Effects of Cow Dung, NPK Fertilizer and Mulching on Zn, Pb Dynamics and Yield of Celosia Argentea

Field experiment was carried out at Teaching and Research Farm of Oyo State College of Agriculture and Technology to evaluate the effects of Cow dung, NPK fertilizer and mulching on heavy metals (Zn and Pb) dynamics in the soil, plant and yield of Celosia argentea. The treatments were; Control (CO), Cow-dung (CD) (5t/ha), NPK (120 kg/ha), mulching (MU) (5 t/ha), CD + MU (2.5 t/ha + 2.5 t/ha), CD + NPK (2.5 t/ha + 60 kg/ha), MU + NPK (2.5 t/ha + 60 kg/ha), CD + MU +NPK (1.67 t/ha +1.67 t/ha + 40 kg/ha). The treatments were laid out in Randomized Complete Block Design (RCBD) replicated three times. Data taken were soil, plant uptake (Zn and Pb) at 3, 6, 9, 12 weeks after planting and yield at harvest. Data collected were analyzed with Analysis of Variance (ANOVA) and the means were separated by Duncan Multiple Range Test (DMRT). Significant (P<0.05) differences were found among the treatments. The use of CD gave the highest Zn content (106.17 g) and CMN had the highest Pb content (516.17 g) in the soil. Treatment Co gave the highest Zn (62.92 g) while CM had the highest Pb uptake (71.32 g) in plant. Although, the use of CMN gave the highest yield (3.11 g) but low in Pb while NPK gave (9.67 g) of Pb in plant but with higher (2.56 g) yield. Thus, the sole use of NPK and Integrated use of either CMN or MN is therefore recommended for optimum production of Celocia argentea and reduction in the uptake of heavy metal (Zn and Pb) which may be threat to human health.