Effect of N, Zn and B Levels on Yield, N, Zn and B Concentration, Uptake and N Use Efficiency in Maize –Wheat Sequence in a Vertisol

A field experiment was conducted during 2010-12 at Research Farm of Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur (Madhya Pradesh) to study the effect of levels of N (0, 60, 120 and 180 kg ha-1), Zn (0, and 10 kg ha-1) and B (0 and 1.0 kg ha-1) on yield, N, Zn and B concentration, uptake and N use efficiency by maize and wheat in maize–wheat sequence in a Vertisol. The treatments of N were applied to maize and wheat crop. While the treatments of Zn and B were applied to only maize crop and their residual effect was observed in wheat crop. Application of increasing levels of N in maize and wheat significantly increased the yield, B concentration in grain and strover/straw and N, Zn and B uptake by maize and wheat over their respective control. The N application of 120 and 180 kg ha-1 in wheat significantly increased the N, Zn and B concentration in grain and straw of wheat over control. The N use efficiency by maize and wheat significantly decreased with increasing levels of N.

The application of 10 kg Zn, 1.0 kg B and combined application of 10 kg Zn + 1.0 kg B and its residual effect significantly increased the grain yield, N uptake, Zn and B concentration in grain and their uptake by maize and wheat, respectively over control. The B application of 1.0 kg ha-1 and its residual effect was found significantly superior to 10 kg Zn ha-1 for grain yield, B concentration in grain, N, Zn and B uptake by maize and wheat, respectively.The B application of 1.0 kg ha-1 significantly increased the N use efficiency by maize over control.