Comprehensive Nitrogen Budgets for Corn and Soybean Fields Under Controlled Tile Drainage for Wetter and Drier Cropping Seasons.

Sunohara, M., Craiovan, E., Topp, E., Gottschall, N., Drury, C.F., and Lapen, D.R. (2014). "Comprehensive Nitrogen Budgets for Corn and Soybean Fields Under Controlled Tile Drainage for Wetter and Drier Cropping Seasons.", Journal of Environmental Quality, 43(2), pp. 617-630. doi : 10.2134/jeq2013.04.0117  Access to full text

Abstract

Excessive N loading from subsurface tile drainage has been linked to water quality degradation. Controlled tile drainage (CTD) has the potential to reduce N losses via tile drainage and boost crop yields. While CTD can reduce N loss from tile drainage, it may increase losses through other pathways. A multiple-year field-scale accounting of major N inputs and outputs during the cropping season was conducted on freely drained and controlled tile drained agricultural fields under corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] production systems in eastern Ontario, Canada. Greater predicted gaseous N emissions for corn and soybean and greater observed lateral seepage N losses were observed for corn and soybean fields under CTD relative to free-draining fields. However, observed N losses from tile were significantly lower for CTD fields, in relation to freely drained fields. Changes in residual soil N were essentially equivalent between drainage treatments, while mass balance residual terms were systematically negative (slightly more so for CTD). Increases in plant N uptake associated with CTD were observed, probably resulting in higher grain yields for corn and soybean. This study illustrates the benefits of CTD in decreasing subsurface tile drainage N losses and boosting crop yields, while demonstrating the potential for CTD to increase N losses via other pathways related to gaseous emissions and groundwater seepage.

Date modified: