Considering the lack of technical information on the water depth and nitrogen fertilization via fertigation in protected cultivation for bell pepper production in northern Brazil, this paper aimed to study the soil water tensions under different nitrogen doses for the cultivation of bell pepper in protected environment. The experiment was conducted in a greenhouse at the Igarapé-Açu School Farm of the Federal Rural University of the Amazon, at 1.0 x 0.50 m spacing, using the experimental design of randomized blocks in a 5x4 factorial scheme, with three replicates. The treatments consisted of five soil water tensions (15, 25, 35, 45 and 65 kPa) and four nitrogen doses (0, 135, 265 and 395 kg ha-1). There was interaction between soil water tension and nitrogen doses only for nitrogen use efficiency, and the best value was obtained with the combination between soil water tension of 15 kPa and nitrogen dose of 135 kg ha-1. Total number of fruits, fruit length and fruit diameter showed significant differences only as a function of soil water tensions. Production per plant, total yield and water use efficiency were statistically significant for soil water tensions and nitrogen doses. Therefore, for the conditions in which this study was carried out, it is recommended to apply a soil water tension of 15 kPa and nitrogen dose of 265 kg ha-1 for bell pepper cultivation in protected environment.

A agricultura sustentável é vital no mundo de hoje, pois oferece o potencial para satisfazer as nossas necessidades agrícolas, algo que a agricultura convencional não consegue fazer. Este tipo de agricultura utiliza uma técnica agrícola especial em que os recursos ambientais podem ser plenamente utilizados e, ao mesmo tempo, garante que nenhum dano lhe seja causado. Assim, a técnica é amiga do ambiente e garante produtos agrícolas seguros e saudáveis. As populações microbianas são fundamentais para processos fundamentais que impulsionam a estabilidade e a produtividade dos agroecossistemas. Várias investigações abordaram a melhoria da compreensão da diversidade, dinâmica e importância das comunidades microbianas do solo e dos seus papéis benéficos e cooperativos na produtividade agrícola. No entanto, nesta revisão descrevemos apenas as contribuições das rizobactérias promotoras do crescimento vegetal (PGPR) e das cianobactérias no desenvolvimento agrícola seguro e sustentável.

Cauliflower and broccoli are important vegetables but have lacking and divergent information about potassium (K) fertilization in soil with a high K content. Two experiments were carried out from 2-1-2010 to 5-20-2010 in Jaboticabal City, São Paulo, Brazil, aiming to evaluate the effect of different K doses (0, 50, 100, 150 and 200 kg ha-1 K2O, in potassium chloride) on the yield of cauliflower ‘Verona’ and broccoli ‘BRO 68’ in Rhodic Eutrudox soil with a high K content. The broccoli and cauliflower responded positively but differently to potassium fertilization. The maximum yield of broccoli (12,476 kg ha-1) was obtained with 160 kg ha-1 K2O, while the yield of cauliflower increased linearly with increasing K dose, yielding 38,285 kg ha-1 with 200 kg ha-1 K2O.

Proper irrigation management is important both to enable adequate water supply and to minimize problems with diseases, nutrient leaching and unnecessary water and power wastes. Thus, this study aimed at improving irrigation management in greenhouses. For that reason, we assessed the effect of various water tensions on yield performance of crisphead lettuce, Raider-Plus cv. , grown with mulching. The experiment was conducted in greenhouse at the Federal University of Lavras. Treatments constituted five different soil water tensions, namely 12, 25, 35, 45, and 70 kPa. The results showed that irrigation must be carried out at water soil tension of around 12 kPa to reach satisfying commercial values for both total and commercial yield, 66 and 50 t ha-1, as well as keeping good vegetable quality. At this tension, total water consumption was of 167.25 mm. The water use efficiency demonstrated quadratic response to treatments, with high water consumption efficiency found in intermediate treatments (35 and 45 kPa), achieving values of 579.87 and 471.71 kg ha -1mm-1, respectively.

Soil health is directly related to sustainable development goals (SDGs) and can be affected by inadequate management practices. In this work, soil edaphic respiration and changes in microbial biomass promoted by cover crops in an integrated crop–livestock system (ICLS) were evaluated using soil health indicators with the respirometry method. The design was completely randomized in a 3 × 6 factorial arrangement, and multivariate principal components analysis (PCA) was performed according to MANOVA. Edaphic respiration was determined based on the respirometry technique. The results showed that edaphic soil respiration was significant in the nine evaluation periods, demonstrating the importance of grass cover in edaphic respiration arising from the biological activity of microorganisms, which is directly related to the amount of soil organic carbon. The cover crops increased soil organic matter and consequently microbial respiratory activity.