ABSTRACT Although numerous studies have been conducted with common bean regarding nitrogen (N) dose, time of application, and source in no-till (NT) soils in Brazil, the heterogeneity of the results makes it difficult to establish technical recommendations based on individualized studies. This meta-analysis aimed to rank the main factors influencing common bean response to N management in NT areas. The database consisted of 99 scientific papers that encompassed 160 trials and 2394 observations. In general, the probability of obtaining a positive response to N application in common bean productivity was 77 %, with an average 18 % increment (358 kg ha-1). The main factors that affect the response of common bean grain yield to N fertilization and the choice of the applied N dose are soil organic matter (OM) content and the preceding crop. In soils with OM content >20 g kg-1, the N dose that determines the highest economic return is 50 kg ha-1. For soils with OM content <20 g kg-1, the N dose to be applied is 70 and 100 kg ha-1 for crops preceded by legumes and grasses, respectively. The timing of the N application did not result in a significant difference in common bean yield in 62 % of the trials. However, the results showed that the average yield increase in the common bean went from 15 % (293 kg ha-1) with a single application to 32 % (622 kg ha-1) with split N applications. All N sources tested showed similar gains to those obtained with N application through urea. Excluding situations with high doses of N application (>100 kg ha-1), inoculating common bean seeds increased grain yields by 6 % on average (118 kg ha-1). The combined analysis of the available results demonstrated that the crop recommendations used in Brazilian soils under NT could be refined considering the soil OM concentration and preceding crop. Additionally, seed inoculation and N dose splitting in the form of common urea should be recommended.

ABSTRACT A good soil fertility management for soybean production must consider the amount of nutrients that are exported by seeds. In recent decades, soybean yield has increased due to better crop management and genetic improvements, which may affect the amount of nutrients removed. Therefore, this study aimed (i) to analyze the relationship between the concentration of macronutrients in soybean seeds in Brazil with soybean yield and genotypes, and (ii) to update nutrient concentration values in soybean seeds for fertilizer recommendation purposes, comparing them with the values described in the main official fertilization recommendation systems used in Brazil. For this purpose, we used 3,017 observations obtained from 67 studies evaluating at least one macronutrient concentration [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S)] in soybean seeds in the last 45 years in Brazil (from 1974 to 2019). Results indicate that the concentration of macronutrients in soybean seed is affected by both soybean yield and genetic material. Modern genotypes of the Intacta Roundup Ready-2 group remove 15, 21, 18, 17, and 23 % more K, P, Ca, Mg, and S and 4 % less N compared to non-Roundup Ready genotypes. The increase in soybean yield was followed by an increase in the concentration of N and a decrease in the concentration of P and K in soybean seed. Data obtained from studies published between 2015 and 2019 indicates that soybean removes, on average, 57.2, 17.6, 5.5, 2.9, 2.6, and 2.5 kg Mg-1 of N, K, P, S, Ca, and Mg, respectively. These macronutrient concentrations in soybean seeds are in disparity with most reference values described in the official fertilization recommendation systems in Brazil, highlighting an urgent need to review the standard values for replacement fertilization of soybeans. Moreover, future studies should focus on the influence of genetics on soybean seeds composition to ensure high soybean productivity with rational use of fertilizers.

Between july 2005 and june 2006, a case-control study was carried out to identify risk factors for hydatidosis in Lima, Peru. As a result, 32 cases were matched according to age, sex and birthplace in 64 controls. The participants were interviewed using a questionnaire designed to evaluate environmental and behavior factors associated to hydatidosis. By using Multiple Conditional Logistic Regression, it was determined that the owners of ≥ 10 dogs in a rural area (aOR=8.7; 95% Cl= 1.3-57.5) and those raising sheep (aOR=5.9; 95% Cl=1.2-28.1) were independently related to a higher risk of hydatidosis. The belief that food may transmit hydatidosis (aOR=0.1; 95% Cl=0.01-0.7) and the activity of raising goats (aOR=0.02; 95% Cl=0.001-0.6) were inversely associated to hydatidosis. Preventive measures to reduce the transmission of hydatidosis to human beings in endemic areas in Peru require: limiting the number of dogs kept in each household, regularly controlling parasites and preventing access of dogs to human food and drinking water; all of this in addition to educational campaigns to change the practices that lead to the transmission of hydatidosis.

Entre julio 2005 y junio 2006, realizamos un estudio caso-control para identificar factores de riesgo para la hidatidosis en Lima, Perú. Treinta y dos casos fueron pareados según edad, sexo y lugar de nacimiento con 64 controles. Los participantes fueron entrevistados usando Un cuestionario estructurado para evaluar factores ambientales y del comportamiento Asociado con la hidatidosis. Con regresión logística condicional múltiple se determinó que ser dueño de ≥ 10 perros en una zona rural (aOR=8.7; 95% CI=1.3-57.5), y el criar ganado ovino (aOR=5.9; 95% CI=1.2-28.1), estuvieron independientemente asociados a un mayor riesgo de hidatidosis. La creencia de que los alimentos podrían trasmitir hidatidosis (aOR=0.1; 95% CI=0.01-0.7), y la crianza de ganado caprino (aOR=0.02; 95% CI=0.001-0.6), estuvieron inversamente asociados a la hidatidosis. Las medidas preventivas para disminuir la transmisión de la hidatidosis al ser humano en áreas endémicas del Perú requieren que se limite el número de perros en el hogar, el tratamiento regular de los canes con antiparasitarios, restringir el acceso de los perros a los alimentos y al agua para consumo humano todo esto acompañado de esfuerzo educativos para cambiar las prácticas que facilitan la transmisión de la hidatidosis.