Improving water and energy productivity using a smart sprinkle irrigation system for mulberry orchard

Mulberry leaves are the only nutrition of silkworms and the quality and quantity of mulberry leaves can directly affect the resulting silk. A study was conducted from June to September 2020 to investigate the effect of surface and sprinkle irrigation methods in comparison with rainfed on the quantity and quality of mulberry leaves and silkworm cocoons in the National Silk Research Center located in Pasikhan, Rasht. Four irrigation treatments including manual sprinkle irrigation (I2), smart sprinkle irrigation (I3), and surface irrigation (I4) versus rainfed cultivation (I1) were compared. The results of variance analysis showed that there was a significant difference between treatments. Mean comparison showed that the highest number of leaves per branch, leaf weight, leaf moisture content, and the ratio of number of leaves to branch length were 87.86, 84.6 gr, 45.67%, and 0.461, respectively, obtained in manual sprinkle irrigation. Manual sprinkle irrigation had the highest yield as compared to other treatments (766.7 gr/tree and 6314.3 kg/ha). The highest branch length was obtained in surface irrigation treatment with 202.7 cm. Statistically, at the level of 5%, smart sprinkle irrigation treatment was not significantly different from manual sprinkle irrigation. The amount of water used in smart sprinkle irrigation treatment was less than that of manual sprinkle irrigation, and therefore water productivity and electricity energy efficiency (kg/kWh) were higher, being 7.24 kg/m3 and 47.1 kg/kWh, respectively. The results showed that irrigation of mulberry orchard can save the plant from water stress and increase yield. Manual sprinkle irrigation has the highest positive effect on the quantity and quality of mulberry leaves and using a smart system can increase water productivity and play an important role in reducing water consumption.