Abstract The main objective of this study is to investigate the cumulative effect of mineral fertilizers and sewage sludge on nutrient status of kale (Brassica oleracea L. cv. ‘GM Dari’) and spinach (Spinacia oleracea L. cv. ‘Shalimar Green’). The experiment was carried out in a completely randomized block design with nine treatments including: no fertilizer or sewage sludge as a control (T 1), 25% Sewage Sludge + 0% Recommended fertilizer dose (RFD) (T 2), 50% Sewage Sludge + 0% RFD (T 3), 75% Sewage Sludge + 0% RFD (T 4), 100% Sewage Sludge + 0% RFD (T 5), 25% Sewage Sludge + 75% RFD (T 6), 50% Sewage Sludge + 50% RFD (T 7), 75% Sewage Sludge + 25% RFD (T 8), and 0% Sewage Sludge + 100% RFD (T 9). The recommended fertilizer doses are made to apply fertilizers to meet the nutrient requirements of the crop and to build up the nutrient level in the soil to a critical soil test level over a planned time frame usually recommended by agronomists. The results of the study showed that the concentration of all macro nutrients (N, P, K, Ca, and Mg), micro nutrients (Mn, Cu, Zn, and Fe) and heavy metals (Cd, Cr, Pb, and Ni) in both kale and spinach were significantly highest in the plots treated with 75% sludge + 25% NPK, whereas, the values of these elements in control treatments were recorded to be the lowest. However, the total nitrogen content in spinach and lead concentration in kale remained significantly higher under the treatment of 50% sludge + 50% NPK. The study lead to an important conclusion that the treatment of soil with 75% sewage sludge + 25% NPK can improve the nutrient accumulation in these plants thereby enhancing yield production.

中文翻译：

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污水污泥和矿物肥料对羽衣甘蓝和菠菜营养状况的评价

摘要 本研究的主要目的是研究矿物肥料和污水污泥对羽衣甘蓝 (Brassica oleracea L. cv. 'GM Dari') 和菠菜 (Spinacia oleracea L. cv. 'Shalimar Green') 养分状况的累积影响. 实验在完全随机区组设计中进行，有九个处理，包括：无肥料或污水污泥作为对照（T 1），25% 污水污泥 + 0% 推荐肥料剂量（RFD）（T 2），50% 污水污泥 + 0% RFD (T 3)、75% 污水污泥 + 0% RFD (T 4)、100% 污水污泥 + 0% RFD (T 5)、25% 污水污泥 + 75% RFD (T 6)、50 % 污水污泥 + 50% RFD (T 7)、75% 污水污泥 + 25% RFD (T 8) 和 0% 污水污泥 + 100% RFD (T 9)。推荐的肥料剂量用于施用肥料以满足作物的养分需求，并在农艺师通常推荐的计划时间范围内将土壤中的养分水平提高到临界土壤测试水平。研究结果表明，所有宏量营养素（N、P、K、Ca 和 Mg）、微量营养素（Mn、Cu、Zn 和 Fe）和重金属（Cd、Cr、Pb 和 Ni）的浓度) 在用 75% 污泥 + 25% NPK 处理的地块中，羽衣甘蓝和菠菜中的含量显着最高，而对照处理中这些元素的值被记录为最低。然而，在50%污泥+50%NPK处理下，菠菜中的总氮含量和羽衣甘蓝中的铅浓度仍然显着较高。