不耕起栽培の評価 ＩＩＩ 作物収量と投入エネルギー

Abstract

We analysed the both direct and indirect energy input to the field with the data of fuel consumption and crop yield from a serial experiments on successive no-tillage farming for seven years.1) The average yield of dent corn in no-tillage plot(NT) was about 88% of that in conventional tillage plot(CT). The yield of turnip in NT was almost as same as that in CT. The both yield of barley and wheat in NT after six years were extreamly poorer then those in CT.2) From the yieid of dent corn, the duration of six years was thought as practical successive limits in no-tillage farming.3) The ratio of energy output/direct energy input was calculated with the yield obtained from our experiments for seven years. The average ratio for three crops in NT were 2-3 times as large as those in CT.4) As production energy of herbicide was generally large, energy input in NT was equivalent to 64% of that in CT for the processes before seeding, and 84% of that in CT for all processes, respectively.The difference of energy input between CT and NT including both direct and indirect energy was smaller than that including direct energy only.