Plant-soil approach for irrigation scheduling of mango trees in the Sultanate of Oman

Efficient irrigation scheduling, through precise determination of crop water requirements, is viable for sustaining agriculture and maintaining groundwater resources in the Sultanate of Oman. We conducted a study to investigate the response of mango (Mangifera indica) trees through determining the relationship between soil and crop status using soil water retention curve (RETC) and tree water status. The indicators were the soil water content (θ), soil matric potential (Ψ_m), and leaf potential (Ψ_l). Finding the relationship was achieved by comparing the behavior of those trees placed under continuous drying with those that received water at field capacity level on regular basis. Results showed that there is a little response of mango trees, in terms of Ψ_lvalues and visual physical signs, to low soil wetness levels. This is probably due to that mango trees tolerated drought by adjusting their internal physiological functions. Results suggest that stress of mango trees is probably better represented by the RETC data rather than leaf potential. Further work is under way to investigate the behavior of mango trees undergoing different levels of soil water deficits under field conditions in Oman.