Do soil carbon sequestration and soil fertility increase by including a gramineous cover crop in continuous soybean?

BELTRAN, MARCELO JAVIER; GALANTINI, JUAN ALBARTO; SALVAGIOTTI, FERNANDO; TOGNETTI, PEDRO; BACIGALUPPO, SILVINA; SAINZ ROZAS, HERNÁN RENÉ; BARRACO, MIRIAM; BARBIERI, PABLO ANDRÉS

SOIL SCIENCE SOCIETY OF AMERICA JOURNAL

SOIL SCI SOC AMER

Lugar: Wisconsin; Año: 2021

0361-5995

ver cropping is a farming practice that may improve C sequestration and soil fertility, but these effects can vary under different edaphoclimatic conditions. The effectsof including a winter gramineous cover crop (CC) in continuous soybeans were evaluated in three long-term experiments (8 yr) on one coarse-textured soil and two finetextured soils in the Pampas region of Argentina. The impacts of CC on soil C sequestration, soil nutrient availability, soil organic C (SOC), and N contents of soil particlesize fractions were also determined. The inclusion of CC only increased SOC stockby 3.1 Mg ha-1 in the coarse-textured soil (CTS). The labile C fraction in the 0?5-cmdepth increased in both the CTS and the fine-textured soils (FTS) by 263% and 93%,respectively. Soil N also increased in the labile fraction by 119% and 112% when aCC was used in the CTS and FTS soils, respectively. Moreover, the inclusion of a CCdecreased soil P availability in one experiment (4.9 kg ha-1) and increased soil manganese in two experiments (11 kg ha-1 on average). The inclusion of a gramineousCC in a soybean monoculture increased the C balance, particularly in coarse-texturedsoils. Considering that soil N was similarly affected, the C/N ratio was not impacted.