Nitrogen, irrigation, and alley management effects on nitrate leaching from raspberry

Abstract

High NO 3 concentrations in the Abbotsford-Sumas aquifer are linked to raspberry (Rubus idaeus L.) production. Passive capillary wick samplers were used to quantify the impacts of N, irrigation, and alley managements on drainage and NO 3 leaching from raspberry rows and alleys over 4 yr. Conventional management (100 kg N ha −1 surface broadcast on the row as a split application, clean cultivation of alleys, and fixed-duration drip irrigation) was compared with different mineral fertilizer N rates, N applied as manure, alleys seeded to a perennial forage grass or an autumn-seeded spring barley (Hordeum vulgare L.) crop, or evapotranspiration (ET)-scheduled irrigation. The temporal pattern of drainage and NO 3 leaching was driven by seasonal precipitation and growing season irrigation. Growing season drainage and NO 3 leaching were much lower under ETscheduled irrigation compared with fixed irrigation. Nitrate leaching was high (up to 90 kg N ha −1), even with no managed N inputs due to high inherent soil fertility and large quantities of N applied in irrigation water. Nitrate leaching was insensitive to N fertilizer rate. Application of N as poultry manure more than doubled NO 3 leaching compared with fertilizer, emphasizing the need to use organic N inputs judiciously. The perennial grass alley cover crop resulted in the greatest overall reduction in NO 3 leaching. Our data indicate that no single management strategy is sufficient to protect groundwater quality. Rather, an integrated package of improved practices (i.e., application of a reduced rate of mineral N through fertigation, combined with ET-scheduled irrigation and perennial alley crop) is necessary to protect groundwater quality.

Nitrogen, irrigation, and alley management affects raspberry crop response and soil nitrogen and root‐lesion nematode dynamics

“…Despite addition of lower amounts of water, and thus lower N inputs through N‐laden irrigation water under ET‐scheduled than fixed‐duration irrigation (28 vs. 60 kg N ha −1 ), there was no difference in berry yield, crop vigor, or crop N status between the I ET and N 100 treatments. Whereas there was no significant difference in soil NO 3 –N concentration measured in the row between the I ET and N 100 treatments, the N 100 treatment had significantly greater NO 3 leaching during the growing season compared with the I ET treatment (Kuchta et al., 2020).…”

“…Water management can also influence N cycling; insufficient water supply limits crop growth and excess water contributes to NO 3 leaching (Neilsen and Neilsen, 2019). There is evidence of NO 3 leaching from the raspberry root zone over the growing season in response to irrigation in this region (Kuchta et al, 2020;Loo, Zebarth, Ryan, Forge, & Cey, 2019). Irrigation scheduling based on evaporative demand may provide a means to improve water and nutrient management and promote water conservation (Neilsen and Neilsen, 2002) relative to the current practice of fixed-duration irrigation management.…”

“…The objective of this study was to quantify the effects of different N, irrigation and alley management strategies on berry yield, indices of crop vigor and crop N status, growing season soil N dynamics, and RLN population dynamics under red raspberry production. The current study was part of a larger study, and information on drainage and NO 3 leaching from all treatments (Kuchta et al., 2020) and on leachate NO 3 concentration and NO 3 isotope composition for two treatments over a 1‐year period (Loo et al., 2017) have been previously reported from this field trial.…”

“…Much of the BC raspberry production occurs in the Lower Fraser Valley and particularly over the Abbotsford–Sumas aquifer (ASA), where the mild climate and well‐drained soils favor production. However, elevated nitrate (NO 3 ) concentrations in the ASA have been linked to raspberry production (Wassenaar, 1995; Zebarth, Ryan, Graham, Forge, & Neilsen, 2015) and recent studies have documented significant NO 3 leaching from the raspberry root zone (Kuchta, Neilsen, Forge, Zebarth, & Nichol, 2020; Kuipers, Ryan, & Zebarth, 2014; Malekani et al., 2018). Consequently, there is a need to identify raspberry management practices that sustain productivity while minimizing NO 3 leaching losses to groundwater.…”

Effects of elevated temperature and abnormal precipitation on soil carbon and nitrogen dynamics in a Pinus densiflora forest

“…In addition, it has been widely observed that the variation and intensity of precipitation are one of the most important factors governing nitrate leaching (e.g., Di and Cameron, 2002;Jabloun et al, 2015;He et al, 2018). Nitrogen in groundwater, especially in an unconfined aquifer, is a direct response to nitrogen leaching from the vadose zone (Hansen et al, 2017;Kuchta et al, 2020). Petrovic (1990) found that there is a great potential for nitrate leaching under increased precipitation in the late fall due to reduced evapotranspiration and decreased microbial activity.…”