Studies on the Suitable Paddy Soil for Application of Rice Straw

볏짚시용(施用)을 위한 답토양(畓土壤) 적지시험(適地試驗)에 관(關)한 연구(硏究)

The suitable paddy soil for application of rice straw under well to moderately well drained soil, the yield and yield components were pronounced more than poorly drained soil. Based on laboratory experiment, application of rice straw promoted the decrease of oxidation-reduction potential in well to moderately well drained soil. This results seems to be enhanced the release of some mineral nutrients such as calcium, potassium, silicon, and increases of availability of soil phosphorus. This explains reason why soil condition became more favorable for the increases of mineral nutrient in rice plant. On the contrary, poorly drained soils, became readily reduced even without application or rice straw, when soil wat submerged. Application of rice straw did not promoted the decrease of oxidation-reduction potential as much as in well drained soil. It was suggested that in this type of soil series, the release of mineral nutrients and the additional increase of available soil phosphorus did not proceed well. It was also suggested that the retardation of root development owing to accumulation of toxic substances such as organic acid, hydrogen sulfide or some other reducing substances formed by the application of rice straw in poorly drained soil series might be considered. In fact, the effect of rice straw on the yield of brown rice became lower.

볏짚시용적지(施用適地)를 구명(究明)하기 위하여 전국(全國) 17개(個) 농가포장(農家圃場)과 현지(現地) 포장토양(圃場土壤)을 채취(採取) 실내(室內)에서 항온시험(恒溫試驗)한 결과(結果) 포장(圃場)에서는 배수양호(排水良好)하며 볏짚을 시용(施用)하므로써 토양환원(土壤還元) 발달(發達)이 무시용구(無施用區)보다 높은 토양(土壤)에서 수도수량(水稻收量) 및 수량구성요소(收量構成要素)가 증가(增加)되었다. 실내(室內) 시험(試驗)에서는 배수양호(排水良好)하며 볏짚시용(施用)으로 환원발달(還元發達)이 양호(良好)한 토양(土壤)에서 규산(珪酸), 가리(加里), 석회(石灰) 등(等)의 유효양분(有效養分)이 증가(增加)되었으며 또한 토양중(土壤中) 인산(燐酸)의 유효도(有效度)와 토양환원발달(土壤還元發達)과는 정상관(正相關) 관계(關係)를 보였다. 그러나 배수불량(排水不良)하며 볏짚을 시용(施用)하더라도 무시용구(無施用區)와 환원발달차(還元發達差)가 현저(顯著)하지 못한 답토양(畓土壤)에서는 토양(土壤) 무기성분(無機成分) 및 인산(燐酸)의 유효도(有效度) 증가(增加)는 현저(顯著)하지 못하였다. 이상(以上)의 결과(結果) 볏짚시용(施用) 적지(適地) 선정(選定)시는 토양(土壤)의 배수정도(排水程度)와 토양환원(土壤還元) 발달정도(發達程度)를 기초(基礎)로 실시(實施)되어야 할 것으로 생각된다.