The Eucalyptus genus is the most planted forest crop in the world, with Brazil being one of the countries with the greatest productive potential. However, the occurrence of weeds can cause losses in productivity. Chemical control is widely used, but the efficiency of herbicides depends on factors such as the presence of straw in the soil and the occurrence of rainfall. Due to the scarcity of results regarding the interaction between herbicide, straw, and water depth in the forest sector, the objective of this study is to evaluate the efficiency of S-metolachlor + glyphosate in the control of grasses in different densities of eucalyptus straw and with simulated rain after the application of the product. The experiment was conducted in DBC, factorial 3×3×2, with four replications. The first factor represented 0, 50 and 100% of the commercial dose of S-metolachlor + glyphosate, the second 0, 5, and 10 ton ha-2 of straw, and the third 25 and 50mm of water depth applied in soil with a mix of grasses previously sowed. The rainfall simulation was performed 24 hours after herbicide application on each straw volume. The fresh mass of the aerial part of the grasses was collected 43 days after sowing and dried in an oven to determine the dry mass. Visual analyzes of the percentage of control were performed with scales ranging from 0 to 100, where 0 represents no control and 100 efficient control. The fresh and dry mass and the grasses' dry mass/water ratio decreased with increasing herbicide dosage and straw density. The dosage of 2.12 + 1.59 kg i.a. ha-1 of S-metolachlor + glyphosate resulted in greater control of grasses, and the treatments without straw and with the application of the herbicide had the highest percentages of control. Applying different water depths (25 mm or 50 mm) did not influence the control. Despite the control of grasses, the efficiency of the herbicide mixture was affected by the presence of vegetation cover.

This study focuses on solving rural problems, sustaining environmental conditions, pastures improvement, and reduction of CO2 concentration, suggesting inoculated vegetation types found in the tropics as a nature-based solution for degraded agroecosystems. Noninoculated plants are intensively used for revegetation of degraded and mined lands, AMF taxonomic and plant-fungal ecological studies. Among those grasses, Urochloa brizantha is a tropical forage, having vigorous deep roots, commonly used for arbuscular mycorrhizae (AMF) multiplication in glasshouse and nursery, developing infective propagules to be conserved in germplasm banks. Other grass species, such as Urochloa decumbens, is also used for arbuscular mycorrhizal multiplication in addition to its cultivation for guaranteeing the sustainable of livestock systems. In the present study, a site of 100 m2 was selected to take soil samples in a plain area, with U. brizantha pasture, and the soil chemical characterization, microcharcoal content and AMF spore identification, were evaluated 3+6showing high amount of potassium (K), high microcharcoal content and the occurrence of 11.32 spores of AMF, most of Glomeraceae, in the rhizosphere of U. brizantha. Due to its economic importance for sustainable agricultural production and other uses besides its environmental services, as important promoters of soil carbon on grazing lands, more detailed research is needed on the biotic interactions and inoculant production in of the studied grasses.

In Tunisia, olive is the most cultivated fruit crop while in the north where rainfall exceeded 400mm.year-1, the olive growing area is in widely extension in marginal soil with high slope gradient. Thus, the inclusion of cover crops is a sustainable solution to increase the ecosystem productivity, improve the soil fertility and oil yields. But, in Tunisia a few study were investigated the effect of legumes cover crop on the olive productivity. Therefore, the aim of this study was to evaluate the short-term (two cropping seasons s 2021 and 2022) effects of different seeded cover crops and soil management practices on the cover crops and soil characteristics, as well as enzymes activities and related microbial diversity. Six intercropping were tested in rainfed olive orchards (cv.Chétoui): Spontaneous vegetation (Spont), Wheat, Vetch, Oat, Fenugreek, mixture Vetch-Oat and compared to control (3 periodic tillage/year without intercropping). During the first cropping season, cover crops were cut as animal feed and only residues were incorporated into the soil. While, during the second year, all cover crops biomass were incorporated into the soil. Results indicate that the dry biomass and carbon uptake were significantly higher in grasses species (Wheat and Oat). But, highest level of nitrogen was found in Fenugreek cover crops. As compared to control, all cover crops including spontaneous vegetation increased soil organic matter and macronutrient level, mainly phosphorus. The most activity of β-glucosidase, phosphatase and arysulphatase was found in the cover crops plot of wheat and oat. In addition, this study improve that the utilization of the carbon sources was dominated by amides, amine and amino-acids in the fenugreek plot; while it was dominated by polymers and carboxylic acids in the case of wheat and oat.

The relationship between DM yield/cutting and fermentable organic matter (FOM) content of tropical grasses was appropriately investigated to re-access optimal grass maturity to feed dairy cattle. Nine different grass species belonging to the genera: Brachiaria spp. (Mulato II, Ruzi), Panicum spp. (Guinea, Hamil, Mombasa, TD58), and Pennisetum spp. (King, Napier, VA06) were chemically analyzed and subjected to an in vitro gas production (IVGP) test. For 72 h, gas production (GP) was continuously recorded with fully automated equipment. A triphasic, nonlinear, regression procedure was applied to analyse GP profiles. Across all the grasses, it was found that the neutral detergent fiber (NDF) contents increased with increasing maturity of the grass while the CP contents decreased with increasing NDF contents. In all nine grasses, digestible organic matter (dOM) was significantly affected by the week of cutting but IVGP was similar between weeks of cutting in Ruzi, Hamil, Mombasa, and Napier grass. Except for Guinea grass, the lowest dOM values were found when the grasses were cut after ≥ 5 weeks of regrowth. Harvesting grass one or two weeks earlier than normal cutting time is a practically relevant intervention in in-creasing forage quality and productivity of dOM and fermentation potential.