Overview of the Worldwide Spread of Conservation Agriculture

The global empirical evidence shows that farmer-led transformation of agricultural production systems based on Conservation Agriculture (CA) principles is already occurring and gathering momentum globally as a new paradigm for the 21st century. The data presented in this paper has been collected by the Food and Agriculture Organization of the United Nations from several sources including estimates made by ministries of agriculture, by farmer organizations, and well-informed individuals in research or development organizations; they provide an overview of CA adoption and spread by country, as well as the extent of CA adoption by continent. CA systems, comprising no or minimum mechanical soil disturbance, organic mulch soil cover, and crop species diversification, in conjunction with other good practices of crop and production management, are now (in 2013) practiced globally on about 157 M ha, corresponding to about 11% of field cropland, in all continents and most land-based agricultural ecologies, including in the various temperate environments. This change constitutes a difference of some 47% globally since 2008/09 when the spread was recorded as 106 M ha. The current total of 157 M ha represents an increase in adoption of CA by more countries but the estimate is on the conservative side as the updated database does not capture all the CA cropland. While in 1973/74 CA systems covered only 2.8 M ha worldwide, the area had grown in 1999, to 45 M ha, and by 2003 the area had grown to 72 M ha. In the last 10 years CA cropland has expanded at an average rate of more than 8.3 M ha per year and since 2008/2009 at the rate of some 10 M ha per year, showing the increased interest of farmers and national governments in this alternate production concept and method. Adoption has been intense mainly in North and South America as well as in Australia and Asia, and more recently in Europe and Africa where the awareness of and support for CA is on the increase. The paper presents an update of the adoption of CA since 2008/09.Au vu des données empiriques mondiales, la transformation des systèmes de production agricole, qui s’appuient sur les principes de l’Agriculture de Conservation (AC), conduite par les agriculteurs eux-mêmes, est déjà engagée et s’impose peu à peu comme un nouveau modèle mondial pour le 21ème siècle. Les données de cet article ont été recueillies par l'Organisation des Nations Unies pour l’Alimentation et l’Agriculture (FAO) auprès de plusieurs sources et sont notamment issues d'études réalisées par des ministères de l'agriculture, des organisations d'agriculteurs et des experts d'organismes de recherche et développement ; elles donnent un aperçu par pays et par continent du niveau d’adoption et de progression de l’AC. Les pratiques de l’AC, qui englobent la perturbation mécanique minimale, voire aucune perturbation mécanique du sol, l’utilisation des paillis organiques et la diversification des espèces cultivées, associées à d’autres bonnes pratiques de gestion des cultures et de la production, sont aujourd’hui (en 2013) mises en œuvre sur près de 157 millions d’hectares, soit près de 11 % des terres cultivées, sur tous les continents et dans la plupart des écologies agricoles, notamment dans les divers environnements tempérés. Cette évolution représente un écart de près de 47 % au niveau mondial par rapport aux années 2008/09, où l'AC était pratiquée sur 106 millions d’hectares. Le chiffre actuel de 157 millions d’hectares reflète une adoption plus large de l'AC dans un nombre croissant de pays mais il s'agit là d'une estimation prudente, la base de données actualisée ne prenant pas en compte la totalité des terres cultivées en AC. Alors que l'AC couvrait seulement 2,8 M ha dans le monde en 1973/74, elle s'est étendue à 45 M ha en 1999 et 72 M ha en 2003. Au cours des dix dernières années, la surface de terres cultivées en AC s’est développée à un rythme moyen de plus de 8,3 M ha par an et d'environ 10 M ha par an depuis 2008/2009, illustrant l’intérêt croissant des agriculteurs et des gouvernements pour ce concept et ces méthodes de production alternatifs. L'adoption de l'AC a été particulièrement soutenue en Amérique du Nord et en Amérique du Sud, ainsi qu'en Australie et en Asie, et, plus récemment, en Europe et en Afrique, où la sensibilisation aux principes de l'AC et l’encouragement de leur adoption ne cessent d'augmenter. Cet article présente un état des lieux de l'adoption de l'AC depuis 2008/09.Las pruebas empíricas a nivel mundial muestran que la transformación de los sistemas de producción agrícola guiada por los agricultores y basada en los principios de la agricultura de conservación ya se está produciendo y está cobrando impulso en todo el mundo como un nuevo paradigma para el siglo XXI. Los datos presentados en este trabajo han sido obtenidos por la Organización de las Naciones Unidas para la Agricultura y la Alimentación de varias fuentes, entre las que se incluyen las estimaciones realizadas por ministerios de agricultura, organizaciones de agricultores y otros entendidos en la materia de organizaciones de investigación o desarrollo, y proporcionan una perspectiva general de la adopción y la propagación de la agricultura de conservación por país, así como el alcance de la adopción de la agricultura de conservación en los distintos continentes. Los sistemas de agricultura de conservación, que incluyen una perturbación mecánica mínima o nula de la tierra, el uso de una capa de mantillo natural y la diversificación de las especies de cultivo, en combinación con otras prácticas positivas de gestión de cultivos y de la producción, se utilizan actualmente (en 2013) a nivel mundial en unos 157 millones de hectáreas, lo que corresponde aproximadamente al 11 % de las tierras de cultivo, en todos los continentes y la mayoría de las agroecologías basadas en el suelo, incluidos los ambientes templados. Este cambio constituye una diferencia de aproximadamente el 47 % en todo el mundo desde los años 2008-2009 cuando la propagación era de 106 millones de hectáreas. La cifra total actual de 157 millones de hectáreas representa un aumento en la adopción de la agricultura de conservación por parte de más países si bien esta estimación es conservadora ya que la base de datos actualizada no abarca todas las tierras de cultivo en las que se practica la agricultura de conservación. Mientras en los años 1973-1974 los sistemas de agricultura de conservación ocupaban solo 2,8 millones de hectáreas en el mundo, esta extensión fue creciendo hasta alcanzar los 45 millones de hectáreas en 1999 y los 72 millones de hectáreas en 2003. En los últimos 10 años las tierras de cultivo en las que se practica la agricultura de conservación se han extendido a un ritmo medio de más de 8,3 millones de hectáreas por año y desde los años 2008-2009 a un ritmo de unos 10 millones de hectáreas por año, lo que demuestra el creciente interés de los agricultores y los gobiernos nacionales en este concepto y método de producción alternativa. La adopción ha sido especialmente importante en América del Norte y del Sur, así como en Australia y Asia, y más recientemente en Europa y África, donde la concienciación y el apoyo a la agricultura de conservación son cada vez mayores. Este trabajo presenta información actualizada sobre la adopción de la agricultura de conservación desde los años 2008-2009

Success of English Language Learners: Barriers and Strategies

For this report, the researchers sought to gather more information on the success of mainstreamed ELL students from both exited students and their content teachers. The researchers\u27 aim was to see how teachers assessed these students’ academic needs, how these students felt about the accommodations executed by their teachers, and where these mainstreamed students were finding success. Furthermore, researchers wanted to gain information on the perceptions of the teachers working with these students. Information was gathered at two different high schools within the same district by interviewing and surveying both mainstreamed ELLs and their content teachers. Student transcripts were also utilized to gain more information about mainstreamed ELLs’ academic success. Results indicated that some classes, specifically those that required frequent memorization of content, were cited by students as more challenging and were classes in which more students were struggling to demonstrate proficiency, as indicated by their grades. Furthermore, results of teacher surveys and interviews highlighted a lack of comfort in understanding how to communicate with families of these students and how best to meet the academic needs of this population of learners. From these results, researchers drew the need for additional classroom-based and school-wide research. Keywords: ELL, sheltered instruction, mainstream, exite

A goal programming methodology for multiobjective optimization of distributed energy hubs operation

This paper addresses the problem of optimal energy flow management in multicarrier energy networks in the presence of interconnected energy hubs. The overall problem is here formalized by a nonlinear constrained multiobjective optimization problem and solved by a goal attainment based methodology. The application of this solution approach allows the analyst to identify the optimal operation state of the distributed energy hubs which ensures an effective and reliable operation of the multicarrier energy network in spite of large variations of load demands and energy prices. Simulation results obtained on the 30 bus IEEE test network are presented and discussed in order to demonstrate the significance and the validity of the proposed method

A new protein evaluation system for horse feed from literature data

Few data on apparent pre-caecal digestibility (APCD) of crude protein (CP) and particularly amino acids (AA) are available from studies with horses. Protein bound in cell walls (i.e. neutral detergent insoluble CP (NDICP)) is unlikely to be decomposed by digestive enzymes in the small intestine. In contrast the corresponding analytical fraction of neutral detergent soluble CP (NDSCP) (NDSCP = CP-NDICP) is likely to be available for auto-enzymatic digestion. A literature analysis on the relationship between NDICP/NDSCP and pre-caecal indigestible/digestible CP was carried out. There was a strong positive relationship between NDICP and pre-caecal indigestible CP, which suggests that NDICP can be used to estimate the part of protein that is not available for digestion in the small intestine. There was also a correlation between NDSCP and pre-caecal digestible protein. The slope of the linear regression line between NDICP and pre-caecal digestible CP was 0.9, suggesting an APCD of NDSCP of 90 %. Thus pre-caecal digestible CP may be predicted by multiplying NDSCP by 0.9. Because the literature identifies a similar AA profile in NDICP and NDSCP within a given feed the presented concept may preliminarily be transferred to AA. The proposed system can at any time be adapted to the scientific progress without altering its structure. Such adaptations would be necessary particularly when new knowledge exist on the distribution of AA onto NDICP/NDSCP, the APCD of individual AA from NDSCP, and the impact of feed processing and chewing on particle sizes and protein digestibility

A new protein evaluation system for horse feed from literature data

Few data on apparent pre-caecal digestibility (APCD) of crude protein (CP) and particularly amino acids (AA) are available from studies with horses. Protein bound in cell walls (i.e. neutral detergent insoluble CP (NDICP)) is unlikely to be decomposed by digestive enzymes in the small intestine. In contrast the corresponding analytical fraction of neutral detergent soluble CP (NDSCP) (NDSCP = CP-NDICP) is likely to be available for auto-enzymatic digestion. A literature analysis on the relationship between NDICP/NDSCP and pre-caecal indigestible/digestible CP was carried out. There was a strong positive relationship between NDICP and pre-caecal indigestible CP, which suggests that NDICP can be used to estimate the part of protein that is not available for digestion in the small intestine. There was also a correlation between NDSCP and pre-caecal digestible protein. The slope of the linear regression line between NDICP and pre-caecal digestible CP was 0.9, suggesting an APCD of NDSCP of 90 %. Thus pre-caecal digestible CP may be predicted by multiplying NDSCP by 0.9. Because the literature identifies a similar AA profile in NDICP and NDSCP within a given feed the presented concept may preliminarily be transferred to AA. The proposed system can at any time be adapted to the scientific progress without altering its structure. Such adaptations would be necessary particularly when new knowledge exist on the distribution of AA onto NDICP/NDSCP, the APCD of individual AA from NDSCP, and the impact of feed processing and chewing on particle sizes and protein digestibility

Magnetic form factor of SrFe2_2As2_2

Neutron diffraction measurements have been carried out to investigate the magnetic form factor of the parent SrFe2As2 system of the iron-based superconductors. The general feature is that the form factor is approximately isotropic in wave vector, indicating that multiple d-orbitals of the iron atoms are occupied as expected based on band theory. Inversion of the diffraction data suggests that there is some elongation of the spin density toward the As atoms. We have also extended the diffraction measurements to investigate a possible jump in the c-axis lattice parameter at the structural phase transition, but find no detectable change within the experimental uncertainties