Responses of root growth and distribution of maize to nitrogen application patterns under partial root-zone irrigation

Document Type: Research Paper

Authors

1 College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling 712100, P.R. China.

2 Key Laboratory for Crop Water Requirement and Its Regulation, Ministry of Agriculture, Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang 453002, China.

Abstract

A field experiment was carried out to investigate the effects of varying nitrogen (N) supply and
irrigation methods on the root growth and distribution of maize (Zea mays L.) in Wuwei,
northwest China in 2011 and 2012. The irrigation treatments included alternate furrow irrigation
(AI), fixed furrow irrigation (FI) and conventional furrow irrigation (CI). The N supply treatments
included alternate N supply (AN), fixed N supply (FN) and conventional N supply (CN), were
applied at each irrigation method. The root growth across the plant row was measured in 0-100 cm
soil profile (20 cm as an interval) at maturity. The results showed that root distribution of two
sides of the row was uniform for AI or CI coupled with CN or AN. Root length density (RLD) in
0-40 cm soil depth was significantly increased by AI compared to other irrigation methods while
decreased by FN compared to other N supply treatments. Though RLD decreased more with soil
layer deepening under AI, RLD in 60-100 cm soil depth in AI treatment was still larger than that
in CI and FI treatments. In general, total fine root (diametersurface area, and grain yield of maize were significantly increased by AI coupled with CN or AN
when compared to other treatments. These results indicate that alternate partial root zone irrigation
coupled with conventional or alternate nitrogen supply is useful to improve the root growth and
grain yield of maize in the arid area.

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