ABSTRACT

Synthetic chelating agents have high cost and low biodegradation in the environment; thus, the use of natural complexing agents for iron increases the sustainability in crop production. The aim of this study was to verify the efficiency of natural organic acids added to the nutrient solution on the Fe acquisition. For that purpose, two experiments were carried out using soybean and maize. Citric acid (CA), malic acid (MA), tartaric acid (TA), and oxalic acid (OA) were used as complexing agents for iron. Fe-EDTA (ethylenediaminetetraacetic acid) and FeSO₄ were also tested. Soluble Fe and chemical speciation in a nutrient solution were determined. Organic acids maintained less complexed Fe in the nutrient solution than EDTA, but the complexed Fe fraction was not associated with the efficiency of the Fe organic acids in supplying Fe to plants. Maize and soybean treated with Fe-MA and Fe-CA had reduced plant development. For maize, the TA treatment at both SRs increased Fe accumulation and promoted Fe translocation similar to EDTA. For soybean, Fe-OA at both SRs promoted biomass, Fe accumulation, and Fe translocation similar to EDTA. Therefore, Fe complexes were able to assure plant growth and nutrition and showed effectiveness depending on the plant species.

摘要

合成螯合剂成本高，在环境中的生物降解性低；因此，使用铁的天然络合剂增加了作物生产的可持续性。本研究的目的是验证添加到营养液中的天然有机酸对铁获取的效率。为此目的，使用大豆和玉米进行了两个实验。柠檬酸 (CA)、苹果酸 (MA)、酒石酸 (TA) 和草酸 (OA) 用作铁的络合剂。Fe-EDTA（乙二胺四乙酸）和 FeSO ₄也进行了测试。测定了营养液中的可溶性铁和化学形态。与 EDTA 相比，有机酸在营养液中保持的络合 Fe 较少，但络合 Fe 部分与 Fe 有机酸向植物供应 Fe 的效率无关。用 Fe-MA 和 Fe-CA 处理的玉米和大豆降低了植物发育。对于玉米，两种 SR 处的 TA 处理都增加了铁的积累并促进了铁的易位，类似于 EDTA。对于大豆，两个 SR 的 Fe-OA 促进生物量、Fe 积累和 Fe 易位，类似于 EDTA。因此，铁配合物能够保证植物的生长和营养，并根据植物种类显示出有效性。