Land Use Impact on Microbial and Biochemical Indicators in Agroecosystems of the Brazilian Cerrado

Abstract

Microbial and biochemical properties are of great importance in soil quality evaluation. In Brazil, and especially in the cerrado (Brazilian savanna), benchmarking studies are needed to assess the impacts of land use on microbial and biochemical indicators. This study aimed to compare the impacts of land use on the microbial, chemical, and biochemical properties of the soil under Cerrado (CE), 32‐yr‐old pine forest (PF) and 11‐yr‐old no‐till (NT). Soil samples were collected at a depth of 0 to 10 cm in January, June, and December of 2008 and were evaluated based on chemical properties, basal respiration, soil organic carbon (SOC), microbial biomass carbon (MBC) and enzymes (β‐glucosidase, dehydrogenase and acid, neutral, and alkaline phosphatases). Comparative analysis of respiratory activity and MBC showed that the NT system had a positive effect and PF a negative one relative to the reference CE. NT soil management practices improve quality mainly by benefiting chemical characteristics (C and N), increasing MBC, and increasing microbial activity relative to CE and PF. Soil enzymatic activity (dehydrogenase, β‐glucosidase and phosphatase) was lower in PF and higher in NT than in CE. Principal component analysis showed that indicator variability, regarding soil sampling period, was higher in NT than in either PF or CE. In conclusion, we recommend β‐glucosidase and MBC as indicators of the impacts of land use practices.

Moisture seasonality, soil fauna, litter quality and land use as drivers of decomposition in Cerrado soils in SE-Mato Grosso, Brazil

“…This result agrees with a recent study by Vinhal-Freitas et al (2013) who reported 1.8 times higher soil microbial biomass carbon in a corn/ soybean cropland under no-tillage when compared to a Cerrado soil. Nevertheless, these observations disagree with numerous studies which emphasise that both microbial biomass and activity are significantly higher in soils under native vegetation compared to converted areas (Bresolin et al, 2010;Frazão et al, 2010;Lammel et al, 2015;Rampelotto et al, 2013).…”

“…Research on Cerrado soils has largely been focused on the improvement of the soil fertility and management practices for farming purposes (Carvalho et al, 2007;Goedert, 1983;Metay et al, 2007). The effects of the land use change have been studied by examining microbial activity in soils (Bresolin et al, 2010;Viana et al, 2011;Vinhal-Freitas et al, 2013), comparing soil fauna communities (Benito et al, 2004;Marchão et al, 2009) and, more recently, by characterising microbial communities through DNA sequences (Lammel et al, 2015;Rampelotto et al, 2013). In general, studies on litter decomposition in Cerrado areas are scarce, particularly those comparing natural vs agricultural areas.…”

Diversity and Function of Bacterial Assemblages in Savanna Vegetation Soils

“…Although several papers did not describe these parameters, where reported these values were similar across the analyzed sites (protected or modified), indicating a predominance of clayey soils (Table 6.3). the median values of the included studies (Pinto et al 2006;Carvalho et al 2007;Quirino et al 2009;Bresolin et al 2010;Frazão et al 2010;Peixoto et al 2010;Viana et al 2011;Araujo et al 2012;Ganz et al 2012;Mendes et al 2012;Vinhal-Freitas et al 2013;Rachid et al 2013;Rampelotto et al 2013;Rossi et al 2013;Souza et al 2013 …”

“…Functionally, phosphatase activity is lower in soils under conventional tillage than in no-tillage or native Cerrado soils (Peixoto et al 2010). Compared with other soil management methods, no-tillage management improves soil quality and promotes microbial content and activity (Peixoto et al 2010;Vinhal-Freitas 2013).…”

Short-term impact of soybean management on ammonia oxidizers in a Brazilian savanna under restoration as revealed by coupling different techniques

“…In contrast, no-till management is associated with better soil quality and higher levels of enzyme activity (Peixoto et al 2010) and microbial carbon C biomass (Vinhal-Freitas et al 2012). In addition, no-till farming appears to have fewer effects on the composition of microbial communities (Rachid 2013).…”