This study investigated variations in the concentration of nutrients, antinutrients and mineral content of Amaranthus caudatus harvested from different soil types at various stages of maturity. Four out the five soils namely; sandy clay loam, silty clay loam, clayey loam and loam were experimentally formulated from primary particles of silt, clay and sand in line with the United State Department of Agriculture’s (USDA) soil triangle protocol. The unfractionated soil was used as the control. After harvesting at pre-flowering (61 days after planting), flowering (71 days after planting) and post-flowering (91 days after planting) stages, nutrient and antinutrient analyses were carried out following Association of Official Analytical Chemists (AOAC) and other referenced methods while the Inductively Coupled Plasma- Optical Emission Spectrometer was used to determine mineral compositions of the plant samples. The results of the study revealed that particle size and physicochemical properties of the soil influenced the number of minerals deposited in plant tissues. It was further observed that the nutritional properties of the plant change as plant ages. For an optimal yield of vitamins A and E, clayey loam proved to be the best soil particularly when A. caudatus is harvested before flowering but for vitamin C, sandy clayey loam yielded the highest output at the same stage. Similarly, clayey loam and loam soils yielded the highest proximate compositions at flowering and pre-flowering; however, mineral elements (micro and macro) were highest in control and loam soils.

本研究调查了在不同成熟阶段从不同土壤类型中收获的尾苋的营养物质、抗营养物质和矿物质含量的变化。五土中的四土即；沙质粘壤土、粉质粘壤土、粘质壤土和壤土是根据美国农业部 (USDA) 的土壤三角协议，由淤泥、粘土和沙子的初级颗粒经过实验配制而成。未分级的土壤用作对照。在开花前（种植后 61 天）、开花（种植后 71 天）和开花后（种植后 91 天）阶段收获后，按照官方分析化学家协会 (AOAC) 和其他标准进行营养和抗营养分析。参考方法，同时使用电感耦合等离子体发射光谱仪来测定植物样品的矿物成分。研究结果表明，土壤的粒径和理化性质影响植物组织中沉积的矿物质数量。进一步观察到植物的营养特性随着植物年龄的变化而变化。为了获得维生素 A 和 E 的最佳产量，粘质壤土被证明是最好的土壤，特别是当A. caudatus在开花前收获时，但对于维生素 C，沙质粘壤土在同一阶段产量最高。同样，粘质壤土和壤土在开花和开花前产生最高的近似成分。然而，矿物元素（微量和大量）在对照土壤和壤土中最高。