Location: Soil Dynamics ResearchTitle: Strategic adaptation of nitrogen management for el nino southern oscillation-induced winter wheat system
|SARKAR, RESHMI - Auburn University|
|ORTIZ, BRENDA - Auburn University|
Submitted to: Mitigation and Adaptation Strategies for Global Change
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/15/2015
Publication Date: 8/6/2015
Publication URL: http://handle.nal.usda.gov/10113/62822
Citation: Sarkar, R., Ortiz, B., Balkcom, K.S. 2015. Strategic adaptation of nitrogen management for el nino southern oscillation-induced winter wheat system. Mitigation and Adaptation Strategies for Global Change. 22:369-398. DOI 10.1007/s11027-015-9676-6.
Interpretive Summary: The rainfall anomaly (RA) associated with El Niño-Southern Oscillation (ENSO) has various unwanted impacts on agricultural systems globally, specifically loss of inorganic nitrogen (N) depending on extreme wet or dry conditions is a major concern. Auburn University researchers in conjunction with an ARS researcher at the National Soil Dynamics Laboratory in Auburn, AL adapted site-specific N strategies to mitigate the effects of ENSO on winter wheat yields. Based on RA, simulated yields were lower during La Niña than El Niño (11 %) and neutral (12 %) on coastal sandy-loam soils in South Alabama and higher during La Niña than El Niño (13 %) and neutral (8 %) on heavy silt loam soils in North Alabama. These simulations indicate there may be potential for growers to alter fertilizer applications based on ENSO phase and location to maximize wheat yields.
Technical Abstract: The rainfall anomaly (RA) associated with El Niño-Southern Oscillation (ENSO) has various unwanted impacts on agricultural system globally. The loss of inorganic nitrogen (N) depending on extreme wet or dry conditions is a major concern. The main objective of this study was to adapt site-specific N strategies to mitigate the effects of ENSO on yields of winter wheat (Triticum aestivum L.; WW) system. After thorough calibration and evaluation, Decision Support Systems for Agrotechnology Transfer (DSSAT, version 4.5) model suite was adapted. Seasonal analysis was used to compare the variability in simulated leached-N, N uptake, and WW yields under long-term historical real-weather conditions. The site X climate interactions and impacts of weather factors on WW yields were assessed across 60 growing seasons in three phases of ENSO: El Niño (EN), La Niña (LN), and neutral (NT). Based on RA, the simulated yields were lower during LN than EN (11 %) and NT (12 %) on coastal sandy-loam soils and higher during LN than EN (13 %) and NT (8 %) on heavy silt loam soils at valley. N strategy with basal of 22 kg N ha-1'+'a split of 112 kg N ha-1 at Feekes (F) 4 stage of WW was adapted for maximum yield and minimum N leaching during LN at valley and NT at coastal sites. However, basal of 22 kg N ha-1'+'two equal splits of 56 kg N ha-1 at both F4 and F6 was found as the most adaptable N strategy during both EN and NT phases at valley and EN and LN at coastal sites.