Cover crops in the Southeastern region of Buenos Aires,
Argentina: effects on organic matter physical fractions and nutrient
availability
In the Southeastern region of Buenos Aires province,
soybean monoculture has led to a decline in soil organic matter (SOM) levels in
soil, mostly the labile fractions. The reduction of SOM has a negative impact
on the soil environment. Cover crops (CC) constitute an alternative to maintain
or improve SOM levels. The aim of this study was to determine the effect of oat
as CC on (a) the SOM dynamics and (b) the availability of macro- and
micronutrients in a representative soil of the Southeastern region of Buenos
Aires province. Total organic carbon (TOC) and nitrogen (TON), as well as their
labile and mineral-associated fractions, and macro- and micronutrient
availability were determined. The treatments were soybean monoculture with and
without oat as cover crop. The increases in SOC and TON were 22.7% and 11%,
respectively, when CC was included to the soybean monoculture. These increases
were observed mostly in the labile fractions, with increases of 61.3 and 38.7%
for the particulate coarse organic carbon (PCOf) and particulate fine organic
carbon (PCOf), respectively, and 79.2% for the particulate coarse organic
nitrogen (NOPg). Regarding the nutrients, an increase of 47.6% was observed in
manganese (Mn) in the first 5 cm of soil depth, and a decrease in phosphorous
(P) availability in the same soil layer due to its consumption and retention by
CC. It can be conclude that CC presented a surface soil effect on the dynamic
of SOM, increasing C, N, and available Mn contents, but decreasing soil P
availability
Oat, Soybean monoculture,
Particulate organic carbon and nitrogen
Beltrán M.J., H. Sainz Rozas, J.A. Galantini, R.I.
Romaniuk, P. Barbieri. 2018.
Cover crops in the Southeastern region of Buenos Aires, Argentina: effects on
organic matter physical fractions and nutrient availability. Environmental
Earth Sciences 77:428. DOI: 10.1007/s12665-018-7606-0.
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