Effects of Irrigation Interval on Growth Analysis of Soybean [(Glycine max (L.) Merr.]

A field experiment was conducted with the ultimate goal of irrigation is to utilize added water efficiently on soybean that can give the greatest seed yield per hectare increase from added water in crop year 2015/2016 BC at Hawassa located at 0703'N and 38028'E, and at 1708 masl. Maximum and minimum daily temperature was 27 and 13oc respectively. This experiment was RCB design with 4 replicates was performed on earth. Each experimental unit with dimensions of 2×2 m and was planted with 5 rows. The irrigation interval includes 3,8,13 days. After collecting data such as stem weight, leaf weight, leaf area, plant weight and plant height. SLA, LAR, NAR and RGR were analyzed. SLA and LAR decreased with age increase under all irrigation intervals and maximum RGR and NAR were achieved at 8 day irrigation interval with a value of 102.5 mg g-1 day-1 and 77.5 mg dm-2 day-1 respectively. The highest biomass of soybean was recorded at irrigation intervals of 3 days with a mean value 176.7163g/m2. Keywords: SLA, LAR, RGR and NA