Abstract

In the mineral nutrition of plants, potassium is considered “the element of quality” of harvested products, and its lack or excess can cause decreased or loss of product quality. In this sense, the aim of the present study was to evaluate the productivity, root quality and mineral nutrient levels of the Pretinha cassava cultivar according to potassium sources and doses. Two sources (potassium chloride and potassium sulfate) and five K₂O doses (0, 30, 60, 90 and 120 kg of K₂O ha⁻¹) were tested, in a randomized block design, with five repetitions. After 11 months of sowing, five plants were manually harvested from the useful area of each plot and the number, diameter, firmness, root moisture and productivity were determined, in addition to the nutritional contents in different plant organs (leaf, stem and root and bark). Fertilization with potassium sulfate promotes higher root productivity, higher P and S levels in leaves and increased N and K levels in root barks. Potassium fertilization promotes a greater number of roots per plant, larger root diameter and greater external firmness, increased K content in plant organs and decreased Ca content in cassava leaves. The use of potassium chloride also increases Cl levels in cassava leaves.

摘要

在植物的矿质营养中，钾被认为是收获产品的“品质元素”，钾的缺乏或过量都会导致产品品质的下降或损失。从这个意义上说，本研究的目的是根据钾源和剂量评估 Pretinha 木薯品种的生产力、根质量和矿物质营养水平。两种来源（氯化钾和硫酸钾）和五种 K ₂ O 剂量（0、30、60、90 和 120 kg K ₂ O ha ^-1) 以随机区组设计进行测试，重复五次。播种 11 个月后，从每个地块的有用区域人工收获 5 株植物，并测定了植物不同器官（叶、茎、根和吠）。用硫酸钾施肥可促进更高的根系生产力、更高的叶子中 P 和 S 水平以及增加根皮中的 N 和 K 水平。施钾促进单株根数增多、根径变大和外部硬度增加，植物器官钾含量增加，木薯叶片钙含量降低。氯化钾的使用也会增加木薯叶中的氯含量。