LAUSR

Abstract Effect of formulated slow release NPK fertilizer [cellulose-graft-poly(acrylamide)/nanohydroxyapatite/soluble fertilizer] composite (SRF) on the performance and yield of maize, kale and capsicum was evaluated in a greenhouse experiment. No significant difference in growth parameters was observed between SRF and commercial fertilizer (CF) treatments. SRF recorded higher dry matter and yields relative to CF with similar application rates, though statistically insignificant. P deficiency was observed in maize at lowest SRF application rate of 45-57-17. N deficiency in CF was observed at the 8th week, but not in SRF with similar application rates during the same period. Kale showed both N and P deficiencies in the 7th week, while capsicum alone showed N deficiency in the 14th week in SRF at low application rates. NPK content in both maize and kale tissues, was significant between the amendments and control. Capsicum tissues had significantly (p ≤ 0.05) higher N content both in SRF and CF higher application rates of 125-159-45 & 100-100-100, respectively, compared to control. At final harvest, soil samples planted with maize and amended with the highest SRF rate showed significantly (p ≤ 0.05) higher P content, compared to lower rates and the control. The agronomic optimal rate of SRF determined by quadratic function were found to be higher than that of CF. SRF was found to enhance growth and yields of crops just like CF and could potentially have greater benefits such as improving soil health and resilience.