Nitrogen-Zinc Content in Maize as Affected by Their Different Sources

A green-house experiment conducted to study N-Zn relationship in corn (Zea mays L.) using different sources of Zn and N in a Zn deficient Typic Torripsamment soil revealed that urea was one-third as efficient N source as ammonium sulphate (AS) and ammonium nitrate (AN). Shoot yield decreased with 400 ppm N from AS and urea but not from AN. Both N and Zn when applied together increased the yield as well as Zn concentration of shoot. However, the reverse was noted at 400 ppm N in case of shoot as well as root. The maximum increase in Zn concentration was observed with AN followed by urea and AS. Different sources of Zn had similar effect on N concentration. Zinc sulphate and rayplex zinc (R-Zn) were almost equally effective and superior to ZnO in increasing dry matter yield and shoot and root Zn concentration. Shoot N concentration decreased with increase in N level from 200 to 400 ppm N when Zn was not applied but reverse was noted in case of root.