Soil carbon sequestration and stocks: short-term impact of maize succession to cover crops in Southern Brazil Inceptisol

Abstract

Aim of study: To evaluate soil organic carbon (SOC) sequestration and stock over the succession of maize to winter cover crops under a short-term no-tillage system.Area of study: A subtropical area in Southern Brazil.Material and methods: The experiment was implemented in 2013. The treatments were: seven winter cover crops single cultivated (white-oats, black-oats, annual-ryegrass, canola, vetch, fodder-radish and red-clover); an intercropping (black-oats + vetch); and a fallow, with maize in succession. Soil samples were collected after four years of experimentation, up to 0.60 m depth, for SOC determination.Main results: SOC stocks at 0-0.6 m depth ranged from 96.2 to 107.8 t/ha. The SOC stocks (0-0.60 m depth) were higher under vetch and black-oats, with an expressive increase of 23 and 20% for C stocks in the 0.45-0.60 m layer, compared to fallow. Thus, SOC sequestration rates (0-0.60 m depth), with vetch and black oats, were 1.68 and 0.93 t/ha·yr, respectively.Research highlights: The establishment of a high-quality and high C input cover crops in the winter, as vetch or black-oats in succession to maize, are able to increase SOC stocks, even in the short term.

Use of winter cover crops improves maize productivity under reduced nitrogen fertilization: a long-term study

“…However, despite its capacity, the red clover did not develop well in the field, promoting a lower residue input along the years of experiment (Table 2). Locatelli et al (2020) found a similar result for the soil carbon stocks in the same study area, where a stock of ~ 96 mg•ha -1 (0-60 m layer) was obtained for the red clover, against ~ 107 mg•ha -1 (0-60 m layer) for vetch. The same was observed in crops of the brassica's family (fodder radish and canola), despite not biologically fixing N like the legumes, those crops were expected to increase N cycling from deeper layers to the soil surface (Silva et al 2007) and then make it available to maize uptake.…”

“…This is relevant even in a soil managed in no-tillage system and with high SOM content (44.23 g•dm -3 ), which can supply partially the N demands of maize. However, in the medium to long term, might reduce the soil carbon stocks (Locatelli et al 2020) and therefore, the supply of N to maize. Still, it is necessary to expand the results of the research, with the disclosure not only of the importance of cultivating cover crops instead of fallow to avoid soil degradation, but their relative contribution to plant nutrition and the total or partial replacement of mineral fertilizers, which lowers costs.…”

“…Data of cover crops dry matter (DM) production from 2013 to 2016 crop seasons were obtained from Locatelli et al (2020) and updated in this work in 2017 winter season (Table 2). Before desiccation, the aboveground DM from cover crops was determined by clipping the plants at soil surface in an area of 0.5 × 0.5 m and oven drying at 60 °C until constant mass.…”

“…In addition to nutrients supply, growing plants in the off-season favors the maintenance of soil cover, reduces erosion and infestations by spontaneous plants (Balbinot Júnior et al 2008), intensifies nutrient cycling (Tiecher et al 2017) and increases soil organic matter (SOM) (Veloso et al 2018;Locatelli et al 2020). Furthermore, its use in autumn/winter periods (e.g.…”

Soybean off-season management practices: impacts on physical and chemical soil properties and crop yield

“…In this way, in the search of a more durable and sustainable option, the use of cover crops has appeared to reduce soil compaction and to promote increases in crop yield (Nicoloso et al, 2008;Blanco-Canqui et al, 2015). Additionally, the management of different crop species with vigorous root system and the addition of adequate amounts of residues, may increase SOM (Locatelli et al, 2020), improve soil physical, chemical and biological quality, promote protection against erosion and maintain the soil moisture (Balota et al, 2014;Frasier et al, 2016).…”