Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/4/2021
Publication Date: 5/10/2021
Citation: Novak, J.M., Watts, D.W., Sigua, G.C., Ducey, T.F. 2021. Corn grain and stover nutrient uptake responses from sandy soil treated with designer biochars and compost. Agronomy. https://doi.org/10.3390/agronomy11050942.
Interpretive Summary: Biochars are an important soil amendment to increase soil nutrient levels, however, few studies have demonstrated enhanced crop nutrient uptake supplied from biochar. Another concern with biochar usage as an amendment is that biochar produced from different sources (e.g., wood versus animal manures) will supply variable amounts of plant nutrients to soil. So, we conducted a four-year corn growth study to examine the effects of different biochar-types applied to sandy soil on phosphorus (P) and potassium (K) uptake. One biochar type was produced from poultry manure and another sample produced from pine trees. We speculated that poultry manure-based biochar would supply greater P and K concentrations to soil compared to pine tree-based biochar. Following biochar application to a nutrient-poor sandy soil, we annually sampled corn grain, stover (all above ground plant parts except grain) and soil samples for their P and K contents. We found that corn stover contained higher P and K concentrations when grown in soil treated with poultry manure-based biochar. Corn grain, however, contained similar P and K contents among all treatments including the control (no biochar applied). By examining corn stover, we concluded that more P and K was taken up by corn after treatment with poultry litter-based than pine tree-based biochar. We suggest that for nutrient poor sandy soils, poultry litter-based biochar is a more appropriate soil amendment because the corn crop responded with better P and K uptake.
Technical Abstract: Biochars are used for soil fertility improvement because they may contain certain elements that plants use as nutrients, however, few studies have demonstrated enhanced crop nutrient uptake. Our study examined nutrient uptake responses of corn (Zea Mays L.) grain and stover over 4 years (Y) after a Goldsboro loamy sand (Fine-loamy, siliceous, sub-active, thermic Aquic Paleudults) received different designer biochars and a compost. The designer biochars were produced from lodgepole pine (Pinus contorta) chip (PC), poultry litter (PL), blends with switchgrass (SG; Panicum virgatum), and a SG compost alone. Topsoil treated with 100% PL biochar and blended PC:PL biochar had significantly greater Mehlich 1 extractable P, K and Na contents compared to the control or other treatments. No significant differences were detected in annual grain nutrient concentrations. In the first corn stover harvest (Y1), significantly greater concentrations of P, K and Na were measured after treatment with 100% PL biochar, with PC:PL blend, and with the SG compost alone when compared to control. By the fourth corn stover harvest (Y4), however, nutrient uptake between treatments were not significantly different. Biochars impact on corn stover nutrients concentrations were time-dependent suggesting repeated biochar applications may be needed to continue soil fertility enhancements.