Nitrate‐Nitrogen Losses through Subsurface Drainage under Various Agricultural Land Covers

Abstract

Nitrate-nitrogen (NO₃-N) loading to surface water bodies from subsurface drainage is an environmental concern in the midwestern United States. The objective of this study was to investigate the effect of various land covers on NO₃-N loss through subsurface drainage. Land-cover treatments included (i) conventional corn ( L.) (C) and soybean [ (L.) Merr.] (S); (ii) winter rye ( L.) cover crop before corn (rC) and before soybean (rS); (iii) kura clover ( M. Bieb.) as a living mulch for corn (kC); and (iv) perennial forage of orchardgrass ( L.) mixed with clovers (PF). In spring, total N uptake by aboveground biomass of rye in rC, rye in rS, kura clover in kC, and grasses in PF were 14.2, 31.8, 87.0, and 46.3 kg N ha, respectively. Effect of land covers on subsurface drainage was not significant. The NO₃-N loss was significantly lower for kC and PF than C and S treatments (p < 0.05); rye cover crop did not reduce NO₃-N loss, but NO₃-N concentration was significantly reduced in rC during March to June and in rS during July to November (p < 0.05). Moreover, the increase of soil NO₃-N from early to late spring in rS was significantly lower than the S treatment (p < 0.05). This study suggests that kC and PF are effective in reducing NO₃-N loss, but these systems could lead to concerns relative to grain yield loss and change in farming practices. Management strategies for kC need further study to achieve reasonable corn yield. The effectiveness of rye cover crop on NO-N loss reduction needs further investigation under conditions of different N rates, wider weather patterns, and fall tillage.

Navigating the Socio-Bio-Geo-Chemistry and Engineering of Nitrogen Management in Two Illinois Tile-Drained Watersheds

“…Cover crops have long been used to protect the soil from erosion; however, few studies have investigated the impact of cover crops on tile nitrate losses. Although Qi et al (2011) did not detect a reduction in tile nitrate yield with a rye cover crop, Strock et al (2004) found a modest reduction in tile nitrate yield of 13%, whereas Kaspar et al (2007) found large tile nitrate reductions (59%) using rye as a winter cover crop. Cover crops may be the only practice that can reduce both erosion and tile nitrate yields.…”

Corn Nitrogen Fertilization Requirement and Corn-Soybean Productivity with a Rye Cover Crop

“…However, changes in soil NO 3 -N during the spring could be influenced more by site-specific N mineralization, soil moisture, and variability in weather conditions than by RCC alone (Andraski and Bundy, 2008;Krueger et al, 2011). Qi et al (2011) found in Iowa that an RCC reduced NO 3 -N concentrations in tile drainage water in March through June, thus having a positive influence on springtime soil NO 3 -N loss. The RCC effectiveness depended on N rate applied to the prior-year corn, soil management, and weather patterns.…”

Legacy Nutrient Dynamics at the Watershed Scale: Principles, Modeling, and Implications

“…Accumulation of N in vadose zone is commonly observed in arid or semiarid region with high N surplus due to low carbon content, strong mineralization and nitrification abilities, and weak immobilization and denitrification abilities (Scanlon et al, 2008;Walvoord et al, 2003;Zhou et al, 2016). In many humid regions, nitrate would further (Puckett et al, 2011;Qi et al, 2011), Europe (39% of monitoring stations exceeded 25 mg L À1 ) (Angelopoulos et al, 2009;Worrall et al, 2015), India (average concentration exceeded 50 mg L À1 in northern India) (Suthar et al, 2009), and China (28% exceeded 10 mg L À1 ) (Gu et al, 2013;Ju et al, 2004). Although ammonia leaching is usually limited along the soil profile, increasing evidences indicated that leaching from landfills and septic tanks or other sewage disposal plants has resulted in a considerable ammonia accumulation in groundwater, presenting a high potential for storing ammonia in residential groundwater (Umezawa et al, 2009).…”