과수지역 토양수분 시공간 분포 예측 및 적정 관개수량 산정기술개발

신승훈,박근형,김희태,김민영,이상봉,최용훈,김종건 강원대학교 농업생명과학연구원 2023 강원 농업생명환경연구 Vol.35 No.1

Moisture stress in the soil is one of the most important factors influencing plant growth. Soil moisture stress refers to a physiological response from excess moisture, such as the loss of more moisture than the moisture absorbed from the soil due to transpiration. Excessive soil moisture also causes considerable stress due to lack of air in the soil. To prevent moisture stress in the soil, it is important to estimate the appropriate amount of irrigation through spatial distribution prediction of soil moisture. At present, irrigation technology for field crop cultivation is being developed based on soil moisture and meteorological information (crop evapotranspiration). Therefore, in this study, we developed spatiotemporal distribution prediction technology by using soil moisture modeling techniques. We also developed a technique for estimating water stress and irrigation amount in open field crop areas by simulating soil moisture in the root zone. For the study area, an orchard located in Saam-ri, Chuncheon-si, Gangwon-do was selected. Soil moisture monitoring was performed according to the spatial distribution of soil moisture and soil depth. The soil moisture data was used as data for estimating and verifying the moisture simulation parameters of the APEX model and for comparing the predictions of root zone soil moisture at the monitoring site. As a result of this study, the spatial area vulnerable to drought within the study area was estimated, and the appropriate amount of irrigation was estimated accordingly. In line with the findings of this study, the spatial distribution of moisture can be predicted using a soil moisture simulation model.

Sentinel-1 SAR 데이터를 이용한 우리나라 농지의 토양수분 산출 실험

이수진,홍성욱,조재일,이양원 대한원격탐사학회 2017 大韓遠隔探査學會誌 Vol.33 No.6

Soil moisture plays an important role to affect the Earth’s radiative energy balance and water cycle. In general, satellite observations are useful for estimating the soil moisture content. Passive microwave satellites have an advantage of direct sensitivity on surface soil moisture. However, their coarse spatial resolutions (10-36 km) are not suitable for regional-scale hydrological applications. Meanwhile, in-situ ground observations of point-based soil moisture content have the disadvantage of spatially discontinuous information. This paper presents an experimental soil moisture retrieval using Sentinel-1 SAR (Synthetic Aperture Radar) with 10m spatial resolution for cropland in South Korea. We developed a soil moisture retrieval algorithm based on the technique of linear regression and SVR (support vector regression) using the ground observations at five in-situ sites and Sentinel-1 SAR data from April to October in 2015-2017 period. Our results showed the polarization dependency on the different soil sensitivities at backscattered signals, but no polarization dependence on the accuracies. No particular seasonal characteristics of the soil moisture retrieval imply that soil moisture is generally more affected by hydro-meteorology and land surface characteristics than by phenological factors. At the narrower range of incidence angles, the relationship between the backscattered signal and soil moisture content was more distinct because the decreasing surface interference increased the retrieval accuracies under the condition of evenly distributed soil moisture (during the raining period or on the paddy field). We had an overall error estimate of RMSE (root mean square error) of approximately 6.5%. Our soil moisture retrieval algorithm will be improved if the effects of surface roughness, geomorphology, and soil properties would be considered in the future works. 토양수분은 지구복사에너지평형과 물순환에 영향을 미치는 중요한 인자이므로, 수문학 연구에 있어서 토양수분의 함량을 파악하는 것은 매우 중요하다. 현재 수동형 마이크로파 위성의 토양수분 자료는10~36 km의 저해상도로서 국지규모의 수문분석에 사용하기에는 어려움이 있다. 또한 현장관측 토양수분자료는 지점 자료이므로 공간연속성을 보장하지 못하는 한계가 있다. 이에 본 연구에서는 Sentinel-1의SAR(Synthetic Aperture Radar) 영상을 이용하여 우리나라 농지에서 10 m 해상도의 토양수분 산출 가능성을 살펴보았다. 2015-2017년 4월부터 10월까지 5개의 토양수분 지상관측지점을 대상으로, Sentinel-1 후방산란을 이용하여 선형회귀와 SVR(support vector regression) 방법으로 토양수분 산출을 수행하였다. 편파에 따라 후방산란계수의 토양수분에 대한 민감도가 다르지만, 산출정확도는 VV 편파와 VH 편파가 유사하였다. 토양수분은 식물계절학(phenology)보다는 수문기상과 지면특성에 보다 더 영향을 받기 때문에토양수분 산출에 있어 특별한 계절성은 발견되지 않았다. 대체로 입사각이 작을수록 후방산란과 토양수분간의 관계 패턴이 더 뚜렷하게 나타났으며, 또한 지면에 수분이 충분히 고르게 분포하는 경우 표면 간섭이 줄어들어(시간적으로는 강수시, 공간적으로는 논에서) 산출정확도가 상대적으로 높게 나타났다. 전체적으로RMSE(root mean square error) 6.5% 정도의 오차를 보였으나, 향후 지면 거칠기, 지형, 토성 등 다양한지면 변수의 영향을 반영한다면 보다 더 정확도 높은 토양수분을 산출할 수 있을 것으로 사료된다.

Pattern similarity based soil moisture analysis for three seasons on a steep hillslope

Lee, Eunhyung,Kim, Sanghyun Elsevier 2017 Journal of hydrology Vol.551 No.-

<P><B>Abstract</B></P> <P>Soil moisture is an important factor for understanding hydrological and solute transport processes at the hillslope scale. The selection of representative points for soil moisture measurement has been explored to investigate temporal variation of average soil moisture with minimum costs and maximum stability. The optimal selection of soil moisture monitoring points has been reevaluated to address hillslope hydrological processes and the impacts of seasonal differences. An alternative method to select soil moisture measurement points was developed to adequately represent immediate soil moisture response patterns to sequential rainfall events. To address the seasonal features of rainfall events and their impacts on soil moisture redistribution along the hillslope, field soil moisture data were collected at 49 points for three seasons over periods of 25days with bi-hourly monitoring intervals. For effective characterization of soil moisture variation, soil moisture datasets were classified using cluster analysis based on Euclidean similarity. Points delineated using the proposed method not only provide better stability of average soil moistures but also adequately represent the response patterns of soil moisture to rainfall events on the hillslope.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We propose a new method for soil moisture monitoring points. </LI> <LI> The Euclidean similarity between datasets was used to characterize soil moisture. </LI> <LI> The method developed provides a better explanation for soil moisture patterns. </LI> </UL> </P>

토양 내 저장 강수율을 활용한 국내 표층 토양수분 메모리 특성에 관한 연구

김기영,이슬찬,이용준,연민호,이기하,최민하 한국수자원학회 2022 한국수자원학회논문집 Vol.55 No.2

The concept of soil moisture memory was used as a method for quantifying the function of soil to control water flow, which evaluates the average residence time of precipitation. In order to characterize the soil moisture memory, a new measurement index called stored precipitation fraction () was used by tracking the increments in soil moisture by the precipitation event. In this study, the temporal and spatial distribution of soil moisture memory was evaluated along with the slope and soil characteristics of the surface (0~5 cm) soil by using satellite- and model-based precipitation and soil moisture in the Korean peninsula, from 2019 to 2020. The spatial deviation of the soil moisture memory was large as the stored precipitation fraction in the soil decreased preferentially along the mountain range at the beginning (after 3 hours), and the deviation decreased overall after 24 hours. The stored precipitation fraction in the soil clearly decreased as the slope increased, and the effect of drainage of water in the soil according to the composition ratio of the soil particle size was also shown. In addition, average soil moisture contributed to the increase and decrease of hydraulic conductivity, and the rate of rainfall transfer to the depths affected the stored precipitation fraction. It is expected that the results of this study will greatly contribute in clarifying the relationship between soil moisture memory and surface characteristics (slope, soil characteristics) and understanding spatio-temporal variation of soil moisture. 물의 흐름을 제어하는 토양의 기능을 정량적으로 계산하기 위한 방법인 토양수분 메모리(soil moisture memory)는 토양에 도달한 강수가 저장되고 배출되기까지 평균적으로 체류하는 시간을 평가한다. 본 연구에서는 2019, 2020년 한반도 지역에서 강수와 토양수분 위성 기반 모델 산출물을 활용하여 표층(0~5 cm)토양에서의 토양수분 메모리를 산출하고 이를 활용하여 연구지역 내 토양수분 메모리의 시공간적인 분포를 지표면의 경사 및 토양의 특성과 함께 평가하였다. 토양수분 메모리를 특성분석을 위해 강수 사건에 따라 토양수분의 증가를 추적하여 저장 강수율()이라는 새로운 측정 지표를 활용하였다. 강수 발생 초기(3시간 후)에는 산맥을 기준으로 토양 내 저장 강수율이 우선적으로 감소하여 토양수분 메모리의 공간적인 편차가 컸으며 24시간 이후 전반적으로 편차가 감소하였다. 토양 내 저장 강수율은 경사가 증가할수록 감소하는 형태가 뚜렷하게 나타났으며 토양 입자 크기의 구성 비율에 따른 토양 내 수분의 배수 활동에 의한 영향을 확인할 수 있었다. 또한 수리전도도 증감에 기여하는 평균토양수분이 저장 강수율에 미치는 영향을 확인하였다. 본 연구 결과는 강수가 지면에 체류하는 시간에 대한 척도인 토양수분 메모리가 지표의 경사와 토양 특성과 갖는 관계를 규명하고 토양수분의 시공간적 변동성을 이해하는 데 기여할 것으로 기대된다.

VIC 모형을 이용하여 모의된 한반도 토양수분 자료의 분석 및 검증

조은샘,송성욱,유철상 한국습지학회 2017 한국습지학회지 Vol.19 No.1

본 연구에서는 지표수문해석모형을 이용하여 과거 30년에 대한 남한과 북한의 토양수분을 모의하고 그 거동 차이를 분석하였다. 아울러 VIC 모형의 모의결과를 평가하기 위해 Soil Moisture CCI에서 제공하는 위성관측 토양수분 자료 를 분석하였다. 모의결과와 관측자료 사이의 비교에는 CSEOF 분석을 적용하여 단순한 토양수분 값의 비교가 아닌 VIC 모형의 성능을 간접적으로 평가하는 방법을 이용하였다. 본 연구의 결과를 정리하면 다음과 같다. 첫째, 토양수 분의 경년변동은 남한과 북한 모두 전체적으로 유사한 경향을 보였으나, 남한의 토양수분이 북한의 토양수분보다 작게 는 1%에서 크게는 7%까지 높은 것으로 확인되었다. 둘 째, 월 단위 토양수분의 경우, 봄철에 해당하는 4 – 6월의 토 양수분 상태는 남한과 북한에서 유사하게 나타났다. 반면, 장마철 이후 토양수분은 남한의 경우 최대 40%까지 증가하 지만, 북한에서는 최대 32% 정도에 머무르는 것으로 확인되었다. 셋 째, 전체적으로 모의된 토양수분이 인공위성에서 관측된 토양수분보다 약 4% 정도 작지만, 과거 30년 동안 나타난 증가 정도는 위성관측 토양수분과 유사한 것으로 확 인되었다. 마지막으로, 위성관측 토양수분과 VIC 모형으로 유도된 토양수분 자료에 대한 CSEOF를 비교해본 결과, 4 월부터 6월까지의 토양수분은 공간적으로 서로 상당히 다른 패턴을 보이는 것으로 나타났다. 그러나 7월과 10월의 경 우에는 약한 유사성을 보이고 있으며, 8월과 9월은 상당히 유사한 패턴을 가지고 있음을 확인하였다. In this study, land surface model was used to simulate the soil moisture of South and North Korea for the past 30 years, and the difference in their variation was analyzed. In addition, satellite observed soil moisture data provided by Soil Moisture CCI was analyzed to evaluate the simulation results of VIC model. For the comparison between the simulated and observed data, the CSEOF analysis was applied to indirectly assess the performance of the VIC model rather than simply comparing soil moisture values. The results of this study are summarized as follows. First, the annual variability of soil moisture showed a similar tendency in both South and North Korea, but it was found that the soil moisture in South Korea was as high as 1%, up to 7%, higher than the soil moisture in North Korea. Secondly, the soil moisture in spring between April to June is similar in South and North Korea, whereas the soil moisture after the rainy season is up to 40% in South Korea, but remains at maximum 32% in North Korea. Third, the overall simulated soil moisture is about 4% smaller than the satellite observed soil moisture, but the degree of increase over the past 30 years is similar to that of satellite observed soil moisture. Finally, a comparison of the CSEOF from the satellite observed soil moisture and the VIC model derived soil moisture showed that the soil moisture from April to June shows a much different pattern from each other. However, in July and October, there was a slight similarity, and it was confirmed that August and September has quite similar patterns.

Sentinel-1A/B SAR와 토양수분자료동화기법을 이용한 고해상도 토양수분 산정

김상우,이태화,천범석,정영훈,장원석,서찬양,신용철 한국농공학회 2020 한국농공학회논문집 Vol.62 No.6

We estimated the spatio-temporally distributed soil moisture using Sentinel-1A/B SAR (Synthetic Aperture Radar) sensor images and soil moisture dataassimilation technique in South Korea. Soil moisture data assimilation technique can extract the hydraulic parameters of soils using observed soilmoisture and GA (Genetic Algorithm). The SWAP (Soil Water Atmosphere Plant) model associated with a soil moisture assimilation technique simulatesthe soil moisture using the soil hydraulic parameters and meteorological data as input data. The soil moisture based on Sentinel-1A/B was validatedand evaluated using the pearson correlation and RMSE (Root Mean Square Error) analysis between estimated soil moisture and TDR soil moisture. The soil moisture data assimilation technique derived the soil hydraulic parameters using Sentinel-1A/B based soil moisture images, ASOS (AutomatedSynoptic Observing System) weather data and TRMM (Tropical Rainfall Measuring Mission)/GPM (Global Precipitation Measurement) rainfall data. Thederived soil hydrological parameters as the input data to SWAP were used to simulate the daily soil moisture values at the spatial domain from 2001to 2018 using the TRMM/GPM satellite rainfall data. Overall, the simulated soil moisture estimates matched well with the TDR measurements andSentinel-1A/B based soil moisture under various land surface conditions (bare soil, crop, forest, and urban).

Seasonal and inter-annual variability of soil moisture stress function in dryland wheat field, Australia

Akuraju, Venkata Radha,Ryu, Dongryeol,George, Biju,Ryu, Youngryel,Dassanayake, Kithsiri Elsevier 2017 Agricultural and forest meteorology Vol.232 No.-

<P><B>Abstract</B></P> <P>It is assumed that the ratio of actual evapotranspiration (AET) to potential evapotranspiration (PET) is mostly controlled by the soil water content available for ET. This control is formulated using the soil moisture stress function (SSF), where the evaporative fraction (EF) or the fraction of the AET to PET (fPET) is assumed to be either a linear or a non-linear function of soil moisture. We examine the effectiveness of the soil moisture stress function to quantify soil moisture control on EF or fPET over a dryland wheat field in Victoria, Australia. Micrometeorological observations from two cropping seasons were used for the analysis. The efficacy of a root-density-weighted soil moisture estimate in predicting EF and fPET was investigated as against the commonly assumed fixed-depth root zone soil moisture. However, results indicate a strong relationship between EF and available soil water fraction (AWF) in the root zone only when solar radiation is higher than 5MJ/m<SUP>2</SUP>/day. As the rooting depth increases with vegetation growth, SSF exhibits the strongest correlation with AWF for increasing soil profile depth. In the early and harvesting crop growth stages, ET is constrained mostly by surface soil moisture (0–5cm). In the mid-growth stages, ET is strongly influenced by soil moisture in the root zone (0–60cm). The shape of SSF, however, changes significantly between the two years (2012 and 2013). It is inferred that different temporal rainfall patterns between the years caused wheat’s different response to water stress.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Net radiation and crop phenology affect soil moisture stress function (SSF). </LI> <LI> Adaptive definition of root depth is important for accurate SSF. </LI> <LI> Root density profile needs to be used when defining root zone soil moisture. </LI> <LI> SSF can change inter-annually with temporal pattern of soil moisture. </LI> </UL> </P>

콩의 생육시기에 따른 토양별 지중관수 공급량의 설계

김진현,김태욱,김설하,이황규,엄덕호,이상훈 경상대학교 농업생명과학연구원 2022 농업생명과학연구 Vol.56 No.5

지중점적 관수(subsurface drip irrigation, SDI)는 작물의 뿌리가 수분을 가장 쉽고 효과적으로 이용할 수 있는 방법으로 알려져 있다. 그러나 지중관수는 지표면 관수와 달리 수분의 공급 상태를 육안으로 확인하기 어려운 단점이 있다. 특히 작물의 뿌리가 수분을 흡수할 수 있는 유효수분 량은 토양에 따라 달라지고 동시에 수분을 보유하는 장력(potential energy)에도 영향을 미치게 된다. 지중관수는 지중에서 수분이 확산되는 위치 와 뿌리의 위치까지 도달될 때 효과가 발생한다. 그러나 실제로 토양 내부에서 수분이 이동하고 확산하는 것을 예측하기는 쉽지 않다. 따라서 본 연구에서는 토양의 조건을 일정하게 하고 토층을 파괴시키지 않기 위해 토양조를 이용하였다. 그리고 수분을 지중에 공급한 이후에 토양을 절개하고 토양의 내부 위치별 토양수분을 측정하였다. 이때 토양 내부의 수분함량이 동일한 분포선을 찾아 유효 수분영역을 구하고 공급한 지중관 수량과 비교하였다. 아울러 토양내부의 습윤 확산 형태와 수분량으로 부터 토성에 따른 수분 확산이론을 예측하였다. 여기서 얻어진 수분확산 예측선도와 콩의 생육 시기별 뿌리의 생장위치를 중첩하여 최종적으로 지중관수량을 구하였다. 콩의 뿌리 생육은 파종이후 일일 평균 10 mm 성장한 것으로 나타나 생육 초기에 10일 간격으로 지중관수 공급량을 설계하였다. 주요 결과는 미사질양토에서 유효수분량을 25-35%로 유지하기 위해, 생육초기인 파종후 10일에는 8000 mL, 파종후 20일에는 7000 mL, 파종후 30일에는 6500 mL를 공급해야 할 것으로 판단되었다. 사질토 에서는 유효수분량을 20-30%로 유지하려면 파종후 10일에는 7500 mL, 파종후 20일에는 6500 mL, 파종후 30일에는 6000 mL를 공급하는 것이 타당한 것으로 판단되었다. 또한 생육 30일 이후에는 미사질양토나 사질토 모두 6000 mL를 공급하는 것이 적절할 것으로 보여 진다. Subsurface drip irrigation (SDI) is known as the easiest and most effective method for the roots of crops to use moisture. However, unlike surface irrigation, subsurface drip irrigation has a disadvantage that it is difficult to visually check the supply state of moisture. In particular, the effective amount of moisture that the root of the crop can absorb moisture varies depending on the soil, and at the same time, it affects the tension that holds moisture. Subsurface drip irrigation occurs when it reaches the location of moisture diffusion and the location of the root. However, it is not easy to predict the movement and diffusion of moisture inside the soil. Therefore, in this study, soil tides were used to keep the conditions of the soil constant and not destroy the soil layer. In addition, after moisture was supplied to the ground, the soil was incised and soil moisture by internal location of the soil was measured. At this time, the distribution line with the same moisture content inside the soil was found to obtain an effective moisture area and compared with the supplied subsurface drip irrigation water supply. In addition, the theory of moisture diffusion according to saturn was predicted from the wet diffusion form and moisture content inside the soil. The water diffusion prediction line obtained here and the growth position of the roots by the growth period of soybeans were overlapped to finally obtain the subsurface drip irrigation water supply. The root growth of soybeans was found to have grown by an average of 10 mm per day after sowing, so the supply of subsurface drip irrigation water was designed at intervals of 10 days in the early stages of growth. The main result was that in order to maintain the effective moisture content at 25-35%, 8,000 mL should be supplied on the 10th day after sowing, 7,000 mL on the 20th day after sowing, and 6500 mL on the 30th day after sowing. In sandy soil, it was considered reasonable to supply 7500 mL on the 10th day after sowing, 6500 mL on the 20th day after sowing, and 6000 mL on the 30th day after sowing to maintain the effective moisture content at 20-30%. In addition, it would be appropriate to supply 6,000 mL of both silt soil and sandy soil after 30 days of growth.

시간 안정성 기반 통계학적 방법을 이용한토양수분 대표지점 선정 연구

강상현,이충근,김민영,김영진,김희태,이상봉 경상국립대학교 농업생명과학연구원 2024 농업생명과학연구 Vol.58 No.1

전 세계적으로 급격하게 성장하는 스마트농업의 중요 요소 중 하나인 자동 관개시스템은 토양수분 센서에서 계측한 데이터를 기반으로 관개시점과관개량을 판단하기 때문에 토양수분 센서의 설치가 필수적이다. 하지만 국내의 경우 토양을 고려하지 않고 단순히 포장의 가운데에 센서를 설치하는등 토양수분 센서의 설치 위치에 대한 기준이 마련되어 있지 않아 토양수분 계측 위치에 관한 기준 검토가 필요하다. 본 연구에서 통계학적 방법을이용하여 토양수분의 대표 계측지점을 선정 연구를 수행하였다. 토양은 수직적 또는 수평적으로 불균일성을 갖기에 구명이 쉽지 않다. 따라서포장 전체에 걸쳐 지속해서 편향이 발생하지만 특정 위치에서의 평균 토양수분이 시간에 따라 유지한다는 시간 안정성 개념을 기반으로, 평균토양수분을 나타내는 대표지점 선정 연구를 수행하였다. 토양수분을 측정하기 위한 시스템을 제작하였고, TDR (Time Domain Reflectometry)센서를 이용하여 총 30개 지점을 측정하였다. 2023년 5월부터 8월까지 측정한 날짜·지점별 데이터를 이용하여, 지점의 편향을 정량화하여 식별할수 있는 MRD (Mean Relative Difference, 평균상대차이)와 측정의 정밀도를 나타내는 RD (Relative Difference, 상대차이)의 SDRD (StandardDeviation of Relative Difference, 표준편차)를 산출하고, MRD와 SDRD를 통합한 지표로써 RMSE (Root Mean Square Error, 평균제곱근오차)를 구하여, 시간 안정성이 가장 높은 지점인 RMSE의 수치가 최소인 지점을 대표지점으로 선정하였다. 토양수분 센서로 측정한 데이터를 사용하여지점별 RMSE를 산출하고 비교하여, 평균적인 토양수분을 나타내는 대표지점을 선정할 수 있음을 확인하였다. The automatic irrigation system, one of the important elements of smart agriculture that is multiplying worldwide, determines theset point and amount of irrigation based on data measured by soil moisture sensors. Therefore, installing a soil moisture sensor is essential. However, in Korea, there are no standards for the installation location of soil moisture sensors, such as simply installing the sensorin the center of the field without considering the soil. So, it is necessary to review standards regarding the location of soil moisturemeasurement. In this study, a study was conducted to select representative location in soil moisture distribution using statistical methods. Soil is not easy to identify because it is vertically or horizontally heterogeneous. Based on the concept of temporal stability, whichstates that the average soil moisture at a specific location is maintained over time even though the soil moisture bias occurs continuouslythroughout the field, a study was conducted to select the representative location that presents the average soil moisture. A system wasmade to measure soil moisture, and a total of 30 points were measured using TDR sensors. MRD, which can be identified by quantifyingthe soil moisture bias of the location, and SDRD of RD, which indicates the precision of measurement, were calculated using data by date and location measured from May to August 2023. RMSE was calculated as an integrated indicator of MRD and SDRD, andthe location with the highest temporal stability was the location with the minimum RMSE value, and this location was selected as therepresentative location. It was confirmed that a representative location presenting average soil moisture could be selected by calculatingand comparing RMSE for each location using data measured by soil moisture sensors.

Effects of Moisture, Temperature, and Characteristics of two Soils on Imazamethabenz Degradation

주진호,Joo, Jin-H. 한국토양비료학회 2001 한국토양비료학회지 Vol.34 No.4

Imazamethabenz 분해에 미치는 토양수분, 온도와 토양특성에 관한 연구를 위하여 두 토양 (1.5% 유기물 함량과 pH 8.0인 Declo sandy loam 토양과 2.1% 유기물 함량과 pH 7.7인 Pancheri silt loam인 토양)이 사용되었다. 토양은 12 주간 조절된 조건 하에서 incubation되었다. 처리는 3개의 토양 수분 (45, 75, 100% field capacity)과 2개의 토양온도로서 factorial arrangement되었다. Imazamethabenz의 분해는 모든 토양수분-토양온도에서 대수직선관계를 나타냈으며, 토양온도와 토양 수분이 증가함에 비례하여 증가되는 경향을 보였다. 토양수분 효과는 토양 수분이 45에서 75%의 field capacity로 증가하였을 때가 75에서 100% 증가한 경우에 비해 더욱 크게 나타났으며, imazamethabenz의 분해는 Pancheri silt loam에서 더욱 빨리 일어났다. X-ray diffraction의 분석에 의하면 Pancheri silt loam 토양은 점토에 hydroxy interlayer를 함유하고 있어, 즉, 보다 적은 양의 imazamethabenz를 흡착할 수 있기 때문에 분해가 빨리 일어난 것이라 생각된다. Imazamethabenz로부터의 첫 번째 생성물인 imazamethabenz acid의 생성은 대부분의 토양수분-토양 온도에서 2차 방정식의 경향을 따랐는데, 초기에는 증가한 후 점치 감소하였다. Effects of soil moisture and temperature on the degradation rate of imazamethabenz were studied in two soils, a Declo sandy loam soil with 1.5% organic matter and pH of 8.0, and a Pancheri silt loam soil with 2.1% organic matter and pH of 7.7. Soils were incubated for 12 weeks under controlled conditions. Treatments were a factorial arrangements with combinations of three soil moistures (45, 75, 100% of field capacity) and two soil temperatures (20, 30C). Imazamethabenz degradation followed first-order kinetics for all soil moisture-soil temperature combinations. Imazamethabenz degradation rate was proportional to increase of soil moisture and temperature. Soil moisture effect on imazamethabenz degradation was greater when soil moisture was increased from 45 to 75% of field capacity (half-life decreased 2.6 fold) than when moisture increased from 75 to 100% of field capacity (half-life decreased 1.2 fold). Imazamethabenz degradation occurred more rapidly in the Pancheri silt loam than the Declo sandy loam soil. Formation of imazamethabenz acid from imazamethabenz followed a quadratic trend for most soil-moisture-soil temperature combinations. Imazamethabenz acid formation initially increased at earlier stages, but later gradually decreased. In most cases, increasing soil moisture and temperature appeared to accelerate it's acid breakdown to other metabolites.