Managing Global Resources for a Secure Future

2017 Annual Meeting | Oct. 22-25 | Tampa, FL

105425 Soil Management Practices and N Fertilization Effects on N2O Emissions in Irrigated Corn in a Mediterranean Agroecosystem.

Poster Number 1455

See more from this Division: ASA Section: Environmental Quality
See more from this Session: Soil Carbon and Greenhouse Gas Emissions General Poster II (Students' Poster Competition)

Monday, October 23, 2017
Tampa Convention Center, East Exhibit Hall

Evangelina Pareja-Sanchez, Departamento de Producción Vegetal y Ciencia Forestal, Unidad Asociada, CSIC, Agrotecnio, University of Lleida, Lleida, SPAIN, Daniel Plaza-Bonilla, Departamento de Suelo y Agua, Estación Experimental de Aula Dei (CSIC), Zaragoza, Zaragoza, SPAIN, Jorge Alvaro-Fuentes, Departamento de Suelo y Agua, Estación Experimental de Aula Dei (CSIC), Zaragoza, Spain and Carlos Cantero-Martinez, Crop and Forest Sciences Department, EEAD-CSIC Associated Unit, Agrotecnio, University of Lleida, Lleida, Spain
Abstract:
An adequate choice of agricultural management practices can help to reduce the emission of nitrous oxide (N2O) from soils, mitigating global warming. The aim of our work was to quantify the emission of N2O from soils and the corn yields according to different soil management practices and nitrogen (N) fertilization rates in a semiarid area recently transformed to irrigation under Mediterranean conditions.

The study was carried out in NE Spain, in a long-term tillage and N experiment (established in 1996), which was transformed to irrigated corn in 2015 and previously consisting in rainfed barley monocropping during the 1996-2014 period. Three types of tillage (conventional intensive tillage, CT; reduced tillage based on strip-tillage, RT; no-tillage, NT) and three mineral N fertilization rates (0, 200, 400 kg N ha-1) were compared. During 2015 and 2016, weekly soil N2O emissions and water-filled pore space (WFPS) were measured (0-5 cm). Corn yield was quantified at harvest to estimate yield-scaled N2O emissions. For each year, the emission factor (EF) was also quantified.

In 2015, the doses of 200 and 400 kg N ha-1 in CT showed the lowest cumulative N2O emission. The highest N rate increased soil N2O emissions especially just after the application of fertilizer, independently of the tillage system. In 2015, the use of NT and RT led to greater yield than CT. However, only N fertilizer treatments significantly affected N2O yield-scaled emissions in 2015. The greatest EF was found when applying 400 kg N ha-1under NT (0.26%). The WFPS was significantly affected by tillage and N fertilization treatments, decreasing in the order NT > RT > CT in 2015 and 2016.

Our preliminary data showed that tillage and N fertilization play an important role on soil N2O emissions and on corn production in Mediterranean agroecosystems recently transformed to irrigation.

See more from this Division: ASA Section: Environmental Quality
See more from this Session: Soil Carbon and Greenhouse Gas Emissions General Poster II (Students' Poster Competition)