Microbial biomass and organic matter in soil of Caatinga, cultivated with melon in Chapada do Apodi, Ceará State

The intensive use of the conventional system over the years of soil preparation may change the soil microbial attributes, causing a reduction of biomass and microbial activity. As so, the present study aimed to analyze, under melon (Cucumis melo L.) cultivation, the microbiological changes as well as soil organic matter content in the depth of 0-0.10, 0.10-0.20, 0.20-0.30 and 0.30-0.40 m over the years under melon cultivation during 3, 5 and 10 years in eutrophic Cambisol, in order to compare them with the natural forest (Caatinga). The samples were randomly collected at Fazenda Melão Doçura, located in the city of Quixeré, Ceará State and forwarded to the Laboratory of Analysis of Soil, Water and Plant of the UFERSA, Mossoró, Rio Grande do Norte State. The content of organic matter (MO), microbial biomass carbon (CBM) and microbial quotient (qMIC) were determined. The experiment was mounted on completely randomized design (DIC), arranged in a factorial scheme 4 x 4 (years of cultivation Factor I, Factor II cause of variation in depth) with three replications. The results showed that organic matter increased from five years of cultivation of the melon. The microbial biomass carbon was higher in the superficial layers independent of the culture period due increased availability of organic matter, water and nutrients and microbial quotient decreased with time, with lower concentration in the 10 years cultivation of the melon, detailing the possible changes arising from agricultural soil use.

microbial carbon; soil management; organic carbon