Introduction. Determining of the K232A polymorphism, in the exon 8 of the acyl-CoA:diacylglycerol acyltransferase 1 gene (DGAT1) genotypic frequencies in dairy cows, and the evaluation of its deviation from the Hardy-Weinberg equilibrium, could be an indirect genetic selection footprint of animals that were selected for improved milk fat content phenotypes. Objective. To determine the prevalence of the K232A DGAT1 polymorphism in Costa Rican Holstein cows. Materials and methods. A total of 500 Holstein cows from 50 farms in three provinces of Costa Rica (Alajuela, Cartago, and San José) were sampled from October 2018 to March 2019. Blood samples were taken from coccygeal vessels. Samples were transported under 4 ºC from farms to the Biology School Laboratory of the University of Costa Rica, where DNA extractions were performed. The K232A DGAT1 polymorphism determination was performed through real time quantitative polymerase chain reaction (RT-qPCR), using specific primers. Results. The genotypes of 15 samples could not be determined due to sample limitations. The frequencies of the AA, KA, and KK genotypes for the remaining 485 cows were 54.6%, 38.8% and 6.6%, respectively. There was no deviation from the Hardy-Weinberg equilibrium (chi-square = 0.03; p > 0.05) in the overall population. Conclusion. Random mating between animals for the DGAT1 polymorphism has occurred in Costa Rica.

Introduction. Heat stress in dairy cattle is a growing problem, especially in tropical climates like in Costa Rica. This phenomenon negatively impacts milk production, animal health, and reproductive efficiency. Therefore, it is crucial to implement mitigation strategies that improve cattle welfare and farm profitability. Objective. To evaluate the effects of an evaporative cooling system (ECS) on the welfare, productivity, and reproductive performance of Jersey cows. Materials and methods. Over a three-month period during the dry season, the herd was divided into two homogeneous blocks: one exposed to the ECS and the other serving as a control. Variables such as temperature, humidity, surface body temperature, milk yield and composition, reproductive performance, and somatic cell count were measured. Additionally, a financial analysis was conducted to assess the economic feasibility of the system. Results. The results showed a significant reduction in the Temperature-Humidity Index (THI) in the area under the ECS, with an average decrease of 2.91 points, and a drop of up to 3.97 °C in surface body temperature of exposed cows. However, no significant improvements were observed in milk production or reproductive parameters. Somatic cell counts also did not increase. From a financial perspective, the investment was not profitable under the current conditions. Conclusion. The evaporative cooling system significantly reduced the surface temperature of cows without negatively affecting udder health, but it did not improve milk production or reproductive indicators under the environmental conditions of the study.

Introduction. Accurate determination of soil particle size distribution (PSD) is essential in soil taxonomy, soil physics, and soil management. Although the pipette method is precise, it is impractical for routine laboratory analyses involving large sample volumes. Objective. To evaluate and propose an efficient and practical method for soil texture determination in soils from Costa Rica. Materials and methods. A total of 24 samples from 12 representative soil profiles were analyzed using two soil sample dispersion procedures: 2) industrial blender, and 2) horizontal shaker; and three hydrometer-based methodologies: 1) Bouyoucos, 2) Bouyoucos corrected by temperature (Bouyoucos T), and 3) Bouyoucos modified (Bouyoucos M), compared against the pipette reference method, for a total of 144 analyses. Performance was assessed through linear regression, RMSE, Willmott’s concordance index, and Nash–Sutcliffe efficiency. Results. The horizontal shaker achieved superior particle dispersion compared to the industrial blender. Among the tested methodologies, the modified Bouyoucos method (Bouyoucos M) exhibited the highest agreement with pipette-derived values (R² > 0.9 for clay fraction), particularly when correcting for sample gravimetric moisture. Direct sand determination by sieving did not improve accuracy over the modified method. Conclusions. The modified Bouyoucos method, combined with horizontal shaker dispersion and moisture correction, provides an effective and reliable alternative to the reference pipette method and is recommended for routine soil texture analysis in Costa Rican laboratories.

Introduction. The concept of a biobank encompasses organized collections of biological material (tissues, fluids, cells, and DNA) and associated data for research purposes in both humans and animals. In Costa Rica, the development of ex situ collections within universities and public and private institutions contrasts with existing regulatory and operational gaps related to governance, custodianship, exchange of biomaterials and data, and the fair distribution of benefits. Objective. This study aims to analyze the ethical and legal principles and challenges associated with animal biobanks within the framework of biolaw. Methodology. A review of recent literature was conducted using the Scopus and Web of Science databases to determine the current state of the art in animal biobanks and the legislation governing them. Analysis. The development of biobanks has been driven by advances in the omics sciences and the emergence of large electronic databases. However, significant challenges persist, including limited digital infrastructure, the absence of clear data management policies, and the reluctance of some researchers to share information. These obstacles vary across scientific disciplines and disproportionately affect early-career researchers. The principles of communality and disinterestedness underpin the ethical obligation to promote data sharing, yet they often conflict with considerations of intellectual property and scientific competitiveness. In the context of animal biobanks, their potential applications include biomedical research on human diseases, genetic and reproductive improvement, and the management of zoonotic disease outbreaks. Nevertheless, robust ethical and legal approaches and clear governance frameworks are required to maximize their utility. Conclusion. Although conventions, universal declarations, and international treaties exist, Costa Rica lacks specific regulations governing animal biobanks. Therefore, dedicated legislation in this area is necessary, particularly given the existence of established animal biobanks at the national level.

Introduction. The Soil and Foliar Laboratory (LSF), part of the Soil Fertility and Crop Nutrition Area (AFSNC) of the Agronomic Research Center (CIA) at the University of Costa Rica, has become a national reference in the study of soil–plant relationships and plant nutrition. Its work has provided key scientific evidence for understanding and diagnosing soil fertility, as well as supporting decision‑making aimed at the sustainable management of agricultural soils. In this context, the present study offers an approach to identify the main scientific contributions of the AFSNC and LSF, the areas with emerging advances, and potential research and/or development in Costa Rica. Methods. A systematic analysis of 308 publications (1960–2025) related to the work of the AFSNC was conducted. Publications were classified according to research area, crop and land use, soil order, and associated elements. Results. Research has been conducted on eight soil orders: Andisols, Inceptisols, Ultisols, Vertisols, Mollisols, Entisols, Alfisols, and Oxisols. Plant nutrition stands out as the main research field (31.7% of studies), followed by soil chemistry, nutritional diagnosis, and soil fertility. Regarding crops and land uses, forest plantations and coffee were the most studied (16% and 14% of publications, respectively). Research was identified for 19 chemical elements. The most studied elements were P, Ca, K, Mg, and N, reflecting their high relevance in national agricultural management. Conclusions. This analysis highlights potential research lines for the AFSNC related to crops and land uses, soil orders, chemical elements, and regions of Costa Rica. These insights can help to strategically guide future research.

Introduction. Technical, economic, and efficient management of natural resources such as soil and water is fundamental and imperative to ensure sustainable agricultural production. Pedotransfer functions (PTFs) are tools for estimating soil hydrological properties, such as water retention, from other easily measurable soil variables. Objective. To evaluate the performance of four functions in estimating soil water content at two reference points field capacity (FC) and permanent wilting point (PWP) in Costa Rican soils. Methodology. Using soil profile data available for Costa Rica, the fitting parameters of the van Genuchten equation were estimated to calculate soil water content (θ) at FC and PWP through two functions: Rosetta1 and Rosetta3. These values were also derived using the empirical equations of Peele and Briggs. The estimated data were compared with laboratory measurements, and predictive performance indices were calculated to assess the accuracy of the functions. Results. The empirical equations of Peele and Briggs exhibited very poor performance in estimating soil water content at FC and PWP. In contrast, Rosetta1 and Rosetta3 demonstrated good performance in estimating the van Genuchten parameters. Nevertheless, considerable deviations between FC and PW7 measured and estimated values were observed, particularly in Andisols. Conclusion. Caution is advised when applying Rosetta1 and Rosetta3 for soil water content estimation, as inaccuracies may affect the appropriate management of soil and water resources. The use of Peele and Briggs’ empirical equations is not recommended for irrigation scheduling.

Introduction. Sugarcane is one of the most relevant crops in Costa Rica due to its economic impact and territorial extension. The cost of fertilization affects the profitability of the crop, and the use of bioferments emerges as a sustainable alternative to improve crop nutrition and productivity. Objective. To evaluate the use of sugarcane agro-industrial residues as substitutes for mountain mulch in the preparation of bioferments and to analyze their effect on the growth and development of sugarcane plants. Materials and methods. Organic litter were prepared using sugarcane residues: leaves, leaves and bagasse, leaves and filter press mud, and leaves with bagasse and filter press mud. Using these organic litter and mountain litter, bioferments were produced and enriched with mineral salts at three levels (0%, 50%, and 100%). The bioferments were applied to sugarcane plants under greenhouse conditions, using a completely randomized design with 18 treatments and 10 repetitions. Physiological, nutritional, and microbial population variables were evaluated. Data were processed through analysis of variance (ANOVA), and mean comparisons were performed using the DGC test, with a significance level (α) of 0.05. Results. Microbial populations varied according to the matrix and salt dosage, with lactic acid bacteria being the most abundant. Bioferments without salts showed higher microbial populations, whereas enriched bioferments exhibited greater mineral concentration. Treatments with bioferments enriched at 50% salt dosage produced better results in plant height, leaf dry weight and stem diameter, surpassing conventional fertilization. Conclusion. Organic litter prepared with sugarcane residues could replace mountain litter in the production of bioferments similar to MM. Furthermore, the use of bioferments enriched with 50% salts could reduce the use of synthetic fertilizers, promoting more sustainable and efficient agriculture.

Introduction. Symbiosis between Rhizobium spp. and common bean (Phaseolus vulgaris L.) enhances plant growth and productivity; however, its effects on grain nutritional quality have received limited attention. Objective. To evaluate the effect of inoculation with two Rhizobium spp. strains on the polyphenol content of grains from two common bean varieties, Cabécar (red) and Guaymí (black). Materials and Methods. A greenhouse experiment was conducted at CIA using autoclaved soil and five treatments: CIAT899, CR4019B, CIAT899 + CR4019B, urea, and a non-inoculated control. Plants were inoculated at sowing (10⁸ CFU mL⁻¹). Soluble and insoluble polyphenols were quantified by ultra-high-performance liquid chromatography at CIGRAS. Grain protein and saponin contents and imbibition time were also determined. Results. Inoculation significantly affected polyphenol fractions. In the Cabécar variety, CR4019B increased soluble polyphenol concentration compared with urea (p < 0.05), while inoculated treatments showed lower insoluble polyphenol levels relative to the same control. The soluble-to-insoluble polyphenol ratio was significantly higher under CR4019B, indicating that Rhizobium spp. modified the grain polyphenol profile. Conclusion. Rhizobium spp. inoculation alters the polyphenol profile of common bean grains by increasing soluble polyphenols and improving the balance between polyphenol fractions, highlighting its potential as a sustainable agronomic strategy.

Introduction. The microbiota is a diverse assemblage of microorganisms that, when associated with plants, provides key benefits such as disease suppression, tolerance to abiotic stress, and improved nutrient acquisition. In Costa Rica, research in this field has primarily relied on traditional methods, while the use of culture-independent approaches, such as high-throughput DNA sequencing, has been more limited. Objective. To analyse the microbiota associated with banana cultivation in Costa Rica and other regions, its relationship with plant health, and the implications of agricultural management practices on its diversity, composition, and functionality. Development. The reviewed studies have characterized the dynamics of the microbiota based on the plant’s phytosanitary status, its different compartments, and the implemented management practices. This review highlights agricultural strategies such as the application of biofertilizers and organic amendments, crop diversification, the use of plant cover, and the management of harvest residues, all aimed at enhancing beneficial microbiota, improving soil health, and reducing disease incidence. Conclusions. Research on banana microbiota has reaffirmed its relevance by demonstrating its interaction with plant health, edaphoclimatic conditions, and agricultural practices. The implementation of advanced tools, such as DNA sequencing, has enabled a more precise characterization of microbial communities. Although the use of these technologies remains limited in Costa Rica, the generated knowledge lays the foundation for future research and the development of more sustainable management strategies.