Effect of Recommended and Graded Doses of Biochar with and without ZMB Biofertilizer and Zinc on the Growth Attributes of Rice (Oryza sativa L.)

A field experiment was conducted during the Kharif seasons of 2022 and 2023 at the Students' Instructional Farm, Acharya Narendra Deva University of Agriculture and Technology, Kumarganj Ayodhya, to assess the impact of graded doses of biochar, varying fertility levels, and the addition of biofertilizers and zinc on rice cultivation under partially reclaimed sodic soils. Nine treatments were applied, including combinations of recommended doses of fertilizers (RDF), biochar (5 t ha⁻¹ and 2.5 t ha⁻¹), biofertilizer (ZMB), and zinc sulphate (ZnSO₄) in a randomized block design with three replications. The treatments were: T1 (Control), T2 (100% RDF), T3 (50% RDF), T4 (50% RDF + 5 t ha⁻¹ biochar), T5 (50% RDF + 5 t ha⁻¹ biochar + ZMB), T6 (50% RDF + 5 t ha⁻¹ biochar + ZMB + ZnSO₄), T7 (100% RDF + 2.5 t ha⁻¹ biochar), T8 (100% RDF + 2.5 t ha⁻¹ biochar + ZMB), and T9 (100% RDF + 2.5 t ha⁻¹ biochar + ZMB + ZnSO₄). The rice variety NDR 2065 was used as the test crop. Growth parameters such as plant height, dry matter accumulation, root length, root volume, number of tillers, and panicle length were evaluated. The results showed that the treatment T9 (100% RDF + 2.5 t ha⁻¹ biochar + ZMB + ZnSO₄) produced the highest growth and quality parameters, indicating a significant improvement in rice performance. The study suggests combining biochar, biofertilizers, and zinc under reduced fertilizer levels can enhance rice growth and productivity in sodic soils, offering a sustainable approach to soil fertility management.