SUMMARYSustainable use of soil, maintaining or improving its quality, is one of the goals of diversification in farmlands. From this point of view, bioindicators associated with C, N and P cycling can be used in assessments of land-use effects on soil quality. The aim of this study was to investigate chemical, microbiological and biochemical properties of soil associated with C, N and P under different land uses in a farm property with diversified activity in northern Parana, Brazil. Seven areas under different land uses were assessed: fragment of native Atlantic Forest; growing of peach-palm (Bactrys gasipaes); sugarcane ratoon (Saccharum officinarum) recently harvested, under renewal; growing of coffee (Coffea arabica) intercropped with tree species; recent reforestation (1 year) with native tree species, previously under annual crops; annual crops under no-tillage, rye (Cecale cereale); secondary forest, regenerated after abandonment (for 20 years) of an avocado (Persea americana) orchard. The soil under coffee, recent reforestation and secondary forest showed higher concentrations of organic carbon, but microbial biomass and enzyme activities were higher in soils under native forest and secondary forest, which also showed the lowest metabolic coefficient, followed by the peach-palm area. The lowest content of water-dispersible clay was found in the soil under native forest, differing from soils under sugarcane and secondary forest. Soil cover and soil use affected total organic C contents and soil enzyme and microbial activities, such that more intensive agricultural uses had deeper impacts on the indicators assessed. Calculation of the mean soil quality index showed that the secondary forest was closest to the fragment of native forest, followed by the peach-palm area, coffee-growing area, annual crop area, the area of recent reforestation and the sugarcane ratoon area.Index terms: bioindicators, land use, metabolic coefficient, microbial biomass, soil enzymes, soil quality. RESUMO: INDICADORES DE QUALIDADE EM UM NITOSSOLO SOB DIFERENTES USOS NO NORTE DO PARANÁO uso sustentável do solo, mantendo ou aumentando sua qualidade, é um dos objetivos da diversificação na propriedade agrícola. Nesse aspecto, bioindicadores relacionados à ciclagem de C, N e P podem ser utilizados na avaliação do tipo de uso na qualidade do solo. O objetivo deste trabalho foi avaliar atributos químicos, microbiológicos e bioquímicos do solo, associados ao C, N e P, sob diferentes tipos de uso em uma propriedade agrícola com atividade diversificada no norte do Paraná. Foram avaliados sete tipos de uso do solo: fragmento nativo de Floresta Atlântica; cultivo de pupunha (Bactrys gasipaes); soqueira de cana-de-açúcar (Saccharum officinarum) recém colhida, em reforma; cultivo de café (Coffea arabica) intercalado com espécies arbóreas; reflorestamento recente (1 ano) com espécies arbóreas nativas, em área anteriormente ocupada com culturas anuais; cultivos anuais em sistema de plantio direto na palha, centeio (Cecale cereale); e mata secun...

Pasture degradation is a concern, especially in susceptible sandy soils for which strategies to recover them must be developed. Microbiological and biochemical soil health indicators are useful in the guindace of soil management practices and sustainable soil use. We assessed the success of three Panicum maximum Jacq. cultivars in the reclamation of a pasture in a sandy Typic Acrudox in the northwest of the state of Paraná, Brazil, based on soil health indicators. On a formerly degraded pasture with Urochloa brizantha (Hochst. ex A. Rich.) R.D.Webster, a trial with three P. maximum (cv. Massai, Tanzânia, or Mombaça) was conducted.Lime and phosphate were applied at set-up, and mineral N and K as topdressing. A remnant of degraded pasture adjacent to the trial was used as control. Twenty-three chemical, physical, microbiological and biochemical attributes were assessed for the 0-10 cm topsoil. The procedures for reclamation improved most of the indicators of soil health in relation to the degraded pasture, such as soil P, mineral N, microbial biomass C, ammonification rate, dehydrogenase activity and acid phosphatase. CO 2 evolution decreased, whereas microbial biomass C increased in the pasture under reclamation, resulting in a lower metabolic quotient (qCO 2 ) that points to a decrease in metabolic stress of the microbial community. The reclamation of the pasture with P. maximum, especially cv. Mombaça, were evidenced by improvements in the microbiological and biochemical soil health indicators, showing a recovery of processes related to C, N and P cycling in the soil.