ABSTRACT The naturally fragile sandy soils of the Pampa Biome (PB) may be degraded with the introduction of poorly managed agricultural crops. Anthropic use can markedly decrease vegetation cover on sandy soils, leaving them more exposed to erosive agents. Decreases in organic matter content, biodiversity, and nutrient availability, increased soil compaction, and decreased water availability are also some of the impacts caused on PB soils by implementing poorly managed agricultural crops. In Rio Grande do Sul, in areas with sandier soils, the intense replacement of PB with commercial crops that has occurred in recent years (2000-2020) may be starting a disastrous cycle of degradation of these soils. However, it is not yet known how much these soils are degraded by recent anthropic use. There are no local scientific publications dedicated to the diagnosis of the degradation of these soils by anthropic use. Therefore, the need for this study was based on the objective of evaluating the physical and hydraulic properties of sandy PB soils with the insertion of agricultural crops. The study was conducted on three different soils, where soil samples were collected under three systems of use (extensive cattle raising on native grassland, eucalyptus afforestation, and soybean crop). Our results show that it can take more than nine years for soybean and ten years for eucalyptus land-use change to indicate some level of degradation in soil physical and hydraulic properties after replacing PB with these cultivated crops.

ABSTRACT. Grapevine is a fruit species of great agronomic interest since both fresh fruit and wine are highly marketable products. Therefore, there is growing interest in this crop among researchers in the pursuit of increased yields and better cultivation conditions. Asexual propagation is the most commonly used method for propagating grapevine seedlings, with cuttings used for rootstock formation and subsequent grafting of materials to form the canopy. The rootstock is responsible for support, water, and nutrient uptake, thus determining the vigor of the plant; therefore, it is essential to understand the suitable conditions in which roots can thrive and thereby enhance plant growth. The type of cutting, type of substrate, and application of exogenous auxins are among the factors that interfere with the rooting of grapevine rootstocks, and determining and implementing the best combination of these factors could provide for more vigorous plants. Reviewing high-quality published scientific research from diverse countries is a method of identifying data, grouping information, and obtaining reliable answers. Furthermore, it can allow for the detection and grouping of the main factors affecting the rooting of grapevine cuttings, thus enabling a clearer recommendation and better understanding of the issue. ABSTRACT products Therefore seedlings canopy support water uptake therefore growth cutting substrate rootstocks plants highquality high quality data information answers Furthermore issue

ABSTRACT The steady infiltration rate of soil profiles is commonly determined for irrigation and soil conservation planning, but the divergence of methods reduces the reliability of measurements. In this study, the steady infiltration rate measured with a double ring infiltrometer (isr-dri) in different layers of a soil profile was compared between layers and with the steady vertical saturated flow rate estimated by the Richards equation (isr-hy). The measurements of isr-dri at the top of the A, E, and Bt horizons were compared to each other and also compared with the isr-hy to detect the occurrence of lateral flow in double ring infiltrometer measurements. The isr-dri in the A horizon (236 mm h-1) was around 10 times higher than in the Bt horizon (20 mm h-1), which implies in a lateral flow of almost 90 % in the surface horizon. The occurrence of lateral flow in double ring infiltrometer measurements was also shown by comparing isr-dri with the vertical saturated flow rate estimated with the Richards equation, isr-hy. The main conclusion is that isr-dri measured at the soil surface overestimates the steady infiltration rate of soil profiles when underlying horizons are less permeable and more restrictive to water flow. In these cases, the use of an effective saturated hydraulic conductivity of the soil profile would imply inaccurate planning of drainage, irrigation, and soil conservation designs.

RESUMO A fitorremediação é uma técnica que usa plantas associadas ou não a agentes de melhoramento, para fitoestabilização em solo contaminado. O objetivo deste estudo foi avaliar o uso de Senna multijuga associada à turfa em fitoestabilização de cobre em solo contaminado. O experimento foi conduzido em casa de vegetação durante 120 dias, usando-se o delineamento inteiramente casualizado em esquema fatorial (2 x 6), com e sem turfa (200 mL L-1 de solo) e seis doses de cobre (0, 60, 120, 180, 240, 300 mg kg-1), com seis repetições por tratamento. Avaliaram-se, aos 120 dias após a semeadura, as plantas quanto à altura, ao diâmetro, massa seca radicular e aérea, conteúdo e quantidade acumulada de cobre no sistema radicular e na parte aérea; índice de qualidade de Dickson, índice de tolerância e de translocação também foram analisados. Os resultados mostraram que a utilização de 200 mL de turfa L-1 de solo não foi eficaz como agente melhorante para solo contaminado por cobre, mas atuou como condicionador do solo aumentando os parâmetros morfológicos de Senna multijuga. A espécie Senna multijuga apresentou baixo potencial de fitoestabilização de cobre em solo contaminado, em seu período inicial de desenvolvimento.

ABSTRACT Phytoremediation is a technique that uses plants, whether associated or not to ameliorating agents, for phytostabilization of contaminated soil. The aim of this study was to evaluate the use of Senna multijuga associated with peat in the phytostabilization of copper contaminated soil. The experiment was carried out in a greenhouse for 120 days, using an entirely randomized design in a factorial arrangement (2 x 6), with and without peat (200 mL L-1 soil) and six doses of copper (0, 60, 120, 180, 240, 300 mg kg-1), with six repetitions of each treatment. At 120 days after seedling, the plants were evaluated for height, stem diameter, root and aerial dry matter, contents and accumulated amount of copper in the root system and aerial part. Also, the Dickson quality indexes, as well as tolerance and translocation indexes were analyzed. The results showed that the use of 200 mL of peat L-1 of soil was inefficient as an ameliorating agent for copper-contaminated soil, but it acted as a soil conditioner, increasing the morphological parameters of S. multijuga. In its initial development period, the S. multijuga species presented low copper phytostabilization potential in contaminated soil.