In recent years increasing attention has been given to the potential use of contaminated lands for biofuel production, because these degraded soils cannot be used for food production. To establish these crops in Mediterranean contaminated areas, where the soil quality is usually very poor, the addition of soil amendments might be necessary to improve soil productivity. In addition, the use of crops with low water demands, adapted to these particular conditions of climate and soil contamination, is a key requirement. We studied the development of Cynara cardunculus and Silybum mariamun crops (both suitable for the production of biomass for biofuel uses under a Mediterranean climate) in trace element contaminated soils under field conditions. To our knowledge, this is the first such work under these particular experimental conditions (soil contamination and field trial). Soil physical (hydraulic), chemical, and biochemical properties were monitored for one year in experimental plots, where we tested the effects of the addition of two different amendments (sugar lime and biosolid compost) on soil functioning and crop productivity. Seed germination and plant biomass production were low, although amendment addition improved both parameters. The chemical and biological indicators (enzyme activities, PLFA profiles, and soil respiration) tended to be slightly improved by the amendments, especially sugar lime. The hydraulic properties of the soil in the experimental area were very deficient, and the effect of the amendments was not enough to improve them; this was probably the main cause of the general low productivity of these rain-fed crops, as water infiltrated poorly through the root zone. To improve crop productivity under these soil conditions, certain aspects could be improved: higher doses of amendments should be applied and deeper tillage of the soil after amendment addition should be performed to facilitate water infiltration.

近年来，人们越来越重视将污染土地用于生物燃料的生产，因为这些退化的土壤不能用于粮食生产。为了在土壤质量通常很差的地中海受污染地区种植这些作物，可能需要添加土壤改良剂以提高土壤生产力。另外，关键的要求是使用低需水量的作物，以适应气候和土壤污染的这些特殊条件。我们研究了Cynara cardunculus和Silybum mariamun的发育田间条件下，土壤中微量元素污染的农作物（都适合在地中海气候下生产用于生物燃料的生物质）。据我们所知，这是在这些特定实验条件下（土壤污染和现场试验）进行的首次此类工作。在试验区对土壤的物理（液压），化学和生物化学特性进行了一年的监测，我们在其中测试了添加两种不同的改良剂（糖石灰和生物固体堆肥）对土壤功能和农作物生产力的影响。种子发芽和植物生物量产量较低，尽管添加修正剂改善了两个参数。化学和生物指标（酶活性，PLFA分布图和土壤呼吸）通过修正趋于略有改善，尤其是糖石灰。试验区土壤的水力特性非常不足，而改良剂的效果还不足以改善它们。这可能是这些雨养作物普遍低产的主要原因，因为水很难通过根部区域渗透。为了在这些土壤条件下提高作物生产力，可以在某些方面进行改进：应使用较大剂量的改良剂，并应在添加改良剂后对土壤进行更深的耕作，以利于水分的渗透。