Shelby R Hoglund

Shelby R Hoglund

Shelby R Hoglund

Speaker | The University of Arizona

Tucson, AZ | srhoglund@email.arizona.edu

Shelby Hoglund is a PhD student at the University of Arizona studying effects of co-composted biochar on soil health in arid croplands to address declining water resources, long-term carbon storage, and cropland productivity. She is a Foundation for Food and Agriculture Research Fellow, which is a followship that focuses on building public and private partnerships to achieve research objectives and disseminate research findings.She often presents to private industry groups and at research symposiums.

Session Code: 6C

Track: CREF Research

Session Name: Biochar, Sargassum; Cocomposting Biosolids

Session Time: Wednesday, January 26, 2:00 PM to 3:30 PM

Presentation Title: Better than Just Compost? Improving Compost Quality and Soil Health in Water-Limited Environments with Biochar

Presentation Description: Compost production and use in arid climates differs from temperate regions because compost and other organic matter inputs fail to persist in arid soils. We must find ways to improve finished compost to enhance its ability to store carbon and improve long-term soil health in arid cropland soils. Co-composting biochar is one potential solution to enhance both the composting process in water-limited regions and improve soil health. Adding biochar to aerobic windrows during composting has been shown to increase concentrations of slow-cycling carbon (i.e., carbon sequestration) and enhance compost’s existing benefits including water and nutrient retention.

We partnered with Tanks Green Stuff to investigate the effects of co-composting commercially available biochar with dairy manure and landscape trimmings on compost quality, soil health, and crop productivity in Tucson, Arizona. We set up a field-scale wheat cropping experiment with soil treatments of (1) compost alone (control), (2) biochar plus mature compost, and (3) co-composted biochar to investigate effects on soil health, carbon storage, and crop productivity for two years. We divided plots into different irrigation treatments to investigate effects of severely and moderately reduced irrigation frequency on crop growth in each soil treatment.

We hypothesized that co-composted biochar would enhance soil health, carbon storage, and wheat growth under all irrigation regimes. To evaluate soil health throughout the two year field study, we monitored carbon cycling, nutrient cycling (nitrogen and phosphorus), and water retention.

Our study revealed that co-composting biochar enhanced quality of mature compost, several components of soil health, and wheat yield. However, soil health and wheat yield improvements were not observed in treatments receiving severely infrequent irrigation. Overall, enhancing compost quality with biochar has the potential to improve cropland productivity in arid climates as long as irrigation is not severely limited.