The Effect of Deficit Irrigation on Temporal Changes of Infiltration in Furrow Irrigation

Full irrigation is recommended for the regions with no limitation to access water for irrigating the farm lands. Due to the population increase and consequently, the increase in cultivation field’s area, the climate changes etc., full irrigation is not possible in many regions (Kheyrabi et al., 1996). Under this condition, using the water management techniques, such as deficit irrigation, is necessary and its importance is undeniable. Deficit irrigation is an optimum procedure in producing the agricultural products under water limitation. In this technique, agricultural product decreases per unit area, but it is enhanced by increasing the cultivation fields. Deficit irrigation is a suitable procedure that allows planting to reduce the product by decreasing the water uptake. The main purpose of deficit irrigation is increasing the water use efficiency with decreasing applied water in each irrigation event. Soil infiltration characteristics are very important in the design and management of furrow irrigation systems (Foroud et al., 1996; She et al., 2014). For this reason, extensive research have been done in the field of water infiltration and soil permeability process in surface irrigation (such as measuring and estimating the infiltration changes, advance time, recession time, surface storage, subsurface movement etc.). Soil infiltration changes over time affect the distribution uniformity of infiltrated water in the field, irrigation duration and finally irrigation efficiency in the furrow irrigation. Soil compaction and also cracking the furrow bottom after irrigation events are the main reasons for these changes, especially, after the initial irrigation events and under deficit irrigation conditions. Investigating the effect of deficit irrigation on the infiltration process and temporal infiltration changes and considering these changes in designing furrow irrigation systems is essential under water shortage condition. Therefore, the main purpose of this study was to investigate the temporal changes of Kostiakov-Lewis equation parameters under deficit irrigation conditions in different irrigation events during maize growing season.