Evaluation of the Efficacy of Polymer Nanocomposite Fertilizer on Growth and Yields of Maize, Capsicum, and Kale

This study carried out a greenhouse experiment to evaluate growth and yield response of maize, capsicum, and kale to a nanocomposite slow-release fertilizer (SRF). Higher biomass and yields were observed in SRF amendments compared with conventional fertilizer (CF) treatments at similar rates though not statistically significant. Crops were mainly reliant on external nutrient supply and revealed deficiency at low application rates. Maize and kale tissue NPK contents from fertilizer-amended soil were significant (p ≤ 0.05) relative to those of untreated soil. Significantly higher N content was recorded in capsicum tissues at high application rates in both SRF and CF amendments relative to control. At final harvest, significantly higher P content was observed in soil that had been planted maize and treated with the highest rates of nanocomposite NPK fertilizer (223:285:83 kg ha−1) than those of lower rates and control. Nanocomposite fertilizer recorded higher values of agronomic optimal rates than CF amendments. The growth and yield response of crops to both SRF and CF treatments were comparable, though SRF could be of greater potential gains such as improved soil quality and resilience.