Vegetable crop residues, such as sugarcane bagasse (SCB), despite their limited biodegradability, are potential materials for anaerobic processes because of their low cost, high availability, and sugar content. The difficulty of biodegrading this type of material is primarily related to its chemical composition and to the complex interactions between its compounds (cellulose, hemicelluloses, and lignin). Thus, the following supercritical and near critical carbon dioxide (CO₂) pre-treatments were evaluated with and without the addition of sodium hydroxide (NaOH): (i) 40°C/70 kgf·cm⁻²; (ii) 60°C/200 kgf·cm⁻²; and (iii) 80°C/200 kgf·cm⁻², aiming to enhance the anaerobic biodegradability of SCB. The methanogenic production of SCB increased in all cases in which the material was pre-treated, except the case in which NaOH was used together with a high temperature. The condition using CO₂ at 60°C/200 kgf·cm⁻² was highlighted with a lignin removal of 8.07% and an accumulated methane production of 0.6498 ± 0.014 L_N (273.15K, 1.01325 × 10⁵ Pa), 23.4% higher than the value obtained with the untreated material. This condition also showed the highest net energy at the energy balance that was calculated for comparison with the tested conditions. The results showed that pre-treatments with near critical and supercritical fluids have the potential to reduce structural obstacles of lignocellulosic materials and to enhance their anaerobic biodegradability.

This study investigated the effects of irrigation using treated sewage effluent (TSE) combined with nitrogen (N) fertilization on the productivity and quality of bermudagrass, and on its economic feasibility under tropical conditions. The treatments employed were SI ? no irrigation and no fertilization; A100 (control) ? irrigation with potable water plus 520 kg N ha−1 year−1 provided as NH4NO3; E0, E33, E66, and E100: irrigation with treated sewage effluent plus 0, 172, 343 and 520 kg N ha−1 year−1 as NH4NO3, respectively. Chemical properties of TSE, shoot dry matter production, N concentration in bermudagrass were determined, and benefit?cost and economic viability analyses were carried out. Tree years of irrigation with TSE had agronomical benefits to bermudagrass such as: (i) saving 33% in N fertilizer by adding of 275 kg N ha−1 year−1, increasing N accumulation in the soil; (ii) providing 70% of the N as NH4 +, which is the form most quickly assimilated by the plants; (iii) building up dry matter production with 7 Mg ha−1 year−1 and (iv) increasing leaf N concentration in leaf tissue. The main benefit of TSE irrigation occurs in drought seasons with the increase in N concentration in bermudagrass shoots. Higher N concentration in leaf tissue elevates the quality and the sales price for the grass harvested, thus optimizing the benefit?cost ratio for the producer. Therefore, TSE irrigation is a viable cost-effective alternative if the N concentration in the leaf tissue is considered in the sales price.201

Trichoderma fungi are considered relevant plant growth promoters for increasing the efficiency in the use of nutrients, as well as acting as biological control agents. This study aimed to select Trichoderma spp. isolates with potential for phosphate solubilization and their application as growth promoters in interaction with homeophatic preparations, in cherry tomato. Among 16 Trichoderma spp. isolates obtained from soils of organic tomato growing areas tested in vitro, together with a commercial product (Trichodermil^®), two of them showed the ability for indole-3-acetic acid production and phosphate solubilization. The Trichoderma “R” had the highest mycelial growth speed index and presented twice as much spores than the commercial product. An in vivo experiment was also conducted in a greenhouse, in order to observe the potential of Trichoderma spp. isolates and homeophatic preparations on the cherry tomato growth promotion, using a randomized block experimental design, in a 4 x 3 factorial arrangement, with three Trichoderma isolates and two homeopathic preparations (Phosphorus 6CH and Carbo vegetabilis 6CH) + treatment without homeopathic preparation. The leaf area and dry mass of leaves and roots were determined. It was possible to observe that the isolate “R”, identified as Trichoderma asperellum, was effective in the cherry tomato growth promotion, while the homeopathic preparations applied did not show any effect.