토지이용별로 토양 물리성 변화를 평가하기 위하여 2009년부터 2017년까지 전국의 밭, 과수원, 논을 대상으로 토양물리성 특성을 4년 주기로 분석하였다. 밭은 작토심, 심토 유기물 함량, 심토 산중식 경도가 증가하고 심토 용적밀도가 감소하며, 개량기준 초과비율도 지속적으로 감소하였다. 과수원은 경운심이 증가하였으나 심토 유기물 함량이 감소하고 적정기준을 초과하는 비율은 4년 전보다 증가하였다. 논은 작토심, 심토 유기물 함량이 감소하고 심토 용적밀도가 증가하며 개량기준 초과비율이 증가하는 등 물리성 불량이 심화되었다. 최근 10년간 밭, 과수원에 비해 논의 물리성이 악화되는 것을 확인할 수 있었으며, 공통적으로 심토 유기물 함량이 감소하고 심토 용적밀도가 증가하는 주요한 요인은 토양유기물로 평가되었다. 따라서 토양물리성 질 관리에 유기물은 중요한 요소이었으며, 특히 논에서 지속적인 유기물 관리와 경운방법 개선 등이 필요하다.

The soil physical quality is a core factor in achieving two of sustainable agriculture’s goals: productivity and environment. The purpose of this study was to assess changes in soil physical properties for nearly a decade through periodic monitoring of three cultivation types: upland, orchard, and paddy. Field surveys and lab analysis were conducted to determine the soils physical properties after every 4 years; upland (2009, 2013, and 2017), orchard (2010 and 2014), and paddy (2011 and 2015). In each year soil samples from 162-338 sites were collected. The bulk density of upland subsoil decreased from 1.53 Mg m-3 to 1.50 Mg m-3 while the plowing depth and subsoil organic matter increased from 13.7 cm to 19.5 cm and from 12.6 g kg-1 to 18.3 g kg-1 respectively during the period 2009-2017. Plowing depth for orchard increased from 16.7 cm to 18.9 cm. However, organic matter content decreased from 15.9 g kg-1 to 15.4 g kg-1 during the 2010-2014 period. For paddy, plowing depth and subsoil organic matter decreased from 17.5 cm to 16.7 cm and from 17.5 g kg-1 to 15.8 g kg-1 respectively. The subsoil bulk density increased from 1.47 Mg m-3 to 1.52 Mg m-3 from 2011-2015. Excess ratio for soil physical standards increased from 16% to 22% in orchard, 56% to 62% in paddy, and decreased from 41% to 29% in upland. The overall soil physical quality had been ameliorated for upland, but degraded for paddy. Improved tillage practices and application of appropriate organic matter is necessary to enhance the quality of soils, especially in the paddy field.

Abstract
 서 론
 재료 및 방 법
  1. 조사대상지 및 조사 방법
  2. 주기 간 토양물리성의 비교
 결과 및 고 찰
  1. 밭 토양 물리적 특성 변화
  2. 과수원 토양 물리적 특성 변화
  3. 논 토양 물리적 특성 변화
 적 요
 REFERENCES

• 조희래(국립농업과학원 토양비료과) | Hee-Rae Cho (Division of Soil & Fertilizer, National Institute of Agricultural Science) Corresponding author
• 장용선(국립농업과학원 토양비료과) | Yong-Seon Zhang (Division of Soil & Fertilizer, National Institute of Agricultural Science)
• 한경화(국립농업과학원 토양비료과) | Kyung-Hwa Han (Division of Soil & Fertilizer, National Institute of Agricultural Science)
• 옥정훈(국립농업과학원 토양비료과) | Jung-Hun Ok (Division of Soil & Fertilizer, National Institute of Agricultural Science)
• 황선아(국립농업과학원 토양비료과) | Seon-Ah Hwang (Division of Soil & Fertilizer, National Institute of Agricultural Science)
• 이협성(국립농업과학원 토양비료과) | Hyub-Sung Lee (Division of Soil & Fertilizer, National Institute of Agricultural Science)
• 김동진(국립농업과학원 토양비료과) | Dong-Jin Kim (Division of Soil & Fertilizer, National Institute of Agricultural Science)