Effects of fixed partial root-zone drying irrigation and soil texture on water and solute dynamics in calcareous soils and corn yield

Water dynamics and salt distribution in the soil were studied under Fixed Partial Root zone Drying irrigation (FPRD) conditions in corn fields in Northern Greece. FPRD irrigation technique was applied without deficit treatment in two calcareous soils, a sandy clay loam and a sandy loam. Soil water content was recorded in the vertical profile of 0.6 m with the use of capacitance sensors in the row and interrow positions of plants. Salt built-up was monitored to the depth of the root zone, bi-weekly, by measuring electrical conductivity (ECe) and the concentrations of soluble cations Ca2+, Mg2+, Na+ and K+ of the saturation extract on irrigated and non irrigated interrow positions. Soil moisture distribution and salt built-up in soil were used to evaluate the potentials and constraints of FPRD efficiency to sustain plant growth and crop production as a low cost drip irrigation technique. The results indicated that FPRD application on both soils was capable of supplying sufficient amounts of water on plant row. Soil analyses showed that salts accumulated to high levels in the soil surface and decreased in depth at the non irrigated interrow positions. Spatial and temporal variability of salt movement and distribution in the soil profile of 0.6 m were ascribed to soil textural differences. The development and yield of corn plants for both soils reached the usual standards for the area with a minor decrease in the sandy loam soil.

► In field evaluation FPRD proved that it is a cost effective irrigation method for row crops.
► Deep percolation under FPRD drip irrigation is limited.
► Salt built up in high levels in the soil surface of the non irrigated interrow positions and decreased with depth.
► Transport and distribution of soluble salts are affected by the soil textural class, the CaCO3 content and possibly the dissolution and precipitation of salts.
► Corn yield reached the usual standards despite the fact that the salinity levels encountered during the sensitive growth stages exceeded the salt tolerance threshold of corn.