Different amounts of sugarcane trash left on the soil: Effects on microbial and enzymatic indicators in a short‐term experiment

• Published in: Soil use and management Vol. 37; no. 3; pp. 658 - 666
• Main Authors: Vieira, Rosana Faria, Ramos, Nilza P., Pazianotto, Ricardo Antônio A., Aitkenhead, Matt
• Format: Journal Article
• Language: English
• Published: Bedfordshire Wiley Subscription Services, Inc 01-07-2021
• Subjects: Biomass; Food processing industry; Glucosidase; Indicators; microbial activity; microbial biomass; Microorganisms; Principal components analysis; Quality management; Quotients; Removal; Renewable energy; Soil; Soil quality; Soil testing; Soils; Sugarcane; Sustainability; Trash removal; Urease; Waste containers; β‐glucosidase
• ISSN: 0266-0032; 1475-2743
• DOI: 10.1111/sum.12584

When using mechanical harvesting, the sugarcane trash can be partially recovered for use as feedstock for bioenergy. However, the amount of trash that can be removed without prejudicing the sustainability of the sugarcane production system has still been little studied. The aim of this study was to evaluate the short‐term impact of removing part of the sugarcane trash using enzymatic and microbiological soil quality indicators. We tested three rates of trash removal: 0% (T0), 50% (T50) and 100% (T100). The microbial biomass C (Cmic) and N (Nmic), β‐glucosidase activity (GA) and the ratios Cmic as a per cent of Ctot and Nmic as a per cent of Ntot were highest for T100. The urease activity decreased with an increase in trash removal. The specific activity of β‐glucosidase did not differ between the treatments, while the specific activity of urease showed the same pattern as the absolute activity. The metabolic quotients (qCO2) were higher for T50 and T100 with no significant difference between them. The principal component analysis showed that the first component, which explained 77.66% of the total variance, was significantly correlated with Nmic, basal respiration and GA and discriminated the three treatments. The results showed that the removal of part of the trash adversely affected some of the soil quality attributes. This suggests the need for monitoring over a period of years in sugarcane areas where part of the trash is removed for industrial purposes, in order to better understand the cumulative impact on soil quality and to ensure the sustainability of bioenergy production.