Method to estimate the critical soil water content of limited availability for plants

This contribution contains a proposal to estimate the critical soil water content of limited availability for plants, below which transpiration starts to decrease due to limited water availability for roots, which is frequently noted as “the point of limited soil water availability”. The method is based on the fact, that soil water content at which transpiration rate is starting to decrease is followed by the biomass production decrease. The method is using the relationship between the relative transpiration and the average soil water content of the soil root zone, and the linear relation between biomass production and transpiration, published earlier.