Synthetic fertilizers are major agents of gaseous emissions including nitrous oxide (N2O), and rice cultivation is a primary source of methane (CH4) emission. Biochar (BC) addition to agricultural ...soils is a potential approach to mitigate N2O and CH4 emissions. This greenhouse study was conducted to assess the simultaneous effects of BC and nitrogen (N) fertilization to reduce N2O and CH4 emissions along with higher biomass accumulation in rice under controlled conditions. Nine treatment combinations of BC amendments at 0, 2 and 4% by weight (weight of BC/weight of soil) mixed into 3500 g of unsterile soil with 0, 70 and 140 kg N ha−1 were used in growing rice. Results show that BC-only treatments enhanced the volumetric water contents (VWC) by 9–14% and soil pH by 5–7% coupled with higher daily and cumulative seasonal CH4–C fluxes by 85–95% and 48–51%, respectively, compared with control treatment. Under 2% and 4% BC amendments, N at 140 kg ha−1 lowered the daily and cumulative seasonal CH4–C fluxes by 24–42% and 20–30%, respectively as compared to 70 kg N ha−1. Furthermore, BC amendments in N-treated soils reduced the daily and total seasonal N2O–N emissions by 27–67% and 49–61%, respectively, relative to N-only treatments. However, N addition in BC-amended soils showed 10–16% decreased VWC compared with the BC-only treated soils. In terms of rice growth, BC-only reduced the above- and below-ground biomass accumulation, delayed the tillering phase, and resulted in fewer vegetative tillers except for BC-treated pots with 140 kg N ha−1. Thus, this study suggests that the use of BC amendment at 2% with 140 kg N ha−1 may be a beneficial strategy to reduce the net GHG emissions from paddy rice in an Alfisol.
•Biochar in paddy soils accelerated complete denitrification coupled with N-deficiency.•BC amendments reduced mean daily N2O emissions by 27–67% in N-fertilized paddy soil.•BC amendments increased mean daily CH4 by 24–27% over that of the N-only pots.•Under BC, N at 140 kg ha−1 reduced the daily CH4 by 24–42% compared to 70 kg N ha−1
Smallholder farmers produce one-third of the world's food and over 80% of China's; therefore, they must be at the forefront of developing a sustainable food system. Greenhouse gas (GHG) emissions ...from these farms cannot be ignored. In this study, we created an agricultural environmental impact evaluation framework for China based on a localized database through an extensive survey. The survey was based on face-to-face interviews by 120 investigators with 1015 smallholders in 100 villages within Chinese major agricultural regions. The GHG emissions of each smallholder farmer's staple grain production was assessed on a case-by-case basis. Structural equation models were used to analyze the influence paths of production behavior. The results showed that GHG emissions from smallholder grain production exceeded average global levels. Despite some regional differences, synthetic fertilizers were the main source of GHG emissions from all farm inputs. Increased farm size can reduce nitrogen fertilizer use. The GHG emissions can be reduced by 203.59–279.90 Tg CO2eq, and profits would increase by 62.05–92.42 billion CNY in China, when all smallholders are managed in the same way as the top 25% or 10% of outstanding producers without applying higher nitrogen fertilizer application than the national recommendation. It is urgent and necessary for smallholders to change production practices to reduce their reliance on fertilizers to achieve climate goals.
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•A Life-cycle assessment based on a localized parameter database was developed to quantify greenhouse-gas emissions of smallholders' staple grain production.•The current emissions were higher than the world's and China's average levels, more than 35.81%.•The average input of fertilizers exceeded 250.90 kg N/hm2, which was 31.58% higher than the nationally recommendations.•Synthetic fertilizer was the major contributor to greenhouse-gases, more than 48.58%.•After fertilizer reduction, the greenhouse-gases can be reduced by 47.75%, and profit will increase by 72.73%.
Background Anthropogenic mediations contribute a significant role in stimulating positive reactions in soil–plant interactions; however, methodical reports on how anthropogenic activities impact soil ...microorganism-induced properties and soil health are still inadequate. In this study, we evaluated the influence of anthropogenic fertilization of farmland soil on barley rhizosphere microbial community structure and diversity, and the significant impacts on agro-ecosystem productivity. This will help validate the premise that soil amendment with prolonged synthetic fertilizers can lead to a significant reduction in bacterial abundance and diversity, while soils amended with organic fertilizers elicit the succession of the native soil microbial community and favor the growth of copiotrophic bacteria. Methods The total metagenomic DNA was extracted from soils obtained from the barley rhizosphere under chemical fertilization (CB), organic fertilization (OB), and bulk soil (NB). Subsequently, these samples were sequenced using an amplicon-based sequencing approach, and the raw sequence dataset was examined using a metagenomic rast server (MG-RAST). Results Our findings showed that all environments (CB, OB, and NB) shared numerous soil bacterial phyla but with different compositions. However, Bacteroidetes, Proteobacteria, and Actinobacteria predominated in the barley rhizosphere under chemical fertilization, organic fertilization, and bulk soils, respectively. Alpha and beta diversity analysis showed that the diversity of bacteria under organic barley rhizosphere was significantly higher and more evenly distributed than bacteria under chemical fertilization and bulk soil. Conclusion Understanding the impact of conventional and organic fertilizers on the structure, composition, and diversity of the rhizosphere microbiome will assist in soil engineering to enhance microbial diversity in the agroecosystem.
Excessive use of nitrogen fertilizer and inappropriate fertilization designs have negative results in agricultural ecosystems, such as considerable nitrogen losses through nitrogen dioxide (NO2) soil ...leaching and ammonia NH3 volatilization. In addition, climate change, with rising summer temperatures and reduced precipitation, leads to production declines and water shortages in the soil. This review aims to highlight the characteristics of natural zeolite and focus on their multiple uses in agriculture. These minerals are tectosilicates showing an open three-dimensional structure involving the cations required to balance the framework electrostatic charge of aluminum and silicon tetrahedral units. Different research groups reported more than fifty natural zeolites; chabazite, clinoptilolite, phillipsite, erionite, stilbite, heulandite, and mordenite are the most well-known. Zeolites are great tools to help the farmer and agronomist cope with several issues, such as soil or water pollution, contamination by heavy metals, loss of nutrients, and loss of water-use efficiency (WUE) of drylands. These natural crystalline aluminosilicates are considered soil conditioners to improve soil chemical and physical properties, such as saturated hydraulic conductivity (Ks), infiltration rate, cation exchange capacity (CEC), and water-holding capacity (WHC). Owing to their properties, these materials are able to reduce nitrate leaching and ammonia volatilization. Zeolites are also known for their carrying capacity of slow-release macronutrients, micronutrients, and fertilizers. However, the potential of these materials in agricultural areas is apparent, and zeolites show the promise of contributing directly to improve agricultural ecosystems as a sustainable product.
Mexico is one of the countries with the highest importation levels of basic foods worldwide; it is therefore highly desirable to adopt measures to guarantee local food autonomy. Agricultural ...production alternatives that present an appropriate relationship with the environment are required. The objective of this study was to generate, implement and evaluate different strategies of participative ecological intensification. These strategies were focused on improving soil quality and agricultural productivity based on the traditional Mesoamerican maize-based “milpa” agrosystem. Management agrosystems were determined and implemented in conjunction with producers in an experimental community plot over a period of two years (2012 and 2013). The alternative management practices included the use of organic amendments (solid and organic) and synthetic fertilizers. Changes in soil chemical characteristics and yields (maize, beans) were measured, as well as indices of economic efficiency, labor and fertilizer use. After 2 years, the organic management treatments showed a clear increase in soil pH (from 5.02 to 5.5–5.6), in contrast to the conventional treatment in which the soil acidified (pH 4.9) and presented reduced P availability. As a result of the higher soil acidity, yields were lower compared to the systems that used organic conditioners. Soil nitrate (NO3) concentration in the year 2012 was greater in plots with chemical fertilizers and vermicompost than in the other treatments. However, in the former, there were higher losses of N through lixiviation that year (112.6 kg ha−1) and in 2013 (212.2 kg ha−1), which were related to the occurrence of high precipitation (972 mm in 2012 and 1231 mm in 2013). Yields of maize were greater in the conventional system but lower than the bean yield. In contrast, in 2013, a stormy year, the organic system (bokashi + lime) was the most resilient in terms of both maize and bean yields. The treatments of highest annual total cost in 2012 and 2013 were those that used liquid amendments, due to the increased number of working days required for fertilizer application. In contrast, the lowest cost treatments in 2012 were those with vermicompost and, in 2013, with bokashi and bokashi + lime. The conventional treatment presented the highest fertilization costs. Application of solid organic fertilizers allowed improvement of the milpa agroecosystem soil chemical characteristics in the mountain region of Guerrero. This system presented the most efficient use of resources and labor and proved to be more resilient against the impact of storms. Moreover, it produced higher bean and maize yields compared to the milpa with conventional inputs.
•Traditional Mesoamerican agrosystem with organic fertilizers produced an improvement in soil quality.•Agrosystems with organic management showed an increase in soil pH.•Conventional agrosystem reduced bean yields recorded.•Organic agrosystems demonstrated resilience in the face of the impact of two storms.•Agricultural conventional system presented the highest fertilization costs.
Fertility enhancement with biochar application is well documented for tropical acidic soils; however, benefits of biochar coapplied with synthetic fertilizers (SFs) on soil fertility are not well ...documented, particularly for alkaline chernozems. We examined the short-term interactive effects of woodchip biochar amendment with fertilizers on selected soil properties, available phosphorus (P), and P fractions of two alkaline Chernozems from Manitoba. Treatments were (1) urea and monoammonium phosphate fertilizers, (2) biochar at 10 g kg−1, (3) biochar at 20 g kg−1, (4) biochar at 10 g kg−1 with fertilizers, (5) biochar at 20 g kg−1 with fertilizers, and (6) a control. Treated soils were analysed for pH, electrical conductivity (EC), and Olsen P concentration biweekly, and for P fractions, cation exchange capacity (CEC), organic carbon (OC), and wet aggregate stability after 70 d of incubation. Biochar amendment without fertilizers significantly increased soil pH and CEC but had no effect on EC, while coapplication with fertilizers significantly increased Olsen P and labile P concentrations. When coapplied with fertilizers, biochar did not significantly increase soil pH relative to the control. Results suggest that biochar improved soil properties and available P in alkaline Chernozems, and the beneficial effects were enhanced when coapplied with SFs.
Root rot and wilt diseases are among the most pressing obstacles to the production of rose flowers in Egypt. Isolation results showed that these diseases are mainly caused by seven soil-borne fungi. ...However, Fusarium roseum, Verticillium dahlia, and Rhizoctonia solani were the most pathogenic fungi against Rosa gallica and R. chinensis compared to other isolated fungi. The present study aimed to investigate the potential of some bio- and synthetic fertilizers, including seaweed extract, Rhizobacterin, NPK, and potassium silicate, as well as the chemical fungicide vitavax 200, to control root rot and wilt and improve growth and flowering traits of both R. gallica and R. chinensis. Under in vitro conditions, the highest linear growth inhibition of pathogenic fungi was achieved by seaweed extract followed by potassium silicate, at 400 ppm each. In addition, vitavax 200 at 400 ppm completely inhibited the linear growth of these fungi. The results also showed that all treatments applied in vivo significantly reduced the incidence of diseases on rose plants in both seasons, leading to an improvement in all growth and flowering parameters and an increase in the content of photosynthetic pigments, total carbohydrates, nitrogen, phosphorus, and potassium. In this regard, seaweed extract (4 and 2 g/L) and potassium silicate (4 g/L) were the most efficient, while Rhizobacterin (2 g/L) and NPK (2 g/plant) were the least effective. However, vitavax 200 was the most effective of all the treatments used. In conclusion, the results proved the possibility of increasing the tolerance of R. gallica and R. chinensis against root rot and wilt, while improving growth and flowering characteristics by using some bio- and synthetic fertilizers.
Ammonia (NH3) represents a perilous gas that poses a substantial hazard to both human well-being and the environment, particularly within agricultural regions. Agricultural activities constitute a ...primary source of ammonia emissions. Thus, effective monitoring and measurement of ammonia sources in agriculture are imperative for mitigating its adverse impact. However, not all existing ammonia detection methods are suitable for discerning the low concentrations typically encountered in agricultural ammonia volatilizing (ranging from 0.01 to 5 parts per million). Consequently, curtailing ammonia volatilization from farmland assumes paramount importance, with real-time monitoring serving as a crucial mechanism for assessing environmental contamination and minimizing agricultural ammonia losses. Deploying appropriate detection methodologies ensures that requisite measures are taken to safeguard human health and the environment from the deleterious repercussions of ammonia exposure. The present paper introduces a comprehensive approach to detecting and analyzing ammonia in agricultural settings. It elucidates the merits and demerits of conventional indoor and outdoor ammonia detection methods, juxtaposing them with the innovative technology of Electronic nose (E-nose). Within the paper, seven widely employed ammonia detection methods in farmland are scrutinized and compared against traditional techniques. Additionally, the constructional aspects and distinct components of E-nose are meticulously delineated and appraised. Ultimately, the paper culminates in a comprehensive comparative analysis encompassing all the aforementioned methodologies, elucidating the potential and limitations of E-nose in facilitating ammonia detection endeavors within agricultural contexts.
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