Increase in Forage Maize Production by Bacterial Fertilisers

Farmers in many countries value green material generated from maize as a high quality forage. Its inclusion in dairy cow diets can improve forage intake, increase animal performance and has the potential to reduce production costs (Phipps, 1994). Restrictions on the use of chemical fertilisers and a renewed interest in organic sustainable farming systems in general, has restored attention to crop rotations The increase of maize production using bacterial fertilisers also gives alternative ways to reduce chemical fertilisers in forage production. Increased uptake of nutrients such as N, P, and K and crop yield was reported with rhizobacteria (Lazarovits & Nowak, 1997). This paper presents studies carried out to evaluate the effects of bacterial fertilisers on maize production

Microbial activity and hydrolase activities during decomposition of root exudates released by an artificial root surface in Cd-contaminated soils

The aim of this study was to assess the stimulatory effects of different low molecular weight organic compounds commonly present in root exudates on microbial activity and hydrolase activities, and the effects of high Cd concentrations in sandy soils collected from contaminated field plots on the stimulatory effects. Glucose, glutamic acid, citric acid, oxalic acid, or a mixture of all compounds were released by an artificial root surface in a simplified rhizosphere system. The effects were measured at 4 mm (bulk soil layer) distance from the root surface, 7 d after the root exudates release. Results showed that different root exudates were mineralized at different extent and had different stimulatory effects on microbial growth estimated by dsDNA content of soil, and on hydrolase activities, mostly localized in the rhizosphere soil layer. Mineralization of root exudates, microbial growth and stimulation of most of the measured hydrolase activities were drastically reduced by high Cd concentrations in soil

Cell-free culture medium of Burkholderia cepacia improves seed germination rate and seedling growth in maize (Zea mays) and rice (Oryza sativa)

The saprophytic bacterium Burkholderiacepacia has been shown to play an active role as plant growth promoting bacteria (PGPB). In this study, the ability of cell-free culture medium (CFCM) of B. cepacia to improve early developmental stages of plants has been assessed on two agronomically important crops, maize (Zeamays) and rice (Oryzasativa). Treating maize and rice seeds for 45 min before germination significantly improved seed germination and consequent seedling growth. The effect of CFCM was confirmed by the increased biomass of the shoot and, mainly, the root systems of treated seedlings. Chromatographic characterization of the CFCM revealed that the spent culture medium of B. cepacia is a complex mix of different classes of metabolites including, among others, salicylic acid, indole-3-acetic acid (IAA) and several unidentified phenolic compounds. Fractionation of the CFCM components revealed that the impressive development of the root system of CFCM-treated seedlings is due to the synergistic action of several groups of components rather than IAA alone. The data presented here suggest that a CFCM of B. cepacia can be used to improve crop germination. © Springer Science+Business Media B.V. 2009.SCOPUS: ar.jinfo:eu-repo/semantics/publishe