Author:
Olusakin S. G, Kolawole G. O., Olagunju A. A. and Raji I. A.

Doi: 10.26480/amdn.02.2025.50.54

This is an open access article distributed under the Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Crop diversity in agroecosystems, such as intercropping, may impact on crop productivity and soil carbon sequestration. We hypothesized that combined application of poultry manure and mineral fertilizer may improve land productivity and soil carbon sequestration in maize/soybean cropping systems compared with mineral fertilizer. Therefore, this study was conducted at the Teaching and Research Farm, Ladoke Akintola University of Technology, Ogbomoso, Oyo State, Nigeria between April and September, 2023 to determine the effects of poultry manure and mineral fertilizer on soil carbon sequestration (SCS) and land productivity in maize/soybean cropping systems. The cropping systems were sole maize (SM), sole soybean (SS), maize/soybean intercrop (MSI) and natural bush regrowth (NBR) as main plot treatments while 120-60-30 kg NPK/ha (MF), 5 tDM poultry manure/ha (PM), 50% each of MF and PM combined (MF+PM) and control (no amendments), were subplot treatments arranged as split-plot in RCBD replicated four times. Data on SCS, land equivalent ratio (LER), maize grain yield (MGY) and soybean seed yield (SSY) were subjected to ANOVA and treatment means separated using LSD0.05.Compared with the pre-planting SCS, NBR reduced post￾harvest SCS by 19%, 17% by SM, 14.3% by SS and 37.3% by MSI. Combined application of MF+PM increased post-harvest SCS by 25.2 and 8.1% under SM and SS respectively compared with NBR. Intercropping had advantage over sole cropping with all LER>1. The MF+PM had the highest LER (2.19). In conclusion, the combined application of poultry manure and mineral fertilizer has the potential to increase SCS and land productivity in maize/soybean cropping systems.