Abstract

Quantification of the interactive effects of irrigation water and nitrogen (N) fertiliser on nitrogen use efficiency (NUE) provides an important insight for more effective water and N management. This study evaluated the effects of different irrigation and N fertiliser management options on water flux, N uptake, NUE and maize grain yield in a semi-arid loamy sand, in Mozambique. The experiments were carried out in field plots in two consecutive cropping periods (CP's) representing contrasting growing seasons: a hot-wet season (CP-1) and a cold-dry season (CP-2). The treatments included two irrigation methods (furrow and drip), two irrigation levels (75 and 100% of the crop water requirement), and two distinct N fertiliser types (a quick-release and slow-release urea) arranged in a randomised complete block design. In both CP-1 and CP-2, NUE tended to be higher for the 75% irrigation level, regardless of irrigation method and N fertiliser type. Higher NUE was generally observed in CP-2 than in CP-1. The highest grain NUE (41.6 kg kg(-1) N) was observed in CP-2 under furrow irrigation combined with 75% irrigation level and quick-release N fertiliser. Slow-release N fertiliser did not improve N uptake, NUE or maize yield. Potential N losses were assumed to be higher in CP-1 than in CP-2, associated with higher estimated deep percolation volumes in CP-1 (mean 127 mm) than in CP-2 (mean 12 mm). In CP-1, deep percolation events mainly coincided with high rainfall events. Furrow irrigation tended to give higher NUE than drip irrigation, especially in CP-2. Reducing of irrigation level by 25% tended to increase N uptake, NUE and maize yield for both CP-1 and CP-2. The effects of slow-release N fertiliser and drip irrigation were inconclusive. (C) 2016 Elsevier B.V. All rights reserved.

Keywords

Irrigation method; Nitrogen fertiliser; Maize; Mozambique; Water balance

Published in

Agricultural Water Management
2016, Volume: 168, pages: 68–77

SLU Authors

• Joel, Abraham

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Wesström, Ingrid

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Messing, Ingmar

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Environmental Management
Environmental Sciences
Agricultural Science


Publication identifier

DOI: https://doi.org/10.1016/j.agwat.2016.02.004

Permanent link to this page (URI)

https://res.slu.se/id/publ/69986