LB 9-91 - Barley physiological response to biochar applications compared to chemical fertilizer and non-fertilizer controls

Background/Question/Methods:

Industrial sourced fertilizers for crop production are effective, but they can have persistent legacy effects if they are not used efficiently. Natural fertilizers are thought to be better for soil health, but an ongoing question is at what application rate is plant demand met? The application of naturally derived biochar in agriculture is a novel approach to reach production goals while maintaining soil health. The purpose of my experiment was to quantify barley photosynthetic and water use efficiency response to different biochar applications compared to a chemical fertilizer treatment and a no-fertilizer control. The treatments were: unmodified biochar, biochar+ iron, fermentation solids, fermentation solids +biochar and two different levels of phosphorus fertilization (low & high). The plots were grown under controlled conditions in a greenhouse and treatments were implemented in a randomized block design. I measured photosynthesis and stomatal conductance to calculate water use efficiency (WUE) at four barley growth stages: tillering, stem extension, heading I, and heading II. I used leaf carbon stable isotopes as an integrative measure of WUE.

Results/Conclusions:

I found that the dairy amendments, fermentation solids and fermentation solids +biochar, create the lowest water use efficiency compared to other amendments. They had the greatest photosynthetic rates and stomatal conductance as well. There was a significant difference statistically between these findings using ANOVA. The distribution of P-values demonstrated that there was a differentiation due to the type of fertilizer used, and the highest being fermentation solids and fermentation solids + biochar. This is a novel approach for the future because it brings back the excess phosphorus into the agricultural systems and uses it in a fertilizer. This keeps the phosphorus from getting into our waterways which in turn decreases the amount of eutrophication happening from agricultural runoff. Using biochar is useful also because it is a carbon store, so it can lower the amount of carbon dioxide in our atmosphere, which is creating climate change.