Abstract This study intends to assess the effect of compost types and rates on lettuce growth. A pot experiment was conducted at the greenhouse of the College of Agriculture and Veterinary Medicine experimental station, Saudi Arabia. Three types (chicken residues, animal residues, and mixed organic residues) and four rates (1%, 2%, 4%, and 6%) were added to sandy soil. Lettuce seeds were sown in a nursery. After two weeks, each seedling was transplanted to a pot that contained 15 kg of soil. The lettuce plants were irrigated regularly for 60 days, then harvested following dry weight (DW) and chemical analyses. The results showed great variation in the DW, nutrient content, and heavy metals concentrations between the different compost treatments. It noted that DW of lettuce decreased with increasing rates of compost in certain treatments. Moreover, no plant growth occurred in some treatments derived from the mixed organic residue with higher application rates. The nutrient status of lettuce tissues varies greatly among different types of compost. The concentration of heavy metals and microelements present within the lettuce tissues was significantly affected by the types of compost. Copper (Cu), Zinc (Zn), Lead (Pb), Cadmium (Cd), and Nickel (Ni) concentrations in lettuce tissues ranged between 7.4 and 9.6, 81.5 and 104, 23.3 and 28.2, 3.7 and 5.8, and 27 and 30 mg kg−1, respectively. It revealed that heavy metals concentration increased in lettuce tissues with an increasing application rate of composts. The content of Zn, Pb, Cd, and Ni in lettuce plants were higher and did not meet the requirement set by national standards.

中文翻译：

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堆肥类型和施用量对生菜植株生长和品质的影响

摘要 本研究旨在评估堆肥类型和比例对生菜生长的影响。盆栽实验在沙特阿拉伯农业与兽医学院实验站温室进行。将三种类型（鸡残留物、动物残留物和混合有机残留物）和四种比例（1%、2%、4%和6%）添加到沙质土壤中。莴苣种子播种在苗圃中。两周后，将每株幼苗移植到装有 15 公斤土壤的盆中。生菜植物定期灌溉 60 天，然后根据干重 (DW) 和化学分析收获。结果表明，不同堆肥处理之间的干重、养分含量和重金属浓度存在很大差异。它指出，在某些处理中，生菜的干重随着堆肥率的增加而降低。而且，在一些来自混合有机残留物的更高施用率的处理中没有植物生长。生菜组织的营养状况在不同类型的堆肥中差异很大。生菜组织中重金属和微量元素的浓度受堆肥类型的显着影响。生菜组织中铜 (Cu)、锌 (Zn)、铅 (Pb)、镉 (Cd) 和镍 (Ni) 的浓度范围介于 7.4 和 9.6、81.5 和 104、23.3 和 28.2、3.7 和 5.8 以及 27 和分别为 30 mg kg−1。结果表明，随着堆肥施用率的增加，生菜组织中的重金属浓度增加。生菜植株中Zn、Pb、Cd、Ni含量较高，不符合国家标准要求。