Short‐term effects of nitrogen source on soil properties and plant growth

A randomized complete block design experiment was performed in a growth chamber study to evaluate the short-term impact of N amendment source on CO2 fluxes, aggregate stability, and aboveground plant biomass. Large intact soil cores (n = 6) were each segmented into three subplot treatment sources: (a) organic N (ORG-N); (b) inorganic N (UAN-32); and (c) no N added (no-N), with both N sources applied at rates of 27.5 kg N ha–1. The experiment was run for 130 d, representing one growing season of winter wheat (Triticum aestivum L.). Soil CO2 fluxes accumulated during the growing season were 47.1, 36.6, and 24.6 mol m–2 for ORG-N, UAN-32, and no-N treatments, respectively. Significantly higher aboveground plant biomass was harvested in the N source treatments compared with no-N. Aggregate stability in ORG-N was significantly higher than inorganic sources, UAN-32 (p < .05). This study highlights that even over a short-term study, organic N sources can increase soil biological activity and aggregation processes, indicating an increased capacity for several soil functions