Soil tillage and cover crop on soil CO₂ emissions from sugarcane fields

Abstract

Soil tillage is an agricultural practice that directly affects the global carbon cycle. Our study sought to assess the implications of adopting sunn hemp cover crops with different tillage practices on CO2 emissions for two soil types (clayey and sandy soil) cultivated with sugarcane in Brazil. The experimental design was a split‐plot with randomized blocks, with the main plots being with cover crop or fallow and sub‐plots being under conventional or minimum tillage. Our results indicate that during the first 50 days after soil tillage, the variation in soil CO2 emissions was stimulated by cover crop and soil tillage, while after that, it became dominated by the root respiration of sugarcane plants. We also found that over the first 97 days after the tillage, the clayey soil showed differences between minimum tillage with cover crop and fallow. Conversely, for sandy soil over the first 50 days following, there were differences between the tillage systems under cover cropping. Emissions from sugarcane rows were found to be greater than those from inter‐row positions. We concluded that soils under different textural classes had distinct patterns in terms of soil CO2 emissions. The correct quantification of CO2 emissions during the sugarcane renovation period should prioritize having a short assessment period (~50 days after soil tillage) as well as including measurements at row and inter‐row positions.

Sustainable soil use and management: An interdisciplinary and systematic approach

“…soil texture). For sandy soils, greater macroporosity tends to be associated with higher CO 2 emissions, while microporosity is associated with lower emissions, which likely related to their respective tortuosity levels (Farhate et al, 2019;Tavares et al, 2015). The use of lime to treat low pH soils may also relate to CO 2 emissions.…”

The Effect of Conservation Agriculture and Environmental Factors on CO2 Emissions in a Rainfed Crop Rotation

“…Soil tillage practices are also conducted by farmers to alleviate soil compaction, but only temporarily [15]. These practices also promote the decomposition of OM and losses of carbon (C) to the atmosphere in the form of CO 2 [16][17][18].…”

Soil physical change and sugarcane stalk yield induced by cover crop and soil tillage

“…Deep subsoiling temporarily benefits soil physical quality (Hoorman et al, 2011), but this tillage has high cost (Chamen et al, 2015). Furthermore, soil disturbance induced by tillage accelerates microbial respiration and soil C losses to the atmosphere as CO 2 (Teixeira et al, 2011;Silva-Olaya et al, 2013;Farhate et al, 2019;Tenelli et al, 2019). Therefore, the impacts of mechanical soil tillage before sugarcane planting still need to be further investigated to establish more sustainable and viable management practices.…”