbage yield increased 46% by black vinyl mulched compared with no-mulching in OF100 treatment. Without mulching, N use efficiency was, 44, 26, 29, and 27% in NPK, OF100, OF70+N30, and OF30+N70, respectively. However, black vinyl mulching much more effectively increased N use efficiencies by 56, 55, 51, and 39% in the same treatments in the order as mentioned above. Conclusively, combined organic and chemical fertilizers application with black vinyl mulching could be good practical technique to reduce a amount of used nitrogen because of its greater ability to enhance N use efficiency.
화학비료 사용량을 줄이고 화학비료를 대체할 수 있는 유기질비료 사용효과를 조사하기 위해 배추의 생육 및 질소 이용효과를 평가하였다. 처리는 배추재배의 NPK 표준시비구 ($N-P_2O_5-K_2O$ : $320-78-198kg\;ha^{-1}$)를 비롯하여, NPK 시비구의 질소시비량을 기준한 유기질 100% (OF100), 유기질70%+질소30% (OF70+N30), 유기질30%+질소70% (OF30+N70) 처리하였고, 비닐 멀칭효과를 분석하고자 동일 처리구에 각각 비멀칭과 흑색비닐멀칭재배를 실시하였다. 배추 재배기간동안 지온을 조사한 결과, 흑색비닐멀칭이 비멀칭재배에 비해 일일 평균 $2^{\circ}C$ 높았다. 토양 중 무기태질소함량은 OF100 처리구가 가장 높았으며, 배추수량도 OF100 처리구에서 흑색비닐멀칭구가 비멀칭구에 비해 46% 증가하였다. 질소이용율은 비멀칭 재배시 NPK 처리구 44%, OF100구는 26%, OF70+N30구는 21%, OF30+N70구는 27%이었고, 흑색비닐멀칭 재배시 NPK처리구는 56%, OF100구는 55%, OF70+N30구는 51%, OF30+N70은 39%의 질소이용율 각각 나타내었다. 따라서 유기질비료와 화학비료를 병용하고 흑색비닐 멀칭을 실시하면 질소 이용율을 높임으로서 비료를 절감을 할 수 있는 방법 중 하나라고 판단되었다.
