One of the benefits of continuous soil moisture monitoring is that it enables you to track and analyze changes in soil moisture content, which in turn allows the user to watch the plants “drink”. This is important because it means that the irrigation regime can be matched to changes in crop demand caused by changing weather conditions and/or crop growth stages. It also indicates when the soil dries out and the plants cannot access adequate moisture to satisfy their daily requirements.
During the day plants transpire water and extract moisture from the soil, At night transpiration slows, reducing crop water use. These events appear as a “staircase” pattern on the separate and summed graphs. The steep vertical steps indicate periods of high crop water use. The shallow steps indicate periods of low crop water use. The flat lines indicate little or no water use.
Understanding crop water use, as a function of volumetric soil moisture change over time, is essential in making irrigation decisions. If soil moisture is available and the evaporative and crop demand remains constant, then daily water use will be the same from day to day. When soil moisture becomes depleted, or there is a reduction in crop demand, there is a reduction in daily crop water use. By displaying this data in as separate graphs you can determine relative crop water use at different depths in the soil profile.