Context: The maize-wheat (M-W) production system dominates semi-arid agroecosystem; however, maize productivity and nutrient-use efficiency (NUE) remain constrained under conventional tillage (CT) and suboptimal phosphorus (P) management. The combined influence of conservation agriculture (CA) and microbial-mediated P fertilization on crop performance and soil nutrient dynamics is not fully understood. Objective: This study evaluated the effect of tillage practices integrated with optimized P fertilization on maize productivity, resource-use efficiencies, soil P and carbon (C) fractions, and the carbon management index (CMI) within the M-W production system. Methods: A two-year field experiment (2016-2017) was conducted under semi-arid conditions using a split-plot design. Main plots included three tillage options: Conventional Tillage without residue (CT-R), Zero Tillage without residue (ZT-R), and Zero Tillage with residue (ZT+R). Sub-plots comprised five P-management practices (0-34.4 kg P ha(-)& sup1;), including a treatment combining reduced P input with phosphate-solubilizing bacteria (PSB). Results: ZT+R combined with the highest P rate (34.4 kg P ha(-)& sup1;) increased maize grain yield by similar to 57% and irrigation water productivity by similar to 49% compared with CT-R without P. Under ZT+R, grain protein yield increased by similar to 29% and nitrogen-phosphorus-potassium (NPK) uptake increased by similar to 31%, similar to 28%, and similar to 30%, respectively. The highest P rate enhanced protein yield by similar to 77% and nutrient uptake by similar to 72-76% relative to the no-P control. The combined application of reduced P (17.2 kg P ha(-)& sup1;) with PSB was associated with improvements in P recovery efficiency (similar to 65%) and agronomic efficiency (similar to 41%) compared to sole P application. ZT+R also increased labile and organic P fractions and improved soil C pools and CMI (similar to 3-10%) relative to CT-R and lower P inputs. Conclusions: Integrating CA practices, particularly ZT with residue retention, with optimized P fertilization improves maize productivity, resources-use efficiency, and soil P and C dynamics in semi-arid M-W systems. The inclusion of microbial-mediated P management showed beneficial associations with P-use efficiency; however, direct measurements of microbial activity and P transformation were not performed, and thus the underlying mechanisms should be interpreted with caution. Implications: These findings suggest that combining ZT+R with efficient P management strategies, including microbial inputs, can contribute to improved productivity and soil health. Further research incorporating biochemical and microbiological assessments is needed to validate the mechanistic role of microbial processes in enhancing phosphorus availability and system sustainability.