The Effect of Soil pH and Cadmium on Nitrogen, Phosphorus and Chlorophyll Contents in Corn (Zea mays L.)
A pot experiment was carried out in the plastic greenhouse at the Institute of Sustainable Agrotechnology (INSAT), University Malaysia Perlis in Sungai Chuchuh, Perlis, Malaysia during the season of cultivation of 2014 to investigate the impact of soil pH and cadmium (Cd) on nitrogen (N), phosphorus (P) and chlorophyll contents of corn plant (Zea mays L.). Twenty-five were arranged in factorial experiments according to the complete randomized design (CRD), with three replicates. Five levels of soil pH were: pH4, pH5.2 (i.e., the original value), pH6, pH7 and pH8 and five levels of Cd: Cd 1, Cd 2, Cd 3, Cd 4 and Cd 0 where the amounts (2, 4, 6, 8 mg. kg−1 soil and control treatment without add Cd) are applied as CdCl2. Thus, the total numbers of pots were 75 pots. The results showed the soil pH7 led to significant effect in increasing the N and chlorophyll contents, while the decrease of soil pH to 5.2 led to significant effect to increase P content in the corn, as well as increase concentration of Cd led to significant decreasing in N, P and chlorophyll contents. As for the interactions between soil pH and Cd, it led interaction between pH 4 and Cd 4 to decrease of the N and chlorophyll contents in the corn, while the interaction between pH 8 and Cd 4 led to decrease in P contents in the corn.