Top-dressing durum with nitrogen to manage protein

Non-Peer ReviewedGrain protein is an important factor in determining the quality of durum wheat (Triticum turidum L.). Durum markets pay a premium for protein content of 13% or higher. During the 1990's, the average protein content of durum produced on the Canadian prairies has been 12.5% or less, leaving a sizable proportion of the durum crop unsuitable for the premium market. The overall objective of this project is to determine the effect and relative efficiency of top-dressed N on grain protein, quality, yield, and economic return of durum wheat. Nitrogen at three rates (20,40 and 60 kg N ha-1) was top-dressed on durum at 4 growth stages; before germination (during seeding), five leaf, flag leaf and flowering. The study was done over three years at two locations (Indian Head and Swift Current, SK). Four cultivars were used. Increasing the rate of top-dressed nitrogen increased the protein content of the durum. Applying all the nitrogen at seeding provided the most consistent increases in protein. However, when the yield potential increased during the growing season due to above normal spring and summer precipitation, protein levels in the durum seed increased when nitrogen was top-dressed during the growing season

Explicações teleológicas no ensino de evolução

O presente estudo tem como finalidade investigar o pensamento teleológico e suas implicações para o ensino e a formação de professores de Biologia. Particularmente, visa a compreender como os professores utilizam os argumentos teleológicos na elaboração das explicações sobre temáticas de evolução no ensino de Biologia. O trabalho empírico focaliza as soluções apresentadas por docentes às diversas situações em que o pensamento teleológico assume em aula, nas quais predominam uma visão linear e progressista sobre evolução. Tomando como referência a análise realizada, argumenta-se que a complexidade do pensamento teleológico não se restringe ao ensino Biologia e, portanto, os usos dados didáticos devem ser analisados em relação às finalidades educativas e não unicamente aos critérios científicos. Apontamos para seu uso consciente e em situações específicas

OARSI year in review 2023:Rehabilitation and outcomes

Objective: We systematically reviewed the literature to identify comparative studies of core treatments (exercise, education, or weight management), adjunct treatments (e.g. electrotherapeutical modalities, bracing), or multimodal treatments (core plus other treatments), for treating osteoarthritis (OA) complaints, published between 1 March 2022 and 1 March 2023. Design: We searched three electronic databases for peer-reviewed comparative studies evaluating core treatments, adjunct treatments, or multimodal treatments for OA affecting any joint, in comparison to other OA treatments. Two authors independently screened records. Methodological quality was assessed using the Physiotherapy Evidence Database (PEDro) scale. A narrative synthesis focusing on pain and function outcomes was performed in studies with a mean sample size of at least 46 participants per treatment arm. Results: 33 publications (28 studies), 82% with PEDro ratings of good or excellent, were eligible for narrative synthesis: 23 studies evaluated knee OA; one knee OA or chronic low back pain; two knee or hip OA; one hip OA only; and one thumb OA. No studies identified a dose, duration or type of exercise that resulted in better pain or function outcomes. Core treatments generally showed modest benefits compared to no or minimal intervention controls. Conclusions: Rehabilitation research continues to be focused on the knee. Most studies are not adequately powered to assess pain efficacy. Further work is needed to better account for contextual effects, identify treatment responder characteristics, understand treatment mechanisms, and implement guideline care.</p

Effect of long-term application of manure and P fertilizer on some physical, chemical, and biological properties of a Black Chernozem

Non-Peer Reviewe

Effect of crop rotations on potentially mineralizable-N and amino compounds in a Black Chernozem at Indian Head

Non-Peer ReviewedThe effect (i) of fertilization on fallow-wheat (F-W), F-W-W, and continuous wheat; (ii) of baling straw on F-W-W (fertilized); (iii) of including sweetclover as green manure (GM) in F-W-W (unfertilized); and (iv) of including bromegrass-alfalfa cut for hay (H) in a 6-yr mixed rotation (F-W-W-H-H-H), on soil organic matter nitrogen (N) characteristics was determined in the top 15 cm of a thin Black Chernozem at Indian Head Saskatchewan after 30 years of treatments. Treatment effects were apparent from analysis of Kjeldahl N, amino N released during hydrolysis with 6M HCl, and with potentially mineralizable N (N0) and its rate constant (k). However, the "potential rate of mineralization" (N0 × k) proved to be the most powerful tool in segregating treatment effects. The relative molar distribution (RMD) of amino acids showed significant increases in aspartic acid and decreases in arginine and leucine, but these differences were mainly related to the influence of the 6-yr and fertilized continuous wheat being different from the shorter or unfertilized systems. It was concluded that fertilizers are as effective as legume green manure or grass-alfalfa in increasing soil organic matter and improving its quality (N supplying power) in this medium fertility soil where moisture is rarely limiting to crop production. Secondly, it was suggested that the parameter N0 × k could be a powerful tool for scientists to use in assessing soil quality. Finally, we estimated that the F-W and F-W-W rotations, especially when not fertilized or when straw was baled, had continued to cause losses in total N; that fertilized F-W-W and unfertilized continuous wheat was maintaining the organic N, while the legume-containing and fertilized continuous wheat systems had increased the organic matter compared to the level at the start of the experiment (i.e., following many years of conventionally tilled F-W and F-W-W

Manual de manejo conservacionista do solo para os estados do Rio Grande do Sul, Santa Catarina e Paraná.

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Agronomic and greenhouse gas assessment of land applied anaerobically digested swine manure

Non-Peer ReviewedManagement of animal wastes from intensive livestock operations (ILO) must be economically feasible, environmentally friendly and socially acceptable. Anaerobic digestion is a promising technology that could provide an option for managing animal waste that may reduce greenhouse gas emissions by utilizing the biogas produced during digestion to displace fossil-fuels and by reducing emissions during lagoon storage. A three-year study was conducted at two locations, Swift Current and Melfort, to compare the agronomic performance and gaseous N loss of land-applied anaerobically digested swine manure (ADSM) to conventionally treated swine manure (CTSM). Treatments included spring and fall applications of CTSM and ADSM at a 1x rate (10,000 and 7,150 L ha-1 respectively) applied each year, and a 3x rate (30,000 and 21,450 L ha-1 respectively) applied once at the beginning of the study. A treatment receiving commercial fertilizer (UAN) and a check (no N) were also included. Nitrogen use efficiency for single applications of ADSM or CTSM at the 3x rate were lower than three annual applications at the 1x rate, while UAN was intermediate. Nitrogen use efficiency of ADSM and CTSM applied in the fall was equal to spring when applied at 1x rate and, in general, agronomic performance of ADSM was similar or better than CTSM. Ammonia loss from ADSM was similar to CTSM, except for CTSM at the 3x rate applied in the fall at Melfort and in the spring at Swift Current, which had significantly higher losses than all other treatments. The percentage of applied N lost as N2O measured at the Melfort site was generally higher for treatments receiving CTSM compared to ADSM or UAN, and losses from ADSM and UAN were similar. The results from this study suggest that ADSM is equal or better than CTSM in terms of agronomic performance, but has lower environmental impact with respect to gaseous N loss

Visões sócio-históricas do professor de ciências no movimento renovador brasileiro (1950/70)

O trabalho analisa os vínculos entre formação docente e ensino de Ciências nas escolas brasileiras (1950/70), no âmbito de um movimento renovador dos currículos das disciplinas escolares em ciências ocorrido no período. Especificamente, busca compreender o papel dos professores expressos em documentos e fontes orais ligadas ao IBECC/SP e ao CECIGUA. Dialogando com o campo do Currículo (Goodson), apóia-se em uma noção de pesquisa histórica que articula o exame de fontes no sentido de produzir uma compreensão de processos institucionalizados, buscando “evidências inexploradas” (Sharpe) e contrapondo-se a uma “história vista de cima” (Burke). A análise evidenciou a produção de retóricas que focalizavam os alunos e que reconheciam uma suposta competência hierárquica dos cientistas, colocando os professores como deficitários e coadjuvantes nos processos de mudança