Interactive effects of acacia biochar, maize hybrids, and irrigation levels on soil health and crop productivity

The demand for sustainable agricultural solutions has increased because of issues like declining soil fertility from inorganic soil changes, increasing crop water demands, shifting weather patterns, and decreasing water resources. The addition of activated acacia biochar to degraded soil can significantly influence soil health by improving its moisture and nutrient retention capacity, as well as crop productivity under water-limited conditions. At present, field experiment under split-plot design was conducted to explore the suitable level of activated biochar (A0, 0 tons ha^-1; A1, 5 tons ha^-1; A2, 10 tons ha^-1;) for maize hybrids (DK-2088, YH-5427, and DK-6317) under different moisture regimes (100% ET_C; full irrigation (FI), 70% ET_C; partially deficit irrigation (PDI), and 50% ET_C; severely deficit irrigation (SDI)) during maize growing year 2023 from February to June. The results showed that the addition of 10 tons ha^-1 activated biochar caused a maximum improvement in soil organic matter (109%), saturation percentage (13%), and mineral profile particularly carbon (83%) and calcium (52%). Under full irrigation (FI), activated acacia biochar amendment in the soil caused an improvement in the physiological and biochemical parameters such as sugar (55%) and protein content (136%), and yield attributes of all maize hybrids, particularly DK-6317. However, under severely deficit irrigation (SDI), the highest improvement in protein content, and yield per hectare was found in DK-2088, <i>i.e.</i>, 11% to 29% higher in 5 tons ha^-1, 10 tons ha^-1 activated biochar amended soil, respectively. The average economic gain percentage was highest in DK-6317, <i>i.e.</i>, 1-fold, and 2.5-fold higher under PDI, and SDI in 10 tons ha^-1 activated biochar amended soil. The present study indicates the significance of organically activated acacia biochar amendments in soil for improving its water retention capacity and enhancing maize growth and yield under moisture-deficit conditions.