Rain Is the Wrong Number for Sowing — What Soil Moisture and Evaporative Demand Actually Say
It rained 30 mm yesterday. Is the field ready to sow? Rainfall alone cannot answer that — the decision lives in the seed zone, where moisture, soil temperature and evaporative demand interact. How VayuMet computes sowing suitability, the FAO-56 water balance behind the irrigation call, the spray window, and why a 25 km grid is guidance rather than a soil sensor.