Abstract The traditional practice of burning at the pre-harvesting of sugarcane has being phased-out in Brazil, resulting in the maintenance of a crop s residue layer on soil surface, namely the Green Cane Trash Blanket (GCTB). New technologies for electricity and second-generation ethanol (2G) production from crop residues have raised the question on what would be the optimum amount of crop residue left on the field to keep the agronomic and environmental benefits of GCTB. To support informed decision making on sugarcane trash management, we updated, evaluated and applied a new version of the SAMUCA model to simulate the sugarcane growth and water use under the GCTB effect. The updated model was calibrated and parameterized for bare soil and GCTB conditions and evaluated across different Brazilian regions. Thirty-year simulations were then conducted with the updated model to quantify the effects of GCTB on sugarcane growth and water use where sugarcane is traditionally grown in Brazil. The updated version of SAMUCA model showed equal or superior performance when compared with widely-used process-based models for sugarcane. Based on our 30-year simulations, the GCTB exhibited a high probability to promote a beneficial effect on sugarcane yields in dry climates (>90%), with the potential for increasing, on average, 14 ton ha−1 of fresh cane yield in Petrolina, Brazil. Although the beneficial effect on yields were not significant in humid regions, the maintenance of 12 ton ha−1 of GCTB was associated with a high probability (>87%) in reducing the water use of sugarcane cropping system by 89 mm, on average, potentially reducing irrigation demand in the early stages of crop development while protecting crop production under dry spell events. The new version of SAMUCA model offers as a tool for decision making on mulch management in sugarcane plantations.

中文翻译：

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模拟垃圾毯对甘蔗生长和用水的影响

摘要 在甘蔗收获前燃烧的传统做法在巴西已被逐步淘汰，从而在土壤表面维持作物残留层，即绿色甘蔗垃圾毯（GCTB）。利用农作物秸秆生产电力和第二代乙醇 (2G) 的新技术提出了一个问题，即留在田间的农作物秸秆的最佳数量是多少，以保持 GCTB 的农艺和环境效益。为了支持有关甘蔗垃圾管理的明智决策，我们更新、评估并应用了新版本的 SAMUCA 模型，以模拟 GCTB 效应下的甘蔗生长和用水。更新后的模型针对裸土和 GCTB 条件进行了校准和参数化，并在巴西不同地区进行了评估。然后使用更新的模型进行了 30 年的模拟，以量化 GCTB 对巴西传统上种植甘蔗的甘蔗生长和用水的影响。与广泛使用的基于过程的甘蔗模型相比，SAMUCA 模型的更新版本表现出同等或更高的性能。根据我们 30 年的模拟，GCTB 显示出在干燥气候下（>90%）促进对甘蔗产量的有益影响的可能性很高，平均有可能增加 14 吨 ha-1 的新鲜甘蔗产量巴西石油公司。虽然在潮湿地区对产量的有益影响不显着，但维持 12 吨 ha-1 的 GCTB 与平均减少 89 毫米甘蔗种植系统用水的可能性很高（> 87％）有关，潜在地减少作物发育早期的灌溉需求，同时保护干旱事件下的作物生产。新版本的 SAMUCA 模型作为甘蔗种植园覆盖物管理决策的工具。