Carbon additions can improve nutrient cycling and fertilizer use efficiency for phosphorus and potassium in a corn-soybean rotation

In Illinois corn (Zea mays L.) production systems, phosphorus (P) and potassium (K) fertilizers are frequently applied to compensate for limited availability of these nutrients in the soil and to achieve high yields. However, these fertilizers are non-renewable and have low recovery efficiencies, emphasizing the need for improvement in the efficiency of their use. The objective of this research was to assess the impacts of granulated biochar or humic acid applications on corn growth, nutrient accumulation, and grain yield, as well as determine whether these impacts vary based on application rate and the presence or absence of applied P and K fertility. Field experiments were conducted in 2022 and 2023 at Nashville, Champaign, and Yorkville, IL and included two carbon amendments (biochar or humic acid) applied at three rates of carbon (90, 180, or 360 lbs carbon acre-1), either with or without P + K fertilization. The fertilizer treatment included MAP (11-52-0) and MOP (0-0-60) at rates of 60 lbs of P2O5 acre-1 and 60 lbs of K2O acre-1, respectively. Treatment applications were broadcast prior to planting and lightly incorporated, with all plots receiving 180 lbs nitrogen acre-1. At the VT growth stage, plant biomass was unchanged by carbon applications, but there were numerous incidents of carbon-induced increases in K accumulation. At R6, biochar applied at 90 lbs C acre-1 or humic acid applied at 360 lbs C acre-1 increased K uptake in the absence of fertility, resulting in grain yield increases of 4.3 and 4.4 bushels acre-1, respectively. When applied with P + K, carbon additions enhanced P content in the grain at R6, leading to significant increases in P harvest index. Notably, none of the carbon additions had a negative effect on grain yield. These data indicate that granular carbon additions can improve corn yield by enhancing soil K and P nutrient cycling and assimilate partitioning, without compromising the availability of P or K from fertilization.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Crop Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2024

Author dc:creator

• Danzl, Darby Kay

Contributors dc:contributor

• Below, Fred E
• Heaton, Emily
• Kent, Angela

• Carbon
• Phosohorus
• Potassium
• Corn
• Soybean
• Biochar
• Humic Acid

Statement dc:rights

• Copyright 2024 Darby Danzl

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/124404

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F124404