Effects of Varied Nitrogen Supply and Irrigation Methods on Distribution and Dynamics of Soil NO3-N during Maize Season

Dongliang Qi,Tiantian Hu

doi:10.5539/jas.v9n1p1

Abstract

A field experiment was carried out to investigate the effects of different supply methods of nitrogen (N) fertilizer and irrigation on the spatial distribution and dynamics of soil NO3-N for maize (Zea mays L.) grown in northwest China in 2012 and 2014. In 2012, there were three irrigation methods: alternate furrow irrigation (AI), fixed furrow irrigation (FI) and conventional furrow irrigation (CI). Three N supply methods: alternate N supply (AN), fixed N supply (FN) and conventional N supply (CN), were applied at each irrigation method. In 2014, the fixed treatments were excluded. Soil NO3-N in horizontal direction was measured to 100 cm soil profile. For 2012, at filling stage, compared to CI, AI increased soil NO3-N concentration under the plant by 4.5 to 7.4% in 0-40 cm soil profile and decreased that by 9.9 to 14.4% in 40-80 cm for three N supply methods. NO3-N concentration between two sides of the ridge was comparable for AN and CN coupled with AI or CI. When compared to CI, AI reduced soil NO3-N concentration in 60-100 cm by 4.8 to 8.7% from 12 collars stage to maturity over different positions when coupled with CN. Soil residual NO3-N at maturityin 0-100 cm was the lowest in AI coupled with CN or AN. The 2014 experiment verified the above results. Therefore, alternate furrow irrigation coupled with conventional or alternate N supply brought an optimum spatial distribution of soil NO3-N during maize season, resulting in little soil residual NO3-N at maturity.

Highlights

Declining freshwater resources have stimulated research into developing novel irrigation strategies to increase crop water use efficiency (Morison, Baker, Mullineaux, & Davies, 2008)
The irrigation method had a significant impact on NO3-N concentration at three positions of the plant in 0-40 cm soil profile, and the significant impact of irrigation method extended to 40-100 cm for north of the plant (NP) and south of the plant (SP)
On the contrary, compared to conventional furrow irrigation (CI), residual NO3-N was significantly decreased by AI in either N supply method. These results indicated that alternate furrow irrigation coupled with conventional or alternate N supply was useful to reduce residual NO3-N in 0-100 cm soil profile at maturity

Summary

Introduction

Declining freshwater resources have stimulated research into developing novel irrigation strategies to increase crop water use efficiency (Morison, Baker, Mullineaux, & Davies, 2008). Partial root-zone irrigation (PRI) is a new strategy of deficit irrigation. In alternate PRI, half of the root zone is irrigated while the other half is dried, and the previously well-watered side of the root system is allowed to dry while the previously dried side is fully irrigated (Kang, Zhang, Liang, Hu, & Cai, 1997). In fixed PRI, a fixed half of the root zone is always irrigated while the other half is always dried. Alternate PRI is considered a water-saving irrigation technique and is being intensively studied on field crops (Kang, Liang, Hu, & Zhang, 1998; Tang, Li, & Zhang, 2010; Shahnazari, Liu, Anderson, Jacobesen, & Jensen, 2007)

Methods

Results

Discussion

Conclusion