Nitrous Oxide Emissions from a Golf Course Fairway and Rough after Application of Different Nitrogen Fertilizers

Abstract

Few studies have quantified nitrous oxide (NO) emissions from intensively managed turfgrass systems on golf courses. Fertilizer treatments consisting of urea with inhibitors of nitrification and urease (INU), polymer-coated urea (PCU), and uncoated balanced methylene urea (BMU) chain, which use different mechanisms to control the release of N substrate, were applied to a golf course fairway and rough three times during the 2011 growing season at a rate of 50 kg N ha per application. The vented chamber method was used to measure turf-soil-atmospheric NO exchange. Cumulative emissions from fairway INU, PCU, and BMU treatments totaled 6.5, 1.9, and 7.6 kg NO-N ha yr, representing a 4.02, 1.25, and 4.75% loss of total N applied, respectively. Summer INU and BMU fertilization to the fairway produced the greatest NO fluxes. Rapid fluxes during the summer were likely related to low physiological activity in cool-season turfgrass and to warm, wet soil conditions that increased denitrification rates. However, PCU applied to the fairway was more resistant to NO losses than other fertilizer treatments. Fertilizer treatments applied to the rough had cumulative emissions of 2.4, 1.50, and 1.49 kg NO-N ha yr from INU, PCU, and BMU treatments, corresponding to a 1.21, 0.62, and 0.61% loss of total N applied, respectively. The lower NO emission on roughs was likely associated with greater carbon pools, lower soil moisture, and lower temperatures. This study supports the effectiveness of PCU to reduce NO emission from cool-season turfgrass fairways when soil conditions favored denitrification during warm periods. Applying INU and BMU when soil was cool and dry was effective in moderating NO losses.

Nitrous Oxide Emissions from Turfgrass Receiving Different Irrigation Amounts and Nitrogen Fertilizer Forms

“…Nitrous oxide emissions during the offseason were similar between urea and PCU. The controlled‐release fertilizer did not result in higher emissions than the quick‐release fertilizer during the nongrowing, offseason period, which is similar to past research (Shoji et al, 2001; Merchán‐Paniagua, 2006; Hyatt et al, 2010; Gillette et al, 2016).…”

“…Contrary to the quick‐release fertilizer urea, N 2 O fluxes in the controlled‐release fertilizer (PCU) did not spike dramatically after N fertilization but rather were similar or slightly higher than in UF. Gillette et al (2016) also reported that PCU‐treated plots were more resistant to rapid spikes in N 2 O fluxes after fertilization, and they credited it to the slower and more controlled N release of PCU, even under high WFPS conditions during the summer. Overall, the controlled‐release fertilizer resulted in lower N 2 O fluxes on a daily basis (17 of 69 total measurement dates) compared with the quick‐release fertilizer.…”

“…by reducing the amount of N in the soil that is available to denitrify. Over a 1‐yr period, Gillette et al (2016) evaluated the effects on N 2 O emissions of three slow‐ and controlled‐release fertilizers (urea with nitrification and urease inhibitors, which inhibit microbial and enzyme activity [a controlled release], PCU, and methylene urea [a reactive slow‐release], which is influenced by microbial activity). All three fertilizers were applied to a golf course fairway and rough, representing two mowing heights.…”

“…All three fertilizers were applied to a golf course fairway and rough, representing two mowing heights. Polymer‐coated urea at fairway height, and methylene urea and PCU at the higher rough mowing height emitted the lowest N 2 O (Gillette et al, 2016). Furthermore, all three slow‐ and controlled‐release forms of N fertilizer had higher N 2 O emissions than unfertilized turf (UF).…”

“…Furthermore, all three slow‐ and controlled‐release forms of N fertilizer had higher N 2 O emissions than unfertilized turf (UF). No quick‐release fertilizer was included for comparison in Gillette et al (2016), since the urea treatment contained nitrification and urease inhibitors and the methylene urea was a reactive slow‐release form. Generally, controlled‐release fertilizers have reduced N 2 O emissions in various agronomic systems compared with quick‐release fertilizers (Delgado and Mosier, 1996; Shoji et al, 2001; Merchán‐Paniagua, 2006; Halvorson et al, 2008; Hyatt et al, 2010).…”