Effect of N dose, fertilisation duration and application of a nitrification inhibitor on GHG emissions from a peach orchard

Despite only occupying 5% of the worldwide arable area, fruit tree crops are of vital economic importance in many regions. Intensive cropping practices can lead to greenhouse gas (GHG) emissions. In order to reduce these emissions, numerous studies have been made on lowering N inputs or applying nitrification inhibitors (NIs) which tend to maintain or even increase yield while reducing N leaching and nitrogenous emissions to the atmosphere. However, very few studies have been conducted on potential GHG emissions from the peach crop. In this work, a three-year study was carried out in a commercial peach orchard with a split-plot design with three replicates, in which the main factor was N dose (25, 50 and 100 kg N ha−1 year−1, and 50 kg N ha−1 year−1 applied during a shorter period of time in 2015 and 2016; and only 70 kg N ha−1 year−1 in 2017). Subplots in the study were used to analyse the effect of the application of a NI (3,4-dimethylpyrazole phosphate; DMPP). The aim was to qualitatively compare the effect of these factors on N2O, N2O + N2, CH4 and CO2 emissions from a peach orchard soil in order to recommend agricultural practices that minimise emissions without concurrent yield reductions. We show that N2O and N2O + N2 emissions were linked to fertilisation and increased with N dose. The N2O emissions were mitigated (up to 49%) by DMPP up to the 50 kg N ha−1 dose (not significantly). It seems that between 70 and 100 kg N ha−1 the application of DMPP loses effectiveness. Methane oxidation increased with N dose and decreased with DMPP application; CO2 emissions increased with DMPP and were unaffected by N dose. The intermediate N dose (50 kg N ha−1) applied during a shorter period of time increased yield (not significantly) and NUE without increasing GHG emissions.info:eu-repo/semantics/acceptedVersio

Effect of irrigation and fertilization on methane and carbon dioxide emissions from paddy soil during the seedling stage in NE Spain

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Ammonia volatilisation from pig slurry and ANS with DMPP applied to Westerwold ryegrass (Lolium multiflorum Lam., cv. Trinova) under Mediterranean conditions

Ammonia volatilisation from agriculture represents an important nitrogen (N) loss which has both environmental and economic impacts. In regions where large amounts of manures are available, there is a need to find appropriate management strategies that help to reuse them without increasing ammonia volatilisation. A study was made of the effect on ammonia volatilisation and yield of fertilising ryegrass with pig slurry (PS) and ammonium nitrosulphate (ANS-26) alone and with the 3,4-dimethylpyrazol phosphate (DMPP) nitrification inhibitor added to them. The study was conducted under Mediterranean conditions at two different sites. The treatments (control, PS, PS + DMPP, ANS-26 and ENTEC®) were established in a randomised block design with three replicates. Ammonia was sampled daily after each fertilisation using semi-static volatilisation chambers. We hypothesised that PS could replace mineral fertiliser without substantially increasing ammonia volatilisation in the studied systems. Temperature positively correlated with ammonia emissions. On the whole, during the two years of the study, the PS treatments presented higher average cumulative ammonia volatilisation (25% of total ammonium nitrogen (TAN) applied at Site 1; 21% of TAN applied at Site 2) than the mineral ones (11% of TAN applied at Site 1; 10% of TAN applied at Site 2). At pre-sowing, ammonia volatilisation was significantly (p < .05) lower (51% at Site 1; 55% at Site 2) than after ryegrass cuts due to burying PS immediately after application. Overall, applying DMPP had no effect on ammonia volatilisation. There were no significant differences in average yield (from 13.7 to 15.8 kg ha−1 at Site 1; from 11.6 to 13.5 kg ha−1 at Site 2) between the fertilised treatments, though ENTEC® tended to increase it. Applying PS (pre-sowing fertilisation) in combination with mineral N or processed PS fractions after ryegrass cuts could be an interesting option for the recycling of this livestock by-product without increasing ammonia volatilisation while maintaining yields.info:eu-repo/semantics/acceptedVersio

Treatment of swine manure: case studies in European’s N-surplus areas

In this study, eight different manure treatment plants were monitored. The plants were four on-farm and four centralized treatment plants, all of them at full-scale level. Assessment includes a total of seven pre-treatment and process units as follows: mechanical separation, with and without coagulant and flocculant addition, pasteurization, nitrification-denitrification, anaerobic digestion, and composting. The plants are located in nutrient surplus areas of three European Member States (Spain, Italy and Denmark), the majority of these areas being Nitrate Vulnerable Zones (NVZ). Results presented herein are data collected over a six-month period and comprise performance data of the treatment plants, pathogen indicators (E.coli and Salmonella) and greenhouse gas (GHG) emissions data under two scenarios: 1) the baseline scenario and 2) the treatment plant scenario. The assessment includes GHG emissions of the storage facilities, transportation, and subsequent intermediate storage, electric consumption, electric production, composting, and land application. All treatment plants studied generated a significant reduction in GHG emissions (between 53 and 90 %) in comparison to the baseline scenario. Organic matter and total solids (TS) content in manure were also greatly reduced, with values ranging between 35-53 % of chemical oxygen demand (COD) and, 24-61 % of TS for anaerobic digestion (AD) treatment plants, 77-93 % COD and 70 % TS in the case of AD combined with nitrogen (N)-removal unit plants. Nitrogen concentrations were also greatly reduced (between 65-85 %) total Kjeldahl nitrogen (TKN) and 68-83 % ammonium (NH4+-N)) in plants with N-removal units