Effect of nickel seed treatment in soybeans

Abstract

Micronutrients such as molybdenum (Mo), cobalt (Co), and nickel (Ni) have been shown to be necessary for maximizing the benefits of biological nitrogen fixation (BNF) in soybeans by mediating enzymatic processes of transforming gaseous nitrogen into mineral nitrogen. The objective of this literature review was to present a research based on a bibliographic review on the influence of nickel application on soybean seeds and its impact on increasing the productivity of this important legume in Brazilian agribusiness. A better understanding of the biochemical processes involved in biological nitrogen fixation in soybeans allowed the recognition of the relevance of nutrients such as Co, Mo, and Ni, especially in the constitution of enzymes such as urease and hydrogenase involved in this important symbiotic relationship between microorganisms and plants. As for nickel, a safe recommended dose for soybean seed treatment with this micronutrient has not yet been established, and relatively few studies have been conducted under Brazilian conditions. When nickel was applied to soybean seeds under various cultivation conditions, positive results were observed (greater nodulation, nodule weight, and enzymatic activity), higher nitrogen content in the plant and protein in the seeds, and higher productivity. Further research involving variables that directly affect nickel availability for soybeans, either through seed treatment or foliar application, still needs to be conducted before recommended dosages can be established.