The aim of this study was to evaluate the effect of the root of vetiver grass (Chrysopogon zizanioides (L.) Robert) on the soil Resistance to penetration (RP) in the margins of the lower São Francisco River. Vetiver grass seedlings were planted on the riverbank margins in order to increase soil resistance to erosion processes, and RP assessments were made at soil depths of 0-0.20, 0.20-0.40, and 0.40-0.60 m in different situations (near the plants and within rows). RP data was obtained using an automated penetrometer. Gravimetric moisture data was also collected, as well as particle size data by densimetry, and root density data by the monolith method. The results of the RP, moisture, and root density studies were subjected to analysis of variance (p <0.05) and then the averages were compared by the Tukey test using SISVAR software. The samples next to the vetiver grass showed an average RP of 1793.94 kPa and an average moisture content of 11.78%, statistically differing from that of the sampled points within rows. RP and soil moisture did not differ statistically at the depth assessed. The vetiver grass produced an adequate ground cover, leading to higher water retention and hence a reduced resistance to penetration.

This study aimed to evaluate the influence of containers and shading on Ilex paraguariensis A.St.-Hil (yerba mate) seedling growth. We used a completely randomized design with a 3 × 2 factorial arrangement (containers × shading). We used PlantPaper^®, Ellepot^® (both biodegradable containers composed of cellulose fibers), and polypropylene tube containers and shaded (75% shading screen) and unshaded (without shading screen) greenhouse environments. We measured height and stem diameter every 30 days and shoot and root dry biomass 210 days after sowing. With these data, we calculated the total dry biomass, Dickson quality index, and height/diameter ratio. The unshaded environment increased yerba mate seedlings growth in height and stem diameter. In unshaded environments, seedlings produced in biodegradable containers had greater growth than those produced in polypropylene tubes. In the shaded environment, however, seedlings produced in polypropylene tubes had better growth. Despite the differences observed between treatments, all seedlings presented adequate growth during the nursery phase. We suggest the use of biodegradable containers to produce yerba mate seedlings in unshaded environments. Study Implications: The production of quality Ilex paraguariensis A.St.-Hil (yerba mate) seedlings results in better mature plants in the field. The use of biodegradable containers reduces residues in the field and improves seedling root formation by eliminating root damage related to seedling extraction from containers. The result is more vigorous plants that perform better in the field. The implementation of better techniques for producing seedlings can help farmers reduce costs and improve the final quality of seedlings.

The Cerrado-Amazonia Ecotone is one of the largest ecosystems in Brazil and is internationally considered a biodiversity hotspot. The occurrence of fires is common in these areas, directly affecting biomass losses and the reduction of vegetative vigor of forest typologies. Information obtained through remote sensing and geoprocessing can assist in the evaluation of vegetation behavior and its relation to the occurrence of forest fires. In this context, the objective of the present study was to analyze temporal vegetation dynamics, as well as their relationship with rainfall and fire occurrence on Indigenous lands, located in the Cerrado-Amazonia Ecotone of Mato Grosso state, Brazil. Normalized Difference Vegetation Index (NDVI) images of the MOD13Q1 MODIS product and burnt area of the MCD45A1 MODIS product, and rainfall images from the Tropical Rainfall Measuring Mission (TRMM) sensor were used. The period analyzed was from 2007 to 2016. After pre-processing the NDVI, TRMM and burnt area images, correlation analyses were performed between the rainfall, vegetation index and burnt area images, considering different lags (−3 to 3), to obtain the best response time for the variables. The analyses of inter-annual vegetation index trends were carried out following Mann–Kendall monotonic trend and seasonal trend analysis methodologies. Significant correlations were observed between NDVI and rainfall (R = 0.84), in grass regions and between NDVI and burnt area (R = −0.74). The Mann–Kendall monotonic trend indicates vegetation index stability with positive variations in grass regions. The analysis of seasonal trends identified different vegetation responses, with this biome presenting a diverse phytophysiognomy and seasonal vegetation with different phases for amplitudes. This variation is evidenced by the various phytophysiognomies and their responses in relation to biomass gains and losses. The correlation and regression of the NDVI and rainfall in the vegetation type of grass areas show that the burnt area tends to increase with the reduction of NDVI. Finally, no defined pattern of vegetation cycles or phases was observed in terms of seasonality and the proposed methodology can be adapted to other world biomes.