Effect of Fertility Levels and Biofertilizers on Growth and Yield of Cowpea (Vigna unguiculata L.) in the Semi-Arid Region of Rajasthan, India
Arvind
Department of Agronomy, MJRP College of Agriculture & Research, Achrol, Jaipur (Rajasthan), India.
Amit Kumar
*
SKM Agriculture College, Padampur, Swami Keshwanand Rajasthan Agricultural University, Bikaner (Rajasthan), India.
Rajveer
Department of Soil Science, Swami Keshwanand Rajasthan Agricultural University, Bikaner (Rajasthan), India.
Kirandeep Kaur
SKM Agriculture College, Padampur, Swami Keshwanand Rajasthan Agricultural University, Bikaner (Rajasthan), India.
Sandeep Kumar
SKM Agriculture College, Padampur, Swami Keshwanand Rajasthan Agricultural University, Bikaner (Rajasthan), India.
*Author to whom correspondence should be addressed.
Abstract
A field experiment was conducted during the Kharif season of 2018 at the Agronomy Farm, MJRP College of Agriculture & Research, Achrol, Jaipur (Rajasthan), to study the effects of different fertility levels and biofertilisers on the growth and yield of cowpea (Vigna unguiculata L.). The experiment was laid out in a Factorial Randomised Block Design (RBD) with three replications, comprising sixteen treatment combinations of four fertility levels [Control (F₀), 50% RDF (F₁), 75% RDF (F₂), and 100% RDF (F₃)] and four biofertiliser treatments [Control (B₀), Rhizobium (B₁), PSB (B₂), and Rhizobium + PSB (B₃)]. Cowpea variety RC-101 was sown at a spacing of 30 cm × 10 cm with a seed rate of 20 kg ha⁻¹.
Growth parameters, yield attributes, and yields were significantly influenced by both fertility levels and biofertiliser application. Among fertility levels, 100% RDF recorded the maximum plant height (67.72 cm), number of branches per plant (9.50), dry matter accumulation (118.63 g plant-1), chlorophyll content (2.61 mg g⁻¹), pods per plant (9.21), seeds per pod (8.34), seed yield (1042 kg ha⁻¹), straw yield (1961 kg ha⁻¹), biological yield (3003 kg ha⁻¹), and harvest index (34.54%), which were statistically at par with 75% RDF but significantly superior to lower fertility levels. Among biofertilisers, the combined inoculation of Rhizobium + PSB consistently outperformed individual inoculations and the un-inoculated control, producing the highest seed yield (1056 kg ha⁻¹), which was 47.33% higher than the control. Test weight (1000-seed weight) was not significantly influenced by either factor. Interaction effects between fertility levels and biofertilisers were non-significant for all parameters, indicating additive effects.
The study concludes that the application of 75–100% RDF along with combined inoculation of Rhizobium + PSB significantly enhances growth, yield attributes, and seed yield of cowpea under semi-arid conditions of Rajasthan. However, considering economic viability and resource efficiency, the treatment combination of 75% RDF + Rhizobium + PSB is recommended for sustainable cowpea production in the region.
Keywords: Cowpea, fertility levels, biofertilisers, Rhizobium, phosphate-solubilising bacteria (PSB), recommended dose of fertiliser (RDF), growth attributes, yield attributes, seed yield, semi-arid Rajasthan