Open AccessGreenhouse Gas Emissions as Influenced by Nitrogen Fertilization and Harvest Residue Management in Sugarcane Production
Author(s) -
Dattamudi Sanku,
Wang Jim Jian,
Dodla Syam K.,
Viator H. P.,
DeLaune Ron,
Hiscox April,
Darapuneni Murali,
Jeong Changyoon,
Colyer Patrick
Publication year - 2019
Publication title -
agrosystems, geosciences and environment
Language(s) - English
Resource type - Journals
ISSN - 2639-6696
DOI - 10.2134/age2019.03.0014
Subject(s) - residue (chemistry) , ammonium nitrate , fertilizer , greenhouse gas , nitrogen , chemistry , urea , crop residue , ammonium , agronomy , nitrate , environmental science , human fertilization , zoology , agriculture , biology , ecology , biochemistry , organic chemistry
Core Ideas Application of urea led to higher N 2 O emissions than urea–ammonium nitrate in sugarcane. Residue retention led to higher N 2 O and CH 4 emissions irrespective of N source. Both N source and residue management did not affect CO 2 emissions.Sugarcane ( Saccharum spp.) is a major row‐crop in the southern United States with high rates of N‐fertilizer application and unique harvest‐residue management. A 2‐yr field experiment was conducted to investigate different N‐fertilizer effects (urea and urea ammonium nitrate, UAN) and harvest‐residue managements (residue‐retain, RR, and residue‐burn, RB) on greenhouse gas (GHG) emissions from soils under sugarcane production. In 2012, a split‐plot design experiment was conducted with residue managements as main‐plots and N‐sources as sub‐plots. In 2013, two experiments were conducted to investigate UAN effect under RR and RB, and N‐source effect under RB on GHG emissions. Nitrogen was applied at 135 and 157 kg ha ‒1 in 2012 and 2013, respectively. Soil GHG emissions were monitored using a closed chamber method. Results showed the majority of N 2 O emissions occurred within 4 wk after N‐application. Average N 2 O emissions from urea‐treated plots were 1.43 to 1.67 times higher compared with UAN for 2 yr. Urea had a N 2 O emission factor of 3.52 and 4.45% under RB and RR, respectively, whereas UAN had 1.67 and 2.46% under the same residue management. Higher N 2 O emission under RR treatment was supported by 15 to 20% more water‐filled pore space (WFPS) in soil than RB plots, which also increased CH 4 emissions. Higher correlation was found between N 2 O emission and WFPS in 2012 compared with 2013 ( r 2 = 0.52 vs. 0.36) because a majority of the rainfall in 2012 was received within 3 wk following N application. Nitrogen sources had no effect on CH 4 and CO 2 emissions.