Effect of soil moisture-based furrow irrigation scheduling on melon (Cucumis melo L.) yield and quality in an arid region of Northwest China

Water shortage and high irrigation rate has increased the need for appropriate irrigation scheduling to improve agricultural water use efficiency for food security in Northwest China. A two-year field experiment was carried out to investigate the response of melon (Cucumis melo L.) yield, quality and water productivity (WP) to various soil moisture levels with controlled furrow irrigation in the arid oasis region of Gansu Province. Soil water content (SWC) with values of 55% and 65% FC (field capacity) during blooming to fruit setting stage, and 45%, 55%, and 65% FC during fruit swelling stage, respectively, was considered as the lower limit for irrigation. Considering the fruit marketable yield, WP, and quality, an overall integrated index was developed and then used as an indicator to assess the appropriate irrigation scheduling. The overall integrated index value was computed by using the catastrophe progression method. Results showed that the melon yield (total, marketable and high quality yields), and vitamin C content were highly sensitive to lower SWC limits with value from 45% to 65% FC during fruit swelling stage. The treatment with lower SWC limit of 55% FC during blooming to fruit setting or fruit swelling stage was found without significant effect on melon yield and WP, and the treatment with lower SWC limit of 55% FC from blooming to swelling stage had negative impact on melon yield and vitamin C. Considering the overall integrated index values, the lower SWC limit of 55% and 65% FC was recommendable for furrow irrigation of melon crops during blooming to fruit setting and fruit swelling stages, respectively, in the arid oasis region of Northwest China.