Differences in Soil Productivities between the Cut Site and Fill Site in a Newly Reclaimed Land

개간지(開墾地)에서 절토지(切土地)와 성토지(盛土地)의 토양생산력(土壤生産力) 비교(比較)

The differences in soil productivity between the cut site and the fill site in a newly reclaimed land were compared with the experimental results conducted during 1978 to 1980 under soybean-barley and sweet potato-barley cropping systems. The results were summerized as follows; The bulk density of the cut site was near $1.5g/cm^3$ with the hardness above 23mm by Yamanaka method and that of the fill site was $1.3g/cm^3$ with the hardness of 14mm at the first year of reclaiming. The bulk densities and soil hardnesses asymptotically approched to $1.4g/cm^3$ and 19mm, respectively. The chemical productivity of the fill site was also significantly higher than that of the cut site. Differently from the bulk density and hardness, chemical compositions of the fill site maintained high untill the third year of cropping. The yields of soybean, sweet potato and barley from the cut site at the first year were very poor and, thereafter, were remarkably increased by 2 to 9 times at the third year of cropping while those from the fill site maintained high from the first year to the third year of cropping.

개간지(開墾地)에서 절토지(切土地)와 성토지(盛土地)의 토양생산력(土壤生産力)을 연차적(年次的)으로 비교(比較)하기 위(爲)하여 경기도(京畿道) 평택(平澤)에서 콩-보리, 고구마-보리 작부(作付)를 대상(對象)으로 3년간(年間) 시험(試驗)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 개간후(開墾後) 절토지(切土地)의 가비중(假比重)과 경도(硬度)는 각각(各各) $1.52g/cm^3$, 23.3mm이었고 성토지(盛土地)는 $1.32g/cm^3$, 14.3mm이었다. 성토지(盛土地)에서 고구마 재배(栽培)는 우량(優良)한 물리성(物理性) 유지(維持)에 효과적(效果的)이었다. 2. 토양화학성(土壤化學性)의 보지능력(保持能力)은 절토지(切土地)에서 낮았고 성토지(盛土地)는 3년차(年次)까지도 높았다. 3. 절토지(切土地)의 작물(作物) 수량(收量)은 낮았으나 작기(作期)에 따라 증가(增加)하는 경향(傾向)이었고 성토지(盛土地)는 개간당년부터 안정(安定)된 수량(收量)을 얻을 수 있었다.