Soil Erosion and Degradation Research Group. Department of Geography, Valencia University, Blasco Ibàñez, 28, 46010, Valencia, Spain.
Department of Cartographic Engineering, Geodesy, and Photogrammetry, Universitat Politècnica de València, Camino de Vera, s/n, 46022, Valencia, Spain.
J Environ Manage. 2021 Jul 15;290:112516. doi: 10.1016/j.jenvman.2021.112516. Epub 2021 Apr 17.
Soil erosion is a threat for the sustainability of agriculture and severely affects the Mediterranean crops. Olive groves are among the rainfed agriculture lands that exhibit soil and water losses due to the impact of unsustainable practices such as conventional tillage and herbicides abuse. To achieve a more sustainable olive oil production, alternative, greener crop management practices need to be tested in the field. Here, a weed cover (CW) treatment is tested at an olive tree plantation that has undergone conventional mechanical tillage for 20 years and results were compared against an adjacent control plantation that maintained tillage as a weed control strategy (CO). Both plantations were under the same tillage management for centuries and macroscopic analysis confirms they are otherwise comparable. Compared to the CO, where tilled soil cover was zero, 20 years of CW (weeds cover 64%; litter cover 5%) had led to significantly higher values of soil bulk density and soil organic matter. Results from rainfall simulation experiments at 55 mm h on 0.25 m plots under CO (N = 25) and CW (N = 25) show that as a result of the improved soil structure, CW (i) reduced soil losses by two orders of magnitude (140 times), (ii) decreased runoff yield by one order of magnitude (from 2.65 till 27.6% of the rainfall), (iii) significantly reduced runoff sediment concentration (from 18.6 till 1.43 g l), and (iv) significantly delayed runoff generation (CO = 273 s; CW = 788 s). These results indicate that weed cover is a sustainable land management practice in Mediterranean olive groves and promotes sustainable agriculture production in mountainous areas under rainfed conditions, which are typically affected by high erosion rates such those found in the CO plots. Due to the spontaneous recovery of plant cover, we conclude that weed cover is an excellent nature-based solution to increase in the soil organic matter content and soil erosion reduction in rainfed olive orchards.
土壤侵蚀是农业可持续发展的威胁，严重影响了地中海地区的作物。橄榄树种植园属于雨养农业土地，由于常规耕作和除草剂滥用等不可持续做法的影响，会出现土壤和水流失的情况。为了实现更可持续的橄榄油生产，需要在田间测试替代的、更环保的作物管理做法。在这里，对一个经过 20 年常规机械耕作的橄榄树种植园进行了杂草覆盖（CW）处理，并将结果与相邻的对照种植园进行了比较，对照种植园一直采用耕作作为杂草控制策略（CO）。这两个种植园都有几个世纪的相同耕作管理，宏观分析证实它们在其他方面是可比的。与 CO 相比，在 CO 中，耕作土壤的覆盖为零，而 20 年的 CW（杂草覆盖 64%；凋落物覆盖 5%）导致土壤容重和土壤有机质显著增加。在 CO（N=25）和 CW（N=25）下，在 0.25 m 小区进行的 55 mm h 降雨模拟实验的结果表明，由于土壤结构得到改善，CW（i）将土壤流失减少了两个数量级（140 倍），（ii）减少了径流量（从降雨的 2.65%减少到 27.6%），（iii）显著降低了径流泥沙浓度（从 18.6 减少到 1.43 g l），以及（iv）显著延迟了径流的产生（CO=273 s；CW=788 s）。这些结果表明，杂草覆盖是地中海橄榄树种植园可持续的土地管理实践，并促进了在雨养条件下多山地区的可持续农业生产，这些地区通常受到高侵蚀率的影响，如 CO 小区所发现的那样。由于植物覆盖的自发恢复，我们得出结论，杂草覆盖是增加雨养橄榄果园土壤有机质含量和减少土壤侵蚀的一种极好的基于自然的解决方案。
