Losses of soil, water, organic carbon and nutrients caused by water erosion in different crops and natural savannah in the northern Amazon

Abstract

Currently in Brazil, the main form of erosion is caused by the impact of raindrops on the soil surface, triggering the process of water erosion and causing serious damage to agricultural areas. This study evaluated losses of soil, water, organic carbon and nutrients in different cultures, bare soil and savanna under natural rain. The experimental design was completely randomized with five treatments (bare soil - BS, cowpea bean - CB, Brachiaria brizantha - BB, corn - CO and natural savanna – SN) with three replications; The treatment of bare soil (BS), followed by the treatment cultivated with cowpea bean (CB) showed higher losses of soil, water, organic carbon and nutrients; The highest losses of soil, water, organic carbon and nutrients in the treatment of bare soil (BS) occurred during the period of greatest erosivity; but for treatments CB, BB and CO, the highest losses occurred during the establishment of the crop, in view of the lower soil cover. Soils cultivated with Brachiaria brizantha - BB, corn - CO and in the Natural Savana - SN area were more efficient in reducing soil and water losses during all months evaluated. Plant cover produced by the (SN) treatment and by the (BB) and (CO) treatments acted to reduce the harmful effects of erosion, minimizing losses of nutrients and organic carbon. The soil should be well protected during periods when rainfall presents the highest values of erosivity index.

Physical fractions of organic matter and mineralizable soil carbon in forest fragments of the Atlantic Forest

“…Soil organic matter (SOM) studies based on C contents are sensitive in identifying changes in soil management and mainly in vegetation modifications (Souza et al, 2019;Ferreira et al, 2020). The fact that the C content is immediately changed when the vegetation is modified occurs by the change in the input of SOM by the deposition of dry mass (Lal, 2018;Assunção 3 Physical fractions of organic matter and mineralizable … Rev.…”

Short-term effect of a crop-livestock-forestry system on soil, water and nutrient loss in the Cerrado-Amazon ecotone

“…In an area of natural savanna in the Brazilian Amazon, a three-month study found that, in addition to the natural vegetation, pasture with Urochloa brizantha and corn plantation were more efficient in containing erosion through soil, water, organic carbon and nutrient loss than cowpea-bean plantation and bare soil (Souza et al 2019). In the latter study, average soil and water loss were, respectively, 8.9 and 3.9 times higher in bare soil than in the other treatments, showing that the harmful effects of erosion were attenuated by the soil cover.…”

Crecimiento y producción de Solanum gilo Raddi en sistemas de cultivo en callejones con adición de estiércol bovino

“…A pesar de la adición de estiércol de bovino se registraron bajos tenores de MOS al final del experimento, esta situación pudo estar influenciada de la acción de la temperatura y humedad del suelo del sitio del experimento, teniendo en cuenta que en las zonas de sabana como las de Roraima, la tasa de pérdida de carbono soy muy elevadas (Melo, Evald, Roberto, & Rocha, 2017;Souza, Melo, Araújo & Araújo, 2019).…”