Open Collections

Hamilton, Morgan Mckenzie Keenie

University of British Columbia

Biochar is an agricultural soil amendment, used both as a carbon sequestration tool and to alter soil physical and chemical properties, and in turn, water and nutrient dynamics. Commonly, studied biochar application rates exceed 10 t/ha, a rate that represents both a large environmental draw and economic investment for farmers. The objective of this study was to evaluate the effects of a low, more realistic biochar application rate (3 t/ha) on leachate, soil, and crop nutrient dynamic in a coarse texture soil. To do so, field and greenhouse studies were conducted over two growing seasons each. In spring 2022 biochar was applied in its “pristine” state, and a “charged” state after being mixed with nutrient-rich slurry dairy manure. Spring wheat (Triticum aestivum L.) was grown at Totem Plant Science Field Station (Vancouver, BC) in both 2022 and 2023, with nutrient concentrations in soil and wheat, along with yield, measured after each season. In the first year, there was an increase in soil K with charged biochar and decreased yield with pristine biochar, relative to the control (no treatment application). By the second year, there were no differences in yields, and only an increase in total soil N was observed with charged biochar. The findings of the field study were complemented by the greenhouse study, in which spring wheat was grown in treatment-amended field soil in columns, and leachates were collected. Similar to the field study, the year one greenhouse study showed an increase in available soil K with both biochar treatments and lower yield with pristine biochar treatment. In the second year there was a temporary increase in leached K with charged biochar, while yield changes from year one did not persist to year two. Ultimately, charging biochar ameliorated the negative impact of pristine biochar on crop response in year one, although by year two, the impact of charging was less pronounced. These studies suggest that a more realistic application rate of 3 t/ha of biochar can significantly affect nutrient dynamics with the charging of biochar leading to predominantly positive outcomes.

Text

2024-08-27

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/89053

Soil Science

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/