主要作物施肥適量試驗(二)甘藷施肥適量試驗

Abstract

本試驗係于民國四十年起至民國四十二年止，分別就全省選定八處舉行。三年之試驗成績結果如下： (1) 肥料處理對辦甘藷莖葉及塊根之影響 氯之施用對甘藷莖葉之增收率最顯著，在坐標上產量對施肥量幾乎成為直線型，並不因過多肥料之施用而降下。對塊根之產量則有一較低的限度。雖依地方而異，一般在60公斤/公頃時可得最高收量，其對無氮區之增產率為20~30%。因此過多氮之施用僅有甘藷蔓之繁茂而對塊根之增產無補於事。燐之施用對甘藷莖葉之收量影響最少。對塊根之收量則除臺北、臺中、臺南、高雄四地區在50公斤施用量時對無燐區之增收率有10至20%外，其他地區均不顯著。鉀之施用對於甘藷藷葉之增收亦無顯著之效果。對於塊根之收量則平均在170公斤/公頃的施用量時有20至30%之增收率。故充分使用鉀肥以提高產量可認為非常重要。 Optimum fertilizer application rate is a basic knowledge on fertilizing technics. Since 1950, Society of soil scientists and fertilizer technologists of Taiwan designed a 5 years plan to determine those values of ten main crops in this province. The foregoing report on rice and wheat has been made to meet the neccessity on this field. Experiments on sweet-potato is designed accordingly to those crops. Five levels in each elements, namely, N from 0 to 120 kg/ha, P2O5 from 0 to 100 kg/ha and K2O from 0 to 200 kg/ha were combined to make 16 treatments and were placed on 8 localities where we expected to he representative on this crop area. Feild experiments were commenced from 1951 and ended in 1954.