An experiment for evaluating the Nitrogen (N) dynamic following green manure has been performed in a 2 ha field sited in south Italy, submitted to semi-arid Mediterranean climate. The trial was carried out in the experimental farm of CRA-SCA, located in Rutigliano (40° 59' 25" N, 17° 1' 52" E, 122 m a.s.l.). The soil was classified as fine, mixed, superactive, thermic Typic Haploxeralfs, according to the Soil Taxonomy, overlying a calcareous bedrock and showing a variable rock fragment content (15% on average). Half-hourly ammonia (NH3) fluxes were measured following the incorporation of fava bean (Vicia faba minor L.), typically cultivated in Mediterranean region few months before the seeding of durum wheat. The NH3 fluxes were monitored by: (i) eddy covariance technique, using a tri-axial ultrasonic anemometer coupled to a QC-TILDAS (Aerodyne, Billerica, USA); (ii) the Aerodynamic Gradient Method (AGM), using the ROSAA analyser; (iii) the inverse dispersion models Windtrax and FIDES, while the concentration was also measured with ALPHA diffusion samplers. Hourly fluxes of nitrous oxide were measured by a static chamber system (SASSFLUX, Ecometrics, IT), employing an infrared gas analyzer. Measurements of gaseous fluxes started just after the incorporation of the green biomass on 22 May 2014 and stopped after 19 days. In order to identify the amount and evolution of the N added to the soil, destructive samples of soil, root and above-ground biomass were collected, following a stratified sampling design. In particular, soil samples were collected before the seeding of the crop, before the green manure and four times thereafter at 0 - 0.2 and 0.2 -0.4 m depths for quantifying the soil water content, mineral N (NO3- and NH4+) and pH. Specifically, NO3- and NH4+ were determined on KCl extracts (2 M), through spectrophotometric quantification. On crop biomass samples, total N (by dry combustion) and NH4+ were measured. Ancillary climatic variables were also measured.
Nitrogen dynamic following green manure in a Mediterranean semi-arid environment: an integrated experimental setup
STELLACCI, ANNA MARIA;
2014-01-01
Abstract
An experiment for evaluating the Nitrogen (N) dynamic following green manure has been performed in a 2 ha field sited in south Italy, submitted to semi-arid Mediterranean climate. The trial was carried out in the experimental farm of CRA-SCA, located in Rutigliano (40° 59' 25" N, 17° 1' 52" E, 122 m a.s.l.). The soil was classified as fine, mixed, superactive, thermic Typic Haploxeralfs, according to the Soil Taxonomy, overlying a calcareous bedrock and showing a variable rock fragment content (15% on average). Half-hourly ammonia (NH3) fluxes were measured following the incorporation of fava bean (Vicia faba minor L.), typically cultivated in Mediterranean region few months before the seeding of durum wheat. The NH3 fluxes were monitored by: (i) eddy covariance technique, using a tri-axial ultrasonic anemometer coupled to a QC-TILDAS (Aerodyne, Billerica, USA); (ii) the Aerodynamic Gradient Method (AGM), using the ROSAA analyser; (iii) the inverse dispersion models Windtrax and FIDES, while the concentration was also measured with ALPHA diffusion samplers. Hourly fluxes of nitrous oxide were measured by a static chamber system (SASSFLUX, Ecometrics, IT), employing an infrared gas analyzer. Measurements of gaseous fluxes started just after the incorporation of the green biomass on 22 May 2014 and stopped after 19 days. In order to identify the amount and evolution of the N added to the soil, destructive samples of soil, root and above-ground biomass were collected, following a stratified sampling design. In particular, soil samples were collected before the seeding of the crop, before the green manure and four times thereafter at 0 - 0.2 and 0.2 -0.4 m depths for quantifying the soil water content, mineral N (NO3- and NH4+) and pH. Specifically, NO3- and NH4+ were determined on KCl extracts (2 M), through spectrophotometric quantification. On crop biomass samples, total N (by dry combustion) and NH4+ were measured. Ancillary climatic variables were also measured.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
