The low organic matter and nitrogen levels in the soils, as well as the high weed pressure, typical of Mediterranean agroecosystems, necessitate a valid and sustainable alternative management. The utilization of cover crops such as Trifolium subterraneum L. may represent an innovative and efficient option for low-input and organic agricultural systems. In a 3-year experiment, we evaluated the effect of T. subterraneum and spontaneous flora cover cropping, with or without burying dead mulch into the soil, on the quali-quantitative composition of the weed seed bank in an apricot orchard. Moreover, the bacteria Nitrosomonas europaea and Azotobacter vinelandii, involved in the soil N cycle, and the content of ammoniacal and nitric soil nitrogen were quantified. For the first time, we demonstrated that T. subterraneum cover cropping with the incorporation of dead mulches into the soil on the one hand reduced weed biodiversity and the seed bank size (− 70% compared to conventional management following the standard commercial practices), while, on the other hand, increased the amount of N. europaea (+ 109%), A. vinelandii (+ 145%), NH₄⁺ (+ 137%) and NO₃⁻ (+ 478%) in the soil. This approach was therefore found to be a major improvement in low-input agriculture and organic farming, and it can be applied in Mediterranean orchards as an eco-friendly strategy with the aim of reducing synthetic herbicides for weed control and mineral nitrogen fertilizers as the sole source of nitrogen supply.

中文翻译：

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三叶草地下覆盖作物改善土壤健康，杂草治理和氮素动态

土壤中的有机物和氮含量低，以及地中海农业生态系统所特有的高杂草压力，都需要有效且可持续的替代管理。三叶草（Trifolium subterraneum L.）等有盖作物的利用可能代表低投入和有机农业系统的创新和有效选择。在一个为期3年的实验中，我们评估了杏皮中杂草种子库的定性组成对地下隐孢子虫和自发植物群覆盖种植（有或没有将枯草覆盖到土壤中）的影响。此外，细菌Nitrosomonas europaea和Azotobacter vinelandii参与土壤氮循环，并对氨氮和硝态氮含量进行定量。首次，我们证明了将地下枯草覆盖并结合了死腐覆盖物，一方面减少了杂草的生物多样性和种子库的大小（与遵循标准商业惯例的常规管理方法相比减少了70％），而，在另一方面，增加的量N.油橄榄（+ 109％），A.固氮菌（+ 145％），NH ₄ ⁺（+ 137％）和NO ₃ ^-（+ 478％）在土壤中。因此，该方法被认为是低投入农业和有机农业的重大改进，可以作为一种生态友好的策略在地中海果园中应用，其目的是减少用于控制杂草的合成除草剂和唯一的矿物氮肥。氮源。