Synthetic fertilization can increase maize yields, but also cause environmental impacts, as well as increasing production costs and food security risks. Sun mushroom (Agaricus subrufescens) is an important Brazilian fungus used to generate large amounts of spent mushroom substrate. This residue can be used for maize fertilization, but little is known about its ideal application rates to reduce maize dependence on synthetic fertilizers. Therefore, this study aimed to evaluate the agronomic performance of a maize crop under different combinations of synthetic fertilizers and two different spent mushroom substrate doses. The experiment was carried out in pots and evaluated maize germinate and biometric parameters, as well as soil and leaf chemical characteristics. The results showed that residue application increased maize germination and Emergence Speed Index. Regarding the maize biometric parameters, height, stem diameter, shoot fresh and dry masses, and leaf area were superior for residue with synthetic fertilization at sowing only at higher doses. Moreover, residue with synthetic fertilization at sowing proved to be more relevant for maize growth according to canonical discriminant analysis. In terms of nutrients, the use of spent mushroom substrate increased significantly leaf P, K, and S levels and mainly K content in the soil, justifying non-application at maize topdressing.

Aim of the study: To evaluate the effects of a mega-fire on the arbuscular mycorrhizal fungi (AMF) community and parameters in soils under Cerrado vegetation. Study area: Chapada dos Veadeiros National Park, Goiás, Brazil. This site suffered the biggest fire in its history on October 10, 2017, with an affected area of 66,000 ha. Material and methods: We analyzed AMF spore density, roots’ mycorrhizal colonization rate, easily extractable glomalin (EEG), as well as the AMF genera present. These parameters were evaluated in burned and unburned areas of five common phytophysiognomies of the region. Main results: Fire presence immediately affected the mycorrhizal community parameters in Cerrado soils, which tended to increase afterwards. The presence of AMF genera did not differ between burned and unburned areas, with Acaulospora, Claroideglomus, Diversispora, Glomus, Funneliformis, Sclerocystis, and Gigaspora being present. The recovery of AMF community conditions in the Cerrado after fire events could also be observed in the mycorrhizal parameters evaluated, as the values of spore density, roots’ mycorrhizal colonization rate, and EEG were similar in the burned and unburned areas. Research highlights: AMF diversity, and especially their community parameters, show great recovery after fire events, since they are crucial in processes like nutrient cycling and soil aggregation.

In this study, the formulation of doughs was investigated using varying percentages of Agaricus bisporus flour, with the aim of utilizing mushroom stem fragments, typically considered production waste. The stem residues were collected from a mushroom cultivation facility, cleaned, and washed to remove impurities. The material was then subjected to two different drying methods: conventional dehydration and freeze-drying. After drying, the material was ground to produce mushroom flour. Doughs were formulated with different proportions of this flour and analyzed for texture profile, color, nutritional value, phenolic content, antioxidant activity, and sensory characteristics. The inclusion of mushroom flour resulted in darker doughs, particularly when the flour was obtained through conventional dehydration due to oxidation processes. This substitution also affected texture parameters, leading to increased hardness and reduced elasticity in most treatments compared to the control sample. In addition, cohesiveness progressively decreased from 0.35 in the control to 0.14 in the sample made with 100% dehydrated flour and 0.20 in the sample made with 100% freeze-dried flour, resulting in brittle doughs. The most significant impact on nutritional value was an increase in protein, fat, and dietary fiber levels, reaching values over 5% of crude fiber in the sample to which 50% of dehydrated mushroom flour was added. Additionally, mushroom flours exhibited a high proportion of phenolic compounds, reaching values near 700 mg gallic acid/100 g in the flour from freeze-dried samples and 320 mg gallic acid/100 g in the flour from dehydrated samples. These values reflect a higher content of phenolic compounds in products made with mushroom flours and an increased antioxidant capacity compared to the control sample. Sensory evaluation showed that the texture remained unaffected; however, flavor perception was altered at a 50% mushroom flour substitution. In terms of external appearance, only the 25% freeze-dried mushroom flour formulation was statistically similar to the control, while all other treatments were rated lower.