MODELLING ROOT-LAYER PHYSICAL CHARACTERISTICS OF SOILS WITH HORIZON DIFFERENTIATION FOR CROP IRRIGATION SCHEDULING

Model for calculating physical characteristics of the root layer of soils with horizon differentiation was developed.
Equations for determining effective values of the field capacity, wilting point, bulk density, pre-watering soil moisture and rate of maximum allowed soil water deficiency, all depending on thickness of root zone during the growing season, are obtained.
The model was applied to solve the differentiation problem of two kinds of Bulgarian Cinnamonic Forest Soils.
We established that the pre-watering soil-root-layer moisture, corresponding to one and the same minimum value of soil water potential, alters to a great extend with increasing the root layer thickness.
This variability showed that the idea of pre-watering soil moisture is not appropriate when irrigation for crops grown on soils with horizon differentiation has to be scheduled.
The model of effective physical characteristics should be used as á component of modern computer technologies for irrigation scheduling.
This approach is a further progress in solving the problems concerning the pre-watering moisture idea applied to soils under consideration.

II International Symposium on Irrigation of Horticultural Crops

I.D. Christov

Soil root layer, soil physical characteristics, soil horizon differentiation, energy level of soil moisture, irrigation scheduling

https://doi.org/10.17660/ActaHortic.1997.449.43