Effectof Cut-off Irrigationand Nitrogen Amendmentson the Growth and Yield of Forage Maize

The objective of this study was to evaluate the effects of cut-off irrigation and N amendments (urea fertilizer, poultry manure, cattle manure, poultry manure + cattle manure as 1:1 ratio) on the growth and yield of forage maize. The experiment was conducted as split–split plot treatment arrangement with four replications. Main plots consisted of two irrigation regimes (complete irrigation and cut-off irrigation at silking stage for two weeks) and sub-plots were control (without N amendment) and application of 200 kg N ha-1in the form of urea fertilizer, poultry manure, cattle manure, and cattle manure + urea fertilizer (1:1). Results indicated thatcut-off irrigation had a significant effect on soil moisture, leaf relative water content, leaf weight /stem weight and fresh forage yield, while soil moisture, leaf relative water content, plant height, leaf area index, fresh leaf weight, fresh stem weight, fresh ear weight, leaf weight /stem weight and fresh forage yield were significantly affected by N amendments.Irrigation and N amendment had significant interaction effects for leaf area index and fresh forage yield. The highest fresh forage yield, equal to 60 Mg ha-1, was recorded for normal irrigation and treated soil with solitary poultry manure, without significant differences with urea fertilizer + cattle manure. In general, solitary application of poultry manure or integration of urea fertilizer with cattle manure achieved the highest yield under normal irrigation and drought stress conditions in comparison to solitary application of urea fertilizer