Nitrogen, Tillage, and Crop Rotation Effects on Nitrous Oxide Emissions from Irrigated Cropping Systems

Abstract

We evaluated the effects of irrigated crop management practices on nitrous oxide (N(2)O) emissions from soil. Emissions were monitored from several irrigated cropping systems receiving N fertilizer rates ranging from 0 to 246 kg N ha(-1) during the 2005 and 2006 growing seasons. Cropping systems included conventional-till (CT) continuous corn (Zea mays L.), no-till (NT) continuous corn, NT corn-dry bean (Phaseolus vulgaris L.) (NT-CDb), and NT corn-barley (Hordeum distichon L.) (NT-CB). In 2005, half the N was subsurface band applied as urea-ammonium nitrate (UAN) at planting to all corn plots, with the rest of the N applied surface broadcast as a polymer-coated urea (PCU) in mid-June. The entire N rate was applied as UAN at barley and dry bean planting in the NT-CB and NT-CDb plots in 2005. All plots were in corn in 2006, with PCU being applied at half the N rate at corn emergence and a second N application as dry urea in mid-June followed by irrigation, both banded on the soil surface in the corn row. Nitrous oxide fluxes were measured during the growing season using static, vented chambers (1-3 times wk(-1)) and a gas chromatograph analyzer. Linear increases in N(2)O emissions were observed with increasing N-fertilizer rate, but emission amounts varied with growing season. Growing season N(2)O emissions were greater from the NT-CDb system during the corn phase of the rotation than from the other cropping systems. Crop rotation and N rate had more effect than tillage system on N(2)O emissions. Nitrous oxide emissions from N application ranged from 0.30 to 0.75% of N applied. Spikes in N(2)O emissions after N fertilizer application were greater with UAN and urea than with PCU fertilizer. The PCU showed potential for reducing N(2)O emissions from irrigated cropping systems.

Nitrogen fertilizer management for nitrous oxide (N2O) mitigation in intensive corn (Maize) production: an emissions reduction protocol for US Midwest agriculture

“…On the other hand, there is growing evidence that enhancedefficiency fertilizers such as slow and controlled release and stabilized N fertilizers can enhance crop recovery of fertilizer N and minimize nutrient losses to the environment (Snyder et al 2007). Their potential to reduce N 2 O emissions is however, unclear; few investigations have documented abatement (Halvorson et al 2008). …”

“…Numerous field studies conducted on N input gradients in row-crop agriculture have found that emissions of N 2 O correlate well with fertilizer N rate (e.g., MacKenzie et al 1998;Bouwman et al 2002a;McSwiney and Robertson 2005;Mosier et al 2006;Drury et al 2008;Dusenbury et al 2008;Halvorson et al 2008;Hoben et al 2010, in review;Millar et al 2010, in review). In all of these studies, increasing the amount of N added to soil resulted in increasing emissions of N 2 O.…”

“…To calculate an emission factor requires sampling N 2 O emissions from more than one test rate (e.g. MacKenzie et al 1997;Mosier et al 2006;Dusenbury et al 2008;Halvorson et al 2008). In these North American studies a maximum of three test rates were investigated in addition to a control, and all studies documented a linear relationships between fertilizer N rate and N 2 O emissions, consistent with IPCC Tier 1 directives.…”

Nitrous oxide emissions from a maize field during two consecutive growing seasons in the North China Plain

“…As reviewed by Mosier et al (1998) and Kroeze et al (1999), agriculture activities contributed about 78% of global anthropogenic N 2 O emission, 67% of which is from agricultural soil. Therefore, a great number of studies have been conducted on N 2 O flux measurements over agricultural fields (e.g., Sehy et al, 2003;Venterea et al, 2005;Stehfest and Bouwman, 2006;Phillips, 2007;Halvorson et al, 2008;Ussiri et al, 2009;Zaman and Nguyen, 2010). These measurements greatly extended the database * Corresponding author.…”

The IMPACT OF THE POLYMER COATING NUTRISPHERE™ IN INCREASING NITROGEN USE EFFICIENCY AND CORN YIELD

“…In years with above average rainfall Wiedenfeld (1986) found that cabbage (Brassica oleracea L. Group capitata) and onion (Allium cepa L.) had increased yield, yield weight and leaf N content when grown with slow-release fertilizers, methylene urea and sulfur-coated urea, but there were no differences when rainfall was below average. Halvorson et al (2008) studied N 2 O gas flux emission from irrigated corn (Zea mays L.), wheat (Triticum aestivum L.), barley (Hordeum vulgare) and dry bean (Phaseolus vulgaris) treated with various N fertilizers on clay loam in the western great plains. Under irrigation, the polymer coated urea reduced N 2 O emissions from the four irrigated crops.…”