Determination of Crop Co-efficient Values of Soybean (<i>Glycine max</i> [L.] Merrill) by Lysimeter Study

Abstract

Local level calibration of crop coefficient (K c ) values is critical for regional level planning and allocation of water resources for irrigation. In this regard, an experiment was conducted at the Irrigation and Water Management Division of Bangladesh Agricultural Research Institute (BARI), Gazipur, in order to estimate crop coefficient values of soybean under the local climatic condition. An improved crop variety-BARI Soybean-6 was used in this experiment. The crop was grown under four irrigation treatments, allowing irrigation at an interval of 10, 15, 20 and 25 days. The treatments were so designed that drainage was allowed between the consecutive irrigations. Irrigation at 15 days interval produced the highest seed yield of 1.26 t/ha and was considered to be suitable for estimating seasonal crop evapotranspiration (ET c ) and K c values. The seasonal highest cumulative ET c was 308.43 mm under this treatment. The K c values of soybean at initial, development, mid-season and late season stages were found as 0.67, 1.46, 1.59 and 0.62, respectively.

Soil Water Status, Mineral Nutrition and Biological Response of Soybean Under Protected Environment Conditions

“…To determine reference evapotranspiration (ETo), we made use of the Class A Pan approach in light of water evaporation measurements taken every other day and by multiplying them by a pan coefficient (Kp) corresponding to 0.75 (PEREIRA et al, 2002). Maximum evapotranspiration (ETm) for soybean crop was obtained by multiplying ETo by the following relative water consumption or crop coefficient values: 0.67 from day after sowing (DAS) 1 to 25; 1.59 from DAS 25 to 105; and 0.62 from maturation stage to harvest (MILA et al, 2016).…”