Soil Water Management Lab.
土壌水管理学研究室
（土水研）
Embedded Files
We are developing UAV-based systems to monitor water conditions in crop fields and pastures and to provide this information to smartphones.
We are also developing a framework that uses HYDRUS to predict temporal changes in soil moisture under different field design and management practices, and then estimates crop water stress over time based on the predicted soil moisture. The resulting water stress indicators are used to evaluate and identify better approaches to field design and management.
ドローンが地区内の各畑や牧草地の水分状況を自動観測してスマートフォンに配信するシステムの開発と、HYDRUSを用いて予測した土壌水分から作物の水ストレスを経時的に予測し、その水ストレスを指標として圃場の整備や管理の方法を検討する評価体系の開発を試みています。
Assessment of water deficit using UAV
UAVによる圃場の水分状況の観測
CWSI calculated from stomatal conductance (Sakaguchi et al., 2021)
CWSI (Jackson, 1981) reflects not only the effects of soil water deficit but also the influence of diurnal physiological responses.
Spatial heterogeneity of canopy temperature caputured by UAV at a maize field
Spatial heterogeneity (RSD) of canopy temperature increses under soil drying.
Spatial heterogeneity of stomatal conductance at a sesame field
Stomatal conductance decreases with soil drying, and spatial heterogeneity (RSD) of stomatal conductance increses.
Spatial heterogeneity of leaf temperature at a sesame field
Spatial heterogeneity primarily occurres at the inter-plant scale.
Feddes root water uptake model (Feddes et al., 1978)
Feddes model provides a useful conceptual framework for interpreting the increse of spatial heterogeneity in crop water stress under soil drying at the inter-plant scale.
Soil moisture distribution within a field (Kameyama et al., 2019)
Wet day (left figure): The plants at the red point and those at the blue point are expected to show the same transpiration rate.
Dry day (right figure): The plants at the red point and those at the blue point are expected to show different transpiration rates.
Modeling field-Scale water flux and scenario analysis using HYDRUS
HYDRUSによる圃場のモデル化とシナリオ分析
Design of sub-surface irrigation
Subsurface irrigation system design for vegetable production using HYDRUS-2D (Sakaguchi et al. 2019)
Numerical simulation on soil water suction and flux
Once the model is able to reproduce the actual observed spread of irrigation water within the soil, as determined through inverse analysis, we will use that model to test various scenarios and select the optimal one.
Future prediction of soil dryness
Blue line: Measured root-zone soil water suction pressure for 2017
Red line: An example of future soil water suction pressure predicted with HYDRUS using weather projections from ELPIS-JP
Growth under predicted soil water condition in the future
Cabbage grown with the soil water suction pressure maintained at the future average value (pF2.6) for the cultivation period was very small, with thick, dark green leaves.
Page updated
Google Sites
Report abuse