Studies on the Mechanization of Rice Culture. Effect of Date and Rate of Seeding and Fertilization on the Growth of Rice Seedling

수도작(水稻作) 기계화(機械化)에 관(關)한 조사연구(調査硏究) (육묘시기(育苗時期), 파종밀도(播種密度) 및 비료용량(肥料用量)이 수도상자묘(水稻箱子苗)의 성장(成長)에 미치는 영향(影響))

The study was conducted to investigate an optimum growing condition for various sizes of seedlings of rice for mechanical transplantation under different sowing rates, different levels of fertilizers, different sowing dates and g rowing days. The plant height, leaf number and dry weight of seedlings increased as the sowing rate decreased and amount of fertilizer applied were increased. Also those seedling characters increased as the rice planted late and the total growing periods increased. The factors affected seedling chracters were ordered as following-sowing times>growing days>sowing rate>fertilizer levels. 200 gr. of seeds per box and 4 gr. of fertilizers were optimum for young seedling growth, when sown early. For medium size of seed ling growth, 50 grams and 100 to 125 grams of rice seemed to be adequate for 25 days old and 35 days old seedling, respectively. However, the 45 days old seedling grew too mach and were not suitable for mechanical transplantation. When planted late, similar results were obtained with more differences among treatments. In other words, the suitable plant density was obtained when 100 gr. of seeds were planted per box. Middle class of seedlings were obtained when 100 to 150 gr. of rice were planted per box and grown for 25 days. The seedlings from the box with 100 to 150 gr. of rice per box were over grown and ratio of suitable seedling was also low if they were grown over 35 days.

수도상자육묘(水稻箱子育苗)에 있어서 이상적(理想的)인 치묘(稚苗)와 중묘(中苗) 그리고 성묘(成苗)의 육성(育成)에 알맞은 재배조건(栽培條件)을 구명(究明)하고져 파종밀도(播種密度)와 비료용량(肥料用量), 육묘(育苗)의 시기(時期)와 일수(日數)의 영향(影響)을 분석(分析)한바, 파종량(播種量)은 적을수록, 시비량(施肥量)은 많을수록, 만파(晩播)일수록, 육묘기간(育苗期間)이 연장(延長)될수록 초장(草長), 엽수(葉數) 및 건물중(乾物重)은 증대(增大)하였는데 그 영향(影響)은 파종기(播種期)>육묘일수(育苗日數)>파종밀도(播種密度)>시비량(施肥量)의 순(順)으로 컸으며 조기파종시(早期播種時)에는 상자당(箱子當) 200g의 파종량(播種量)과 4g까지의 시비량하(施肥量下)에서 알맞은 치묘육성(稚苗育成)이 가능(可能)하였고 적당(適當)한 중묘(中苗)는 25일간(日間)의 육묘시(育苗時)에는 50g의 박파(薄播)에서, 그리고 35일묘(日苗)에서는 100~125g 범위(範圍)의 파종밀도하(播種密度下)에서 육성가능(育成可能)하나 45일묘(日苗)는 지나치게 웃자라 기계이앙용(機械移秧用)으로는 부적당(不適當)하였다. 만파시(晩播時)에도 같은 경향(傾向)이나 처리간차이(處理間差異)가 확대(擴大)되었으며 치묘(稚苗)는 상자당(箱子當) 100g 이하(以下)의 박파조건(薄播條件)에서 육성가능(育成可能)하였고 100내지(乃至) 150g의 파종밀도(播種密度)에 25일간(日間) 육묘(育苗)하므로서 알맞은 중묘(中苗)를 얻을 수 있었으나 35일(日) 이상(以上) 육묘일수(育苗日數)를 연장(延長)하면 지나치게 생장(生長)하거나 도장(徒長)하였고 성묘비율(成苗比率)도 현저(顯著)히 저하(低下)하였다.