Biochar is a growth-promoting alternative to peat moss for the inoculation of corn with a pseudomonad

Abstract

Peat moss has been a standard carrier of inoculum for experimentation and in agriculture. Peat moss is, however, a non-renewable resource. Alternatively, biochar could serve as an inoculum carrier. Here, we tested the effect of biocharbased seed coatings as a carrier for the phosphoroussolubilizing Pseudomonas libanensis inoculum, on corn growth after soluble and insoluble P addition. The survival of P. libanensis was determined based on the measure of colony-forming units from samples of four inoculated guar gum-based biochar coatings and was compared to peat. Storage experiments were performed on inoculated biochars for 22 weeks at 25°C and on coated corn seeds for 16 weeks at 4°C. Seed coatings were prepared with inoculated and uninoculated biochars (100 seeds treatment −1 ), and effects of these treatments are reported on indices of seed germination after 7 days. A greenhouse experiment investigated the effects of the inoculated and uninoculated biochar seed coating on corn plants. The parameters measured from the greenhouse-grown corn plants were germination, fresh weight, dry weight, height, root length, basal stem diameter, leaf area, chlorophyll content, and tissue phosphorous. Our results show that corn plants grown from seeds coated with a biochar from hardwood feedstock are 2 to 10 g heavier than controls and that controls are 4 to 26 % shorter than the plants grown from biocharcoated seeds, where soluble phosphorous is applied.Moreover, corn seeds that were coated with a biochar produced from softwood feedstock germinated more quickly, based on the speed of germination index. Overall, we show that a biochar-based seed coating can benefit sustainable agriculture by carrying P. libanensis and enhancing the growth of corn, but according to parametric statistical tests, it does so without increasing the phosphorous content of the plants.

Biochar-based Bradyrhizobium inoculum improves growth of lupin (Lupinus angustifolius L.) under drought stress

“…In greenhouse experiments, the biochar (Dynamotive) formulated bacterial inocula increased seed germination of corn and stimulated plant biomass compared to untreated control plants [43]. Overall, we made a general conclusion from our study that the use of HTC as a carrier substrate increased the survival of Bradyrhizobium sp.…”

Biochar Based Inoculants Improve Soybean Growth and Nodulation

“…Peat moss-PM was the control inoculant carrier (PRO-MOSS TBK, Rivière-du-Loup, Québec). Biochar physical and chemical characteristics were described by Głodowska et al [4].…”

“…Głodowska et al [4] demonstrated that phosphorus (P) mobilizing P. libanensis can survive in biochar inoculant up to 22 weeks. Gorelick et al [5] investigated the use of combusted organic matter such as charcoal as carriers, and showed that a very high concentration of Brucellasuis can be sustained in a charcoal-cellophane system.…”

Changes in Soil Microbial Activity and Community Composition as a Result of Selected Agricultural Practices

“…Biochar and its highly porous structure can provide a suitable habitat for many microorganisms by protecting them from predation and desiccation, providing carbon (C) as a source of energy and mineral nutrients [68]. Glodowska et al [69] showed that some biochars can sustain viability of plant growth promoting bacteria for more than 6 months and that biochar can be a suitable carrier for bacterial inoculation. Anderson et al [70]…”