Proposal of a system for measuring apparent electrical conductivity and moisture of soil for small farmers

In the last 30 years soils decreased 73 % of their productive capacity in the world. One of the main reasons for this decrease has been the politics implemented, as well as the absence of opportunity for the small producer to implement improvement strategies that can increase their productivity in the field. Therefore, in this research a soil measurement system is proposed for small farmers, based on the design of two sensors of low cost: (i) Apparent electrical conductivity (ECa) sensor and (ii) moisture sensor. These measurement variables have the particularity that their characteristics can be associated with the physical properties of the soil for decision-making. The sensors developed in this work employ two techniques: Wenner's method for ECa and electrical impedance measurement to identify the dielectric permittivity associated with the water content of the soil. The system is controlled by the Raspberry Pi 3 board through developed software that allows correlating data with its geolocation. The device was tested in controlled laboratory measurements with calibrated instruments, obtaining a coefficient of . Finally, on-site tests were made to validate their use for small farmers.

Durante los últimos 30 años, los suelos han disminuido un 73 % su capacidad productiva, a nivel mundial. Una de las principales razones para esta cifra a la baja son las políticas implementadas, así como la falta de oportunidad para que el pequeño productor adopte estrategias de mejora, con lo cual, pueda aumentar la productividad. Por lo anterior, en esta investigación, se propone un sistema de medición de suelo para pequeños productores, a partir del diseño de dos sensores de bajo costo: (i) sensor de conductividad eléctrica aparente (CEa) y (ii) sensor de humedad. Estas variables de medición tienen la particularidad que sus características se pueden asociar a las propiedades físicas del suelo, para tomar decisiones. Los sensores desarrollados en este trabajo usan dos técnicas: el método de Wenner, para la CEa y la medición de impedancia eléctrica, para identificar la permitividad dieléctrica asociada con el contenido de agua del suelo. El sistema es controlado mediante la tarjeta Raspberry Pi 3, a través de un software desarrollado, que permite correlacionar los datos con su geolocalización. El dispositivo, se probó en mediciones controladas en laboratorio, con instrumentos calibrados, obteniendo un coeficiente . Finalmente, se hicieron pruebas in situ, con el fin de validar su uso por pequeños agricultores.

Criterios campesinos para la selección de maíz (Zea mays L.) en Villaflores y Villa Corzo, Chiapas, México / Farmers' criteria for maize (Zea maysL.) selection in Villaflores and Villa Corzo, Chiapas, Mexico

RESUMEN La producción de maíz en Chiapas implica la decisión de cultivar maíces locales o híbridos. Estos últimos, tienen rendimientos más altos, pero requieren mayor cantidad de insumos, asociados con la degradación de suelos, contaminación del agua, pérdida de diversidad genética y del conocimiento sobre las variedades locales. El objetivo de esta investigación fue identificar los criterios que usan los pequeños productores, en la selección del material genético, para la siembra de maíz en los municipios de Villaflores y Villa Corzo, Chiapas. Se realizaron entrevistas semi-estructuradas a productores participantes del programa ASERCA. El maíz híbrido presentó mayor preferencia en ambos municipios, aunque algunos productores prefirieron los maíces locales o cultivaron ambos, por razones de usos y costumbres. La selección de maíces híbridos en los dos municipios se hizo principalmente con base en el rendimiento, seguido de la mayor resistencia a plagas y enfermedades. Otros criterios empleados para elegir semillas híbridas fueron: mayor resistencia al acame, mayor resistencia a la humedad, menor altura a la planta, menor pudrición de semillas y mayor tolerancia a la sequía. En maíces locales, el rendimiento fue un parámetro de importancia en ambos municipios, pero la mayor resistencia a plagas y enfermedades fue solo considerada en Villa Corzo. Y el mejor precio de venta del grano no se consideró en ninguno de los dos municipios. Otros criterios empleados para seleccionar las semillas locales fueron: mayor tolerancia a la sequía, menor costo de la semilla, mayor tamaño de la mazorca, interés por conservar dicho material, mejor sabor y permitir la rotación de variedades locales. Las seis características deseables a mejorar en el maíz local fueron: una menor altura de planta, un mayor rendimiento, una mayor resistencia a la humedad y al acame, un mayor peso del grano, un mayor tamaño de mazorca y de granos.

ABSTRACT The maize production in Chiapas implies the decision to grow local or hybrid maize. The latter present higher yields characteristics, but demand more inputs, particularly those related to soil degradation, water pollution, genetic diversity and knowledge losses over local maize varieties. The objective of this research was to identify the criteria used by small maize farmers in the election of seed for sowing in the Villaflores and Villa Corzo municipalities (Chiapas). The data were gathered through semi-structured interviews with farmers' participating in the ASERCA program and analyzed by percentages and frequencies. The hybrid maize is the most preferred variety by the small farmers in both municipalities, although some still prefer local maize (native) or bet on the cultivation of both due to use and customs reasons. The selectionof hybrid maizeseeds in both municipalities is based mainly on better yield characteristics, although in Villa Corzo, the selection of local varieties is due to their better resistance against pests and diseases. Additional criteria used to select the local seeds were: better lodging resistance, better moisture resistance, lower plant height, less seed rot and better drought tolerance. In local maize varieties, seed yield was considered an important factor in both municipalities, but a greater resistance against pests and diseases was only considered in Villa Corzo. The highest sale price was not an important consideration in neither of the two municipalities. Other criteria used to select the local seeds were better drought tolerance, seed lower cost, greater ear size, personal interest in conserving the local resource, better flavor and the possibility for the rotation of local varieties. The six wished characteristics of local maize varieties to be improved were: a lower plant height, a better yield, a better resistance to humidity and lodging, a greater grain weight, and a bigger size of ears and grains.

Where is sugarcane cropping expanding in the brazilian cerrado, and why? A case study

ABSTRACT Sugarcane growing area in Brazil sharply expanded between 2000 and 2010 due to the increasing world demand for sugar and ethanol. Since this expansion of sugarcane is said to occur in areas covered by degraded pastures, it is likely not threatening the environment or food production. In order to verify this assumption, we investigate at farm and field levels which types of land use sugarcane cropping replaced between 2005 and 2010 and the reasons for farmers shifting or not shifting to sugarcane, as a case study in two counties in the state of Goiás. Within the studied period, sugarcane cropping expansion was related to large farms, lower risk perceived by farmers, and higher profitability compared with soybean and beef cattle-raising. For smallholders, particularly dairy farmers, the need to comply with the set-aside rules under Brazilian Forest Code (Código Florestal Brasileiro) made a shift to sugarcane less attractive, as it would have forced them to reduce farm cultivable area, with loss of incomes. From 30,408 ha under sugarcane surveyed, 45.7% had used to be pastures, 31% had previously been pastures rotated with soybean and maize, and 23.3% had been cropped exclusively with soybean or maize.

Representación de los extensionistas rurales argentinos sobre los pequeños productores / Representação dos extensionistas rurais argentinos sobre os pequenos agricultores / Argentine rural extensionists' representation of small farmers

Actualmente asistimos a un resurgimiento de la extensión rural en América Latina. Procurando contribuir a la comprensión de los fundamentos psicosociales de las prácticas extensión, se estudió la representación social que los extensionistas tienen de los pequeños productores a partir de una encuesta realizada a técnicos que trabajan en distintas instituciones publicas argentinas (n=219). Las preguntas abiertas fueron categorizadas siguiendo los principios de la Teoría Fundamentada. Luego, los resultados de esta etapa fueron cuantificados, asociados con diferentes variables sociodemográficas y utilizados para la construcción de clusters. Existen cuatro grandes áreas de la representación que se relacionan de manera compleja con distintos modelos de extensión rural. La primera área describe a los productores como aprovechados o dejados de lado por actores más poderosos, la segunda como portadores de escasos recursos para salir adelante, la tercera con características internas negativas y la cuarta como poseedores de capacidades y recursos.

Assistimos atualmente a um ressurgimento da extensão rural na América Latina. Buscando contribuir á compreensão dos fundamentos psicossociais das práticas de extensão, estudou-se a representação social que os extensionistas rurais têm dos pequenos produtores através duma enquete feita a técnicos que trabalham em diferentes instituições públicas da Argentina (n = 219). As perguntas abertas foram categorizadas de acordo com os princípios da Grounded Theory. Depois, os resultados obtidos nesta etapa foram quantificados, relacionados com diferentes variaveis sociodemográficas e utilizados para a construção de aglomerados (clusters). Há quatro áreas principais de representação as quais estão relacionados de forma complexa com diferentes modelos de extensão rural. A primeira área descreve a os produtores como explorados ou deixado de lado por actores sociais mais poderosos, a segunda como tendo recursos limitados para progredir na vida, a terceira como pessoas que têm características internas negativas, e quarto como tendo capacidades e recursos persoais.

Nowadays, rural extension is resurging in Latin America. Aiming at contributing to understand the psychosocial foundations of rural extension practices, the rural extensionists' social representation of small farmers was studied. In this vein, 219 extensionists working in different Argentine public institutions were surveyed. The open questions were analyzed following Grounded Theory. Then, the results of this phase were quantified and related to different socio-demographic variables. Also, a cluster analysis was conducted. Four areas of the representation highlight. One describes small farmers as set aside and taken advantaged of by more powerful social actors; the second as not having resources to 'get ahead'; the third as possessing negative internal characteristics and the last one as owners of useful capacities and resources.

Expectativas de los agentes de desarrollo rural argentinos sobre la Psicología y sobre la inserción profesional de los psicólogos en el ámbito de la extensión rural / Argentine rural development agents' expectations about Psychology and about the employability of psychologists in the area of rural extension

La Psicología posee una importante potencialidad para trabajar en el ámbito de la extensión y el desarrollo rural. No obstante, no existe evidencia empírica suficientemente amplia de las expectativas de los agentes de desarrollo sobre la Psicología. Por este motivo se realizó una investigación transversal de carácter cuantitativo. La muestra fue no probabilística incidental e incluyó participantes de todas las regiones de Argentina. Se encuestó a extensionistas rurales que trabajan en las principales instituciones que realizan extensión rural en el ámbito público. La encuesta, que fue respondida por 219 sujetos (9.06% del total nacional) incluyó preguntas cerradas sociodemográficas y abiertas respecto de las expectativas sobre la Psicología. Las preguntas abiertas fueron categorizadas y organizadas con el apoyo de la teoría fundamentada y el software Atlas Ti. Las categorías fueron convertidas en variables para estudiar su relación con las preguntas sociodemográficas con apoyo del software SPSS. Se concluye que la mayor parte de los extensionistas rurales del ámbito público argentino (un 88%) considera que la Psicología podría ayudarlos a resolver algunos de los problemas a los que se enfrentan, por ejemplo, brindando capacitación y asesoramiento a extensionistas rurales así como participando en equipos interdisciplinarios de extensión rural. Además, podrían trabajar directamente con productores en la gestión de procesos grupales. En términos generales, se destaca la potencialidad de la Psicología en el ámbito del trabajo grupal, la comunicación, el apoyo emocional y el cambio de actitudes y prácticas. Finalmente, se destacan las limitaciones de la investigación realizada.

Many scholars have argued that rural extension and development processes need an interdisciplinary approach, one that includes contributions from different sciences, particularly social ones. In this context, social and community psychology have a great potential to address this topic. In spite of this potentiality, psychology has produced scarce useful contributions to rural development and to extension processes. Additionally, limited empirical support has been given to probe this potentiality, which makes this a theoretical argument. Thus, a cross-sectional, quantitative investigation was conducted in Argentina. An incidental, non-probabilistic sample was used, which included participants from all regions of the country. Rural extension agents working in the National Institute of Agrarian Technology, the ProHuerta Program and the Under secretariat of Family Farming of the Ministry of Agriculture, Husbandry and Fisheries were surveyed via email. Local authorities of these institutions helped the researchers to send and receive the completed surveys indifferent ways. The reply to the poll was voluntary. 219 completed forms (143 men and 76 women) were received, which represent 9.06% of rural extensions working in public institutions in Argentina. The survey included socio-demographic,closed questions, and open ones regarding the problems faced by rural extensions in their everyday practice and their expectations about Psychology as a mean to address them. In order to analyze the open questions, different categories of analysis were built and thoroughly described to cope with ambiguous cases, which were used to categorize all replies. In this process, grounded theory and Atlas Ti software were utilized. Next, these categories were transformed into dichotomist variables, expressing the presence of the category presence of the variable and its absence, the absence of the variable. Then all variables were incorporated to SPSS software, which allowed for the quantification of the results and the study of statistical relationships between different variables. The most important result of this investigation is that 88% of the Argentine rural extensionists working in the National Institute of Agrarian Technology, the ProHuerta Program and the Under secretariat of Family Farming consider that Psychology can contribute to solve at least some of the problems they face when doing rural extension. Interestingly, this represents a very high and unexpected percentage, given psychology is not a social science traditionally related to rural issues or settings. In consequence, it is clear that there is a potential demand for psychologists in the field of rural development processes, which is not being addressed. Additionally, the replies allowed for the description of the role psychologists should fulfill when working in this field, from rural extensions’ point of view. They argue that psychologists could work with both, them and farmers. On the one hand, they could train, advice and provide with practical tools to rural extensionists. Additionally, they could take part in interdisciplinary rural extension teams. In practical terms, they could contribute in fields such as cooperative processes and group management, design and implementation of projects, understanding of small farmers’ rationale, conflict resolution, lack of adoption of technologies, and scarce participation and commitment to development projects. On the other hand, psychologists also could work directly with small farmers, providing training in different topics, and managing groups, particularly in the case of participatory processes. Additionally, they could strengthen small farmers’ self-esteem, a problem that rural extensionists related to passive attitudes and fatalism. To conclude, it is important to underline that, knowing this expected role, psychologists should start a dialogue with rural development agents in order to generate a shared conception of psychologist working in the field of rural extension, which includes both, psychologists’ and rural extensionists’ point of view.

Valores éticos en decisiones de pequeños agricultores confrontados con percepciones de estudiantes de agronomía (universidad de Caldas) / Ethical alues inn decisins of small farmers confronted with agronomy sttudents' perceptions (universidad de caldas, Colombia)

En este trabajo se determinan valores que guían a los agricultores frente a decisiones de producción, vida colectiva y ambiente en confrontación con las percepciones de los estudiantes de Agronomía y agrónomos egresados de la Universidad de Caldas. Mediante una metodología descriptiva, se trabajó con tres comunidades de pequeños agricultores para designar sus valores mediante una entrevista semiestructurada, y con sus resultados se cursó una encuesta a estudiantes y agrónomos, se identificaron puntos de encuentro y desencuentro y se sugirieron propuestas formativas en ética agronómica. Los pequeños agricultores reconocen como sus valores de expresión colectiva: responsabilidad, familia, tradición, trabajo, honorabilidad, cooperación, solidaridad, la educación como valor deseado y como valores de expresión individual: orgullo, pertenencia, bienestar, autosuficiencia. Todos los estudiantes de la Facultad coinciden en reconocer algunos de los valores sociales centrales enunciados por los productores agrarios como son: responsabilidad, solidaridad, trabajo, cooperación; en la medida en que avanzan en su formación profesional añaden otros valores y cuando egresan se centran solo en los dos primeros. Hipotéticamente, los estudiantes del programa de Agronomía se ubican de manera ideal en niveles postconvencionales en la escala de valores de Kohlberg, no obstante cuando egresan parecen retroceder en sus concepciones en la medida en que en niveles superiores y entre los egresados aparecen niveles convencionales y preconvencionales.

In this work, values that guide small farmers when facing production decisions, collective life and environment, in confrontation with the perceptions of the Agronomy alumni from Universidad de Caldas are determined. Using a descriptive methodology, three small farmer communities were worked with to designate their values using a semi-structured interview which results were used to apply a survey to students and agronomists. Agreement and disagreement points were identified and formative proposals in agronomic ethics rose. Small farmers identify their collective expression values: responsibility, family, tradition, work, honesty, cooperation, solidarity, education as a desired value; and as individual expression values: pride, membership, welfare, self-sufficiency. All the students from the Faculty coincide in recognizing some of the central social values stated by the agricultural producers such as: responsibility, solidarity, work, cooperation; as they progress in their professional education, they add other values but when they graduate they focus on the two first ones. Hypothetically, the Agronomy Program students are placed in post-conventional levels in Kohlberg's value scale. However, when they graduate it seems to be they back down in their conceptions while in superior levels and among the alumni conventional and pre-conventional levels appear.

Revisión de los trabajos realizados por la psicología sobre pequeños productores agropecuarios / Review of psychological papers on small farmers

Tradicionalmente, la psicología no ha puesto su foco en las poblaciones rurales sino en las urbanas. En consecuencia, las características y especificidades propias de los sujetos que habitan en ámbitos rurales, particularmente los campesinos, así como los procesos específicos que acontecen en tales contextos, no han recibido suficiente atención. De esta manera, buscando aportar al desarrollo de una psicología rural, el presente trabajo se ocupa de identificar, clasificar y organizar los aportes realizados por la psicología a estas cuestiones. Para hacer esto, se recuperaron y clasificaron los trabajos que abordan esta temática presentes en la base de resúmenes científicos PsycINFO de la American Psychological Association. Se concluye que la mayor parte de los trabajos realizados corresponden a las áreas 'Desarrollo y Prácticas Productivas', 'Salud y Salud Mental' y 'Psicología Social'. Igualmente, llama la atención la escasez de estudios en el área de la 'Psicología de la Educación'.

Traditionally, psychology has not set its focuss on rural populations but on urban ones. Consequently, the characteristics and specificities of the people living in rural areas, particularly in the case of peasants, as well as the specific processes that occur in such contexts, have not received enough attention. Thus, striving to contribute to the development of rural psychology, this article aims to identify, classify and organize the papers related to these issues. In order to do this, we recovered and classified the scientific abstracts that address the topic in the PsycINFO database of the American Psychological Association. We conclude that the most part of the papers related to psychology and small farmers fall into three categories: 'Development and Production Practices', 'Health and Mental Health' and 'Social Psychology'. Besides, it draws attention the paucity of papers on 'Psychology of Education.

Cobertura de solo e produção de porongo sob diferentes configurações de cultivo / Soil cover and yield of bottlegourd under different crop configurations

Em pequenas propriedades rurais, o cultivo tradicional de porongo é ainda frequente em solos declivosos e rasos, resultando na degradação do solo e na baixa produtividade. O trabalho teve por objetivo estudar diferentes densidades e épocas de cultivo para a espécie Lagenaria siceraria (Mol.) Standl. (porongo), a fim de proporcionar rápida cobertura vegetal do solo, maior produtividade e melhor qualidade de frutos comercializáveis. Três experimentos sob delineamento inteiramente casualizado com quatro repetições foram instalados em 15/09/07, 06/10/07 e 27/10/07, no norte do Rio Grande do Sul, em um Latossolo Vermelho preparado sob sistema plantio convencional (SPC). A semeadura foi em covas nas densidades de 1600 e 400 covas ha-1, representados por espaçamentos de 2,5x2,5m e 5x5m (tradicional da região), respectivamente. Foram avaliados o ciclo da cultura, o número e o comprimento das ramas principais aos 60 dias após a emergência (DAE), a cobertura vegetal do solo aos 0, 30, 60, 90 e 150DAE, a qualidade e a produtividade dos frutos. Após análise conjunta dos dados dos experimentos, observou-se que as plantas semeadas em 27/10/07, em ambas as densidades, apresentaram ciclo (150 dias), tamanho de frutos e produtividade menores; porém, sob a densidade de 1600 covas ha-1 (espaçamento de 2,5x2,5m), houve, aos 30DAE, a maior cobertura vegetal do solo (93,7 por cento) em relação às demais épocas. Sob essa densidade, o cultivo em qualquer época estudada apresentou cobertura do solo mais rápida e produtividades de frutos comerciais (cuias) maiores que o cultivo sob densidade tradicional.

In small farms, the traditional cropping system on slope and shallow soils is often common, resulting in soil and water degradation and low productivity. The study aimed to investigate different configuration of cultivations (density and times of sown) of Lagenaria siceraria (Mol.) Standl. species (bottlegourd), intending to promote faster soil mulching, to increase productivity and to obtain better quality of marketable fruits. Three experiments in completely randomized design with four replicates were installed at 15/09/07, 06/10/07 and 27/10/07 in the northern Rio Grande do Sul in a Red Latosol under conventional tillage system (SPC). The sown was made on holes with 2.5x2.5 and 5.0x5.0m spacing, considered traditional, and with 1,600 and 400 holes ha-1 density, respectively. It was evaluated the crop cycle, the number and length of main stems 60 days after emergence (DAE), the soil mulching at 0, 30, 60, 90 and, 150DAE and, quality and fruit productivity. A joint analysis of data from experiments showed that the plants sown on 27/10/07, in both spacing, showed lower cycle (150 days), fruit size and productivity, but under 1,600 holes ha-1 (2.5x2.5m of sown spacing), there was at 30DAE a faster soil mulching (93.7 percent) than in other sown times. In the same holes density, at any time of sown, it was shown that 2.5x2.5m spacing, reaches the faster soil mulching and higher yield of fruits than those under traditional sown density.