Influence of Biochar and Manure on the Hydrological Properties of Eroded and Depositional Landscape Positions.

The addition of biochar to improve soil hydrological properties has been evaluated by many researchers. However, most studies have been conducted in controlled laboratories or greenhouses. This study was conducted in the field with the objective of evaluating the impact of biochar on the hydrological properties of soils at eroded and depositional landscape positions. Three plant-based biochar materials, produced from C-optimized gasification of corn stover (Zea mays L.) (CS), ponderosa pine (Pinus ponderosa Lawson and C. Lawson) wood residue (PW), and switchgrass (Panicum virgatum L.) (SG); dairy manure (DM); and a mixture of manure and pinewood biochar (DMP), were applied at a rate of 10 Mg ha−1. The data indicated that the biochar and manure treatments significantly impacted the soil hydrological properties at both landscape positions. Soil moisture content (kg kg−1) at field capacity was 4, 16, 8, 12, and 24% higher with CS, PW, SG, DM, and DMP, respectively, than the control treatment after soybean [Glycine max (L.) Merr.] harvest in 2014. Biochar with manure showed a relatively larger improvement in soil hydrological properties than the other treatments. The effects of biochar varied for different years and soil types because of differences in the feedstocks used to produce the biochars. The biochar treatments were not effective for reducing soil penetration resistance (SPR); however, DM significantly decreased the SPR. Data from this short-term study suggest that biochar can be used to improve soil hydrological properties. Future studies with different rates and types of biochar under different climatic conditions are needed.