The optimization of calcareous soil cation exchange capacity via the feather hydrolysate and N-P fertilizers integration.

Adding organic amendments to agricultural systems as sustainable practices is one of the most important stages toward creating a more sustainable and environmentally friendly food system. By increasing soil fertility and nutritional content, organic fertilizers increase plant productivity. Cation Exchange Capacity (CEC) is a vital indicator of soil fertility and plant nutrient availability, which is considered one of the most significant chemical parameters that affect agricultural soil quality. The main goals of the present study were to generate protein lysate from discarded feathers (enriched in different amino acids) through solid-state fermentation using Box-Behnken design (BBD). Then, assess the efficacy of hydrolyzed feather product (as an organic amendment), time, and N-P fertilizers on soil-CEC planted with maize in calcareous soil utilizing an optimization strategy that employed the central composite design and the response surface methodology (RSM). The results revealed that the protein concentration in the customized conditions was 1173.53 µg ml