Vinasse application and cessation of burning in sugarcane management can have positive impact on soil carbon stocks

Abstract

Bioenergy crops, such as sugarcane, have the potential to mitigate greenhouse gas emissions through fossil fuel substitution. However, increased sugarcane propagation and recent management changes have raised concerns that these practices may deplete soil carbon (C) stocks, thereby limiting the net greenhouse gas benefit. In this study, we use both a measured and modelled approach to evaluate the impacts of two common sugarcane management practices on soil C sequestration potential in Brazil. We explore how transitions from conventional (mineral fertiliser/burning) to improved (vinasse application/unburned) practices influence soil C stocks in total and in physically fractionated soil down to one metre. Results suggest that vinasse application leads to an accumulation of soil C of 0.55 Mg ha−1yr−1 at 0–30 cm depth and applying unburned management led to gains of ∼0.7 Mg ha−1yr−1 at 30–60 cm depth. Soil C concentration in the Silt+Clay fraction of topsoil (0–20 cm) showed higher C content in unburned management but it did not differ under vinasse application. The CENTURY model was used to simulate the consequences of management changes beyond the temporal extent of the measurements. Simulations indicated that vinasse was not the key factor driving increases in soil C stocks but its application may be the most readily available practice to prevent the soil C losses under burned management. Furthermore, cessation of burning may increase topsoil C by 40% after ∼50 years. These are the first data comparing different sugarcane management transitions within a single area. Our findings indicate that both vinasse application and the cessation of burning can play an important role in reducing the time required for sugarcane ethanol production to reach a net C benefit (payback time).

Vinasse Waste from Sugarcane-Based Bioethanol Production Plants Kills Moniliophthora Perniciosa, the Causative Agent of Cacao Witches' Broom Disease

“…The utilization of vinasse has associated pollution problems that only recently are being recognized [3], but altogether it appears to be beneficial [6][7][8][9]. Our results clearly show the potential of vinasse to control the filamentous fungus M. perniciosa, cacao Witches' Broom Disease causative agent.…”

“…This appears to be a virtuous cycle, since vinasse is rich in potassium and other minerals [4], avoiding the need for chemical fertilization [5]. In the long run, vinasse is apparently beneficial for soil quality and sugarcane production yield [4,[6][7][8][9]. But in reality, the amounts of vinasse produced per year are far bigger than the fields can absorb, leading to saturation.…”

Kajian Potensi Vinase Sebagai Bahan Fertigasi di Perkebunan Tebu (Saccharum Officinarum L.)

“…Beberapa studi menunjukkan bahwa aplikasi vinase meningkatkan simpanan karbon di tanah (Jiang et al 2012;Soobadar and Ng Kee Kwong 2012;Zani et al 2018). Zani et al (2018) menemukan bahwa aplikasi vinase menyebabkan akumulasi karbon tanah sebesar 0,55 Mg per hektar per tahun pada kedalaman 0-30 cm. Vinase merupakan sumber karbon terlarut (Christofoletti et al 2013).…”

Different managements in conventional sugarcane reform in sandy soils: effects on physical properties and soil organic carbon

“…Another point to be considered concerns the addition of K + by vinasse. Exchangeble K is a monovalent cation with a high degree of hydration with less force of electrostatic attraction, which favors the dispersion of clay (Zani et al, 2018;Tavares Filho et al, 2010). So, the presence of K + in high amounts in the soil solution can increase clay dispersion and cause less stability of the organo-mineral complexes formed (Melo et al, 2020).…”

“…The greater accumulation of carbon in the tillage+sugarcane management system than the tillage+cover crop and tillage+soy systems is probably due to the constant supply of organic by-products (filter cake) after the reform period. The large amount of organic matter deposited in the soil by this by-product can provide a rapid increase in the levels of the organic fraction (Zani et al, 2018). The low C:N ratio of vinasse tends to accelerate the decomposition and humification processes of this organic material in the soil, which thus increases its stability and ensures greater persistence of the organic fraction (Santos et al, 2020); hence, greater amounts of carbon.…”