Sustainable Agricultural Systems: Enhancing Efficiency and Reducing Environmental Impact

Dear Colleagues,

The global awareness of environmental issues has increased and become a theme considered by consumers and policy makers, often used as international trade barrier and even to promote new market niches. Agricultural production systems have been targeted as sources of environmental impact, motivating the adoption of rational input use as a goal for decision makers.

This Special Issue aims to collect studies that contribute to environmental awareness through systemic approaches toward achievable production chains or components of them. Tools to improve environmental efficiency, such as (bio)technological adoption, alternative production means, waste utilization, the food–water–energy relationship, etc., that can be quantified to measure environmental footprints are examples of the cutting edge studies being published.

This Special Issue invites manuscripts regarding environmental footprints to highlight the solutions suggested, keeping sustainability at the forefront of investigations, where the paths that are explored should lead to the higher efficiency of biosystems. All types of manuscript submissions are welcome and will undergo a rigorous peer-review process.

Prof. Dr. Thiago Libório Romanelli
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Agronomy is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• sustainability
• systems management
• smart farming
• digital agriculture
• regenerative agriculture
• cleaner production

Title: Spatial-temporal evolution and convergence analysis of China’s agricultural carbon emissions
Author: Sarkar
Highlights: 1. China’s agricultural carbon emissions fluctuated upwards from 2000-2019, peaking in 2007 in the eastern region. 2. The central region had the highest emissions, exceeding the national average in 2008. 3. Western region emissions remained below the national average. 4. Factors like urbanization, income, and policies influenced emission intensity and regional differences.

Title: Cover Crops Can Reduce the Carbon Footprint of No-Till Maize in Southern Brazil: Insights from a Long-Term Field Experiment
Authors: Guilherme Rosa da Silva 1, Adam J. Liska 2,* and Cimélio Bayer 1
Affiliation: 1 Federal University of Rio Grande do Sul, Department of Soil Science, 7712 Bento Gonçalves Ave., 91540-000, Porto Alegre, RS, Brazil; [email protected] (G.S.); [email protected] (C.B) 2 Department of Biological Systems Engineering, University of Nebraska-Lincoln, Nebraska 68583, USA; * Correspondence: [email protected] (A.J.L.)
Abstract: Brazil is one of the countries that has the most area under no-till (NT). This research study aims to evaluate the greenhouse gas (GHG) emissions of grain maize production in farming systems that used different cover crops under NT in Southern Brazil. The data for this study was from a long-term 41-year field experiment in Southern Brazil. The long-term experiment evaluated the effect of fallow (F) and cover crops (oat (O), vetch (V), cowpea (C), pigeon pea (P), and lablab (L)) on nitrous oxide (N2O) and methane (CH4) emissions, and carbon (C) sequestration in maize (M) cropping systems. Five cropping systems, FM, OV/M, OV/MC, PM, and LM were evaluated. Our results showed that the use of cover crops reduced GHG emissions from 30 to >100% through C sequestration. The systems with winter cover crops (OV/M, and OV/MC cropping systems) had higher GHG emissions (0.5 kg CO2e kg-1 of maize or 2.5 Mg CO2e ha-1) than the system with winter fallow (0.08 kg CO2e kg-1 maize or 0.3 Mg CO2e ha-1). The use of summer cover crops (pigeon pea, and lablab) obtained negative GHG emissions (average -0.27 kg CO2e kg maize-1 or -1.7 Mg CO2e ha-1) and increased maize grain yield. This study shows that cover crops can reduce the carbon footprint of not-till maize in southern Brazil.

Title: Coconut Fiber AS Conditioner on the Photosynthetic Processes of Ornamental Sunflower Under Salinity
Authors: Juliana Bezerra Martins; Patrícia Angélica Alves Marques; José Amilton Santos Júnior; Gabriela Dellangelica Carvalho de Oliveira; Isac Santos de Oliveira
Affiliation: University of São Paulo
Abstract: The use of brackish water as a water source for irrigation is a reality in regions with water scarcity. The deleterious effects of salts on plants can lead to undesirable changes in crops, making it necessary to use techniques to minimize the damage. Therefore, the present study aimed to analyze coconut fiber conditioner through analyses of chlorophyll "a" fluorescence, gas exchange, and dry matter of ornamental sunflower plants, cv. ‘Garden dwarf’. Two cycles were conducted, one in Spring/2020 and the other in Summer/2021, in the Municipality of Piracicaba - SP, Brazil. An experimental design in randomized blocks was Adopted and analyzed in a Split-Plot Scheme, each of the cycles, with 4 replicates. For this, four levels of electrical conductivity of irrigation water (0.5, 2.0; 3.5, and 5.0 ds M-1) were tested with 4 proportions of coconut fiber (0, 15, 20, and 25% of the substrate volume). The following variables were analyzed: shoot dry matter, initial fluorescence, maximum fluorescence, variable fluorescence, quantum and maximum yield of photosystem II, as well as photosynthetic rate, internal CO2 concentration, transpiration, stomatal conductance, instantaneous carboxylation efficiency, and instantaneous water use efficiency. The data were subjected to variance analysis, using the F test, at a 0.05 probability level. Using 20% coconut fiber at the tested electrical conductivities above 0.5 dS m-1 is recommended, with no advantage in using coconut fiber in treatments without salinity.

Title: Economic Feasibility and Decarbonization Incentives of Alternative Sugarcane Biogas Production Pathways
Authors: Flávio Eduardo Fava¹, Thiago Libório Romanelli²*
Affiliation: ¹ University of Sao Paulo, “Luiz de Queiroz” College of Agriculture, Graduate Program on Agricultural Systems Engineering. Av. Padua Dias, 11, Postal Box 9, Piracicaba, SP, CEP 13418-900, Brazil ² University of Sao Paulo, “Luiz de Queiroz” College of Agriculture, Department of Biosystems Engineering Av. Padua Dias, 11, Postal Box 9, Piracicaba, SP, CEP 13418-900, Brazil. * corresponding author.
Abstract: The challenges inherent in investment decisions for new fuels remain present due to the still highly uncertain scenarios regarding the price formation that will remunerate investments. There is also the question of what can still be added to plants in order to improve production efficiency and waste utilization, whether in the form of biomass itself or by-products within the processes, all of which contribute to increasing bioenergy in the system. This paper evaluates the economic potential of biomethane production within sugarcane biorefineries through the principles of the circular economy and the economic feasibility. Using price data for CBios, Brent crude oil, and natural gas, stochastic models based on GBM and Monte Carlo simulations were applied to project prices and assess revenue potential over a 10-year horizon. The price data were incorporated to assess market correlations and revenue scenarios. Key findings reveal that biomethane's price stability, driven by its strong correlation with oil markets, supports its viability as a renewable energy source, while CBio presented s weak correlation and limited price predictability present challenges for long-term planning. Economic modeling indicates high investment returns, with IRR values surpassing 35% in conservative scenarios and payback periods from 2 to 6 years. These results highlight biomethane's potential to enhance energy efficiency, reduce carbon emissions, and create new revenue streams through waste valorization. The study concludes that targeted investments in biomethane infrastructure, coupled with policy and market support, are essential for achieving global sustainability goals