Influence of Biochar and Nitrogen Integration on Maize Yield, Soil Available Nitrogen and Uptake

Abstract

Aims: To evaluate how the integration of corn cob-derived biochar with nitrogen fertilizer affects maize yield and soil nutrient status during the Rabi season in Telangana, India. Study Design: Randomized Block Design with eight fertilizer treatments and three replications. Place and Duration of Study: Regional Agricultural Research Station, Polasa, Jagtial, Professor Jayashankar Telangana Agricultural University, Telangana, 2024-25 Rabi season. Methodology: Eight treatments were compared: control (0:80:80 NPK kg ha-1), recommended dose of fertilizers (240:80:80 NPK kg ha-1), various combinations of biochar urea mixes at 75%, 100%, and 125% of recommended nitrogen dose (RDN) for two biochar:urea ratios (1:1 and 1:1.5). Maize (DHM-117) was grown in sandy clay loam soil (pH 6.74, EC 0.15 dS m-1, organic carbon 0.51%). Biochar was produced from corn cob via slow pyrolysis, characterized and mixed with urea before split application. Crop growth parameters (plant height, SPAD) Yield attributes (stover, grain), test weight and total N uptake, where as soil pH, EC, organic carbon and available nitrogen were measured at post harvest stage. Results: The treatment T6 (125% RDN as biochar urea mix 2, 1:1.5) achieved the highest plant height (264.6 cm), chlorophyll content (54.5), test weight (32.9 g), stover yield (9095 kg ha-1) and grain yield (8051 kg ha-1) and total N uptake (220.2 kg ha-1). Enhanced soil properties were observed: pH (7.62), EC (0.28 dS m-1), organic carbon (0.72%) and available N (126.4 kg ha-1). Control plots showed lowest values in crop growth, yield, uptake and soil metrics. Conclusion: Applying biochar with nitrogen fertilizer, especially at 125% RDN in a 1:1.5 ratio, improved maize yield and soil quality. Biochar helped by releasing nutrients slowly and lowering the need for chemical fertilizers. Still, its role in sustainable farming is only supportive and should be considered along with economic, environmental and social aspects.