A Study on Penetration of Pea Seedling Taproots as Influenced by strength of Soil

토양(土壤)의 경도(硬度)가 완두뿌리의 신장(伸長)에 미치는 영향(影響)

  • Accepted : 1977.02.25
  • Published : 1977.03.20

Abstract

This experiment was conducted in the laboratory in order to find out the relationships between the root growth and soil physical properties. The soils selected for this study were Sangju sandy loam, Yeongog loam, Hwadong silty clay loam, which have been considered to be a typical upland soils of Korea. Artificial core samples were made with various moisture contents and bulk densities. Elongation rate of pea seedling taproot and soil strength were measured respectively in these core samples. The results obtained are summarized as follows: 1. The soil strength increased with the bulk density and deceased with moisture content. 2. The correlation between root elongation and soil bulk density was significantly recognized at the same moisture content and the root elongation was influenced by the bulk density more significantly at dry condition. 3. The elongation rate of pea seedling taproot was significantly decreased by increasing the strength (Yamanaka tester and Fine probe) of the soils. 4. The soil strength of $21kg/cm^2$ in fine metal probe or 24mm in Yamanaka tester was considered to be the critical point for plant growth, which was restricting root elongation smaller than 1/4 of the maximum growth rate.

작물생육(作物生育)과 토양물리성(土壤物理性)과의 관계(關係)를 구명(究明)코져 우리나라의 대표적(代表的) 밭토양(土壤)인 상주(尙州) 사양토(砂壤土), 연곡(延谷) 양토(壤土), 화동(華東) 미사질(微砂質) 식양토(埴壤土)를 갖이고 수분함량(水分含量)과 가비중(假比重)을 달리하여 Core를 만들어서 토양(土壤)의 경도(硬度)와 완두뿌리의 신장속도(伸長速度)를 측정(測定)하였던 바 그 결과(結果)는 다음과 같다. 1. 토양경도(土壤硬度)는 가비중(假比重)이 증가(增加)할수록 커지며, 수분함량(水分含量)이 많을수록 가비중(假比重) 증가(增加)에 따른 경도변화(硬度變化)는 적어진다. 2. 동일(同一)한 수분함량(水分含量)에서 뿌리의 신장(伸長)과 가비중(假比重)과는 고도(高度)의 상관(相關)을 보여 주었으며 그 기울기는 수분함량(水分含量)이 적을수록 컸다. 3. 완두뿌리의 신장(伸長)은 경도(硬度)(Yamanaka 경도계(硬度計) 및 침경도계(針硬度計))가 증가(增加)할수록 감소(減少)되었으며, 두 인자(因子)간에는 고도(高度)의 유의(有意)한 상관(相關)이 있었다. 4. 완두생육에 있어서 최저(最低) 뿌리 신장속도(伸長速度)를 0.3mm/hr(최대신장속도(最大伸長速度)의 약(約) ${\frac{1}{4}}$에 해당(該當))라고 보면 금속침(金屬針)에 의한 토양경도(土壤硬度) $21kg/cm^2$, Yamanaka경도(硬度) 24mm이 완두재배(栽培)에 있어 한계경도(限界硬度)라고 볼 수 있다.

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