Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
J Ethnobiol Ethnomed ; 14(1): 38, 2018 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-29843757

RESUMO

BACKGROUND: The traditional ecological knowledge of land of the Ch'ol originary people from southeast Mexico forms part of their cultural identity; it is local and holistic and implies an integrated physical and spiritual worldview that contributes to improve their living conditions. We analyzed the nomenclature for soil classification used in the Mexican state of Tabasco by the Ch'ol farmers with the objective of contributing to the knowledge of the Maya soil classification. METHODS: A map of the study area was generated from the digital database of parcels in the ejido Oxolotán in the municipality of Tacotalpa, to which a geopedological map was overlaid in order to obtain modeled topographic profiles (Zavala-Cruz et al., Ecosistemas y Recursos Agropecuarios 3:161-171, 2016). In each modeled profile, a soil profile was made and classified according to IUSS Working Group WRB (181, 2014) in order to generate a map of soil groups, which was used to survey the study area with the participation of 245 local Ch'ol farmers for establishing an ethnopedological soil classification (Ortiz et al.: 62, 1990). In addition, we organized a participatory workshop with 35 people to know details of the names of the soils and their indicators of fertility and workability, from which we selected 15 participants for field trips and description of soil profiles. RESULTS: The color, texture, and stoniness are attributes important in the Ch'ol nomenclature, although the names do not completely reflect the visible characteristic of the soil surface. On the other hand, the mere presence of stones is sufficient to name a land class, while according to IUSS Working Group WRB (181, 2014), a certain amount and distribution of stones in the soil profiles is necessary to be taken into consideration in the name. Perception of soil quality by local farmers considers the compaction or hardness of the cultivable soil layer, because of which black or sandy soils are perceived as better for cultivation of banana, or as secondary vegetation in fallow. Red, yellow, or brown soils are seen as of less quality and are only used for establishing grasslands, while maize is cultivated in all soil classes. CONCLUSIONS: Farmers provided the Ch'ol nomenclature, perceived problems, and uses of each class of soil. Translation of Ch'ol soil names and comparison with descriptions of soil profiles revealed that the Ch'ol soil nomenclature takes into account the soil profile, given it is based on characteristics of both surface and subsurface horizons including color of soil matrix and mottles, stoniness, texture, and vegetation.


Assuntos
Solo/classificação , Terminologia como Assunto , México
2.
Trop Anim Health Prod ; 43(1): 215-20, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20711753

RESUMO

The objectives were to evaluate the silage quality of sugarcane silage enriched (as fed) with corn grain ground (10%), urea (1.5%), and mineral premix (0.5%) and its effects as a feed supplement on growth performance of beef steers grazing stargrass. Firstly, in micro-silages, whole sugarcane enriched with corn grain, urea, and minerals (WSCE) were ensilaged by 0, 20, 40, and 60 days. Crude protein (CP) and lactic acid (LA) increased linearly (P < 0.05) and true protein decreased linearly (P < 0.05) as fermentation time increased. The pH values in silages were affected quadratically by fermentation time. Thus, after a 20-day fermentation, the pH values were below 4.5. Secondly, in micro-silos WSCE and stem sugarcane enriched with corn grain, urea, and minerals (SSCE) with and without calcium propionate were ensilaged by 30 days, but it did not affect any chemical composition trait in the silage. The SCCE silages had higher CP and LA and lower pH than WSCE silages. Finally, for 120 days, 20 beef steers (378 ± 33 kg initial BW) grazing stargrass were supplemented (daily by 1-h free access) with WSCE silage. Supplemental silage increased total dry matter intake, total gain, and the average daily gain, without any affectation on feed conversion and total tract digestion of dry matter. It is concluded that whole sugarcane silage is an alternative feed supplement to improve growth performance in beef steers grazing stargrass.


Assuntos
Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Bovinos/fisiologia , Alimentos Fortificados/análise , Saccharum/química , Silagem/análise , Animais , Fermentação , Concentração de Íons de Hidrogênio , Masculino , México , Fatores de Tempo , Oligoelementos , Ureia , Zea mays
3.
Interciencia ; Interciencia;30(12): 775-779, dic. 2005. ilus, tab
Artigo em Espanhol | LILACS | ID: lil-443039

RESUMO

Se aportaron dosis de 0, 20, 40 y 60Mgúha-1 de una mezcla lombricompostada de cachaza y estiércol bovino (1:1) a un suelo vertisol para evaluar su efecto sobre las propiedades físicas de éste. El aporte de la enmienda se realizó en ene 2003; a partir de esa fecha se mantuvo el suelo sin alteración mecánica durante 18 meses. En jun 2004 se levantó un muestreo que permitió medir la densidad aparente, elaborar láminas delgadas, fraccionar los agregados del suelo de acuerdo a su tamaño y estabilidad, y determinar el carbono total asociado a cada fracción. La estructura y macroagregados se visualizaron por técnicas de láminas delgadas y microscopía. La densidad aparente disminuyó conforme se incrementó la dosis de lombricompuesto (r2= 0,9945, p=0,06). A través de las láminas delgadas se identificó una reconfiguración estructural en la superficie del suelo; en donde se aprecia que en los tratamientos de 40 y 60Mgúha-1 hay un mayor número de macroagregados y espacio poroso. Los resultados del fraccionamiento por tamaños de agregados en húmedo indican que hay una mayor cantidad de macroagregados estables en los suelos que recibieron dosis mayores de la enmienda. Se observó que en los microagregados (<250µm) hay una menor concentración de carbono asociado; mientras que la mayor concentración se observó asociada a pequeños macroagregados (250-500µm)


Assuntos
Solos Argilosos , Esterco , Agricultura
4.
Interciencia ; Interciencia;28(7): 404-407, jul. 2003. tab
Artigo em Espanhol | LILACS | ID: lil-356811

RESUMO

Después de dos años de reciclar rastrojos de cosecha en un vertisol cultivado con caña de azúcar, el suelo fue evaluado para determinar el efecto de los rastrojos sobre sus propiedades físicas, químicas, así como el rendimiento del cultivo. Los tratamientos aplicados fueron T1) quema de rastrojos (testigo; T2) rastrojos colocados en bandas sobre los surcos centrales de la parcela y T3) rastrojos picados y esparcidos en la parcela. Se empleó un diseño de bloques complejos al azar con cuatro repeticiones. Las variables estudiadas fueron materia orgánica (MO), nitrógeno total (Nt), fósforo (P), pH, densidad aparente (DAp), humedad residual (HR) y rendimientos de cosecha (RC). Los resultados no mostraron diferencias estadísticas excepto en HR, donde el porcentaje fue mayor en los meses secos del ciclo evaluado. Las tendencias de las medias marcan a T2 con una menor media en RC (45,03ton.ha-1), aunque MO,DAp, y Hr en términos edáficos tienen mejores indicadores (1,79 por ciento; 1,15ton.m-3 y 52,18 por ciento, respectivamente).


Assuntos
Trombiculidae , México , Ciência
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA