A Comparative Study of Plant Growth Affected by Soil Amendments with Recovered Nutrients, Drought Conditions, and Seasonal Temperatures

Nutrients recovered from municipal and dairy wastewaters in a bioelectrochemical system constructed with terracotta and biochar were used in different soil amendments. These amendments included addition of terracotta (TS), biochar (BS), terracotta and biochar nutrient-rich mixtures from bioelectrochemical systems, DWW (dairy wastewater), and SWW (synthetic wastewater), respectively. Corn growth affected by these amendments was compared with control, termed straight soil (SS). The first experimental setup consisted of 60 plants, four replications per group, and nutrient loadings (0%, 50%, and 100% Hoagland Nutrient Solution, HNS) in the fall season. After harvesting, the plants and soil were analyzed for agro-physical characteristics by various methods. At the 100% nutrient treatment, the TS soil had the best yielding plants. Overall, plants grown in DWW and SWW soil amendments with 0% and 50% nutrient treatments had the best results in plant height, total plant dry weight, the average number of leaves per plant, leaf surface area, shoot dry weight, root/shoot ratio, root surface area, and NBI when compared to the control group. Another test was carried out with 80 corn plants grown using five different soil mediums and using four different nutrient treatments in the spring season. Twenty of the plants were put through a simulated drought to evaluate drought resistance (as measured by plant growth) in different soil amendments. In this test, the SWW soil amendment had a negative effect at 0% HNS and in warm weather. The SWW soil medium had large retention in soil moisture, which had a negative growth effect. It is recommended that the irrigation be monitored closely when applying the SWW soil amendment to avoid overwatering. This research provides critical insights into nutrient reuse in crop production.