ABSTRACT: Currently, the Brazilian savanna (Cerrado) represents the main agricultural area of the country, comprising a great variety of landscapes and soils, geological formations and vegetation patterns, as well as the major watershed. We studied the hydropedology and morphometry of a representative catchment (Frutal river), on a high tableland (Chapada) in the Triângulo Mineiro region, Brazil, describing the soil-water-landscape relationships to understand land use and water resources. To this end, we applied physical, chemical, micromorphological, and morphometric methods. When dry, compaction was observed in well-structured Ferralsols (Latossolos) with medium texture under intensive agriculture, reducing the water recharge capacity. The soil carbon stock was highest in hydromorphic savannas (veredas), reaching an organic matter content of 316.8 g kg-1 in the studied Umbric Gleysols, representing poorly drained lowlands. Physical and micromorphological properties were relevant parameters to understand the water recharge in soil; in agricultural fields, bulk density tended to increase and hydraulic conductivity to decrease, particularly under long-term sugarcane; morphometric parameters in the Frutal catchment indicated a low flooding risk and high flow capacity. This reinforces the need for soil conservation strategies to enhance water infiltration and groundwater recharge, with a view to maintain the water longer in the catchment. For surface water dynamics, slope morphology is an important property, affecting soil erosion, water retention and crop productivity.

ABSTRACT The application of wastewater to irrigate soils may be an attractive option for paper mills, especially when the effluents can also provide nutrients to plants. Since there could be negative environmental effects, such activity must be preceded by a thorough evaluation of the consequences. The changes in soil quality of a Neossolo Flúvico Distrófico (Typic Udifluvent) were evaluated over a period of six years of irrigation with treated effluent from a wood pulp company. Although effluent application for six years did not affect soil resistance to penetration and soil hydraulic conductivity, it promoted a decrease in the mean size of aggregates and an increase in clay dispersion. Effluent application increased soil pH but did not change exchangeable Ca and Mg contents and organic carbon. After a full rotation of eucalyptus cultivation common in Brazil (six years), no negative effects in tree growth were found due to effluent irrigation. However, effluent addition caused higher values of Na adsorption ratio and intermediate electrical conductivity in the soil, which indicates a possible negative effect on soil quality if the application continues over a longer period. Therefore, a monitoring program should be carried out during subsequent crop rotations, and alternatives must be studied to obtain better effluent quality, such as adding Ca and Mg to the wastewater and using gypsum in the soil.

O transporte de nutrientes até as raízes é essencialmente efetuado por fluxo de massa e difusão. O objetivo deste trabalho foi quantificar a contribuição desses dois mecanismos na aquisição de macronutrientes (N, P, K, Ca, Mg e S) e de micronutrientes catiônicos (Fe, Mn, Zn e Cu) por plantas de milho, e o volume e a composição do exsudato xilemático em resposta ao tamanho dos agregados e à disponibilidade de água. O experimento foi conduzido em casa de vegetação com amostras de um Latossolo Vermelho, retiradas sob dois sistemas de manejo: cerradão sem manejo (CER) e cultivo contínuo com milho em manejo convencional por mais de 30 anos (CCM). Os tratamentos corresponderam ao arranjo fatorial [2 x (1 + 2) x 2], sendo dois sistemas de manejo (CER e CCM), (1 + 2) solo passado em peneira de 4 mm e duas classes de agregados (< 0,5 mm e entre 0,5 e 4,0 mm), e dois potenciais de água do solo (-40 e -10 kPa). Eles foram dispostos em delineamento em blocos casualizados, com quatro repetições. Aos 70 dias após a semeadura, finalizou-se o ensaio. A influência do tamanho do agregado e do potencial de água do solo nos mecanismos de transporte de nutrientes é maior nas amostras de solo com maiores concentrações de nutrientes em solução, sistema CER, tendo a difusão crescido em importância na condição de maior disponibilidade de água e nos agregados < 0,5 mm. O volume de exsudato xilemático colhido de plantas de milho aumenta com a diminuição do tamanho do agregado e com o aumento da disponibilidade de água do solo, no sistema CER. As maiores concentrações de Ca e Mg no exsudato xilemático das plantas cultivadas em amostras retiradas do sistema CER, dependeram das altas concentrações desses nutrientes na solução do solo neste sistema de manejo.

Nutrients are basically transported to the roots by mass flow and diffusion. The aim of this study was to quantify the contribution of these two mechanisms to the acquisition of macronutrients (N, P, K, Ca, Mg, and S) and cationic micronutrients (Fe, Mn, Zn, and Cu) by maize plants as well as xylem exudate volume and composition in response to soil aggregate size and water availability. The experiment was conducted in a greenhouse with samples of an Oxisol, from under two management systems: a region of natural savanna-like vegetation (Cerradão, CER) and continuous maize under conventional management for over 30 years (CCM). The treatments were arranged in a factorial [2 x (1 + 2) x 2] design, with two management systems (CER and CCM), (1 + 2) soil sifted through a 4 mm sieve and two aggregate classes (< 0.5 mm and 0.5 - 4.0 mm) and two soil matric potentials (-40 and -10 kPa). These were evaluated in a randomized block design with four replications. The experiment was conducted for 70 days after sowing. The influence of soil aggregate size and water potential on the nutrient transport mechanisms was highest in soil samples with higher nutrient concentrations in solution, in the CER system; diffusion became more relevant when water availability was higher and in aggregates < 0.5 mm. The volume of xylem exudate collected from maize plants increased with the decrease in aggregate size and the increased availability of soil water in the CER system. The highest Ca and Mg concentrations in the xylem exudate of plants grown on samples from the CER system were related to the high concentrations of these nutrients in the soil solution of this management system.

Objetivou-se, neste experimento, verificar os efeitos da adição de óleo de soja e/ou de extrato etanólico de própolis na alimentação de cabras leiteiras sobre o consumo, a digestibilidade de nutrientes, a produção e composição do leite e alguns parâmetros de fermentação ruminal. Foram utilizadas dezesseis cabras Alpinas (quatro fistuladas no rúmen). Os animais foram alocados em quatro quadrados latinos 4x4, em arranjo fatorial 2x2 dos tratamentos. Foram adicionados ao concentrado 0 ou 120 g de óleo de soja e 0 ou 10 mL de extrato etanólico de própolis/animal/dia (30% p/v de própolis bruta moída em solução alcoólica a 70% em água). As dietas foram isoprotéicas, com 11,5% de PB, e compostas de 67% de silagem de milho e 33% de concentrado à base de fubá de milho e farelo de soja. O óleo de soja reduziu os consumos de matéria seca (%PV e g/kg PV0,75), de fibra em detergente neutro (FDN) e de carboidratos não-fibrosos; diminuiu a digestibilidade da FDN; aumentou a digestibilidade da PB e do EE e o teor de nutrientes digestíveis totais (NDT); reduziu a produção e aumentou os percentuais de gordura, proteína e sólidos totais no leite; aumentou o pH; e reduziu a relação acetato:propionato no líquido ruminal. Houve interação entre óleo de soja e extrato etanólico de própolis, de modo que o óleo de soja reduziu os consumos de MS, MO e FDN (em kg/animal/dia) somente na presença de própolis e aumentou o consumo de PB na ausência de própolis. O óleo de soja mostrou-se mais efetivo em alterar as variáveis analisadas que o extrato etanólico de própolis.

The objective of this experiment was to verify the effects of soybean oil and/or ethanolic extract of propolis, in the diets of dairy goats, on intake, on digestibility of nutrients, on milk production and composition and some ruminal parameters. Sixteen Alpine female goats were used, in which four animals fistulated in the rumen. The animals were allocated in four 4x4 Latin squares, in a 2x2 factorial arrangement of treatments. It was added to the concentrate 0 or 120 g of soybean oil and 0 or 10 mL of ethanolic extract of propolis/animal/day (30% weight/volume of grinded crude propolis in alcoholic solution at 70% in water). The diets had the same protein content, with 11.5% CP and contained 67% corn silage and 33% concentrate based on corn and soybean meal. The soybean oil decreased the intakes of dry matter (%BW and g/kg BW0.75), neutral detergent fiber (NDF) and non-fibrous carbohydrates; decreased the digestibility of NDF, increased the digestibilities of CP and EE and increased the total digestible nutrients content (TDN); decreased the production and increased the percentual contents of fat, protein and total solids in the milk; increased the pH and decreased the acetate:propionate ratio in the ruminal fluid. There was interaction between soybean oil and ethanolic extract of propolis, in which soybean oil decreased the intakes of DM, OM and NDF, in kg/animal/day, only in the presence of propolis and increased the intake of crude protein in the absence of propolis. The soybean oil was more effective in changing the evaluated variables than the ethanolic extract of propolis.