EFFECTS OF TWO BIOCHAR TYPES ON ENZYMATIC ACTIVITY IN THREE AGRICULTURAL SOILS WITH DIFFERENT DEGREES OF DEGRADATION

BERGER M.G.; DOMINCHIN M.F.; AOKI A.; VERDENELLI R.A.; MERILES J.M.

Buenos Aires

Jornada; XX Jornadas anuales de la Sociedad Argentina de Biología (SAB), XVII Jornadas de la Sociedad Uruguaya de Biociencias (SUB), Segundas Jornadas Rioplatenses de Biología.; 2018

Land degradation or soil quality deterioration is an environmental problem with a significant influence on production. Several factors may be cited as causes of land degradation; however, changes in land use and crop managements are currently one of the main drivers of soil disturbance. Particularly, in Argentina agriculture intensification and application of inadequate crop management practices have affected soil quality and productive potential of soils. Biochar a carbon-rich material produced by thermal decomposition of biomass under oxygen-limited conditions, can increase soil productivity by improving both chemical and physical soil properties. In the present study two types of biochar were used. Thus, the conducted research aimed at assessing the effect of poultry litter and peanut shell biochar on the enzymatic activity in agricultural soils with different degrees of degradation. Typical Haplustoles soils were sampled in Córdoba Province (31°19? Sur; 64°13? Oeste), Argentina. Three test sites were selected: 1) native forest as a control (L1), 2) lot with rotation 2: 1 (soybean-corn) and no-till (L2) and 3) lot with soy monoculture under conventional tillage (L3). The edaphic deterioration gradient was categorized according to the OM content. Soils were treated with three doses of biochar (0%, 1% and 3%) and incubated for 120 days. The enzymatic activity of the microbial communities was evaluated using the FDA (fluorescein diacetate activity), dehydrogenase activity (DHA) and β-glucosidase activity estimated by multiple substrates (MUF).For L2 and L3 soils, amendment with 3% of quail excreta biochar or 1% of peanut peels biochar significantly increased FDA activity. DHA was higher in L2 soil with 0% and 1% of quail excreta biochar. However, the application of peanut shells biochar did not affect DHA. Finally, β-glucosidase activity increased significantly in L1 soil compared with L2 and L3 soils. At dose of 1% and 3%, both quail excreta and peanut shell biochar, increased β-glucosidase activityBiochar application modifies enzymatic activity in soils with different degrees of deterioration, principally in those with less OM content. A greater influence of biochar application in total microbial activity (FDA) and β-glucosidase was observed. No major differences were observed between biochars.