Yield potential and water use of broad bean (Vicia faba L.) as influenced by irrigation and phosphorus levels

A field experiment was conducted at Nadia during Rabi, 20102011 to evaluate the performance of broad bean in respect of its grain yield, nutrient uptake, water use under different irrigation and P levels. Three levels of irrigation in main plots (I₁: Rainfed, I₂: Ø =-0.05 MPa at 30 cm soil depth, I₃: Ø =-0.03 MPa at 30 cm soil depth) and 4 levels of phosphorus insubplots(P₁=0, P₂=25, P₃=50 and P₄=75kg P₂O₅/ha) were evaluated in a Split plot design with three replications. Broad bean irrigated at Y =-0.03 MPa at 30 cm soil depth (I₃) showed 5.13% and 34.79% higher seed yield compared to I₂ and I₁, respectively and was significantly superior. The plots (with medium P availability) receiving 75 kg P₂O₅/ha (P₄) was significantly superior (with 5.31 t/ha seed yield) to both 50 and 25 kg P₂O₅/ha. The former enhanced seed yield to the tune of 9.26% over P₃ and 28.57% over P₂ treatments. The yield attributing characters also followed the same trend as that of seed yield. Maximum N, P, K uptake were recorded by the crop irrigated at Y =-0.03 MPa at 30 cm soil depth (I₃) and fertilized with 75 kg P₂O₅/ha (P₄). Among different P levels the maximum P uptake (24.1 kg/ha) was recorded with 75 kg P₂O₅/ha (P₄) with higher recovery of P (32.2%). In the light of interaction effects, combination of irrigation at Y= 0.03 MPa at 30 cm soil depth and fertilization at 75 kg P₂O₅/ha was found most appropriate as this had highest net return and B: C ratio.