Influence of farmyard manure compost and biochar in the amelioration of soil fertility and crop productivity under drought stress conditions

Drought stress is a leading environmental concern which restricts plant growth and nutrients availability. A greenhouse pot experiment was designed to examine the impact of farmyard manure-based biochar (FMB) and compost (FMC) on soybean osmoprotectants, antioxidants, nutrient uptake, and soil biochemical characteristics under three different moisture levels of w100, 75, and w50. Results of the study revealed that drought stress significantly reduced plant's physiochemical and gaseous exchange attributes whilst combine treatment of FMB30 + FMC30 substantially improved soybean root growth, leaf area index, total chlorophyll content, and stomatal conductance by 37.41, 19.55, 32.59, and 27.61%, respectively, at W50 moisture level. Additionally, leave relative water content also boosted up to 18.62% at W50 moisture under FMB30 + FMC30 treatment. Additionally, leaves catalase, peroxide and superoxidase dismutase notably decreased up to 49.15, 41.64, and 76% respectively under the co-amendment of FMB and FMC. Moreover, soil MBC (22%), MBN (124%), MBP (97%), NO₃-N (167%), NH₄-N (158%), Olsen P (54%), K (23), and SOC (7.51%) increased remarkably under FMB30 + FMC30 treatment at w50 drought level. Overall, these results indicate that biochar and compost both are crucial amendments particularly in semi-arid and arid regions to get better crop yield.