title: Nanoscale Sulfur as a Novel Fertilizer for Promoting Wheat (Triticum aestivum L.) Growth and Yield
Creators: name: Smith, Jordan
Publisher: name: University of Massachusetts Amherst
Year: 2023

description: As the population continues to rise, there becomes an ever-increasing need for sustainable food production not only to produce enough food but also to ensure the feasibility of our farmland for years to come. In an effort to curb this problem, nanotechnology is an up-and-coming strategy that acts as a sustainable method of boosting a crop’s growth and yield, especially the use of nanoscale sulfur. The work included in this thesis is an investigation into the question of whether this technology has the potential to increase these parameters in Spring wheat var. Louise (Triticum aestivum L.). In order to answer this question, several application methods including soil amendment, foliar spray, and seed priming were utilized and the results of which are presented below. Methods used to compare each of the treatments include recording different growth parameters such as the Soil Plant Analysis Development (SPAD) value and ethanol assays for the chlorophyll content along with the linear electron flow and Fv/Fm (a sensitive indicator of plant photosynthetic performance or maximum quantum yield of photosystem II) values to assess plant stress. Short-term and maturity experiments were performed and after harvest, parameters such as dry biomass (straw and root), tiller number, flag leaf length, ear length, harvest index, and seed yield were recorded to further assess whether nano sulfur has beneficial impacts on wheat. The goal of this research is to provide additional insights into the use of nanosulfur in wheat agriculture and act as a supplement to other research being performed in this field.
From the results, it was found that when plants were treated with the sulfur treatments using the foliar spray application method, there were many increases in the parameters being investigated for increased growth and yield. Agronomic parameters included the flag leaf length, dry straw weight, and seed weight per plant while photosynthetic parameters included SPAD, Fv/Fm, and LEF. At all three concentrations (50, 100, and 200 ppm) foliar applications, the nanosulfur (NS)and nanosulfur coated with stearic acid (NS SA) and sulfate showed a significant increase in chlorophyll 6.3-10.7%), dry biomass (7.9-14.6%), Fv/FM (2.8-3.0%) whereas the bulk sulfur was less effective. Further, 50 ppm, there are highly significant increases across all treatments (BS, sulfate, NS, NS SA, and NS PVP) with 26.9%, 26.1%, 24.5%, 18.4%, and 16.3% increases, respectively, compared to the control group. At 100 ppm application rates, there are highly significant increases in BS (24.8%), sulfate (29.5%), NS SA (15.3%), and the NS treatment (11.2%). When 200 ppm was used, there were highly significant results in BS (34.0%), sulfate (20.9%), NS SA (53.2%), and NS PVP (42.8%) treatment groups, while plants treated with NS SA had a slight but significant increase (13.5%) when compared to the control. From these, it was shown that the sodium sulfate and stearic acid coated nanosulfur had the most consistent significant increases in these parameters, leading to this conclusion. For soil amendment assay, the results were not very conclusive but overall NS and NS SA group showed significant increases in the number of tillers and the length of primary ears whereas BS and sulfate treatments caused a significant decrease in these parameters. From this research, the data that resulted from the soil amendment and seed priming experiments were somewhat inconclusive, indicating that additional research is required to further understand the mechanism for these two application methods.