Comparison of ammonia emissions from animal wastes and chemical fertilizers after application in the soil

Comparison of ammonia emissions from animal wastes and chemical fertilizers after application in the soil Majid Rostami 0 1 Stefano Monaco 0 1 Dario Sacco 0 1 Carlo Grignani 0 1 Elio Dinuccio 0 1 Stefano Monaco 0 1 Dario Sacco 0 1 Carlo Grignani 0 1 Elio Dinuccio 0 1 0 Mechanics Section, Department of Agricultural, Forest and Food Sciences, University of Turin , L.go Braccini 2, 10095 Grugliasco , Italy 1 Department of Agricultural, Forest and Food Sciences, University of Turin , L.go Braccini 2, 10095 Grugliasco , Italy Background Application of different chemical fertilizers and manures is a major source of ammonia (NH3) emission. The rate and total amount of NH3 emission are related to different parameters such as climatic conditions, soil characteristics and kind of fertilizer. The current study has indicated the NH3 emission from bovine slurry, pig slurry and ammonium nitrate fertilizer after application on two soils. Two different methods were used to measure NH3 emissions: the method that use acid traps and the method that use photoacoustic infrared gas analyzer. Results In both soils the rate of NH3 emission was the greatest from the denser bovine slurry, declined in the pig slurry followed by the ammonium nitrate treatment and the control. The rate of soil infiltration could be the main factor that explained these differences. For all treatments the amount of total NH3 losses reduced in the more acidic soil. For all fertilizers the highest NH3 fluxes were measured in the first hours after spreading. A good agreement observed between the two methods is used for determining of NH3 emission. The use of a multi-gas monitor (MGM) is simple and accurate and produces a continuous series of NH3 concentration in time. Conclusion The rate and amount of NH3 emission was related to the kind of fertilizers and interaction of these treatments with soils. The results of current study confirmed that comparison of chemical fertilizers and slurry for NH3 emission is difficult because the reaction of these two groups of fertilizer is totally different. Ammonia emission; Mineral fertilizer; Slurry - Ammonia (NH3) may be released into the atmosphere from basically all ammonium-containing products. Livestock and especially animal manures are the most important sources of NH3 emissions in Europe, followed by the application of mineral nitrogen fertilizers (Leip et al. 2011). The increase in animal stocking and in the price of chemical fertilizers encourage farmers to use animal manure and slurry as an option to reduce the use of commercial fertilizers. However, the handling and spreading of these fertilizers may pose an agronomic and environmental risk, not only because of leakage of nitrate to ground waters but also because of gaseous losses of NH3 (Asman 1992). Ammonia can form secondary particulate matter in the atmosphere that may have adverse effects on human health (Moldanova et al. 2011). Ammonia emissions from manure applied to the soil are produced primarily by physical and chemical processes and secondarily by biological ones (Monaco et al. 2012). Ammonia losses from manure are harmful from the agronomic point of view, because they decrease the amount of manure N available for the crop (Smil 1999). Olivier et al. (1998) estimated that about 70 % of global NH3 emission is related to food production and, in particular, to manure management. A comprehensive understanding of the post application fate of fertilizers is essential for the development of best management practices that aim to minimize off-site transport and maximize nutrient use efficiency. Different variables affect both the rate and extent of emissions following soil application of manures (Meisinger et al. 2001). The dominant factors influencing losses can be categorized as: manure characteristics (dry matter content, pH, NH4N content), application methods (incorporation, time of application), soil properties (soil moisture, soil texture, soil pH), and environmental factors (temperature, wind speed, rainfall, relative humidity). A number of techniques have been developed to quantify NH3 emission. Accuracy and mechanism of these methods are very different. Such techniques fall generally in two groups: micro-meteorological methods (usually used for large scale areas) and enclosure methods (commonly used on small plots for comparative experiments). Chamber methods that belong to second category are usually used for measuring emission at the small scale both in the field and in the laboratory. Three measurement schemes are commonly used for the chamber methods: the open chamber, the closed static chamber and the closed dynamic chamber. All methods employ an inverted chamber covering a small area of soil. The lower edge of the chamber usually is inserted into the soil to a shallow depth. The analysis of NH3 emission have been carried out using different methods as acid traps or direct measurement through a multi-gas monitor (MGM). Between them, using MGM is easier because this system provides a real-time analysis of NH3 concentration (Dinuccio et al. 2008). Experiments for measuring NH3 emissions are usually carried out in the field where soil and moisture conditions and other environmental factors are variable and hard to control. Unfortunately, little effort has been made to standardize the laboratory methods for NH3 emission measurement. The objectives of this experiment were to Table 1 Physical and chemical properties of soils measure NH3 emissions from different slurries using closed dynamic chambers with both acid traps and MGM method under controlled environmental conditions and assessing the influence of two different soils on modifying NH3 emissions. Materials and methods The amount of volatilized NH3 after surface application of different fertilizers in two soil types was assessed under constant and controlled environmental conditions using dynamic chamber technique (Roelle and Aneja 2002). The soils used in the experiment presented different physical and chemical characteristic (Table 1) and were representatives of arable soil types of the western Po river plain (Northern Italy). In particular, Poirino soil came from a farm field cultivated mainly with maize for grain in rotation with wheat receiving chemical fertilizations, while Tetto Frati soil (TF) was collected from an experimental field continuously cultivated with maize for grain fertilized with cattle slurry and urea. The soil samples were collected from the tilled top 20 cm layer on, air-dried and sieved using 2 mm. Cylindrical glass jars (3.1 l) were filled with 1.1 l of each soil type moistened to reach the field capacity (FC). In particular, 1595 and 1475 g of dry soil was moistened with 367 and 428 ml of deionized water for Poirino and TF soil, respectively. Soil moisture content at FC (-33 kPa) was measured on 4 replicates for each soil type using pressure plates and was equal to 0.23 and 0.29 g of H2O per g of dry soil fo (...truncated)