Seasonal dynamics of nitrate and ammonium ion concentrations in soil solutions collected using MacroRhizon suction cups

Cezary Kabala,Anna Karczewska,Bernard Gałka,Józef Sowiński,Mateusz Cuske

doi:10.1007/s10661-017-6022-3

Cezary Kabala, Anna Karczewska + Show 3 more

Open Access

https://doi.org/10.1007/s10661-017-6022-3

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Abstract

The aims of the study were to analyse the concentration of nitrate and ammonium ions in soil solutions obtained using MacroRhizon miniaturized composite suction cups under field conditions and to determine potential nitrogen leaching from soil fertilized with three types of fertilizers (standard urea, slow-release urea, and ammonium nitrate) at the doses of 90 and 180 kg ha−1, applied once or divided into two rates. During a 3-year growing experiment with sugar sorghum, the concentration of nitrate and ammonium ions in soil solutions was the highest with standard urea fertilization and the lowest in variants fertilized with slow-release urea for most of the months of the growing season. Higher concentrations of both nitrogen forms were noted at the fertilizer dose of 180 kg ha−1. One-time fertilization, at both doses, resulted in higher nitrate concentrations in June and July, while dividing the dose into two rates resulted in higher nitrate concentrations between August and November. The highest potential for nitrate leaching during the growing season was in July. The tests confirmed that the miniaturized suction cups MacroRhizon are highly useful for routine monitoring the concentration of nitrate and ammonium ions in soil solutions under field conditions.

Highlights

The environmental consequences of nitrogen fertilization are mainly related to easy nitrate leaching to the ground and surface waters that has extensive negative environmental and economic consequences (Berge et al 2001; Csathó et al 2007; Zakarauskaite et al 2008)
Miniaturized composite suction cups MacroRhizon enable the precise monitoring of the concentration of nitrate and ammonium ions under field conditions, at various soil depths and in a large number of replications
Both the ammonium and nitrate ions reached their maximum concentrations in the soil solutions during the growing season in June–July and the minimum concentrations in September–October

Summary

Introduction

The environmental consequences of nitrogen fertilization are mainly related to easy nitrate leaching to the ground and surface waters that has extensive negative environmental and economic consequences (Berge et al 2001; Csathó et al 2007; Zakarauskaite et al 2008). Mineral fertilizers that contain nitrogen in nitrate form present a particular threat to the waters; other nitrogen fertilizers, including those considered to be Bsafer^ due to their slow decomposition rates, undergo transformation in the soil and are a source of forms susceptible to leaching to the groundwater or to release to the atmosphere (Fotyma et al 2010; Bouwman et al 2013). European Union member states have adopted both the BNitrate Directive^ (1991/676/EC) with the aim of. 304 Page 2 of 12 protecting waters against pollution caused by nitrates from agricultural sources and a directive (2006/118/EC) on the protection of groundwater against pollution and deterioration. Legal regulations in individual member states, including Poland (Regulation 2002), are compliant with the requirements of both these directives. The threshold concentration of nitrates (NO3−) in groundwater has been determined as 50 mg dm−3, which corresponds to 11.3 mg dm−3 of nitrate nitrogen (N-NO3−)

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