Experimental investigation into effects of drip irrigation with saline groundwater on water use efficiency and quality of honeydew melons in Hetao Region, Inner Mongolia

A study on the suitability of honeydew melons drip-irrigated with saline groundwater was conducted in Changsheng Experimental Station in Hetao Region, where secondary soil salinity has been a problem for a long time. Saline groundwater, ranging from 3.3 dS/m in the early season to 6.3 dS/m at the harvest, was used as the source of the drip irrigation system. Four irrigation treatments were used for the experiments, namely, 30%, 60%, and 90% of evaporation and control. The control was not irrigated throughout the season as is the local practice. zero, 1, 2, and 3 laterals of equal flow rate were used in the drip system for applying water to control, 30%, 60%, and 90% treatment respectively at the same period of time and same frequency. The results showed that the yield of honeydew melons increased and the quality of those under treatments of drip irrigation improved, as compared with those under control, with highest increases in yield of honeydew melons under 60% treatment. The water use efficiency as determined by lysimeter measurements for different treatments had the same trend. The water-production efficiency of the four treatments was 25, 20.5, 18, and 11.37 kg/m³, respectively. The pattern of soil salinity for three drip treatments was similar. Salts accumulated at the top layer of soil (0～10 cm) adjacent to the emitter. As well, it seemed that higher soil salinity was found at locations 50 cm from emitters than those 10 cm from emitters. However, it seemed that a great amount of salts were leached beyond the root zone under the treatments with 60% and 90% of evaporation, which suggested the feasibility of drip-irrigating honeydew melons grown in the saline soils with saline water.