Planting density can influence the biomass generation and element uptake capacity of various plants, which are two critical factors that determine the phytoremediation efficiency of plants. A series of 70 d experiments was performed to evaluate the influence of the planting density (10, 15, 20, 25, and 30 g seeds·m^− 2, namely D10, D15, D20, D25, and D30, respectively) of Festuca arundinacea on the decontamination of Cd-polluted soils. The variations in the biomass yield, falling tissue (senescent and dead leaf tissues) proportion, and Cd extraction capacity of the species under different cultivation strategies were determined. The results showed that the biomass generation of the species per square meter increased as the planting density increased, reached a peak at D20, and then decreased significantly. In addition, planting density can change the proportions of different leaf types, and the highest amount of senescent and dead leaves which accumulated significantly more Cd compared with the emerging and mature leaf tissues was observed at D20. A suitable planting density can also drive the species to secrete more dissolved organic matter (DOM), especially hydrophilic fractionations in to the soil, activating more Cd. Therefore, the phytoremediation efficiency of the species was determined by the dry weight of the falling tissues, which contained more than 75% of the leaf Cd. A suitable planting density can enhance the Cd decontamination capacity of F. arundinacea, and the adjustment of the planting density is a practicable and economical method that can be performed in real fields.

种植密度会影响各种植物的生物量产生和元素吸收能力，这是决定植物修复效率的两个关键因素。进行了一系列 70 d 的试验，以评估羊茅种植密度（10、15、20、25 和 30 g 种子·m ^{- 2}，分别为 D10、D15、D20、D25 和 D30）的影响松果科对镉污染土壤的净化。测定了不同栽培策略下该物种的生物量产量、落叶组织（衰老和枯叶组织）比例和Cd提取能力的变化。结果表明，随着种植密度的增加，该物种每平方米的生物量产生增加，在D20达到峰值，然后显着下降。此外，种植密度可以改变不同叶型的比例，在 D20 观察到最高数量的衰老和死叶，与新兴和成熟叶组织相比，积累了更多的 Cd。合适的种植密度还可以促使物种分泌更多的溶解有机质 (DOM)，尤其是土壤中的亲水性分馏物，从而激活更多的 Cd。所以，该物种的植物修复效率取决于落下组织的干重，其中包含超过 75% 的叶子 Cd。适宜的种植密度可以提高植物对镉的去污能力F. arundinacea，调整种植密度是一种可行且经济的方法，可在实际田间进行。