Agriculture and Agribusiness

Soil Water Management and Irrigation Scheduling

Most irrigation is applied on a fixed rotation because it is easier than deciding, which means water goes on when it is convenient rather than when the crop needs it, and both over and under irrigation cost yield. This course replaces the rotation with a decision. Delegates work through soil water: field capacity, permanent wilting point, available water and the readily available fraction a crop can use without stress. Soil texture and rooting depth are related to the water a field can actually hold. Measurement follows across tensiometers, capacitance and neutron probes, gravimetric sampling and the placement that determines whether a reading means anything. Water balance scheduling is covered, using evapotranspiration and rainfall to track depletion. Crop stress indicators and deficit irrigation are addressed, including where deficit is a deliberate strategy. Salinity and leaching requirement are covered. Waterlogging and aeration follow. The course closes on record keeping, on scheduling across a whole farm and on judging whether the schedule improved anything.