Abstract. This study evaluates an optimized cropping system (including no-tillage, cover crops and organic amendments), as an alternative to conventional management for rainfed cereal cropping in a calcareous soil in a semi-arid Mediterranean climate zone in Navarre (Spain), based on the analysis of soil water retention curves (SWRC) and soil structure. In an agricultural area, plots were randomly selected on a soil unit (Fluventic Haploxerept), with contrasting managements: (a) optimized system; which includes no-tillage (18 years continuous) after conventional tillage, crop rotation, use of cover crops and occasional application of organic amendments, and (b) conventional management; which involves continuous conventional tillage (chisel plow), mineral fertilization, no cover crops and a lower diversity of crops in the rotation. Undisturbed soil samples from the soil surface (0–5 cm) and disturbed samples from the tilled layer (0–30 cm) were collected for both systems. The undisturbed samples were used to obtain the detalied SWRCs in the suction range 0 kPa to 110 kPa using a Hyprop® device. From these SWRCs, the Dexter S index was determined. Disturbed samples were used in the laboratory to assess soil structure by means of an aggregate-size fractionation. SWRCs showed significant differences between the two studied agricultural systems, corresponding to different pore size distributions. However, the S index did not show significant differences between the two cropping systems. In addition, the soil under conventional management showed greater macroporosity (gravitational water). As a result, the soil under the optimized system stored up to 10 % more water for the crop at the studied depth. Likewise, more stable macroaggregates were observed in the optimized system than in the conventional one, as well as more organic C storage, greater microbial activity, and biomass. Overall, these results reflect a better quality –or less degradation– of the soil after 18 years under the optimized system than its conventionally managed counterpart.

中文翻译：

---

基于保水曲线的雨养谷类农田耕地改良长期优化管理策略评价

摘要。本研究评估了优化的种植系统（包括免耕、覆盖作物和有机改良剂），作为在纳瓦拉（西班牙）半干旱地中海气候区钙质土壤中雨养谷物种植的常规管理的替代方案，基于土壤保水曲线（SWRC）和土壤结构分析。在一个农业区，在一个土壤单元（ Fluventic Haploxerept ）上随机选择地块，采用对比管理：（a）优化系统；其中包括常规耕作后免耕（连续 18 年）、轮作、使用覆盖作物和偶尔使用有机改良剂，以及 (b)常规管理; 这涉及连续常规耕作（凿犁）、矿物施肥、无覆盖作物和轮作中作物的多样性较低。两个系统都收集了来自土壤表面（0-5 cm）的未扰动土壤样品和来自耕作层（0-30 cm）的扰动样品。未受干扰的样品用于使用 Hyprop® 装置在 0 kPa 至 110 kPa 的吸力范围内获得详细的 SWRC。根据这些 SWRC，确定了 Dexter S 指数。在实验室中使用扰动样品通过骨料大小分级来评估土壤结构。SWRCs 显示出两个研究的农业系统之间的显着差异，对应于不同的孔径分布。然而，S 指数并未显示两种种植系统之间的显着差异。此外，常规管理下的土壤表现出更大的大孔隙率（重力水）。结果，优化系统下的土壤在研究深度为作物储存了多达 10% 的水分。同样，在优化后的系统中观察到比传统系统更稳定的大聚集体，以及更多的有机碳储存、更高的微生物活性和生物量。总体而言，这些结果反映了在优化系统下 18 年后土壤质量优于传统管理的对应物。以及更多的有机碳储存、更大的微生物活动和生物量。总体而言，这些结果反映了在优化系统下 18 年后土壤质量优于传统管理的对应物。以及更多的有机碳储存、更大的微生物活动和生物量。总体而言，这些结果反映了在优化系统下 18 年后土壤质量优于传统管理的对应物。