Effect of spacing and nutrient levels on growth, yield and economics of fodder rice bean [Vigna umbellata (Thunb.)].

A field experiment was conducted at College of Agriculture, Vellayani, Trivandrum to standardize the spacing and nutrient levels of fodder rice bean [Vigna umbellata (Thunb.)]. The treatments consisted of three spacing (s1-30 cm × 10 cm, s2-30 cm × 20 cm and s3-30 cm × 30 cm), three levels of nitrogen (n0-0 kg N ha−1, n1-20 kg N ha−1 and n2-30 kg N ha−1) and three levels of phosphorous (p0-0 kg P2O5 ha−1, p1-20 kg P2O5 ha−1 and p2-40 kg P2O5 ha-1). Result showed that sowing of rice bean at spacing of 30 cm × 10 cm (s1) recorded highest plant height (49.04 cm) at 30 DAS and leaf: stem ratio (0.63) at harvest. The treatment n1 (20 kg N ha−1) resulted in highest plant height and it was on par with n2 (30 kg N ha−1), while leaf to stem ratio was the highest at n2 at harvest. Similarly the highest green (14.57 t ha−1) and dry fodder yield (2.91 t ha−1) were recorded at spacing of 30 cm × 10 cm (s1) and at n2 (30 kg N ha−1) resulting in greater net returns (Rs. 35, 761 ha-1) and B: C ratio (3.22).