Name: LUCAS RODRIGUES NICOLE
Publication date: 23/02/2017
Advisor:
Name |
Role |
|---|---|
| FÁBIO RIBEIRO PIRES | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| DIEGO LANG BURAK | External Examiner * |
| FÁBIO RIBEIRO PIRES | Advisor * |
| GIOVANNI DE OLIVEIRA GARCIA | External Alternate * |
| IVONEY GONTIJO | Internal Alternate * |
| ROBSON BONOMO | Co advisor * |
Summary: NICOLE, Lucas Rodrigues; M.Sc.; Federal University of Espírito Santo; February
2017; Cover crops and soil quality in the Coastal Tablelands region; Advisor:
Fábio Ribeiro Pires; Co-advisors: Robson Bonomo, Dione Pereira Cardoso.
In the North of Espírito Santo, in the Coastal Tablelands region, in the face of water
scarcity in recent years, there have been observations of a migration of previously
cultivated areas with papaya and coffee, under central pivot irrigation, to grains in the
no-tillage system, particularly beans and corn. In these areas, newly started in the
system, the formation and persistence of straw mulch has been one of the major
limitations. The use of cover crops, besides the formation of straw mulch, is capable
of improving the physical, chemical and biological attributes of the soil, making a
more sustainable agricultural system. The objective of this study was to evaluate the
soil quality in relation to the cultivation of cover crops and their potential for straw
mulch formation aiming at the adoption of no-tillage system in the North of Espírito
Santo, under different irrigation water regimes. The experiment was conducted in the
field, in a dystrophic Yellow Argisol, experimental design in RBD, in subdivided plots,
with four repetitions. The treatments were composed in the plots by two water
regimes and in the subplots by six covering crops, four cultivars of Pennisetum
glaucum (L.) R. Brown (millet: ADR 300, ADR 500, ADRf 6010 and BRS 1501), a
Canavalia Ensiformis (L.) DC. (jack bean) and a Brachiaria ruziziensis Germain &
Evrard, cv. Common (brachiaria). The agronomic performance of the cover crops
were evaluated (plant height, leaf area, chlorophyll content, root development, cover
index, phytomass production, remaining phytomass and decomposition rate) and soil
quality under these plants (chemical and biological attributes). The jack bean and
ADRf 6010 millet show resistance to water deficiency for most of the agronomic
performance variables studied. The jack bean and Brachiaria ruziziensis show the
lowest decomposition rates and longer half-life. Among the millets this occurs for the
cultivar ADR 300. Considering soil cover index, dry matter production and
decomposition rate, ADR 300 millet, in both irrigation regimes, is the most indicated
crop for straw formation and soil cover. The water regime interferes in soil chemical
attributes, with higher influence on pH, K+
, Na+
, H+Al, V and MO, especially on the 0-
xiii
20 cm layer. The use of cover crops promotes the increase of soil chemical
attributes. The cultivar of millet ADRf 6010 and Brachiaria ruziziensis promote
improvement in the biological quality of the soil, increasing the levels of MBC and
qMIC and decreasing qCO2. The accumulation of organic matter on the surface and
consequent mineralization results in increases in the biological quality of the soil. In
view of the main results, there is potential for consolidation of the no-tillage system in
the Coastal Tablelands region, increasing the chemical and biological attributes of
the soil with the use of cover crops adapted to the water deficiency condition.
