土壤湿度计,又名张力计、负压计,是测量土壤吸(水)力的一种仪器。土壤是一种非均质的多孔体,当其孔隙还未完全充满水时,都具有吸水的能力,所以土壤能保持水。植物要从土壤中吸水,必须以更大的力来克服土壤对水的吸力和溶解在水中的溶质吸力才能进行。土壤吸力的大小关系到农作物吸收水分和养分的难易,要 Soil hygrometer, also known as tensiometer, negative pressure gauge, is an instrument to measure soil suction (water) force. Soil is an inhomogeneous porous body that absorbs water when its pores are not yet completely filled with water, so the soil can hold water. To absorb water from the soil, plants must overcome the soil’s suction of water and the solute suction dissolved in water with greater force. The size of the soil suction related to the crop to absorb moisture and nutrients difficult to be