Yield and water use efficiency of Amaranthus cruentus grown under sms-based irrigation system
The study was carried out to evaluate water use efficiency and yield of Amaranthus cruentus grown under soil moisture sensor-based (SMS-based) irrigation system. SMS-based irrigation controller was designed to automate irrigation events based on 100 %, 75 % and 50 % field capacity (FC) for the growth of Amaranthus cruentus. The findings of the study revealed that the SMS-based irrigation based on 50 % FC saved 57.17 % irrigation water, 75 % FC saved 43 % while 100 % FC saved 25.33 % irrigation water. Water use efficiency (WUE) ranged from 1.39 – 2.43 for WUE based on fresh weight while WUE based on dry weight ranged from 0.22- 0.4. SMS-based on 50 % FC had the highest WUE of 2.43 while manual irrigation had the lowest WUE of 1.39 based on vegetable fresh weight. The total fresh weight and shoot fresh weight ranged from 62.47g – 84.16 g and 52.22 - 66.92 g respectively. Total dry weight and shoot dry weight ranged from 9.13 - 13.30 g and 7.58 - 11.28 g respectively. SMS-based irrigation based on 100% FC had the highest total and shoot fresh yield while SMS-based irrigation based on 75 % FC had the highest total dry and shoot dry weight. Generally, the yield of Amaranthus cruentus were statistically similar for all the treatments. The relationship of total fresh weight and shoot fresh weight and number of leaves with WUE and volume of irrigation water were statistically significant p≤0.05 while that of total dry weight, shoot dry weight and plant height with WUE and volume of irrigation water were not statistically significant at p≥0.05. SMS-based irrigation had higher irrigation water use efficiency more than manual irrigation which resulted to irrigation water saving compared to the manual irrigation without reducing the yield of Amaranthus cruentus.
Keywords: Soil Moisture, Water Use Efficiency, Amaranthus, Fresh weight, Plant height