Vol. 4, Issue 2, Part A (2022)

Despite of supplying recommended leaching fraction, the soil of Sahl El-Tina region in Egypt is moderately saline due to the land systematic irregularity of surface irrigation. The current experiment investigated the effectiveness of changing the land microtopography only during leaching by establishing internal field canals and drains. The baseline measurements showed little salinity of irrigation water, moderate soil salinity and high drainage water being 73 times of irrigation water. Failures were observed in internal canals’ berms attributed to soil salinity and its consequent dispersion and low breaching resistance. Canals’ cross section was maintained weekly until stability was achieved after four weeks, then the daily leaching discharge increased accelerating the salinity removal rate. The results showed strong inverse relationships between leaching water quantity and both drainage water and soil salinities. There was also a strong direct relationship between soil and drainage water salinity in internal field drains. The drainage water salinity and soil salinity decreased to 50% and 23% of initial values, respectively after 64 days with an accumulated water height of 71.4 cm. After 76 days, the drainage salinity decreased to 15% of initial value equivalent to only 10 times of irrigation water salinity and the soil salinity decreased to 17% with an accumulated water height of 104 cm. The experiment ended after 90 days as the drainage salinity became unchanged. The citizen science approach was applied by involving the landowner and farmers in construction, maintenance, measurements, and data analysis.