Deep sands on the south coast sandplain of Western Australia (WA) have multiple soil constraints including water repellence, high soil strength, low nutrient levels and subsoil acidity. The aim of the study was to test contrasting methods of managing water repellence and to assess their impacts on one or more soil constraints to crop production. These methods included seeding tyne design (knife point, winged points, paired row), soil wetting agent addition, strategic inversion tillage (rotary spading, mouldboard ploughing to 0.35 m) and clay-rich subsoil addition (170 t ha⁻¹ with incorporation by spading to 0.20 or 0.35 m). Limesand (2 t ha⁻¹) was applied as a split plot treatment prior to tillage. Cumulative crop yields were increased by 2.1–2.6 t ha⁻¹ over five years by the strategic deep tillage and clay application treatments compared to the control. Water repellence was reduced by the inversion ploughing and subsoil clay addition treatments only. The effect of water repellence on crop establishment was expressed only in low rainfall years (Decile < 4) and mitigated by the paired row, wetting agent, spader and clay-amended treatments. In all years, plant numbers were adequate to achieve yield potential regardless of treatment. Soil K and plant tissue K and B were increased where clay had been applied. Inversion tillage reduced soil pH, organic carbon (OC) and macro nutrients in the 0–0.1 m layer although in most years there was no significant decline in plant tissue macro nutrient levels. Soil strength was reduced as a result of the inversion tillage to a depth of 0.35 m. However, the alleviation of soil strength and the crop yield responses diminished with time due to re-compaction. No crop response to the applied lime was found over five years at this site since the soil pHCaCl₂ exceeded 4.7 within the root zone. In terms of soil constraints, we conclude that compaction was the dominant constraint at this site followed by water repellence and K deficiency.

中文翻译：

---

土壤管理系统克服了西澳大利亚州南海岸水有限环境中深沙旱地作物的多种限制

西澳大利亚州（WA）南海岸沙洲上的深沙具有多种土壤约束条件，包括疏水性，高土壤强度，低营养水平和底土酸度。这项研究的目的是测试控制疏水性的对比方法，并评估它们对一种或多种土壤限制对作物生产的影响。这些方法包括播种泰恩针设计（刀尖，有翼尖，成对的行），添加土壤润湿剂，策略性倒置耕作（旋转铲，犁土板犁至0.35 m）和富含粘土的底土（170 t ha ^-1并掺入）。最大为0.20或0.35 m）。在耕作之前，将Limesand（2 t ha ^-1）作为分割地块处理。作物累计单产提高了2.1–2.6 t ha ^-1与对照相比，通过战略性的深耕和黏土施用处理，在五年多的时间里。仅通过反向翻耕和添加地下土壤粘土来降低拒水性能。拒水对农作物生长的影响仅在低降雨年份（十分位数<4）中表达，并通过成对的排，湿润剂，铲子和粘土改良处理得到缓解。在所有年份中，无论采用何种处理方式，植物数量都足以实现增产潜力。在施用黏土的情况下，土壤K和植物组织K和B均增加。反向耕作降低了0-0.1 m层的土壤pH值，有机碳（OC）和大量养分，尽管在大多数年份中，植物组织的大量养分水平没有显着下降。反向耕作使土壤强度降低至0.35 m的深度。然而，由于重新压实，土壤强度的减轻和农作物产量的响应随时间减少。由于土壤pHCaCl，五年内在该地点未发现作物对施用石灰的反应₂在根区域内超过4.7。在土壤约束方面，我们得出结论，压实是该位置的主要约束，其次是疏水和缺钾。