6,641 research outputs found

    Improving Pasture Productivity and Persistence by Renovating or Rejuvenating

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    Forages make up a large part of the feed requirements of beef cattle, and grazing remains the most economical form of feed delivery. However, several years after pasture establishment, forage productivity and longevity usually decline. Maintaining productive forage stands in the long term becomes a major challenge that beef producers face. A 3-yr on-farm study was conducted to determine the comparative effects of several pasture rejuvenation methods, such as spraying of herbicides to control weeds and brush, Spray herbicide + direct seed in spring (RSS), forage seeding methods, fertilizer application (FERT), and pasture rest as well as aeration/spiking in fall (AF) and aeration/spiking in spring (AS) on forage dry matter (DM) yield and forage quality. Breaking & reseeding (B&R), which is a grassland renovation method, was compared to these four pasture rejuvenation methods. A no treatment method (control) was included for comparison. Three years after treatments were implemented, pasture rejuvenation methods did significantly affect (P\u3c 0.05) grass botanical composition but did not significantly influence (P\u3e 0.05) total DM yield and legume botanical composition. The only method that involved land cultivation and reseeding (B&R) showed higher total input costs than other methods. Overall, RSS as well as AS, AF and FERT had greater 2-year total forage production, revenue and returns, and profit over control than the other treatment methods

    ESTUDIO COMPARATIVO DEL DESARROLLO DE LA ALFABETIZACIÓN EN POBLACIONES DE EDUCACIÓN PRIMARIA Y PREESCOLAR

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    A comparative study about early literacy of 33 children from elementary school and 27 children from kindergarden was carried out, applying the Instrumento de Observación de los Logros de la Lectoescritura Inicial (Escamilla, Andrade, Basurto y Ruíz, 1996). The purpose of the present work was to characterize the level of early literacy considering the knowledge of the language written in both groups. The groups were evaluated in the first two weeks of the month of September and of October of the school cycle 2011-2012. In the results it was observed that they were only significant differences in the identification of letters. The results are discussed in relation to the concept of early literacy

    Biosimilars in rheumatology: what the clinician should know

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    Biosimilars are now a reality in rheumatology. Although analytical and non-clinical procedures to establish similarity have evolved significantly, clinical trials demonstrating equivalent efficacy and safety are absolutely required for all biosimilars. The design of such trials, including equivalence and non-inferiority statistical approaches, are discussed. Clinical evidence on biosimilars that have been approved recently or are presently being developed for use in rheumatology is also reviewed and contrasted with that available for biomimics (or intended copies), which are non-innovator biologics that are marketed in several countries but have not undergone review according to a regulatory pathway for biosimilars

    Changes in Crude Protein and Fiber Contents of Small Grain Cereals for Forage over Time

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    Oat, triticale, wheat and barley are small grain cereals used as forage in many temperate Mexican regions. The objective was to determine crude protein and van Soest fiber contents of these forages cut at 80, 96, 108, 121, 138 and 153 days after seeding. Cultivars used were: Chihuahua (OC) for oat; Arne (TA), Bicentenario (TB) and Siglo XXI (TS) for triticale; Saturno (WS) for wheat; and San Marcos (BSM) for barley. Experiment was under greenhouse conditions from November 2015 to May 2016. Crude protein (CP), neutral (NDF) and acid (ADF) detergents fibers were determined on the forage harvested at each time. Statistical analysis was by linear regression with cultivar as a dummy variable (R2= 0.5843 to 0.6861), response variables were CP, NDF and ADF contents over days after seeding (R2≥ 0.7693), the model included first grade interaction. Models developed were compared based on the slopes calculated. First grade interaction was significant (p\u3c 0.05) in CP due to the pattern change in TS, and in NDF due to the pattern change in OC and in ADF due to the pattern change in TA. So that, individual models and coefficient confident intervals were developed for each species and cultivar to compare them and to declare similarities or differences at p\u3c 0.05. Overall, CP decreased (p\u3e 0.05) from 0.11 to 0.39; while NDF and ADF increased (p\u3e 0.05) from 0.60 to 1.10, and from 0.20 to 0.83 percentage units day-1 respectively. It was concluded that crude protein, neutral and acid detergent fiber contents in small grain cereals are not dependent on harvesting time when measured at development stages close to physiological maturity

    Soil properties following reforestation or afforestation of marginal cropland

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    Aims Reforestation or afforestation of marginal agricultural lands offers opportunities to sequester soil organic carbon (SOC), improve the quality of degraded soils, and provide ecosystem services. The objectives of this study were to identify the extent and distribution of marginally productive cropland in the state of Iowa and to quantify the changes in SOC and relevant soil properties following tree planting. Methods A geographic information system (GIS) analysis was used to identify 1.05 million ha of marginal cropland within the state. Soil samples were collected from four locations with (\u3c51 yr-old) forest plantations and adjacent crop fields. Soil samples were analyzed for SOC, total nitrogen (TN), pH, cation exchange capacity (CEC), ammonium acetateextractable K, Ca, Mg, and Na, and particle size. Results The forested soils had 30.0±5.1 % (mean ±standard error) more SOC than the tilled cropland. The average annual change in SOC following tree planting was estimated to be 0.56±0.05 Mg C ha−1 yr−1. Differences were observed in several soil properties but strong correlations with SOC content were only observed for bulk density and extractable Ca. Conclusions These results indicate that within 5 decades of tree planting on former cropland or pasture there was consistently and significantly greater SOC in soil beneath the trees
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