Coconut Shell Biochar and Sheep Manure for Food Security of Maize on Samas Coastal Sandy Land

Coastal sandy soils have limited productivity due to their low organic matter content, cation exchange capacity, and water-holding ability, thus requiring environmentally friendly soil management innovations. Coconut shell biochar is known to improve soil physico-chemical properties, while sheep manure serves as a source of readily mineralizable organic nutrients. However, the interaction between the two in maize cultivation systems on coastal sandy soils has not been extensively studied. This study aimed to evaluate the effects of combined doses of coconut shell biochar and sheep manure on soil chemical properties and maize productivity in the sandy soils of Samas Coast. The research employed a Randomized Block Design (RBD) with two factors: biochar dose (0, 10, 15, and 20 tons/ha) and sheep manure dose (0; 2,5; 5; and 7,5 tons/ha). Observed parameters included soil organic C, cation exchange capacity (CEC), plant dry weight, and maize yield (tons/ha). Data were analyzed using analysis of variance (ANOVA), followed by post-hoc tests to determine differences among treatments. The results showed that the addition of biochar and sheep manure had significant effects on all observed parameters. The combination of medium biochar dose (20 tons/ha) and high sheep manure dose (30 tons/ha) (B2K3) resulted in the highest increase in CEC (28.5 me%), organic C (1.25%), plant dry weight, and maize yield exceeding 10 tons/ha. This indicates a synergistic effect between biochar and sheep manure in improving soil fertility and maize productivity on sandy soils. These findings contribute to the development of sustainable coastal soil management strategies, reducing dependence on chemical fertilizers and thereby supporting food security.