ABSTRACT Proper waste management is a major worldwide concern; waste is disposed of directly into the environment, affecting water, soil and air quality. The development and production of green energy sources is strongly encouraged in modern society. The aim of this study, in accordance with Sustainable Development Goals (SDGs) 1, 2 and 7 of the 2030 Agenda of the UN, is to combine the correct disposal of animal waste with the generation of energy to mitigate the energy insecurity of families in an extremely vulnerable semi-arid region in the north-east of the country using biodigesters. To this end, a conceptual proposal was drawn up for a low-cost, easy-to-maintain and easy-to-use biodigester. A small-scale prototype was used to assess its operation by evaluating the main factors that affect biogas production (pH, temperature and the biomass properties: total solids, fixed solids, volatile solids, concentration of volatile fatty acids and C/N ratio). Evaluation of the test prototype gave satisfactory results that corroborate other studies and make it possible to propose an economically viable and efficient full-scale biodigester for biogas production. concern environment water quality society study SDGs (SDGs 1 203 UN semiarid semi arid northeast north east biodigesters end lowcost, lowcost low cost, cost low-cost easytomaintain easy maintain easytouse use smallscale small scale pH, pH (pH properties solids CN C N ratio. ratio . ratio) fullscale full 20

ABSTRACT One of the most important aspects for sustainable aquaculture is the proper management of feed, for which the best strategy is the implementation of automatic feeders that allow optimizing feed rations and optimizing productive performance. The present study evaluated the impact of automatic feeding on soil quality in the cultivation of Litopenaeus vannamei in three experimental pools in a period of three months; where were evaluated the amount of organic matter, organic carbon, pH, nitrogen and the carbon-nitrogen ratio (C/N) to evaluate if there are differences in the feeding and lung-type zones. In the final analyzes no statistical differences (p ≥ 0.05) were observed in the parameters between the feeding areas and between the pools. These results demonstrate that automatic feeding does not cause changes in soil quality in the cultivation of L. vannamei.

RESUMEN Uno de los aspectos más importantes para una acuacultura sustentable es el manejo adecuado del alimento, para lo cual la mejor estrategia es la implementación de alimentadores automáticos que permiten optimizar las raciones de alimento y optimizar el rendimiento productivo. El presente estudio evaluó el impacto de la alimentación automática sobre la calidad del suelo en el cultivo de Litopenaeus vannamei en tres piscinas experimentales en un periodo de tres meses; se evaluaron las cantidades de materia orgánica, carbono orgánico, pH, nitrógeno y la relación carbono-nitrógeno (C/N) para discernir si existen diferencias en los puntos de alimentación y de tipo pulmón. En los análisis finales no se observaron diferencias estadísticas (p ≥ 0.05) entre los puntosde alimentación y entre las piscinas. Estos resultados demuestran que la alimentación automática no provoca cambios en la calidad del suelo en el cultivo de L. vannamei.

ABSTRACT Acid sulphate soils (ASS) can be classified as marginal soils due to their limited carrying capacity for rice (Oryza sativa L.) growth and production such as very low soil pH, high Fe content, and low soil nutrient content. A number of reclamation projects of ASS have not provided satisfactory outcomes due to a limited grasp of both the characteristics of the ASS and effective management methods. However, the precise cultivation system allows rice plants to grow well. The Banjarese-local rice cultivation system (BLRCS) is indigenous technology developed by Banjarese tribe in Kalimantan Island to enabling rice plant to grow and produce well in ASS. This review was addressed to provide scientifically describe and explain the chemical processes occurring in the soil under the BLRCS practice in ASS utilization for rice cultivation, consequently the utilization of ASS becomes more productive and environmentally friendly. The BLRCS is capable of enabling local rice plants to grow and produce well in ASS due to the improvement of ASS soil properties during growing season. Planting schedules were arranged based on the land hydrological conditions and use local rice varieties. The proper of land preparation and organic matter (OM) management in submerged condition during the growth and development stages of the rice plant lead Fe solubility becomes control, soil pH increase and nutrient in sufficient level for plant.

Abstract One of the major limitations to proper weed management is the lack of knowledge about the biology of the species. The aim of this study was to understand the influence of temperature and light on the germination and emergence of Commelina benghalensis and Richardia brasiliensis, as well as the influence of burial depth in the soil and the presence of mulch. The experiment regarding the influence of light and temperature on germination was conducted using a 2x4 factorial design, with two light conditions (presence for 12 hours and absence for 24 hours) and four temperature alternations every 12 hours (20-25 ºC, 20-30 ºC, 20-35 ºC, and 15-35 ºC), with four replications. The second experiment was conducted in a completely randomized design with four replications, testing seven sowing depths (0.0; 0.5; 1.0; 2.0; 4.0; 6.0; 10.0 cm) in clay-textured soil. In the third experiment, millet, black oat, and sun hemp straw were placed on the surface of the pot where the weeds were sown. R. brasiliensis showed high germination rates at 15°-35°C and in the presence of light, indicating positive photoblastism, as the germination percentage was 63.50% in the presence of light and 1% without light. C. benghalensis showed higher germination rates at 20-35ºC, with a germination percentage of 46.5% under light treatment and 44% in the absence of light. R. brasiliensis exhibited the highest germination percentage at a depth of 0.5 cm, with 72.50%. C. benghalensis showed better germination at depths of 1 and 4 cm, with 48.33% and 49.16%, respectively. Both crotalaria and millet caused significant inhibition of germination in both weed species. R. brasiliensis and C. benghalensis exhibit higher seed germination under alternating temperatures, with R. brasiliensis displaying positive photoblastism and C. benghalensis being neutral. Greater seeding depths negatively influence germination, and cover crops such as crotalaria and millet can be used to suppress these weeds. species mulch x 2x 2 2025 20 25 (20-2 ºC 2030 30 20-3 2035 35 1535 15 15-3 , ºC) replications 0.0 00 0 (0.0 05 5 1.0 10 2.0 4.0 40 6.0 60 6 100 10. cm claytextured clay textured oat sown R 15°35°C 1535C C 15° 35°C 6350 63 50 63.50 2035ºC, 2035ºC 35ºC, 35ºC 20-35ºC 465 46 46.5 44 0. 7250 72 72.50% 4833 48 33 48.33 4916 49 16 49.16% respectively temperatures neutral 202 (20- 203 3 20- 153 15- (0. 1. 2. 4. 6. 35C 635 63.5 46. 725 7 72.50 483 48.3 491 49.16 (20 (0 63. 72.5 48. 49.1 (2 ( 72. 49.

Resumo Um dos grandes limitantes no manejo adequado de plantas daninhas é a falta de conhecimento acerca da biologia das espécies. Assim sendo, objetivou-se entender a influência da temperatura e luz na germinação e emergência de Commelina benghalensis e Richardia brasiliensis, bem como a influência da profundidade de enterrio no solo e da presença de cobertura vegetal. O experimento sobre influência da luz e temperatura na germinação foi conduzido em esquema fatorial 2x4, com duas condições de luminosidade (presença por 12 horas e ausência por 24 horas) e quatro temperaturas alternas a cada 12 horas (20-25 ºC, 20-30 ºC, 20-35 ºC e 15-35 ºC), com quatro repetições. O segundo experimento, foi conduzido no delineamento inteiramente casualizado com quatro repetições, com 7 profundidades de semeadura (0,0; 0,5; 1,0; 2,0; 4,0; 6,0; 10,0 cm) no solo de textura argilosa. No terceiro experimento, a palhada de milheto, aveia preta e crotalária foram colocadas sobre a superfície do vaso, onde foram semeadas as plantas daninhas. A R. brasiliensis apresentou altas taxas de germinação em 15°-35°C e presença de luz, indicando fotoblastismo positivo, pois na presença de luz a porcentagem de germinação foi de 63,50% e sem luz foi de 1%. A C. benghalensis apresentou maiores taxas de germinação na alternância 20-35ºC, apresentando porcentagem de germinação de 46,5% no tratamento com luz e 44% com a ausência de luz. R. brasiliensis apresentou maior porcentagem de germinação na profundidade de 0,5 cm, com 72,50%. A C. benghalensis apresentou melhor germinação na profundidade de 1 e 4 cm com 48,33 e 49,16%, respectivamente. A crotalaria e milheto provocaram grande inibição da germinação de ambas as plantas daninhas. R. brasiliensis e C. benghalensis apresentam maior germinação de sementes em temperaturas alternadas, sendo fotoblástica positiva e neutra, respectivamente. Profundidades de semeadura maiores influenciam negativamente na germinação e os adubos verdes crotalaria e milheto podem ser utilizados na supressão destas plantas daninhas. espécies objetivouse objetivou se vegetal 2x4 x 2 2025 20 25 (20-2 2030 30 20-3 2035 35 1535 15 15-3 , ºC) repetições 0,0 00 0 (0,0 05 5 1,0 10 2,0 4,0 40 6,0 60 6 100 10, argilosa vaso R 15°35°C 1535C C 15° 35°C positivo 6350 63 50 63,50 1% 2035ºC, 2035ºC 35ºC, 35ºC 20-35ºC 465 46 46,5 44 0, 7250 72 72,50% 4833 48 33 48,3 4916 49 16 49,16% respectivamente alternadas neutra 2x 202 (20- 203 3 20- 153 15- (0, 1, 2, 4, 6, 35C 635 63,5 46, 725 72,50 483 48, 491 49,16 (20 (0 63, 72,5 49,1 (2 ( 72, 49,

ABSTRACT Favorable soil conditions are essential to the proper growth and production of any crop worldwide. Only 9 % of the Ecuadorian Amazon Region (EAR) territory is suitable for agriculture and/or livestock farming, due to limitations imposed by physio-edaphoclimatic factors. This study evaluated the soil potential suitability for coffee, cocoa and tropical pastures to determine optimal, moderate and marginal areas in three provinces in the EAR (Orellana, Sucumbios and Pastaza) under different agroecological conditions. On-site field work was carried out to analyze the soil profile to determine the mineral composition. Eight environmental variables were evaluated through the integration of GIS-based modeling to determine the agroecological zoning of the crops. The results showed that the main determining factors for optimal areas of soil suitability within the three provinces included soil depth (30 cm), organic matter content (5.3 %), concentration of macronutrients (2,700 mg kg–1), and slope (< 10 %), whereas annual temperature (18-26 °C), annual precipitation (1200-3000 mm), altitude (0-500 m), and pH (4.38) were included for moderate and marginal areas. Depending on the crop and the province, soil suitability was classified into two or three classes (optimal, moderate, and marginal areas), relying on the agroecological conditions specific to each crop. This study highlights that all crops showed mostly optimal soil suitability for proper development under the agroecological conditions analyzed, which contributes to the provision of valuable information to decision-makers about key limiting factors, land-use planning and mapping soil suitability when considering the best location for a specific crop. worldwide (EAR andor farming physioedaphoclimatic physio edaphoclimatic coffee Orellana, Orellana (Orellana Pastaza Onsite On site composition GISbased GIS based 30 (3 cm, cm , cm) 5.3 53 5 3 (5. %, %) 2,700 2700 2 700 (2,70 kg–1, kg1 kg kg–1 1 kg–1) < ( 1826 18 26 (18-2 °C, C °C °C) 12003000 1200 3000 (1200-300 mm, mm mm) 0500 0 500 (0-50 m, m m) 4.38 438 4 38 (4.38 province (optimal areas, areas) analyzed decisionmakers decision makers landuse land use 5. (5 2,70 270 70 (2,7 kg– 182 (18- 1200300 120 300 (1200-30 050 50 (0-5 4.3 43 (4.3 2,7 27 7 (2, (18 120030 12 (1200-3 05 (0- 4. (4. 2, (2 (1 12003 (1200- (0 (4 (1200 (120 (12

Abstract: Groundwater resources, a crucial water supply in the Sahel regions of northern Africa, have to be evaluated to ensure its sustainability. In the last decade, Lake Chad Basin (LCB), experienced extreme variabilities in the surface water, which impacted groundwater levels as studied by different authors. Consequently, evaluating the modes of variability of each compartment of the terrestrial water storage (TWS) plays an essential role in LCB water resources management. Therefore, the main objective of this study is to invert groundwater storage (GWS) over LCB using surface water storage (SWS) derived from satellite altimetry and imagery, soil moisture storage (SMS) from the Global Land Data Assimilation System hydrological model (GLDAS), and TWS inferred from Gravity Recovery and Climate Experiment (GRACE) measurements. Here we apply a proper signal separation approach to extract GWS from TWS, which is taken as observations in a least-squares sense to reconstruct GWS. The analysis of the reconstructed GWS series using correlation coefficient, root-mean-square error, and the Nash-Sutcliffe efficiency, shows an improvement of 114%, 26%, and 147%, respectively, compared to the GRACE-based results. These findings could be crucial in the surface and sub-surface water management over LCB. Abstract Africa sustainability decade LCB, , (LCB) authors Consequently (TWS Therefore (GWS SWS (SWS imagery SMS (SMS GLDAS, GLDAS (GLDAS) GRACE (GRACE measurements leastsquares least squares coefficient rootmeansquare root mean square error NashSutcliffe Nash Sutcliffe efficiency 114 114% 26 26% 147 147% respectively GRACEbased based results subsurface sub (LCB (GLDAS 11 2 14 1

ABSTRACT Since the industrial revolution, human activities have emitted approximately 2,500 Gt of CO2, increasing the concentration of atmospheric CO2 by 50 % compared to pre-industrial levels. To better understand the potential for mitigating greenhouse gas (GHG) emissions through proper management of degraded pasture areas, we conducted a systematic literature review and identified 23 publications reporting carbon sequestration values for pastures managed under different conditions in the south and southeast regions of Brazil. From this dataset, 17 publications considered to be in line with the research premises were selected to estimate the potential for soil carbon sequestration (SEQ) through pasture recovery in the southern region of Brazil, using conservative and regenerative agricultural management practices. Results show that managed pastures can sustain carbon sequestration rates of around 2.50 Mg C ha-1 yr-1 over approximately 20 years. However, due to the numerous variables influencing SEQ rates, the limited number of publications, and the lack of data for some variables among them, a more extensive analysis of publications and data is needed to establish causal and preponderance relationships regarding the effect of each variable on the found SEQ rates. Under current pasture occupation conditions in Brazil’s south region, it is estimated these areas could sequester between 0.433 and 1.273 Gt CO2 at the end of 20 years if managed under appropriate practices. These numbers are not representative to reduce atmospheric CO2 concentration from legacy emissions and significantly mitigate physical impacts of climate change, reinforcing the importance of prioritizing the reduction of global GHG emissions as the primary mitigation strategy. On the other hand, from the perspective of mitigating the national agricultural sector’s annual GHG emissions, this potential cannot be considered negligible. Carbon sequestration by soils under agricultural management can play a vital role in mitigating climate change, integrating the set of necessary solutions and actions for a Paris Agreement goals compatible trajectory of limiting global warming to between 1.5 and 2 °C by the end of the century. revolution 2500 500 2,50 CO 5 preindustrial pre levels (GHG Brazil dataset 1 (SEQ practices 250 2.5 ha1 ha ha- yr1 yr yr- However them Brazils s 0433 0 433 0.43 1273 273 1.27 change strategy hand sectors sector negligible 15 1. century 2,5 25 2. 043 43 0.4 127 27 1.2 2, 04 4 0. 12

ABSTRACT. This study investigates the meteorological variables exerting the most significant influence on the growth and productivity of four tomato hybrids cultivated for industrial processing in the Brazilian Savannah of Goiás State. Data on morphological and meteorological variables were collected in five locations (Hidrolândia, Itaberaí, Palmeiras de Goiás, Piracanjuba, and Silvânia) during the year 2020. Morphological characteristics assessed included plant height, number of branches, and leaf area index (LAI). Meteorological variables considered were average air temperature, global solar irradiance, thermal sum, and soil water availability. Pearson correlations, canonical correlations, and multivariate Stepwise regression were employed to analyze the relationships between morphological and meteorological variables. The study revealed that soil water availability significantly impacts tomato crop development, indicating the need for improved irrigation management. Adequate irrigation management contributed to an 86.1% increase in plant height and a 79.7% boost in leaf area index, while average air temperature influenced a 34% increase in the number of branches. In conclusion, proper irrigation management is crucial for enhancing tomato crop growth and development and optimizing water use. ABSTRACT State Hidrolândia, Hidrolândia (Hidrolândia Itaberaí Piracanjuba Silvânia 2020 branches LAI. LAI . (LAI) irradiance sum correlations 861 86 1 86.1 797 79 7 79.7 34 conclusion use 202 (LAI 8 86. 79. 3 20 2

RESUMEN La gestión inadecuada de los residuos sólidos agrícolas resulta perjudicial tanto para la salud de los seres vivos como para las propiedades del suelo, resultando en la infertilidad de los terrenos contaminados. Dado que la agricultura es la principal generadora de residuos sólidos, tanto peligrosos como no peligrosos, resulta crucial implementar una gestión adecuada en las áreas rurales. El objetivo de este estudio radica en analizar la gestión de los residuos sólidos agrícolas en la parroquia de Pimocha, ubicada en el cantón Babahoyo de la provincia de Los Ríos, Ecuador. La investigación se basa en el enfoque cualitativo, recopilando información no estandarizada mediante encuestas y entrevistas no experimentales realizadas a los residentes de las zonas rurales de la Parroquia Pimocha. Los resultados de este estudio subrayan los riesgos y desafíos asociados con la gestión inadecuada de los residuos agrícolas, incluyendo la contaminación ambiental, el incumplimiento de normativas, la falta de conocimiento sobre el tratamiento apropiado de los desechos y la baja tasa de reciclaje. Es de vital importancia promover una gestión adecuada de estos residuos, fomentando la prevención, la reutilización, el reciclaje y el cumplimiento de las normas establecidas para salvaguardar el medio ambiente y la salud pública.

ABSTRACT Inadequate management of agricultural solid waste is detrimental to both the health of living beings and the properties of the soil, resulting in the infertility of contaminated land. Since agriculture is the main generator of solid waste, both hazardous and non-hazardous, it is crucial to implement proper management in rural areas. The objective of this study is to analyze the management of agricultural solid waste in the parish of Pimocha, located in the Babahoyo canton of Los Ríos province, Ecuador. The research is based on the qualitative approach, collecting non-standardized information through surveys and non-experimental interviews conducted with residents of the rural areas of Pimocha Parish. The results of this study highlight the risks and challenges associated with inadequate management of agricultural waste, including environmental contamination, non-compliance with regulations, lack of knowledge about proper waste treatment, and low recycling rate. It is of vital importance to promote proper management of these wastes, encouraging prevention, reuse, recycling and compliance with established regulations to safeguard the environment and public health.

RESUMEN En la subcuenca del Lago Poopó en el altiplano boliviano, cuyas aguas tributan al dicho lago, se encuentran los municipios de Huanuni, Poopó, Pazña, Machacamarca y Antequera, en los que se tienen acumulaciones de desmontes y relaves de operaciones mineras pasadas, además de descargas de relaves de operaciones de la minería cooperativizada actual, que se caracterizan por ser altamente generadoras de drenajes ácidos de roca, que son la principal fuente de contaminación por metales pesados de las aguas superficiales y subterráneas de la subcuenca. Por otra parte, y desde otro enfoque, las comunidades mineras de la sub cuenca Poopó, no cuentan con plantas de tratamiento de aguas residuales urbanas y tampoco con rellenos sanitarios para la disposición de residuos sólidos urbanos, lo que hace que, tanto las aguas negras o servidas y la basura, finalmente vayan a parar a los ríos, magnificando los impactos a los ecosistemas acuáticos de la zona y el riesgo a la salud de sus pobladores. Además, por efecto del cambio climático, las zonas mineras son cada vez más vulnerables en términos de la escasez de agua, lo que hace pensar que, habrá, si es que no se ha iniciado ya, una pugna entre si el agua deficitaria será para uso de las operaciones mineras cooperativizadas o para cubrir el abastecimiento a las poblaciones mineras y su producción agrícola. Adicionalmente, los índices productivos agrícolas son cada vez menores por la falta de agua (precipitaciones anuales promedio de 360 mm) y por la calidad de las aguas de riego, contaminadas con metales pesados tóxicos disueltos; en ese contexto, la falta de productos agrícolas incide fuertemente en la seguridad alimentaria, no sólo de las comunidades mineras, sino también de las ciudades. En el contexto arriba descrito, es fácil establecer cuáles han sido los efectos significativos de impacto ambiental que ha causado la aplicación de una economía lineal en el desarrollo económico local de las comunidades mineras; por lo que, se hace imprescindible desarrollar una propuesta de un modelo de desarrollo económico local circular que genere las bases técnicas para implementar la circularidad en el desarrollo económico local de comunidades mineras en zonas de escasez hídrica del altiplano boliviano ubicadas en la sub cuenca Poopó, a objeto de contribuir a mejorar la calidad de vida de sus pobladores a partir del establecimiento de un propuesta enfocada en: El cierre ambiental a bajo costo de los pasivos ambientales mineros que están alterando la calidad de las aguas de riego; además, postular un manejo inteligente de los recursos hídricos, que involucra el diseño, dimensionamiento e implementación de plantas de tratamiento, tanto de las aguas ácidas en interior mina, como para las aguas residuales urbanas de las comunidad minera, para su uso tanto en el procesamiento mineral y riego; y también, el adecuado manejo de los residuos sólidos urbanos (basura), generados por la población minera, a objeto de producir compost, a partir tanto de la fracción orgánica de los mismos y de los lodos de tratamiento de aguas servidas de la comunidad, que serán usados tanto para la fertilización de suelos para mejorar la producción agrícola en carpas solares, como para la obtención de top soil artificial para para la rehabilitación mediante coberturas secas de los sitios de almacenamiento de residuos generadores de DAR, empleando a mujeres palliris (rescatadoras de minerales de desmontes). La propuesta se basa en los resultados de varios trabajos de investigación que han sido desarrollados por separado y a lo largo de una década.

Abstract In the sub-basin of Lake Poopó in the Bolivian altiplano, whose waters flow into the lake, are the municipalities of Huanuni, Poopó, Pazña, Machacamarca and Antequera, where there are accumulations of waste and tailings from past mining operations, these are characterized by the high generation of acid rock drainage, which is the main source of heavy metal contamination of surface and groundwater in the sub-basin. On the other hand, and from another perspective, the mining communities of the Poopó sub-basin do not have urban wastewater treatment plants or sanitary landfills for the disposal of solid urban waste, which means that both sewage and garbage eventually end up in the rivers, magnifying the impacts on the aquatic ecosystems of the area and the risk to the health of its inhabitants. Furthermore, due to climate change, mining areas are increasingly vulnerable in terms of water scarcity, which suggests that there will be, if it has not already begun, a struggle between whether the water shortage will be for the use of cooperative mining operations or to cover the supply to the mining populations and their agricultural production. In addition, agricultural production rates are decreasing due to the lack of water (average annual rainfall of 360 mm) and the quality of irrigation water, contaminated with dissolved toxic heavy metals; in this context, the lack of agricultural products has a strong impact on food security, not only in mining communities, but also in the cities. In the context described above, it is easy to establish which have been the significant effects of environmental impact caused by the application of a linear economy in the local economic development of mining communities; therefore, it is essential to develop a proposal for a circular local economic development model that generates the technical bases to implement circularity in the local economic development of mining communities in areas of water scarcity in the Bolivian highlands located in the Poopó sub-basin, in order to contribute to improve the quality of life of its inhabitants from the establishment of a proposal focused on: The low-cost environmental closure of mining environmental liabilities that are altering the quality of irrigation water; in addition, postulate an intelligent management of water resources, involving the design, sizing and implementation of treatment plants, both for acidic water inside the mine, as for urban wastewat er from the mining community, for use in both mineral processing and irrigation; and also, the proper management of urban solid waste (garbage), generated by the mining population, in order to produce compost, from both the organic fraction of the same and the sludge from wastewater treatment of the community, which will be used both for soil fertilization to improve agricultural production in solar tents, and for obtaining artificial top soil for the rehabilitation through dry covers of the storage sites of waste generating ARD, employing women palliris (rescuers of minerals from waste dumps). The proposal is based on the results of several research papers that have been developed separately and over the course of a decade.

ABSTRACT The objective of this study was to analyze the feasibility of using thermal images to estimate the water status of melon plants (Cucumis melo L.) in tropical semi-arid climates. The study was conducted in a randomized block design with a split-plot arrangement. The plots comprised of soil cover (with and without mulching), and subplots were constructed using five irrigation regimes (120, 100, 80, 60, and 40% crop evapotranspiration), with five replicates. The following variables were evaluated: canopy temperature (Tcanopy), leaf water potential, air temperature (Tair), soil moisture, crop yield, and thermal index (ΔT), which is defined as the difference between Tcanopy and Tair. ΔT exhibited high correlations with crop yield and water consumption, indicating that thermography is an efficient tool for identifying the water status of melon plants, which could be employed for proper irrigation scheduling under tropical semi-arid scenarios. Moreover, thermal images identified the beneficial effects of soil cover on leaf water status and crop yield, primarily under moderate deficit irrigation. These results demonstrate that mulching is essential for increasing melon yield and water productivity in tropical regions. Cucumis L. L semiarid semi arid climates splitplot split plot arrangement mulching, , mulching) 120, 120 (120 100 80 60 40 evapotranspiration, evapotranspiration evapotranspiration) replicates evaluated Tcanopy, (Tcanopy) potential Tair, Tair (Tair) moisture ΔT, (ΔT) consumption scenarios Moreover regions 12 (12 10 8 6 4 (Tcanopy (Tair (ΔT 1 (1 (

RESUMO O objetivo principal deste trabalho foi avaliar o uso de imagens térmicas para estimar o estado hídrico de plantas de meloeiro (Cucumis melo L.) sob clima tropical semiárido. O estudo foi realizado em delineamento de blocos casualizados, em esquema de parcelas subdivididas. As parcelas foram compostas pela cobertura do solo (com e sem cobertura morta) e as subparcelas por cinco regimes de irrigação (120, 100, 80, 60 e 40% da evapotranspiração da cultura - ETc), com cinco repetições. Foram avaliadas as seguintes variáveis: temperatura do dossel (Tdossel), potencial hídrico foliar (Ψfolha), temperatura do ar (Tair), umidade do solo, produtividade da cultura e índice térmico (ΔT), sendo este definido como a diferença entre Tdossel e Tair. O ΔT apresentou altas correlações com a produtividade da cultura e o consumo de água da cultura, evidenciando que a termografia é uma ferramenta eficiente para identificar o estado hídrico das plantas de meloeiro e pode ser empregada para uma adequada programação da irrigação em cenários do semiárido tropical. Além disso, o uso de imagens térmicas também permitiu identificar os efeitos benéficos da cobertura do solo sobre o estado hídrico foliar e a produtividade das culturas, principalmente sob moderado déficit de irrigação (DI). Os resultados obtidos também demonstram que a cobertura morta é essencial para aumentar a produtividade do melão e a produtividade da água em regiões tropicais. Cucumis L. L casualizados subdivididas 120, 120 (120 100 80 6 40 ETc, ETc , ETc) repetições variáveis Tdossel, (Tdossel) Ψfolha, Ψfolha (Ψfolha) Tair, Tair (Tair) ΔT, (ΔT) disso culturas DI. DI . (DI) tropicais 12 (12 10 8 4 (Tdossel (Ψfolha (Tair (ΔT (DI 1 (1 (

Resumen Los cultivos en el estado de Campeche se están intensificando, esto ocasiona transformaciones en las propiedades fisicoquímicas y biológicas del suelo. El objetivo fue determinar el efecto de los agroecosistemas sobre la macrofauna edáfica y las propiedades del suelo. Se tomaron 10 puntos de muestreo por agroecosistema, con tres repeticiones cada. Los sitios se escogieron de acuerdo con el uso agropecuarios (pastizal, monte, agrícola intensivo y tradicional) y tiempo de uso (≥8 años). Se tomó 1 kg de cada muestra a 20 cm de profundidad, colocadas posteriormente en bolsas de polietileno. Se determinó pH, conductividad eléctrica, materia orgánica, fósforo disponible, nitrógeno total y macrofauna edáfica. Con los datos de cada variable se realizó un análisis de varianza y para determinar las diferencias entre usos de suelo y sitios, se efectuó una prueba de medias según el estadístico de Tukey (p≤ 0.05), mediante el software Statistica versión 7.1. El agroecosistema Pastizal de Palizada presentó las mejores características en los suelos, con pH de 7.29, P, MO, N de 1.31 mg kg-1, 5.05% y 0.31%, respectivamente y fauna edáfica con 66 individuos. El agroecosistema con menor calidad en el suelo fue cultivos intensivos de Hopelchén, con pH moderadamente ácidos (6.44), mayor cantidad de P (33.42 mg kg-1), menor MO (2.59%) y contenidos elevados de N (0.23%) y sin macrofauna edáfica. El manejo del suelo en los agroecosistemas agrícolas no favorece la presencia de macrofauna edáfica ni mantiene los nutrientes necesarios para el buen funcionamiento y calidad de suelo.

Abstract Crops in the state of Campeche are intensifying, this causes transformations in the physicochemical and biological properties of the soil. The objective was to determine the effect of agroecosystems on soil macrofauna and soil properties. Ten sampling points per agroecosystem were taken, with three repetitions each. The sites were chosen according to the agricultural use (grassland, forest, intensive and traditional agricultural) and time of use (≥8 years). One kilogram from each sample was taken at a depth of 20 cm, then placed in polyethylene bags. The pH, electrical conductivity, organic matter, available phosphorus, total nitrogen and soil macrofauna were determined. With the data of each variable, an analysis of variance was performed and to determine the differences between land uses and sites, a mean test was carried out according to the Tukey statistic (p≤ 0.05), using the software Statistica version 7.1. The grassland agroecosystem of Palizada presented the best characteristics in the soils, with pH of 7.29, P, OM, N of 1.31 mg kg-1, 5.05% and 0.31%, respectively and soil fauna with 66 individuals. The agroecosystem with the lowest soil quality was intensive crops of Hopelchén, with moderately acidic pHs (6.44), higher amount of P (33.42 mg kg-1), lower OM (2.59%) and high N contents (0.23%) and without soil macrofauna. Soil management in agricultural agroecosystems does not favor the presence of soil macrofauna nor does it maintain the nutrients necessary for the proper functioning and quality of the soil.

Abstract Peru has a great potential for forestry plantations, nevertheless, importations of this type of products are getting very expensive. Soils under forest are acidic and infertile to support sustainable economically valuable forest tree species such as teak. Information is lacking on proper fertility management in forest plantations such as teak. Therefore, the objective of this study was to explore the effect of lime, and organic and inorganic fertilizers on the early growth and nutrient composition of 12-month old teak grown on acidic soil of Peru. The soil under field study was acidic with a pH of 4.99, low in fertility. A factorial design of 2x3: Lime (No Lime and Liming) and fertilizer (organic, inorganic and mixture), with 9 repetitions was adopted. Tree biometric parameters (height, diameter, biomass) and N, P, K, Ca, Mg, Fe, Cu, Mn, Zn foliar concentrations were determined during early the growth of teak. Treatments with addition of dolomite lime favored higher biometric parameters, and use of organic fertilizers promoted more growth than inorganic fertilizers. In the case of nutrients, no major differences were observed between limed and unlimed treatments while organic fertilizer promoted Ca, K and S nutrition. The results show that the application of lime and organic fertilizers is essential for the successful management and establishment of teak plants in acidic soils of Peru.

Resumen La eficiencia de las labores agrícolas mecanizadas incide en el rendimiento general de los cultivos y en la uniformidad de la producción, variables determinantes en la definición adecuada de las zonas de manejo diferenciado. Las pruebas de uniformidad de los implementos repercuten en la toma de decisiones para adquirir implementos y la administración de ellos. El objetivo de este trabajo es promover el uso eficiente de la maquinaria agrícola en el campo y evaluar las operaciones agrícolas para el uso adecuado de los recursos de producción. Se determinaron coeficientes de uniformidad del trabajo realizado con cada uno de los implementos probados, además otras variables operativas que influyen en el desempeño de ellas. Las labores más uniformes son las realizadas con implementos de labranza vertical (CU > 80%), aunque se conoce que demandan mayor potencia para romper la estructura del suelo, la sembradora volumétrica es más uniforme a velocidades de avance bajas (CU = 86,73%) y la pulverizadora presentó aplicaciones más homogéneas a bajas presiones de operación (CU = 98%). Las mediciones de uniformidad y actividades de calibración de los implementos permitieron identificar puntos críticos en la maquinaria, y fundamentar la importancia de determinarlos para la mejora continua de las operaciones agrícolas tendientes a lograr rendimientos del cultivo homogéneos.

Abstract The efficiency of mechanized agricultural work affects the general yield of crops and the uniformity of production, determining variables in the adequate definition of differentiated management areas. Implement consistency tests impact implement purchasing and implement management decisions. The objective of this work is to promote the efficient use of agricultural machinery in the field and to evaluate agricultural operations for the proper use of production resources. Uniformity coefficients of the work carried out with each of the implements tested were determined, as well as other operative variables that influence their performance. The most uniform tasks are those carried out with vertical tillage implements (CU > 80%), although they demand more power to break the soil structure, the volumetric seeder is more uniform at low speeds (CU = 86.73%) and the sprayer presented more homogeneous applications at low operating pressures (CU = 98%). The uniformity measurements and calibration activities of the implements allowed identifying critical points in the machinery, and substantiating the importance of determining them for the continuous improvement of agricultural operations aimed at achieving homogeneous crop yields.

ABSTRACT Nitrogen loss minimization is the main challenge to sustainable crop production and reducing environmental and economic losses. There is a new approach to urea application in liquid form (LU) so that the NH4 + can be evenly distributed throughout the soil profile, soil particles adsorb it and reduce the local substrate concentration inhibiting further transformation. Liquid urea has been hydrolyzed even prior to soil a pplication, whereas the urea in granulated urea (GU) must be hydrolyzed after application before it can be transformed to NH4 +. Increased urea application frequency with lower doses can lower the NH4 + concentration in soil compared to a single application. These mechanisms reduce the N loss potential and increase the N crop uptake potential of applied N by conforming to the proper synchronization between N availability and crop N demand as well as reduce N loss potential as NH3 volatilization, NO3 - leaching and N2O emission. The inconsistent results and clarifications from various studies highlight the importance and benefits of relating the effect of LU application on N loss minimization, N availability and corn (Zea mays L.) yield. This review summarizes the potential ways of N losses and their management and provides the scientific reference to achieve sustainable corn yield and reduce N losses.