Abstract ‘IAC Sempre Verde’ is a medium-seeded runner-type peanut highly resistant to late leaf spot and rust, the main diseases in peanut cultivation in Brazil. The newly released cultivar showed remarkable yield advantage over controls when diseases were not controlled and represents the first possibility for peanut cultivation under “Organic” management.

The objective of this study was to analyze variability, linear and spatial correlations of forage dry mass yield (FDM) and dry matter percentage (DM%) of Brachiaria decumbens with the bulk density (BD), gravimetric (GM) and volumetric (VM) moisture, mechanical resistance to penetration (RP) and organic matter content (OM), at depths 1 (0-0.10 m) and 2 (0.10-0.20 m), in a Red Latosol (Oxisol), in order to select an indicator of soil physical quality and identify possible causes of pasture degradation. The geostatistical grid was installed to collect soil and plant data, with 121 sampling points, over an area of 2.56 ha. The linear correlation between FDM × DM% and FDM × BD2 was low, but highly significant. Spatial correlations varied inversely and positively, respectively. Except for DM% and BD, at both depths, the other attributes showed average to high variability, indicating a heterogeneous environment. Thus, geostatistics emerges as an important tool in understanding the interactions in pasture ecosystems, in order to minimize possible causes of degradation and indicate better alternatives for soil-plant-animal management. The decrease in FDM and increased BD1 are indicators of physical degradation (compaction) of Red Latosol (Oxisol), particularly in the places with the highest concentration of animals and excessive trampling, in Cerrado conditions, in the municipality of Selvíria, Mato Grosso do Sul State, Brazil.

O sistema de cultivo de arroz predominante no Brasil, o de terras altas, fica na dependência da precipitação pluvial e de sua distribuição. Determinadas práticas ou distúrbios, que atuam sobre o solo, levam a alterações que os microrganismos, por ser sensíveis, podem detectar. O trabalho objetivou estudar as alterações microbiológicas (carbono da biomassa microbiana (CBM)) e do CO2 (C-CO2) liberado, do quociente metabólico (qCO2) e micorrização), fertilidade do solo e produtividade do arroz de terras altas, cultivado sob diferentes manejos de solo e água. A cultivar utilizada foi a BRS Talento, e o delineamento experimental foi o de blocos casualizados, com quatro repetições. Os tratamentos foram arranjados em fatorial de três manejos de solo: plantio direto (PD), grade pesada + grade niveladora (GG), escarificador + grade niveladora (EG) e três manejos de água: sem irrigação (L0); lâmina 1 (L1), que corresponde à irrigação nas fases reprodutiva e de maturação; e lâmina 2 (L2), que corresponde à irrigação durante todo ciclo. Os fungos micorrízicos arbusculares mostram-se sensíveis aos manejos de solo e água. O PD apresentou as maiores médias para MO, Ca, SB e V% e as menores de H + Al. Este manejo acrescido da irrigação, apenas nas fases reprodutiva e de maturação propiciaram resultados satisfatórios para a produtividade e características microbiológicas.

In Brazil, the upland rice culture system is predominant, but its water supply depends of precipitation and its distribution. Some practices or disturbances on soil conditions may cause alterations that can be detected by microorganisms, which are quite sensitive. This experiment was developed to study microbiological alterations (microbial biomass carbon (MBC), released CO2 (C-CO2), metabolic quotient (qCO2) and mycorrhization), as well as alterations in soil fertility and productivity of upland rice, cultivated under different soil and water managements. Cultivar BRS Talento was used in the experiment. The experimental design was a completely randomized block design, with four replications, using three soil managements: no-tillage (NT), heavy disk + leveling disk harrowing (HL), and chisel plowing + leveling disk harrowing (CL), plus three water managements: no irrigation (WD0); water depth 1 (WD1), with irrigation at the reproductive and maturation periods; and water depth 2 (WD2), with irrigation throughout the rice cycle. Autochthones arbuscular mycorrhizal fungi proved to be sensitive to soil and water management. The NT presented the highest values for MO, Ca, SB and V% and the lowest for H+Al. This management, together with irrigation at the reproductive and maturation periods of BRS Talento cultivar, promoted goods results for crop yield and microbiology characteristics.