The demand for a better agricultural productivity and the available phosphorus (P) limitation in plants are prevailing worldwide. Poor P availability due to the high pH and calcareous nature of soils leads to a lower P fertilizer use efficiency of 10–25% in Pakistan. Among different technologies, the use of biologically acidified amendments could be a potential strategy to promote soil P availability and fertilizer use efficiency (FUE) in alkaline calcareous soils. However, this study hypothesized that an acidified amendment could lower soil pH and solubilize the insoluble soil P that plants can potentially uptake and use to improve their growth and development. For this purpose, the test plant Zea mays was planted in greenhouse pots with a recommended dose rate of 168 kg ha⁻¹ of P for selected phosphatic fertilizers, viz., DAP (diammonium phosphate), SSP (single superphosphate), and RP (rock phosphate) with or without 2% of the acidified product and a phosphorus solubilizing Bacillus sp. MN54. The results showed that the integration of acidified amendments and PSB strain MN54 with P fertilizers improved P fertilizer use efficiency (FUE), growth, yield, and P uptake of Zea mays as compared to sole application of P fertilizers. Overall, organic material along with DAP significantly improved plant physiological-, biochemical-, and nutrition-related attributes over the sole application of DAP. Interestingly, the co-application of RP with the acidified product and MN54 showed a higher response than the sole application of DAP and SSP. However, based on our study findings, we concluded that using RP with organic amendments was a more economically and environmentally friendly approach compared to the most expensive DAP fertilizer. Taken together, the current study suggests that the use of this innovative new strategy could have the potential to improve FUE and soil P availability via pH manipulation, resulting in an improved crop productivity and quality/food security.

The key plant nutrients determine the crop’s nutritional status and vigor, while their deficiency impairs the plant growth resulting in absolute failure of crop productivity. Phosphorus is the second major essential nutrient for the growth and establishment of crops. Drastic variations in climatic conditions across the world and low soil fertility, especially phosphorous (P) fixation in alkaline calcareous soils of arid climate have become serious issues threatening the productivity of crops. In this regard, the application of different organic fertilizers in combination with the lower dose of chemical fertilizers has been proved as an effective strategy to improve plant growth and yield. Thus, a pot experiment was conducted in order to evaluate the combined effects of animal manures (normal and processed) along with the recommended and half of the chemical fertilizer di-ammonium phosphate (DAP) on the growth, physiology, nodulation, and yield of chickpea. Results show that the animal manure (normal and processed) with half or recommended dose of DAP significantly improved the growth, yield, and physiological attributes of the chickpea. However, the combined application of normal animal manure with half DAP showed the highest results among all other treatments. It increased the contents of leghaemoglobin, P, K, primary branches, pods, and seed weight up to 113.7%, 97.8%, 80.6%, 78.5%, 119%, and 145% over control, respectively. This treatment also increased protein contents, nodule count, and nodule weight up to 78.38%, 147%, and 93.59% than the control, respectively. Maximum chlorophyll b contents (0.78 μg/mL) were obtained with the application of a recommended dose of DAP alone. These indigenous manure applications provide a novel value addition that is critical to boosting crop yield and agricultural sustainability.