|VOZHDAYEV, GEORGIY - University Of Minnesota|
|MOLDE, JOSEPH - University Of Minnesota|
|HEILMANN, STEVEN - University Of Minnesota|
|WOOD, BRANDON - University Of Minnesota|
|VALENTAS, KENNETH - University Of Minnesota|
Submitted to: Plant and Soil
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/24/2015
Publication Date: 7/8/2015
Citation: Vozhdayev, G.V., Spokas, K.A., Molde, J.S., Heilmann, S.M., Wood, B.M., Valentas, K.J. 2015. Response of maize germination and growth to HTC filtrate type and concentration. Plant and Soil. 396(1-2):127-136.
Interpretive Summary: This article details the evaluation of the liquid residual present after the hydrothermal processing of different manure wastes and their corresponding impact on corn germination and early seedling growth. The research demonstrated that at high application rates, these residual liquids are inhibiting to corn germination and growth. However, with dilution these inhibitory effects are eliminated. These results suggest that this liquid product could be considered for fertilizer use. This would represent a renewable source for nitrogen fertilizers, which would improve agricultural sustainability. These results are significant to farmers and policy makers and will assist scientists and engineers in using more sustainable fertilizer sources.
Technical Abstract: Hydrothermal carbonization (HTC) is a thermochemical treatment process that allows for the conversion of biomass slurries into value added products. The option of using HTC filtrate as a liquid based fertilizer for agricultural crop production was evaluated through germination and plant growth studies using corn (Zea Mays L.). Impacts on germination were studied by quantifying germination time and of corn seeds in response to various amounts of condensed distillers solubles (CDS) and swine HTC filtrate. Corn growth trials were conducted in a growth chamber with artificial lighting and controlled temperature programming in washed silica sand amended with condensed distillers soluble (CDS), swine manure, or poultry litter HTC filtrates. Seedling trials were conducted over a period of three weeks and evaluated for overall plant height, above ground biomass, below ground biomass, and total biomass in response to filtrate application. Overall, inhibitory effects on corn seed germination and seedling growth showed a dependence on HTC filtrate type and application amount, where greater filtrate concentrations (below a 1:2 dilution) typically inhibited seed germination for CDS and swine based filtrates by extending the seed germination delay (lag phase). Lower applications amounts were equal to fertilizer control responses. These studies suggest a potential opportunity for utilization of HTC filtrates as an agricultural liquid fertilizer, thereby recycling critical plant nutrients. However, additional work is needed to characterize the chemical diversity present in these filtrates prior to the widespread adoption of this potentially more sustainable source of agricultural fertilizers.