Nitrogen flow in livestock waste system towards an efficient circular economy in agriculture

Abstract

The race is on to achieve an important level of efficiency in the attainment of a circular economy in agriculture especially with the aim of sustainable nitrogen management. This cycle in the agricultural sector cuts across livestock farming, agriculture-induced waste generation, recycling and utilization, energy generation, crop production, ecosystem protection and environmental management through the mitigation of climate changes. In this work, we assess the process and functionalities of livestock waste generated from the piggery farm and their combinations with other by-products such as biochar and ash in comparison with mineral fertilization as sources of nitrogen applied in agricultural soil. The experiment was performed in a controlled environment with wheat ( Triticum aestivum L.) grown in a neutral and an acidic soil. Pig manure was used as the primary feedstock, fed and processed to biogas and nutrient-rich digestate by the anaerobic digestion process. The results revealed that the co-amendments of pig manure digestate with biochar and ash had complimentary positive effect on measured indices such as mobile potassium, phosphorus, biomass yield and nitrogen use efficiency. The mineral nitrogen fertilizer significantly induced carbon dioxide emissions from day 35 when compared to emissions from the organic amendments. In contrast, the organic amendments influenced nitrous oxide emissions from the onset till day 30 before flattening out. The individual combination of pig manure digestate with biochar and ash had a negative influence on enzymatic activity (dehydrogenase). Soil microbial biomass carbon was induced across all treatments in both soil types. Pig manure digestate + ash and pig manure digestate had 32.1 and 48.8% soil microbial biomass increase in neutral soil and acidic soil, respectively. Overall, the processing and application of single-use amendment or in combination with biochar and ash holds huge potential in the optimization of nitrogen and carbon efficiency towards sustainable soil management via improving soil quality, carbon sequestration and climate change.

Economic efficiency of using digestate from biogas plants in Ukraine when growing agricultural crops as a way of achieving the goals of the European Green Deal

“…As a result of the conducted experiments, when the digestate from the biogas plant was applied, it was established that the yield of potatoes increased by 30%, the yield of perennial lawn grasses increased by three times, cabbage and tomato seedlings increased by 12-15%, and biomass in general increased by 30-50% (Datsko and Maistrenko 2012). The conducted studies showed high efficiency of digestate as an organic fertilizer in the technologies of growing watermelon and cauliflower (Alburquerque et al 2012), kohlrabi (Lošák et al 2016), alfalfa and spring wheat (Koszel et al 2016), corn (Buligon et al 2023), wheat (Doyeni et al 2022;Doyeni et al 2021a;Barłóg et al 2019), tomatoes (Panuccio et al 2021;Stoknes et al 2018), lettuce (Kathijotes et al 2015;Brtnicky et al 2022), parsley (Pokhrel et al 2018), sorghum (Rakascan et al 2021), basil (Asp et al 2022), garden crops (Restrepo et al 2013), closed soil vegetables (Stewart et al 2005;Stoknes 2020;Barzee et al 2019;Liu et al 2011;Lee et al 2020), vegetables and other crops in non-soil systems on a digestate substrate (Restrepo et al 2013;Stoknes 2018), open ground vegetables and mushrooms, especially when anaerobic fermentation is combined with hydroponics (Stoknes et al 2016), etc., compared to traditional mineral and organic fertilizers.…”

“…Solving the problem of providing agricultural production with nitrogen is closely intertwined with the development of animal husbandry, which is the main source of traditional types of organic fertilizers. In addition, animal husbandry itself faces the problem of waste generation and disposal, and the protection of ecosystems and the environment, especially in conditions of global warming (Doyeni et al 2022;Möller and Müller 2012;Directive 2008;BIS 2010;Gelaye et al 2019).…”

Analysis of the Nexus between Structural and Climate Changes in EU Pig Farming

“…However, the identified list of best practices is not exhaustive, while the successful control and reduction in GHGEs depend on many factors. For example, academic research highlights the role of animal genetics [48], age and weight [16,34], activity and density [16,42], climate characteristics and season [16,45], building characteristics, including equipment, such as ventilation [16,49], frequency of manure/slurry removal from buildings [39,50], storage practices [46], emissions that depend on the particular manure utilisation techniques [15,46,51], etc. In fact, the GHGE potential in MSs depends on the multi-choice options on farms, and research that covers the aforementioned aspects and assists in the selection of the most effective and economically viable GHGE reduction alternatives remains critical for the development of sustainable pig farming systems.…”

“…The strong focus on environmental concerns and climate change mitigation arises from the pre-2004 MSs because most of these MSs have developed a highly concentrated production system and provide remarkable contributions to GHGEs due to EU pig farming. Over the past decade, researchers provided fundamental studies that investigated both the outcomes of climate change in pig farming [12][13][14] and the impact of pork production on climate change [15][16][17]; some researchers went beyond and analysed its impact on sustainability and introduced holistic approaches to investigate pig production systems [18][19][20][21][22]. Recent studies have mainly focused on individual MSs or groups of EU countries, while EU-wide research on changes in pig farming has attracted less academic attention.…”

Development of a Sustainable Circular Agricultural Economy: A Bibliometric Analysis

“…До числа українських учених із найбільшою кількістю публікацій із циркулярної економіки належать T. Shevchenko (12), Y. Danko, V. Koval, I. Zvarych, R. Zvarych (по 6). В Україні дослідження з циркулярної економіки найбільше фінансують Європейська комісія (14), Міністерство освіти і науки України (4), Рамкова програма «Горизонт 2020» (3).…”