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Nahed-Toral J.,Colegio de Mexico | Sanchez-Munoz B.,Autonomous University of Chiapas | Mena Y.,University of Seville | Ruiz-Rojas J.,Autonomous University of Chiapas | And 7 more authors.
Journal of Cleaner Production | Year: 2013

In the municipality of Tecpatan, Chiapas, in southeastern Mexico, it is highly feasible to convert traditional agrosilvopastoral systems of dairy production to the organic production model. The objective of this study was to characterize silvopastoral systems and evaluate the feasibility of converting traditional agrosilvopastoral systems to the organic model. We studied 75 cattle farms belonging to three Rural Production Societies (RPS; rural cooperatives): (i) RPS Grijalva (RPS-G: n = 35), (ii) RPS Pomarroza (RPS-P: n = 22), and (iii) RPS Malpaso (RPS-M: n = 18). For this, we used as a guide the multi-criteria methodology of the Organic Livestock Proximity Index (OLPI) proposed by Mena et al. (2011), adapting it to suit our purposes. In the current study, we designed a new OLPI with 35 variables which integrate 10 indicators. Information was obtained through direct observation and a questionnaire applied to producers. Statistical analysis of the results of 10 indicators used did not show significant differences among rural production societies. The same was true for the organic conversion index (p > 0.05: RPS-G = 62.5%; RPS-M = 63.4%, and RPS-P = 64.6%). The data suggest that all cattle farms need to substantially improve veterinary care, safety of milking, quality of milk and dairy products, ecological management, and sustainable grassland management. In general, producers of the three rural production societies should be trained in a variety of organic cattle production and management techniques so that cattle farms may achieve a closer approximation to the organic model of production and thus may be certified. © 2012 Elsevier Ltd. All rights reserved. Source


Vela M.D.,IFAPA Chipiona | Gine A.,Polytechnic University of Catalonia | Lopez-Gomez M.,IRTA Sustainable Plant Protection | Sorribas F.J.,Polytechnic University of Catalonia | And 3 more authors.
European Journal of Plant Pathology | Year: 2014

The present research was undertaken to evaluate the effects of soil temperature on the life cycle of root-knot nematodes (RKN) on zucchini-squash in growth chambers and to assess the relationship between Meloidogyne incognita soil population densities at planting (Pi), its multiplication rate, and crop losses of zucchini in field conditions. Thermal requirements for M. incognita and M. javanica were determined by cultivating zucchini plants in pots inoculated with 200 second stage juveniles (J2) of each Meloidogyne species at constant temperatures of 17, 21, 25, and 28 °C. Number of days from nematode inoculation until appearance of egg laying females and until egg hatching were separately recorded. For life cycle completion, base temperatures (Tb) of 12 ºC and 10.8 ºC and accumulated degree-days above Tb (S) of 456 and 526, were estimated for M. incognita and M. javanica, respectively. The relationship between fruit weight and M. incognita Pi fits the Seinhorst damage function, but differed accordingly to the cropping season, spring or autumn. Tolerance limits for M. incognita on zucchini were 8.1 J2 per 250 cm3 of soil in spring and 1.5 in autumn cropping cycles, and the minimum relative yields were 0.61 in spring and 0.69 in autumn. Zucchini-squash was a poorer host for M. incognita in spring than in autumn, since maximum multiplication rates (a) and equilibrium densities (E) were lower in spring (a = 16–96; E = 274–484) than in autumn (a = 270–2307; E = 787–1227). © 2014, Koninklijke Nederlandse Planteziektenkundige Vereniging. Source


Nahed-Toral J.,Colegio de Mexico | Sanchez-Munoz B.,Autonomous University of Chiapas | Mena Y.,University of Seville | Ruiz-Rojas J.,Autonomous University of Chiapas | And 7 more authors.
Journal of Animal and Veterinary Advances | Year: 2012

In the municipality of Tecpatan, Chiapas, in Southeastern Mexico, traditional agrosilvopastoral systems of dairy production have great potential for conversion to the organic production model. The objective of this study was to characterize silvopastoral systems and evaluate the potential of converting traditional agrosilvopastoral systems to the organic model. Researchers studied 75 cattle farms belonging to three Rural Production Societies (RPS; rural cooperatives): RPS Grijalva (RPS-G: n = 35), RPS Pomanoza (RPS-P: n = 22) and RPS Malpaso (RPS-M: n = 18). For this, researchers used as a guide the multi-criteria methodology of the Organic Livestock Proximity Index (OLPI) proposed by Mena adapting it to suit the purposes. In the current study, researchers designed a new OLPI with 35 variables which integrate 10 indicators. Information was obtained through direct observation and a questionnaire applied to producers. Statistical analysis of the results of 10 indicators used did not show significant differences among rural production societies. The same was true for the organic conversion nidex (p>0.05: RPS-G = 62.5%; RPS-M = 63.4% and RPS-P = 64.6%). The data suggest that all cattle farms need to substantially improve veterinary care, safety of milking, quality of milk and dairy products, ecological management and sustainable grassland management. In general, producers of the three rural production societies should be trained in a variety of organic cattle production and management techniques so that cattle farms may achieve a closer approximation to the organic model of production and thus may be certified. © Medwell Journals, 2012. Source


Diaz-Hernandez J.L.,IFAPA Camino de Purchil
Chemosphere | Year: 2010

An accurate evaluation of the carbon stored in soils is essential to fully understand the role of soils as source or sink of atmospheric CO2, as well as the feedback processes involved in soil-atmosphere CO2 exchange. Depth and strategies of sampling have been, and still are, sources of uncertainties, because most current estimates of carbon storage in soils are based on conventional soil surveys and data sets compiled primarily for agricultural purposes. In a study of the Guadix-Baza basin, a semiarid area of southern Spain, sizeable amounts of carbon have been found stored in the subsoil. Total carbon estimated within 2-m was 141.3kgCm-2 compared to 36.1kgCm-2 if estimates were based solely on conventional soil depths (e.g. 40-cm in Regosols and 100-cm in Fluvisols). Thus, the insufficient sampling depth could lead to considerable underestimation of global soil carbon. In order to correctly evaluate the carbon content in world soils, more specific studies must be planned and carried out, especially in those soils where caliche and other carbonated cemented horizons are present. © 2010 Elsevier Ltd. Source


Gine A.,Polytechnic University of Catalonia | Lopez-Gomez M.,IRTA - Institute of Agricultural-Alimentary Research and Technology | Vela M.D.,IFAPA Chipiona | Ornat C.,Polytechnic University of Catalonia | And 3 more authors.
Plant Pathology | Year: 2014

Several studies were carried out to determine (i) thermal requirements for development, egg production and emergence of juveniles, and completion of the life cycle of Meloidogyne incognita and Meloidogyne javanica on cucumber, (ii) the maximum multiplication rate and the equilibrium density of root-knot nematodes on cucumber and yield losses in pot and plastic greenhouse experiments, and (iii) the relationships between relative leaf chlorophyll content (RLCC) and relative cucumber dry top weight biomass (RDTWB) in relation to increasing nematode densities at planting (Pi) in pot experiments. Thermal requirements of M. incognita and M. javanica on cucumber did not differ, irrespective of the biological stage. In the pot experiments, M. javanica completed one generation. The maximum multiplication rate (a) was 833, and the equilibrium density (E) varied according to the effective inoculum densities. The relationship between RDTWB and Pi fitted the Seinhorst damage function model. The RLCC value at 40 or 50 days post-inoculation also fitted the damage model and was related to RDTWB. In greenhouse experiments, conducted from 2009 to 2012, M. incognita completed three generations. The values for a and E were 1147 and 625 second stage juveniles (J2) per 250 cm3 soil, respectively. The tolerance limit was below zero, and the minimum relative yield ranged from 0·12 to 0·34. © 2014 British Society for Plant Pathology. Source

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