Hostipastoral systems in small farming units that integrate horticulture crops, as main cash crop, with sheep/cattle raising on cultivated forage, in Uruguay, present physical restrains to crops because of high consistency and compaction of the vertic soils and unique tillage requirements. The objective of this study was to evaluate the effect of different hortipastoral systems on soil organic matter, aggregation, porosity, permeability and onion yield during a cropping year in onion-forage hortipastoral systems. A long-term experiment was installed in 1995 in the National Institute for Agricultural Research (INIA-Las Brujas) in Uruguay, on fine (mixed) smectitic thermic superactive Vertic Argiudolls. The soil was previously under native grasslands, and treatments consisted of cropping systems for onion (Allium cepa L.) production, maintained for three years and then rotated. Onion yield was evaluated during the period 1998–2006, and in the cropping year 2006–2007, corresponding to the end of a 3-year cropping cycle, we evaluated soil organic matter and physical properties and functioning in the cropping systems: alfalfa, fescue, forage consortium (birdfoot trefoil, alfalfa and white clover), onion after alfalfa, onion after fescue, and onion after consortium. At four times during the cropping year, aggregate stability and organic matter were determined for the 0–0.05 m soil layer, whereas soil bulk density, porosity, and hydraulic conductivity were determined in 0–0.10 and 0.10–0.20 m layers. The results showed high variability in onion yields from 1998 to 2006 (10.8–36.4 Mg ha⁻¹), mainly related to high rainfall (higher than 150 mm) that affected crop planting, and the low rainfall (lower than 30 mm) that affected growth and development. In two out of eight years, there were significant differences in onion yield among treatments, where alfalfa (1999) and fescue (2006) crops are more beneficial to onion yield than pasture consortium. To establish the onion crop in the vertic soil tillage is needed, but tilling the soil under forage crops reduces macro and increases microaggregation (reduces GMDw from 1.8 to 0.8 mm), increases macroporosity (close 0.07 to 0.25 m³ m⁻³) and functioning in terms of water and air permeability (Ka increase above 3 µm² after tillage) and decreases the degree of compaction (under forages decreased DC from 69-84% to 58–60% in surface layer). In conclusion, there is a significant potential of hortipastoral systems and proper management of soil organic matter to minimize adverse effects of climate, and improve productivity stability of intensive production systems. Single forage crops, either legume or grass, are more beneficial to onion yield than consortium of grass plus legumes.

在乌拉圭，将园艺作物作为主要经济作物与以耕作草料饲养羊/牛相结合的小型农业单位的寄宿系统，由于垂直土壤的高度稠度和压实以及独特的耕作要求，对作物产生了物理限制。本研究的目的是评估不同园艺系统对洋葱-草料园艺系统中一个种植年度的土壤有机质、聚集、孔隙度、渗透性和洋葱产量的影响。1995 年，乌拉圭国家农业研究所 (INIA-Las Brujas) 对精细（混合）近晶质热超活性 Vertic Argiudolls 进行了长期实验。土壤以前是在原生草原下，处理方法包括种植洋葱（Allium cepaL.) 生产，维护三年，然后轮换。洋葱产量在 1998-2006 年期间进行了评估，在 2006-2007 种植年度，对应于 3 年种植周期的结束，我们评估了土壤有机质和物理特性以及种植系统中的功能：苜蓿、羊茅, 草料联合体（鸟足三叶草、苜蓿和白三叶草），洋葱后苜蓿，洋葱后羊茅，洋葱后联合体。在种植年度的四次，测定了 0-0.05 m 土层的团聚体稳定性和有机质，而测定了 0-0.10 和 0.10-0.20 m 土层的土壤容重、孔隙度和导水率。结果表明，从 1998 年到 2006 年，洋葱产量的变化很大（10.8-36.4  Mg  ha ^-1)，主要与影响作物种植的高降雨量(大于150 mm)和影响生长发育的低降雨量(小于30 mm)有关。在八年中的两年中，处理之间的洋葱产量存在显着差异，其中紫花苜蓿（1999）和羊茅（2006）作物比牧草财团更有益于洋葱产量。需要在垂直土壤耕作中种植洋葱作物，但在饲料作物下耕作土壤会减少宏观并增加微团聚（将 GMDw 从 1.8 减少到 0.8 毫米），增加大孔隙度（接近 0.07 到 0.25 m ³ m ^-3）和功能在透水性和透气性方面（Ka 增加到 3 µm ²以上耕作后）并降低压实度（在草料下将 DC 从 69-84% 降低到表层的 58-60%）。总之，园艺系统和土壤有机质的适当管理具有很大的潜力，可以最大限度地减少气候的不利影响，并提高集约化生产系统的生产力稳定性。单一的牧草作物，无论是豆类还是草，比草加豆类的联合体更有利于洋葱产量。