Sulfur Source Effects on Soil Sulfur Concentration, Vegetation Indices, Biomass, and Sulfur Uptake in Potato

Abstract

Abstract Potato is an important tuber crop, consumed globally by over a billion people. Among the essential nutrient for optimum potato growth, sulfur (S) is the most crucial after nitrogen, phosphorous, and potassium. In addition, the S is necessary for amino acid production, disease resistance, protein synthesis, and N assimilation. In this study, we tested the performance of three S sources: magnesium sulfate (EPTOP), gypsum, Ammonium sulfate (AS) applications at 45 and 90 kg ha− 1 for soil S availability, vegetative indices, above- and below-ground biomass, and potato S uptake. It was found that maximum soil S availability was reported when applied as EPTOP, followed by gypsum and AS at 90 kg ha− 1 compared to 45 kg ha− 1. For vegetative indices such as normalized difference vegetative index (NDVI), normalized difference red-edge index (NDRE), and chlorophyll content (CC), the maximum values were reported when gypsum and EPTOP were applied compared to AS. These differences were decreased later in the crop stages. Besides, individual band reflectance red and red-edge values decrease with time and near infra-red increases with time, following the same trend as of vegetative indices. For S uptake, sources or rates did not affect shoot S uptake, but for tuber S uptake, the factors such as S source, rate, and sites had a significant interaction. The maximum S (9.65 kg ha− 1) among the tubers was removed when EPTOP was applied at 45 kg ha− 1. It was reported that the EPTOP can release the S slowly so can retain in the soil for longer time which eventually reflects in its responses as biomass production and S removal.