In-situ measurement of stable isotope to access the effects of mulching on soil water and thermal environment

稳定同位素的原位测量以了解覆盖对土壤水和热环境的影响

• 批准号: 22KF0223
• 负责人: 中村 公人
• 金额: $ 1.34万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for JSPS Fellows
• 财政年份: 2023
• 资助国家: 日本
• 起止时间: 2023-03-08 至 2025-03-31
• 项目状态: 未结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-22KF0223/
• 关键词: マルチ; 土壌水分動態; 土壌温度; 酸素・水素安定同位体比

畑地農業におけるマルチングは，土壌からの蒸発量を制御できるために，点滴灌漑などのマイクロ灌漑技術と組み合わせることによって，節水型灌漑を行うことができる．また，土壌温度環境を適切に制御できる可能性もある．したがって，マルチングは農業における気候変動に対する適応策として重要で有効なツールとなりうる．適切に土壌中の水・熱環境を管理するためには，マルチング下での土壌中の水・熱移動現象を明らかにし，これをモデル化する必要があるが，例えば土壌表面とビニールマルチ表面間での水蒸気と液状水の相変化（蒸発・凝結過程）が土壌水分・熱環境に及ぼす影響は定量的に評価されていない．本研究では，土壌水分・地温観測に加えて，蒸発・凝結過程で同位体分別により値が変化する水の酸素・水素安定同位体比を計測することにより，マルチの影響下にある土壌中の水・熱移動現象を明らかにすることを目的とする．2022年度は，大学内で行う土壌カラムを用いた実験システムの構築を行った．使用する材質や色の異なる複数種類のマルチ，土壌水分量センサ，土壌水分ポテンシャルセンサ，温度センサ，気象観測システム，土壌水採取装置を用意し，これらの動作確認を行った．供試土壌は現地畑地土壌とし，土壌物理性を把握した．2023年度からの実験開始が可能となった．和歌山県に位置するマルチを敷設した畑地実圃場での土壌水分観測を継続した．深さ方向の土壌水分変化とその経時変化から，ビニールマルチを敷設している圃場では，深さ5cmの土壌水分の低下速度が，それ以深の低下速度よりも緩やかになる場合があることが観察された．これが蒸発・凝結に伴うものであるかどうか，検討の余地があることが確認できた．また，酸素・水素安定同位体比を用いた土壌水分移動解析に関する研究レビューを行い，蒸発・凝結を組み込むための同位体の平衡分別と動的分別の表現方法に関する知見を得た．

The agricultural and agricultural crops in rural areas are in poor condition, and the evaporation capacity of the soil is used to control the temperature of the soil. The technology of irrigation is used to control the temperature of the soil, and the irrigation technology is used to control the temperature of the soil. It is important to carry out the transportation of water and water in the soil. The management of the water environment in the rural areas is affected. The movement of water in the soil is similar to the transportation of water in the rural areas. In this study, soil moisture, soil temperature, soil moisture, soil temperature, temperature and temperature were measured. In the process of evaporation and condensation, the isotope ratio of hydrochloric acid, water diazepam and diazepam is calculated, and the movement of water in the soil is similar to that in the soil. 2022 In the university, the local water content is different, the soil water content is different, the temperature is different, the soil water content is different, the soil water content is different, the temperature is different, the temperature is different, the soil water content is different, the temperature is different, the temperature is different, the soil water content is different, the temperature is different, the temperature is different, the soil water content is different, the soil water content is different, the temperature is different, the soil water content is different, the temperature is different, the soil water content is different, the soil water content is different, the temperature is different, the temperature is different, the soil water content is different, the soil water content is different, the temperature is different, the soil water content is different, the soil water content is different, the temperature is different, the temperature is different, the soil water content is different, the soil water content is different, the temperature is different, the temperature is different, the soil water content is different, the soil water content is different, the The soil physics has a good grasp of the soil quality. It may be difficult to start the season in 2023. And the location of the mountain in Kaoyama is to apply the soil moisture to the soil. The soil moisture content in the deep soil is warm, and the soil moisture content in the deep soil is warm. The soil moisture content in the deep soil is warm, and the soil water content is low in the 5cm area. At a low speed, the temperature is very low, and the temperature is very low. The temperature is very low, and the temperature is very low. The temperature is very low and the temperature is very low. At a low speed, it is necessary to make sure that the temperature is low. The water stability of acid and water is much higher than that of soil moisture transport analysis and analysis of water transport. The method for the determination of the balance of the steam condenser system is satisfactory.