Land use choices differentially affect soil physical and biological properties. Tillage choices in particular affect soil erosion, the retention of soil organic matter, and the biological activity that organic matter supports. The present study evaluated the consequences of different cropping and tillage systems (undisturbed forest, coffee plantation, conventional, and no-tillage row cropping) for soil microbial indicators and sulfur mineralization after 24 years of cropping on an Oxisol (Typic Haplorthox) in an experimental area at Londrina, Brazil. Soil samples were taken at 0-5, 5-10, and 10-20 cm depths and evaluated for microbial biomass P and S, S mineralization, and phosphatase and arylsulfatase activities. Land use affected microbial biomass P and S, and enzyme activity at all depths studied. The cultivated sites had lower values of microbial activity than the undisturbed forested site. Although the coffee site was not tilled and had high organic carbon content, there was low microbial activity, probably due to higher soil acidity and Al content. The estimates of pool stock for microbial P and annual P flux through the soil microbial biomass suggest that these pools are large enough to significantly affect plant nutrient availability. The greater microbial biomass and activity under forested and no-tillage sites may be attributed, at least partially, to higher organic matter content. The soil microbial variables examined proved to be strong indicators of soil sustainability.
Malnutrition occurs when the supply of available nutrients is less than organic demand. It is an underdiagnosed problem in veterinary medicine and can result in several negative metabolic consequences, with greater morbidity and mortality. Currently, the classification of nutritional status (NS) is performed subjectively in veterinary medicine, so studies and discoveries about laboratory markers (objectives) of malnutrition are desirable. This study evaluated the correlations between several laboratory variables (practical and low-cost measurements) and the nutritional status (NS) of 246 dogs from a veterinary school hospital in southern Brazil. In this way, the laboratory profile of malnutrition in this population is evident. NS was classified by body condition score (BCS) and muscle mass score (MMS). A patient was considered to be malnourished if the BCS was less than 3 (values from 1 to 9). The laboratory variables analyzed were hemogram, cholesterol, total protein (TP), albumin, C-reactive protein (CRP), CRP/albumin ratio, total iron-binding capacity (TIBC), transferrin (TF), transferrin saturation index (TSI), and transthyretin. The means and standard deviations of the variables, correlation analyses, and comparative analyses (Kruskal-Wallis in α = 5%) were calculated. This research aimed to identify objective and practical malnutrition markers that help in the elaboration of a protocol for nutritional evaluation in diseased dogs. Low values of TF, TIBC, TP, hemogram, and TSI elevation were indicative of malnutrition. Additionally, cholesterol and albuminemia are not good markers of malnutrition in dogs with systemic diseases. For the graduation of the inflammatory state (important to differentiate inflammatory hypoproteinemia from protein malnutrition), it is more reliable to measure the CRP/albumin ratio. Canine transthyretin cannot be measured with reagents designed for humans, such as those used in this study. It was possible to conclude that laboratory indicators of malnutrition in sick dogs include low values of TF, TIBC, and TP, anemia, and elevations of TSI. The joint changes in these markers gradually reinforced the diagnosis.
Studies regarding soil quality and health often need to be up-to-date, as they feed new models for quantifying agricultural impacts on the environment. This study was established to understand how types of vineyard cultivation (organic and conventional) affect soil chemical and microbial attribute dynamics throughout different seasons. Vineyard management had a strong effect on chemical soil attributes. Organic carbon and phosphorus were 2.8 and 2.0 times greater, respectively, in organic vineyards than in conventional vineyards. Metabolic quotient (qCO2) values were lowest in summer and autumn, with an average of 2.31-2.49 µg C-CO2 h-1 g-1 soil, under organic management, indicating greater microbial growing efficacy. Regardless of season and sampling position, organic soil had a higher C microbial biomass than conventional vineyards, with values ranging from 179.79 to 284.71 µg g-1 soil, which were similar to those of the adjacent forest soil. Overall, there were increases in both the microbial and the chemical attributes of soil under organic vineyards compared relative to conventional management, which might have been due to the continuous input of organic matter, crop rotation, and alternative plant protection and fertilizer compounds used in organic farming.
Farmers sometimes sow soybean (Glycine max (L.) Merrill) in dry soil in the expectation of rain in the short time. However, the forecast may not confirm, letting the inoculated seeds in the dry soil indefinitely. We assessed the survival of inoculated Bradyrhizobium and physiological quality of soybean seeds sown in dry soil. In the first experiment, irrigation was applied with 2 h, 1, 4, 11, 18, or 21 days after sowing; in the second experiment, sowing was carried out 2 h, 1, 5, 12, 14, or 20 days before irrigation. Each time represented a treatment in a completely randomized design. Bradyrhizobium cells dropped from ~8-9 × 104 colony forming units per seed soon after inoculation to -60% at 2 h after sowing in dry soil, and decreased to close to zero with time in both experiments. Although there was no effect on germination (59% and 81% in the first and second experiments, respectively), the exposure to dry soil reduced the emergence speed index from 19.5 (2 h) to 12.0 (21 days) in the first experiment and from 37.8 (2 h) to 13.8 (21 days) in the second. In the first experiment, the number of abnormal seedlings increased from 7% (2 h) to 24% (21 days); in the second, cotyledons showed cracks, which increased from 1% (2 h) to ~50% (≥ 5 days). Sowing in dry soil negatively affects not only the inoculated Bradyrhizobium, but also the physiological quality of soybean seeds.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.