Soil tillage influences early-growth, uniformity, and productivity of commercial forests. Best tillage practices for soils with constraints of compaction, drainage or shallow soils, all reducing the effective rooting-depth, are widely unknown for subtropical forest plantations in South America. The study aimed to quantify the effects of different tillage methods on breaking up and/or turning over the soil and on physical properties in three different soils, and relationships with early growth (up to 24 months of age) of clonal Eucalyptus saligna in southern Brazil. The tillage methods consisted of subsoiling to 50 cm plus rototilling, subsoiling to 50 cm plus ridging, and subsoiling to 70 cm plus rototilling. The soils were low-drainage Planosol, shallow sandy Regosol, and compacted clayey well-drained Nitisol. The dendrometric evaluations for initial growth show the best tillage method depended on soil type and dendrometric variable. Tree height is maximized by deep subsoiling (70 cm) in Nitisol, and by shallow subsoiling (50 cm) plus ridging in Regosol and Planosol. Tree diameter at breast height and basal area were maximized by shallow subsoiling with or without ridging in Planosol, deep subsoiling in Nitisol, and shallow subsoiling with ridging or with deep subsoiling in Regosol. When considering all the studied dendometric variables (tree height, diameter at breast height, and basal area), subsoiling plus ridging is recommend for low-drainage or shallow soils, whereas deep-subsoiling is necessary in clay soils.

土壤耕作会影响商品林的早期生长，均匀性和生产力。对于压实，排水或浅层土壤有限制的土壤，所有耕作方法都会减少有效生根深度，因此在南美亚热带森林人工林中尚无最佳耕作方法。这项研究旨在量化不同耕作方法对三种不同土壤的分解和/或翻土以及对物理性质的影响，以及与无性桉树的早期生长（至24个月龄）的关系。在巴西南部。耕作方法包括深耕至50厘米加旋转耕作，深耕至50厘米加褶边耕作，深耕至70厘米再加耕作。土壤为低排水的普莱诺索尔，浅沙性雷戈索尔和压实的粘性良好排水的尼提索尔。初始生长的树状评价表明，最佳耕作方法取决于土壤类型和树状变量。在尼蒂索尔（Nitisol）深深开土（70 cm），在雷戈索尔（Regosol）和普莱诺索尔（Planosol）中，通过浅深开土（50 cm）再加上树桩，可以使树高最大化。通过在Planosol中有或没有褶皱的浅层深层土壤，在Nitisol中有深层的深层土壤，以及在Regosol中有褶皱或有深层深层的浅层深层土壤，可以最大化胸高和基部面积的树木直径。考虑所有研究的树状密度变量（树高，胸径，