Búsqueda avanzada


Área de conocimiento




131 resultados, página 2 de 10

Estimating lime requirements for tropical soils: Model comparison and development

Fernando Aramburu Merlos João Vasco Silva Frédéric Baudron Robert Hijmans (2023, [Artículo])

Acid tropical soils may become more productive when treated with agricultural lime, but optimal lime rates have yet to be determined in many tropical regions. In these regions, lime rates can be estimated with lime requirement models based on widely available soil data. We reviewed seven of these models and introduced a new model (LiTAS). We evaluated the models’ ability to predict the amount of lime needed to reach a target change in soil chemical properties with data from four soil incubation studies covering 31 soil types. Two foundational models, one targeting acidity saturation and the other targeting base saturation, were more accurate than the five models that were derived from them, while the LiTAS model was the most accurate. The models were used to estimate lime requirements for 303 African soil samples. We found large differences in the estimated lime rates depending on the target soil chemical property of the model. Therefore, an important first step in formulating liming recommendations is to clearly identify the soil property of interest and the target value that needs to be reached. While the LiTAS model can be useful for strategic research, more information on acidity-related problems other than aluminum toxicity is needed to comprehensively assess the benefits of liming.

Exchangeable Acidity Aluminum Saturation Calcium Carbonate Equivalent CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CHEMICOPHYSICAL PROPERTIES LIMES TROPICAL ZONES ACID SOILS ALUMINIUM BASE SATURATION CALCIUM CARBONATE

Influence of novel coconut oil and beeswax edible coating and MAP on postharvest shelf life and quality attributes of lemon at low temperature

Mohammad Mainuddin Molla Ashfak Ahmed Sabuz Md Abdul Matin (2023, [Artículo])

Weight loss, turning of peel colour from green to yellow and microbial infections are the major postharvest problems of lemon. Lipid-based edible coatings and modified atmospheric packaging (MAP) are effective techniques in maintaining postharvest quality of fruits for long-term storage. With this view, an investigation was conducted for the preservation of green lemon using coconut oil and beeswax edible coating and MAP during storage at low temperature. Physiologically matured lemons were collected and washed with potable water; fruit surface water was removed and then coated with coconut oil-beeswax (90:10) or only coconut oil. After coating, lemons were packaged in MAP or kept in open crates and stored at 12±1 °C and 85±5% relative humidity (RH) for 8 weeks and a week interval, the sampling was conducted. The results revealed that coconut oil-beeswax coating had immense effect on retaining shiny green colour, reducing respiration, weight loss, shrivelling and preserving firmness and ascorbic acid of lemon throughout the storage. On the other hand, MAP mainly helped to retain moisture & firmness and reduce shrivelling. Uncoated lemons kept open lost the highest amount of ascorbic acid and retained only 13.7 mg/100 g that is significantly (p < 0.05) less than the lemons of all other treatments at 8th week of storage period. While lemons coated with coconut oil-beeswax and packaged in MAP was preserved the highest amount (24.2 mg/100 g) of ascorbic acid and there was no significant difference (p < 0.05) with the amount of ascorbic acid content of lemons coated with only coconut oil and packaged in MAP at the last week (8th week) of storage. Hue angle value was 93.4 in uncoated lemons packaged in MAP while it was 113.67 in coconut oil-beeswax coated lemon kept open and 112.64 in lemon coated with coconut oil-beeswax and packaged in MAP at 8th week of storage. Based on all sensory, physical and chemical parameters uncoated lemons kept open was acceptable up to 1 week, coconut oil-beeswax coated lemon kept open was 6 weeks and coconut oil-beeswax coated lemon packaged in MAP was 8 weeks with good quality and shiny green colour.

Edible Coating Sensory Quality Hue Angle Yellowing CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA EDIBLE FILMS RESPIRATION RATE LEMONS MODIFIED ATMOSPHERE PACKAGING COLD

Impact of different on-farm management practices on bread wheat quality: a case study in the Yaqui Valley

Facundo Tabbita Iván Ortíz-Monasterios Francisco Javier Pinera-Chavez Maria Itria Ibba Carlos Guzman (2023, [Artículo])

BACKGROUND: Continuous development of new wheat varieties is necessary to satisfy the demands of farmers, industry, and consumers. The evaluation of candidate genotypes for commercial release under different on-farm conditions is a strategy that has been strongly recommended to assess the performance and stability of new cultivars in heterogeneous environments and under different farming systems. The main objectives of this study were to evaluate the grain yield and quality performance of ten different genotypes across six contrasting farmers' field conditions with different irrigation and nitrogen fertilization levels, and to develop suggestions to aid breeding programs and farmers to use resources more efficiently. Genotype and genotype by environment (GGE) interaction biplot analyses were used to identify the genotypes with the strongest performance and greatest stability in the Yaqui Valley. RESULTS: Analyses showed that some traits were mainly explained by the genotype effect, others by the field management conditions, and the rest by combined effects. The most representative and diverse field conditions in the Yaqui Valley were also identified, a useful strategy when breeders have limited resources. The independent effects of irrigation and nitrogen levels and their interaction were analyzed for each trait. The results showed that full irrigation was not always necessary to maximize grain yield in the Yaqui Valley. Other suggestions for more efficient use of resources are proposed. CONCLUSIONS: The combination of on-farm trials with GGE interaction analyses is an effective strategy to include in breeding programs to improve processes and resources. Identifying the most outstanding and stable genotypes under real on-farm systems is key to the development of novel cultivars adapted to different management and environmental conditions.

Wheat Quality Bread Wheat Bread-Making CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA SOFT WHEAT QUALITY FARMING SYSTEMS

Impact of automation on enhancing energy quality in grid-connected photovoltaic systems

Virgilio Alfonso Murillo Rodríguez NOE VILLA VILLASEÑOR José Manuel Robles Solís OA Guirette-Barbosa (2023, [Artículo])

Rapid growth in the integration of new consumers into the electricity sector, particularly in the industrial sector, has necessitated better control of the electricity supply and of the users’ op-erating conditions to guarantee an adequate quality of service as well as the unregulated dis-turbances that have been generated in the electrical network that can cause significant failures, breakdowns and interruptions, causing considerable expenses and economic losses. This research examines the characteristics of electrical variations in equipment within a company in the industrial sector, analyzes the impact generated within the electrical system according to the need for operation in manufacturing systems, and proposes a new solution through automation of the regulation elements to maintain an optimal system quality and prevent damage and equipment failures while offering a cost-effective model. The proposed solution is evaluated through a reliable simulation in ETAP (Energy Systems Modeling, Analysis and Optimization) software, which emulates the interaction of control elements and simulates the design of electric flow equipment operation. The results demonstrate an improvement in system performance in the presence of disturbances when two automation schemes are applied as well as the exclusive operation of the capacitor bank, which improves the total system current fluctuations and improves the power factor from 85.83% to 93.42%. Such a scheme also improves the waveform in the main power system; another improvement result is when simultaneously operating the voltage and current filter together with the PV system, further improving the current fluctuations, improving the power factor from 85.83% to 94.81%, achieving better stability and improving the quality of the waveform in the main power grid.

This article belongs to Special Issue Advances and Optimization of Electric Energy System.

Power quality Capacitor bank Voltage and current filter Photovoltaic system INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS OTRAS ESPECIALIDADES TECNOLÓGICAS OTRAS OTRAS