Impact of variable rate nitrogen and reduced irrigation management on nitrate leaching for potato

Abstract

Nitrogen (N) loss from cropping systems has important environmental implications, including contamination of drinking water with nitrate. A 2‐yr study evaluated the effects of six N rate, source, and timing treatments, including a variable rate (VR) N treatment based on the N sufficiency index approach using remote sensing, and two irrigation rate treatments, including conventional and reduced rate, on nitrate leaching, residual soil nitrate, and plant N uptake for potato (Solanum tuberosum L. cv. Russet Burbank) production in 2016 and 2017 on a Hubbard loamy sand. Nitrate leaching losses measured with suction‐cup lysimeters varied between 2016 and 2017 with flow‐weighted mean nitrate N concentrations of 5.6 and 12.8 mg N L−1, respectively, and increased from 7.1 to 10.4 mg N L−1 as N rate increased from 45 to 270 kg N ha−1. Despite reductions in N rate of 22 and 44 kg N ha−1 in 2016 and 2017, respectively, for the VR N treatment, there was no significant difference in nitrate leaching compared with the existing N best management practices (BMPs). Reducing irrigation rate by 15% decreased nitrate leaching load by 17% through a reduction in percolation. Residual soil nitrate N in the top 60 cm across all treatments (7.9 mg N kg−1) suggests a risk for nitrate leaching during the nongrowing season, and plant N uptake did not explain yearly variation in nitrate leaching and residual soil nitrate. Although existing N BMPs are effective at controlling N losses, development of alternative practices is needed to further reduce the risk of groundwater contamination.

Effects of Fertilization Management under WSPI on Soil Nitrogen Distribution and Nitrogen Absorption in Apple Orchard in Loess Plateau

“…It can be speculated that high nitrogen application could increase the risk of nitrogen leaching and increase the risk of groundwater pollution in long-term fertilization. A similar conclusion was showed by Bohman [35].…”

Genotype and Variable Nitrogen Effects on Tuber Yield and Quality for Red Fresh Market Potatoes in Minnesota

“…The release of nitrogen into the environment is a problem with standard cultivation practices for a variety of crops. The effects of variable timing, spacing, and rate of N fertilizer application has been studied in wheat (Triticum aestivum) [4,5], barley (Hordeum vulgare) [6], sugar beet (Beta vulgaris) [7], safflower (Carthamus tinctorius) [8], potato [5,[9][10][11][12][13], and many other crops. However, changes in management can make limited progress without corresponding changes in the genetics of the crops themselves [14].…”

Effect of Irrigation Scheduling Methods on Maize Grain Yield and Nitrate Leaching in Central Minnesota

“…Lack of efficient irrigation management is one of the major reasons for the negative environmental impacts of irrigated agriculture (Gabriel et al, 2012;Quemada et al, 2013;Sheikhzeinoddin and Esmaeili, 2017). Various farm management practices are observed to reduce agricultural NO 3 -N leaching (Bohman et al, 2020;Everett et al, 2019;Gabriel et al, 2013;Sigua et al, 2016). In particular, leaching of nitrates below the crop root zone can be reduced by managing nutrient and water inputs to the crop (Chen et al, 2017;Gheysari et al, 2009;Jia et al, 2014).…”

“…A recent study by Bohman et al (2020) in Minnesota showed that, a 15% reduction in irrigation rate decreased nitrate leaching by 17% through a reduction in deep percolation. Moreover, prior research also confirms a positive relationship between N and water use efficiencies (Muschietti-Piana et al, 2018;Quemada Miguel, 2016), which makes studying the impact of irrigation scheduling on nitrate leaching imperative.…”