Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

The avocado is considered as a prof itable production system and job generator. This fruit is part of the policy of productive reconversion of the State of Mexico. The objective was to evaluate the prof itability and competitiveness at private prices of small-scale in the Tropical Forest Region of the Mexico. the policy analysis matrix was used in its f irst line. The system were agruped into distances and ages. The highest prof itability was $ 23 726 mexican pesos in young systems with distance of 6 meters and the worst performance was $ -24 438 mexican pesos in system of 8 meters distance and from 7 to 9 years of age. The system between 4 and 6 years of age are prof itable and competitive favors the expansion of the cultivar. The plantations older than 10 years of age recorder negative indicators. The yield was evaluated with a split-plot design. No statistical dif ference in yield between the plantations.

Enveloping data analysis is a technique that allows productivity to be analyzed in terms of relative eff iciency, eff iciency, quality, and economy to solve the productivity of production systems. The objective of the research was to analyze the economic and technical eff iciency of 13 representative units of production (URP) cow-calf in Mexico through The Enveloping Data Analysis (DEA) to test the hypothesis whether URPs with a larger production scale are more eff icient than those of lower production scale and the amount of ineff iciency. The production scales of the URPs were 35 to 500 cows in production and located in the f ive main producers of the cow-calf system. The most economically eff icient URPs were TM70, TM100 and VE150; with higher JA35 technical eff iciency and higher overall eff iciency JA35, CH40, TM70, TM100 and VE150. The average economic eff iciency was 73.7±18.2%, the technique 44.6±27.4% and total 87.1±16.6%, meaning that URPs can increase their economic eff iciency by 18.2%, technical eff iciency 55.4% and total efficiency 16.6%; to have the most eff icient URP productivity. In addition, using either input provided the same total eff iciency parameters. Therefore, producers of the cow-calf system in Mexico have their greatest opportunity for growth and development by improving technical parameters; although they can also do so, but to a lesser proportion, with economic parameters

The Malvaceae family has species widely distributed worldwide, some of them, such as cotton (Gossypium hirsutum), cacao (Theobroma cacao) and hibiscus (Hibiscus sabdarif fa) are widely used in the agri-food industry and the textile industry; even so, not all the bioactive potential of these species has been exploited, such is the case of H. sabdarif fa, since most of the seeds are considered as agro-industrial waste; there are species of this family, such as some members of the Sterculia and Ceiba genus, that have not been exploited on a massive scale in various industries, despite the fact that there are numerous studies that demonstrate their nutraceutical and medicinal potential.

En regiones con problemas de salinidad, la mejora continua de las propiedades físicas y químicas de los suelos, el incremento de los porcentajes de germinación de la semilla, así como el manejo de la nutrición mineral, deberían incrementar el rendimiento de los cultivos. El objetivo de este estudio consistió en determinar los efectos de la incorporación de paja de trigo al suelo [(IP) (cero y 5000 kg ha-1)], la inoculación de la semilla con zinc [(Zn) (cero y 100 mg kg-1 de Zn)], y la fertilización con nitrógeno [(N) (0, 115, 230 y 460 kg ha-1)] sobre trigo cultivado bajo condiciones de salinidad. El cultivo se estableció durante el ciclo otoño-invierno (2016-17 y 2017-18). El diseño experimental fue factorial triple y bajo un diseño de bloques completos al azar con cuatro repeticiones. Las variables de respuesta fueron crecimiento, nutrición y rendimiento del cultivo, así como la residualidad de los tratamientos en el suelo. La interacción de N × IP, afectó el crecimiento, la concentración de nitratos en el extracto celular de tallo y rendimiento del trigo. Aplicar 460 kg N ha-1 produjo el mayor número de espigas m-2; La adición de 115 kg N ha-1 alcanzó el mayor peso de grano. El índice de cosecha resultó mayor con la IP pero se redujo al inocular la semilla con Zn. La salinidad del suelo se redujo con la IP; mientras que la interacción Zn × IP modificó el pH, nitratos, fosfatos y la materia orgánica del suelo (MO). La MO se afectó por la interacción N × IP. En conclusión, la productividad del cultivo fue favorecida por la IP al mejorar varias propiedades importantes del suelo; por el Zn inoculado a la semilla, que incrementó el crecimiento; y por el N, que maximizó el rendimiento de trigo.

Arbuscular mycorrhizal fungi (AMF) are obligate symbionts that require a host plant (tramp) and support (substrates) to be applied as bio-fertilizers in agriculture. The objective of this study is to assess eight native AMF consortia of semi-arid zones (C1-ART, C2-GEC, C3-PAR, C4-VIE, C5-CUC, C6-SAC, C7-SAB, and C8-MUZ) and their reproduction response in three organic substrates: coffee pulp (CP), bovine manure (BM) and sugarcane bagasse (SB) on bean Phaseolus vulgaris. Plant height, stem diameter, number of leaves, root length, fresh and dry biomass, and mineral content in root were measured. The organic substrates (CP and BM) and C5-CUC and C8-MUZ consortia increased plant height, root length, and total fresh and dry biomass considerably. After day 75 of inoculation, root colonization oscillated from 5.7% in C8-MUZ to 46.1% in C2-GEC and C4-VIE; the greatest number of spores (201) was obtained in CP substrate in a 100-g sample. N, P, K, Ca, Mg, Fe, Zn, Cu, and Mn contents in root and leaves were signif icantly high (P ≤ 0.001). To conclude, native AMF inoculation and substrates had positive effects on biomass content and nutrient levels in leaf and root with the C2-GEC and C3-PAR consortia and CP and BM substrates, which produced better effects in beans, making them a biofertilization alternative in agricultural crops.

Estimates of carbon storage and release depend mainly on vegetation type, land-use change, vegetation age and ecosystem type (closed or open). The carbon sequestered and stored has a positive environmental value, while its release to the atmosphere due to land-use change causes environmental damage by contributing to global atmospheric warming. Natural grasslands in Mexico occupy around 10% of the National territory, from which halophytes have been scarcely studied in terms of their contribution to the carbon cycle. Therefore, the objective of our study was to estimate the aboveground and belowground biomass and carbon content of vegetation type. We defined an effective sampling area of 70 ha in halophilic grasslands of the state of Puebla, and the quadrant method was proposed under a sampling design with nested fixed plots. To determine the carbon content, samples were collected in the field and transported to the laboratory to be dried at a constant temperature. The total carbon content calculated for halophilic grassland was 1.33 Mg ha-1, ranging from 0.55 to 2.6 Mg ha-1. The aboveground part was estimated at 0.49 Mg ha-1 in terms of biomass, while the belowground part was 2.34 Mg ha-1. The belowground biomass measured in the field showed a high correlation with total carbon (r = 0.87), hence, it could be considered as a viable option for carbon estimation using the proposed regression model.

El pastoreo racional Voisin (PRV) promueve el manejo armonioso del ganado, las plantas, el agua y el suelo, lo cual puede inducir cambios positivos en las propiedades de los suelos degradados por la práctica del pastoreo extensivo. El objetivo de la presente investigación fue determinar los cambios en las propiedades f isicoquímicas y biológicas del suelo, perdidas por la práctica del pastoreo extensivo, mediante la implementación del PRV en dos ambientes de pastoreo. Se seleccionaron dos potreros dominados por vegetación secundaria (VegSec) de selva baja y dos monocultivos (MonGra) de Hyparrhenia rufa (todos sujetos a pastoreo extensivo). Un potrero de cada ambiente continuó bajo pastoreo extensivo (14 meses) y en los otros dos se implementó el PRV (14 meses). Se tomaron muestras de suelo y hojarasca al inicio y al f inal del periodo de estudio. Algunas propiedades físicas y químicas variaron por efecto del momento de muestreo (P < 0.05), al f inal del periodo, la densidad aparente (DA), nitrógeno total (NT), materia orgánica (MO) y carbono orgánico (CO) mejoraron mientras que potasio disponible (K) aumentó marginalmente. Hubo efecto del manejo anidado en ambiente de pastoreo (P < 0.05); en VegSec, DA (P < 0.05) y P disponible (P < 0.05) mejoraron con PRV y permanecieron igual en MonGra; en MonGra, la MO (P < 0.05) y CO (P < 0.05) aumentaron solo con pastoreo extensivo (P < 0.05). La abundancia relativa y riqueza de morfoespecies de fauna edáf ica se incrementaron con PRV en ambos ambientes de pastoreo (P < 0.05), donde dominó el orden Isóptera. Se concluye que a 14 meses de implementado el PRV, algunas propiedades físicas, químicas y biológicas del suelo empiezan a regenerarse.

An experiment was carried out in the f ield with the objective of evaluating the ef fects of the application of three green legume fertilizers on some chemical properties in an iron luvisol (K’an kab in Mayan), representative of the agricultural areas of the state of Campeche. A randomized complete block design was used with seven treatments: Mucuna pruriens L., Vigna unguiculata L. and Phaseolus lunatus inoculated or not with endomycorrhizae and benef icial nitrogen-f ixing bacteria, compared with the control constituted by the incorporation of weeds plus diammonium phosphate (DAP). The results show that all the studied soil properties: organic matter (MOS), electrical conductivity (CE), pH characteristics, as well as the determination of the macronutrient content (N, P, K, Ca, Mg and Na), micronutrients (B, Fe, Mn, Cu, Zn), add exchangeable bases (meq/100 g) and the C:N ratio, behaved in a similar way in statistical terms (P < 0.05). The green manures achieved nutrient contributions comparable to the fertilization that combined the DAP with the incorporated biomass of weeds, which shows that the use of green manures, even of legume species cultivated as food in the agroecosystems of the Yucatan Peninsula, can replace conventional fertilization in ferric luvisols from Campeche, Mexico.

Citriculture is one of the most important productive activities in the State of Tamaulipas, Mexico. However, in most orchards the yields of these fruit trees are low and frequently of poor quality due to a low supply of iron and other micronutrients. The calcareous characteristics of the soils such as a moderately alkaline pH –around 8– and a calcium carbonate content higher than 40% induce the precipitation of iron in the form of oxides and hydroxides, causing low availability of Fe for the plant. Therefore, the objective of this work was to evaluate the effect of the FeEDDHA chelate applied to the soil. In our study we used 25-year-old Italian lemon trees (Citrus limon (L.) Osbeck) grafted on sour orange rootstocks, with visual symptoms of iron deficiency and severe and persistent yellowing of new leaves. The application of different concentrations of FeEDDHA chelate (50, 100 and 150 g tree-1) to the soil and the control treatment were evaluated. We applied FeEDDHA to the soil with the purpose of determining the most appropriate dose of the chelator to correct the iron deficiency in Italian lemon trees under calcareous soil conditions of the Central zone of the State. The application of the chelate to the soil in doses between 50 and 100 g tree‑1 of FeEDDHA increased the SPAD index in the leaves, corrected the Fe deficiency in the trees, and significantly increased the foliar concentration of Fe to an optimal level (77 mg kg-1 Fe), the fruit yield (40 Mg ha-1) and the economic income. In addition, the application of a higher dose, 150 g tree-1 of FeEDDHA, did not significantly increase iron assimilation and fruit production in Italian lemon trees.

A study was performed to evaluate the variation in pH, availability, and chemical associations of Cd in two previously contaminated Latosols amended with mineral and organic amendments. The Latosols were contaminated with Cd and amended with vermicompost, sugarcane f ilter cake, palm kernel pie, lime, phosphate rock, or zeolite. Cadmium availability was evaluated monthly in the contaminated soil/soil amendment mixtures with the DTPA and Mehlich-3 extractants for twelve months of incubation. At the end of this period, a sequential extraction procedure was performed in the mixtures to identify the Cd forms present in the several geochemical fractions. Lime immobilized Cd at a larger extension (60%), being the metal transferred to less available fractions. The Mehlich-3 extractant had a high correlation (0.96**) with the available fraction examined by the sequential extraction procedure. In general, organic amendments produced small ef fects on the f inal pH of soil/soil amendment mixtures as compared with the initial soil pH. Mineral amendments caused enhancement of soil pH and the most pronounced ef fect occurred with the use of lime.