Effects of Water Stress and Nitrogen Fertilizer on Multi-Cut Forage Pearl Millet Yield, Nitrogen, and Water Use Efficiency

Forage pearl millet (Pennisetum americanum var. Nutrifeed) is a new forage crop in Iran. A field experiment was conducted at the University of Tehran to evaluate the response of pearl millet to four nitrogen (N) levels (0, 75, 150, and 225 kg N ha−1) and four irrigation regimes (40%, 60%, 80%, and 100% of available soil water abbreviated to I40, I60, I80 and I100, respectively) during 2006–2007. Total dry matter production reached a maximum of 24.4 and 23.5 t ha−1at I40 and I60 at N225, respectively. Nitrogen use efficiency decreased by adding more fertilizer and minimum nitrogen use efficiency was recorded at N225 over all irrigation regimes. At N225, water use efficiency reached the maximum of 3.57 and 4.10 kg m−3 in I80 and I100, respectively. Pearl millet forage could be produced in the regions where water is scarce and additional N fertilizer could increase total dry matter and water use efficiency.