vol. 11 núm. 2 (2020)

Contextualization: The Paramo of Rabanal has wetlands that provide the water resource, indispensable for the development of the economy and food security of the region. This ecosystem is being altered by the pressure exerted by the various productive and economic human activities, which means that the wetland loses the capacity to retain and store water, facilitating the expansion of exotic species that increase sedimentation, reducing water retention and storage levels, degrading soil and preventing the growth of native species. The associated vegetation allows the regulation of the hydrological cycle and promotes a measure of adaptation to the changing climate.Research gap: there is little information on the influence of vegetation associated with water bodies that contribute to their conservation in the wetlands of the Rabanal paramo.Purpose: identify the vascular flora present in the areas surrounding the artificial wetlands of the Rabanal paramo.Methodology: the characterization, composition and structure of vascular vegetation was carried out in the areas surrounding the Teatinos, Gachaneca I and II reservoirs in the Rabanal paramo, in the municipalities of Ventaquemada and Samacá, Boyacá, in five field trips was made the survey of 32 plots depending on the physical characteristics of the vegetation following a nested design. The plant material was processed at the Herbarium of the Pedagogical and Technological University of Colombia, Tunja (UPTC); the determination was made with the support of taxonomic keys, databases and experts. In terms of richness, diversity was compared between reservoirs using a Variance Analysis in ranges or Kruskall-Wallis test.Results and conclusions: The greatest richness of Margalef species was presented in plot P2 (5,40), the greatest dominance of Simpson was for plot P2 (0,95), the greatest diversity of Shannon corresponds to plot P2 (4,39) of the Teatinos Reservoir, the similarity index of Sörensen indicates that the reservoirs Gachaneca I and II, have 52,63% similarity. Evidence of productive and economic anthropic activities leads to loss of native vegetation and fragmentation of the ecosystem.

Contextualization: Artificial Neural Networks are models designed from numerical methods called Artificial Neural Networks. The use of these, as a Biochemical Oxygen Demand (BOD) prediction tool, has shown various advantages, among others, the reduction of time and the economic costs associated with this parameter. BOD usually requires 5 to 7 days, as well as multiple chemical reagents, to obtain the levels of organic materials in the waters. Research gap: Artificial Neural Networks models allow calculating BOD in real time from physicochemical variables recorded in situ. Despite this, artificial neural networks have not been used until now as a method of estimating BOD in Colombian seawaters. Purpose: Taking this aspect into account, an artificial neural network model that allows estimating the BOD in waters of the Colombian Caribbean Sea was developed in this research. Methodology: For the elaboration of the model it was necessary to carry out five simulations (consisting of a number of 2 to 3 hidden layers, and 5 to 20 neurons per layer). The predictive performance of each of these simulations was evaluated through the correlation coefficient. Results and conclusions: The highest values of this statistical indicator (0.937, 0.951, 0.953, and 0.941), were obtained for the model that used 3 layers, of 20 neurons each, in its four learning sets (training, validation, testing, and all data). These values indicate a close fit between the observed data and estimations made by the network. These results also demonstrate that Biochemical Oxygen Demand can be estimated numerically, in seawaters, through artificial neural networks models.

Contextualization: Guasave is a municipality located in the northwest of Mexico, it is part of the 18 municipalities of the State of Sinaloa, it´s considered one of the richest regions in the country's agricultural activity, according to the volume of production and nationally sown area. Research gap: The global warming, the pollution and erosion of soils and waters, have seriously affected agriculture, therefore, it is necessary to implement sustainable strategies that allow this sector to continue developing. The importance of this article lies in addressing the shortage of instruments that contribute to the creation of value in companies dedicated to this activity, the implementation of this will allow us to obtain useful empirical information for the identification of sustainable practices that generate value for agricultural organizations. Purpose: The purpose of this article is to publicize the construction and validation process, as well as to disseminate the instrument "Sustainable practices for value creation in agricultural organizations" in northern Sinaloa, Mexico. Methodology: There are 38 items of value scale, organized in the three dimensions of sustainable development and value creation that make up the instrument. The approach used was quantitative, the target population was 32 agricultural organizations in the municipality for the reliability test using Cronbach's Alpha internal consistency coefficient and 10 experts in the case of validation. Results and conclusions: The results obtained allow us to affirm that the instrument is appropriate to measure the sustainable practices that create value in the agricultural organizations of the northern part of the entity, when determining a coefficient of .941 and a pertinent validity.

Contextualization: The determination of foliar nitrogen is one of the indexes that measures the nutritional need of the plant in oil palm crops. It is also of equal importance in this research to focus on a general trend in laboratories called green chemistry, which focuses on minimizing the use of chemical reagents in different laboratory analyzes. Knowledge gap: Using medium and near infrared spectroscopy (MIR and NIR), the intention was to greatly minimize the generation of contaminants produced by the Kjeldahl method, in addition to reducing analysis times. Objectives: Determine the amount of foliar nitrogen by constructing predictive models from the mid and near infrared spectra for the determination of foliar nitrogen using Kjeldahl as a reference method. Methodology: In the development of the experiment, 198 palm leaf samples were analyzed and their respective MIR and NIR infrared spectra were taken. Each of the spectra was pretreated by different mathematical methods to correct for scattering effects of radiation. In total, 8 pretreatments were performed on each of the spectra, including the raw spectra. These were taken to choose the best prediction model for both NIR and MIR spectra. Results and conclusions: Using the SNV pre-treatment in the model, an RMSE of 0.265 and an R2 of 0.51 were obtained for the near-infrared and for the mid-infrared, the model formed with the absorbance of the untreated spectra yielded RMSE values ​​of 0.245 and an R2 of 0.46. Although it can be used in a general way as a prediction model, anomalous points can be observed that increase the error and decrease the R2, from these data the need to classify the groups of foliar samples in a better way and if it is it is necessary to make prediction models for each of the groups.

Contextualization: Livestock production in Colombia is developed in a large part of the national territory, with a 53% share of livestock gross domestic product. It is considered an important socioeconomic line for the field progress. It occupies a significant fraction of land use, destined predominantly to pasture and forage for cattle. This activity is carried out in large areas and increases in productivity depends on the efficient management of forages and the introduction of improved forage species able to offer better quantity and quality of food. Research gap: A serious problem in forage management is the high production costs of fertilizers chemically synthesized and the fact that farmers do not take advantage of organic fertilization alternatives. Purpose: Taking into account that few farmers consider grass as a crop, in agree with appropriate agronomic practices, this research aimed to evaluate the response of two interesting forage species for livestock (Cynodon nlemfuensis and Brachiaria brizantha cv. Toledo) to fertilization with aerobic fermented organic liquid fertilizer (ALOFA), with respect to different variables (height, coverage, vigor, biomass production and nutritional composition) in order to compare this commercial biofertilizer with traditional fertilization. Methodology: A complete randomized block design (BCA) with three replications was used. Applications were made with intervals of 10 days according to the doses established by treatment. Three evaluations were carried out every 40 days and the response variables were height, coverage, vigor, infestation of pests, incidence of diseases, production of dry matter and nutritional quality. Results and conclusions: A.L.O.F.A at 2.5% showed the best performance in dry matter (DM) production with C. nlemfuensis, exceeding the control by 17.55%; B. brizantha cv. Toledo ALOFA 2.5% + Mycorrhizal Inoculant (IM) and BP-150 0.5% + IM treatments exceeded the control by 35%, which allows increasing the animal load by 0.4 and 1.82 UGG / ha in both crop species. The highest percentage of DM was obtained with T4 treatment and taking into account that in terms of protein content there are no differences between treatments, it is concluded that these treatments do not affect the nutritional quality of the forages.

Contextualization: The traditional agricultural practices includes application of agrochemical products to fertilize and control pests, weeds, and diseases. After the application, those products are transported through diffusion phenomena to water bodies. At the same time, surface water bodies are used as a source of water in human consumption, agriculture, industrial and recreational activities, among others, and are the support of aquatic ecosystems. Knowledge gap:  Although there are several available parametric methods to value the vulnerability of groundwater, methods to surface water bodies are scarce. Purpose of the study: The main aim was to apply a methodological proposal to value the vulnerability categories of surface water bodies to the diffuse contamination triggered by agricultural activities in the Cerrito river watershed (Colombia), as an instrument to support the planning of prevention, mitigation and recovering actions. Material and methods: In this sense, it was proposed a methodology based on a multicriteria analysis and geographic information system techniques to identify and to map the vulnerability of surface water bodies in tributary watersheds of Cauca river in Valle del Cauca Department (Colombia). This framework was applied to Cerrito river watershed, which showed several land covers, slopes greater than 12% in its upper part and technified agriculture in its lower part. Results and discussion: The result obtained was a raster map of vulnerability index values of surface water bodies to diffuse contamination triggered by agrochemicals (IVCDA). This estimation indicated that a high percentage of watershed area (75.3%) presented a medium vulnerability, mainly associated to sugarcane crops in its floodplain zone and associate to grasslands in its hillslope zone. Moreover, it was obtained small and dispersed areas of high vulnerability (0.6%), associated to vegetable, citric and grape crops. Forest zones and remaining grasslands were categorized with low and very low vulnerability. The spatial distribution of IVCDA permitted to conclude that the main factors causing vulnerability in hillslope zone of Cerrito river watershed were slope and erosion, while at the floodplain zone it was the inadequate agricultural practices. In terms of land cover, it was concluded that vineyard, vegetable and citric crops promoted a major vulnerability level in the watershed.

Contextualization: The article addresses the application of multivariate data analysis techniques in the agricultural sector, in order to characterize two groups of hass avocado farmers, based on data collected by entities that traditionally provide rural technical assistance in the country, the municipal technical assistance units (UMATAS), as well as facilitate data collection in the field and shedding light on the creation of new performance indicators Knowledge gap: Poor application of data analysis methods and instruments in the rural technical assistance process, which allow defining recommendations for activities, inputs and labor more specific to the reality of the different associations or individuals of agricultural producers Objectives: 1) Analyze the data collected through the diagnostic instrument to the farms, RUAT, which is used by the Umatas to fulfill their role of rural technical support; 2) Apply the statistical techniques of classification and organization of data most pertinent to said characterization instrument; and 3) Determine the importance of the variables included in the diagnostic instruments for farms for the construction of indicators. Methodology: From the review of several theoretical references on the steps necessary for the creation and selection of indicators, the following methodological steps were followed: Development of a conceptual framework, selection of variables, normalization of data, multivariate analysis and weighting of information; Other subsequent steps such as information aggregation, robustness and sensitivity analysis, may be part of subsequent work. Results and conclusions: It was found that the variables that had greater weight in the characterization and grouping of producers were those belonging to the group of good agricultural practices and to that of production, demonstrating that with only 8 variables it is possible to have a good approximation to the characterization of the producers, instead of the more than 36 variables that make up the diagnostic instrument called the Registry of Users of Technical Assistance (RUAT)

Contextualization: Colombian rural areas have a deficit in the coverage of safe water supply service. In addition, the treatment systems already implemented are not efficient enough in the removal of pathogens. Research gap: The waters used for consumption are not treated properly, added to the poor coverage of its supply, and despite the fact that the population carries out the water treatment on its own, it is not guaranteed that it is in optimal conditions for its consumption. Purpose: The objective of this investigation was to determine the removal efficiency of an unconventional household system for the supply of safe water in the San Fernando District – Municipality of Pasto, Colombia. Methodology: Three phases were developed. The first phase was the diagnosis of the study zone, which included a risk map, characterization of the supply source, physical-spatial, socioeconomic and cultural characterization, selection of the population under study and formulation of indicators; the second phase defined the technology to be implemented through the multicriteria analysis and hierarchical analysis process with 6 experts, where the participatory transfer strategy for hygiene and sanitation was also designed and implemented, complemented with the teaching-learning strategy; the third phase  determined the efficiency of the safe water supply system implemented. Results and conclusions: By mean of 3 monitoring samples and the comparison with the raw water samples obtained in the characterization, it was determined that the treatment system was 99% efficient in the turbidity removal, total coliforms and fecal coliforms, which guarantees the consumption of safe water in this population. On the other hand, it is important to consider that the success of unconventional technologies is linked to the social transfer that is applied throughout their implementation; the appropriation that the community gives to the system is vital for its sustainability over time and for the follow-up process developed by the social leaders of the area.

Contextualization: Currently, it is internationally recognized that the reservoirs alters the natural carbon, they are strong GHG emitters and, in the quantification of their emissions, important uncertainties still prevail. Only, up to now, the initiatives of direct measurements in the field have begun to generate knowledge about the true magnitudes of the emissions produced from these hydrosystems.    Research gap: The high costs to develop in-situ measurements, analysis of samples and quantification of emissions, have been a major impediment to the production of sufficient information that leads to a global understanding of the behavior of these hydrosystems in terms of emissions. Purpose: Based on the results obtained from GEITRO Project (2012-2014), whose main objective was to quantify the GHG emissions generated in the Riogrande II dam based on exhaustive in situ monitoring, it was possible to explore alternative methods to allow of quantify emissions generated in dam by means of application or development of models based on the use of measured issues from remote sensors like tele-detection. The main objective of this research was to evaluate how the conjoint use of measured spatial data and models relating this data to gas surface concentrations as well as its transfer velocity coefficient, could be used to estimate CO2 diffusive flow emissions in time and space avoiding huge in situ monitoring efforts.  Methodology: methods were based on the analysis of the information from the field data for the development and validation of the models, as well as the deduction of water surface temperatures measured from remote sensors for the final estimation of emissions from the deduced models. Results and conclusions: As a result, we developed two models: one for the estimation of surface CO2 concentrations and another for the estimation of the normalized transfer velocity coefficient normalized under the Schmidt's number of 600 (K600). The result of the application of these two models allowed to the estimation of CO2 diffusive flux from the dam. The validation processes of the models allowed to conclude that they manage to reproduce more than acceptable (relative error of 15 ± 0.07% on average) the diffusive CO2 fluxes measured in the RGII reservoir between 2012 and 2014. Finally, based on this results, we used Water Surface Temperature (WST) measured by MODIS-Terra for the estimation of the diffusive flux of CO2 on the dam.

Contextualization: For the safe handling of chemical substances, weaknesses of the company under study were identified, in terms of management, use, storage and internal transportation of chemical substances. Research gap: This method contributes as an input to the substance management knowledge in relation to possible poisoning by absorption and inhalation by workers.. Purpose: The main aim of this study was to design a procedure for the safe handling of chemical substances in a company that manufactures polyurethane-based soles and insoles, helping to prevent workplace accidents and occupational diseases on workers at the company under study, with a cross-sectional descriptive, observational and quantitative approach. Methodology: It was carried out in a factory of soles and insoles based on polyurethane in Cali (Colombia) on 33 workers from the main production processes, with exposure to chemical substances. A survey was applied to identify the knowledge level of employees regarding to the substance management. A questionnaire was designed, based on Colombian regulations, applying the simplified method for chemical risk assessment of the French Institute - INRS. Results and conclusions: The analysis according to the risk determination table, produced a critical result for six of the ten evaluated substances. Ten chemicals considered dangerous were identified and four of them were classified as group A2, suspected of causing cancer, being considered as toxic and harmful substances to health and environment. The absence of a procedure for the development of critical tasks such as filling tanks, painting and injection was evident, as well as the lack of an epidemiological surveillance program to monitor personnel with greater exposure. Finally, a guide procedure for the safe handling of chemical substances and an action plan for implementation were designed. The dangerousness of some chemical substances used based on polyurethane is high, so much so that the agency of Public Health Service, the Agency for Toxic Substances and the Registry of Diseases of the USA, lists isocyanates (TDI and MDI) as highly reactive chemicals.

Contextualization: In Risaralda, Colombia, coffee production systems have been characterized by production models that follow factors such as climate conditions, topography and producer needs. For the population, ecosystem services are those that come from the nature, which have traditionally been related to an increase in productivity, and a more enjoyable landscape with recreation activities, among other benefits. Members of the High-Quality Coffee Association “Cuchilla de San Juan”, from Belen de Umbria, Risaralda, have seen a detriment in said benefits such as low productivity, increase of pests and diseases, among others. Research Gap: The relevance of ecosystem services, seen through the producer’s perspective, has rarely been considered in the case of coffee production systems. Determining this relevance becomes a major information source for decision making. This could reveal more comprehensive perspectives in regards of the territory that cover the environmental, economic and cultural spheres. Purpose: The purpose of this study was to determine the most relevant ecosystem services for 15 coffee producers. Methodology: multi-criteria analysis for prioritization and qualification; for data collection, workshops with the producers were implemented. Results and conclusion: The results show that regulation services had the highest qualification (water regulation and soil conservation), followed by supply services (food and nutrients supply). Also, through meetings, management strategies have been development to improve management decisions and improve ecosystems services to coffee production systems.

Contextualization: In livestock production, food supplementation is carried out with commercial feed that increases production costs and thus affects the profit margins of livestock companies. Research gap: Orange silage is seen as a nutritional and economic alternative for livestock companies in search of sustainability under the following questions: What is the effect of orange silage on the productivity and quality of bovine milk? Is it possible to reduce the Feeding costs by including this silage and reducing the feed without affecting the productive parameters in milk cattle? Purpose: The main objective of this study was to evaluate the effect of orange silage (EN) supply on bovine milk composition at the Villa Marina Experimental Farm of the University of Pamplona. Methodology: A randomized complete block design was used with 12 animals whose genetics are influenced by the Gyr, Holstein, Jersey and Swedish Red breed, distributed in a treatment with the substitution of 20% of commercial balanced food (T1) and a control (T2). The EN was elaborated with fruits produced on the farm with 30 days of fermentation. A period of 10 days of accustoming was carried out. The milk composition (fat, protein, non-fat solids (SNG), minerals and lactose) were measured every seven days for 90 days. The data obtained were subjected to an analysis of variance and correlation. Results and conclusions: The inclusion of EN generated a higher (P<0,05) fat content (4,36%) in the cow’s milk, compared to the control treatment (3,75%). There was no effect of treatments on the remainder milk components evaluated. The daily production of milk was not affected (P>0,05) by treatments. The replacement of commercial balanced food by 20% with EN improves the milk fat content and decreases the costs of feeding, compared to conventional management, becoming a sustainable feeding alternative in crossbreed lactating cows.