Seasonal and soil-type dependent emissions of nitrous oxide from irrigated desert soils amended with digested poultry manures
Graphical abstract
Introduction
Organic soil amendments such as compost and digested manure are often used to improve soil fertility (Edmeades, 2003, Azeez and Van Averbeke, 2010). Among others, poultry manure that contains large amounts of organic matter (~ 85%) and N (3–4%) (Guerra-Rodríguez et al., 2001) is widely used as a soil amendment, as is or commonly after anaerobic digestion (Delgado et al., 2012, Kelleher et al., 2002).
However, even after anaerobic digestion, poultry manure applications to the soil might have negative environmental consequences, such as the introduction of various pollutants, pathogens and increased emissions of nitrous oxide (N2O) (Ding et al., 2013, Nicholson et al., 2005, Posmanik et al., 2011). Addition of quicklime (CaO) towards the end of the digestion process has been suggested as an additional stabilization step to prevent sanitary problems and environmental contamination by digested poultry manure (Gross et al., 2012, Posmanik et al., 2011; Shargil et al., 2015).
Nitrous oxide is a potent greenhouse and ozone-scavenging gas with a global warming potential 298 times greater than that of CO2 (Czepiel et al., 1995, IPCC, 2014). Most N2O emissions (70–80%) are attributed to microbial nitrification and denitrification and sourced mainly to agricultural practices (Butterbach-Bahl et al., 2013; Rowlings et al., 2015). Under aerobic conditions, N2O is produced mainly through the activity of ammonia-oxidizing microorganisms (Butterbach-Bahl et al., 2013, Stieglmeier et al., 2014), while under oxygen-limiting conditions, N2O is produced mainly by denitrifying microorganisms (Harter et al., 2016, Snyder et al., 2009). In addition to microbial nitrification and denitrification, some fungi species also have the capability to produce N2O through nitrate respiration under oxygen-limiting conditions (Takasaki et al., 2004, Tanimoto et al., 1992).
Due to a rapidly increasing world population, agricultural activity has been expanded to drylands to increase crop production for human consumption (Marasco et al., 2012). The scarcity of water, due to low precipitation inputs and high evaporation combined with nutrient-poor soils, mainly N, limit primary production in drylands (Austin et al., 2004, Hooper and Johnson, 1999). Consequently, dryland agriculture depends strongly on irrigation and fertilization (Garcia-Gil et al., 2000, Segal et al., 2010, Shahid and Al-Shankiti, 2013). However, emission of N2O from dryland agricultural soils has not received much attention (Barton et al., 2013a, Kidron et al., 2015), and there is a lack of information regarding the consequences of amending irrigated agricultural soils with poultry manure in hot arid regions on N2O emissions.
In general, desert soils are alkaline with high salinity (Day and Ludeke, 1993) and are exposed to high radiation, together with extreme day/night and seasonal temperature fluctuations (Barton et al., 2013a, Walton et al., 2005). These extreme conditions impose great challenge on microbial activity and nutrient cycling (Schimel et al., 2007). Consequently, the objective of this study was to examine seasonal N2O emissions from two nearby irrigated soil types (sand and loess) under arid conditions and in a controlled field experiment. It was hypothesized that the different water holding capacity of sand and loess would impact the nitrogen-transforming processes and consequently N2O emissions.
Section snippets
Study site
The research was conducted at the Ashalim agricultural experimental station in the central Negev Desert, Israel (30°58′55 N, 34°42′25E). The station is located on a natural border between sand and loess soils. Average ambient daily minimum winter temperatures are 5 ± 1 °C, typically ranging from 0.5–12 °C (December–March), and average ambient daily maximum summer temperatures are 36 ± 2 °C, typically ranging from 32 to 41 °C (June–September). The average annual rainfall is 90 mm (December–February) in a
Biological activity along the soil profile and soil properties
Parameters indicative of microbial activity and soil chemical properties were determined along a depth profile (0–120 cm) of the sand and loess soils (Table S3). The data indicated that the surface layer of the amended soils (0–5 cm) clearly differs from the deeper soil layers. The surface layer exhibited higher values of biological activity as demonstrated by the higher CO2 production in both soils (Fig. 1). More specifically, the production of N2O is attributed to the surface layer where higher
Discussion
The impact of manure digestate application in irrigated desert soils on N2O emission was the focus of this study. Raw poultry manure has a high content of organic N (~ 4%, w/w) mostly in the form of uric acid. Therefore, its application has the potential for emissions of gaseous ammonia in addition to nitrous-oxide (Gross et al., 2008, Nkoa, 2013). The anaerobic digestion of poultry manure following ammonia striping (Gross et al., 2012, Posmanik et al., 2013), may form manure digestate with
Study implications and conclusions
Continuous increase in application of manure and biosolids to agricultural soils is specifically relevant in drylands because of global shifts into desert farming to ensure sufficient food production (Marasco et al., 2012). Therefore, the environmental footprint of this practice should be better quantified. This study discusses less understood issues regarding the environmental impact of organic supplements in hot desert climates and specifically those related to N2O emissions from manure
Acknowledgements
The authors wish to thank the staff from Ashalim agricultural experimental station who helped conduct the long-term field experiment. Special thanks to Prof. Naftali Lazarovich who helped in the calculation of surface soil temperatures. We also thank Dr. Tali Brunner for her help with the laboratory analyses, Yaniv Kriger and Michael Kugel for their help in designing the field instrumentation and Dr. Deborah Sills, Bucknell University, for languish improvements in the manuscript.
References (74)
- et al.
Nitrogen mineralization potential of three animal manures applied on a sandy clay loam soil
Bioresour. Technol.
(2010) - et al.
Is liming soil a strategy for mitigating nitrous oxide emissions from semi-arid soils?
Soil Biol. Biochem.
(2013) - et al.
Influence of crop rotation and liming on greenhouse gas emissions from a semi-arid soil
Agric. Ecosyst. Environ.
(2013) - et al.
Temperature dependence of nitrous oxide production of a luvisolic soil in batch experiments
Process Biochem.
(2015) - et al.
Carbon and nitrogen mineralization in acidic, limed and calcareous agricultural soils: apparent and actual effects
Soil Biol. Biochem.
(2007) - et al.
Soil physics meets soil biology: towards better mechanistic prediction of greenhouse gas emissions from soil
Soil Biol. Biochem.
(2012) Contribution of nitrification and denitrification to N2O emissions from urine patches
Soil Biol. Biochem.
(2007)- et al.
The effect of lime and compost amendments on the potential for the revegetation of metal-polluted, acidic soils
Geoderma
(2011) - et al.
Environmental assay on the effect of poultry manure application on soil organisms in agroecosystems
Sci. Total Environ.
(2012) - et al.
Effect of long-term compost and inorganic fertilizer application on background N2O and fertilizer-induced N2O emissions from an intensively cultivated soil
Sci. Total Environ.
(2013)