Diversity and species composition of arbuscular mycorrhizal fungi across maize fields in the southern part of Belgium.

Arbuscular mycorrhizal fungi (AMF) are key actors among soil microbial inhabitants, forming beneficial associations with most horticultural plants and crops (e.g., maize). For maize, the world most cultivated cereal, data on AMF species diversity in fields is sparse and even totally nonexistent in the southern part of Belgium where maize represents 8% of the cultivated area. In the present study, 14 maize fields in South Belgium under conventional, conversion, or organic management were analyzed for AMF diversity and species composition using 454 pyrosequencing. A large part (54%) of the 49 AMF species observed were unknown or have not been described in the literature. AMF diversity highly varied among fields, with the number of species ranging between 1 and 37 according to the field. A statistically significant effect of management was measured on AMF diversity, with the highest Hill index values (diversity and richness) under the organic management system compared with conventional management or conversion. Our results suggest a positive effects of organic management on AMF diversity in maize. They also highlight the rather high diversity or richness of AMF and the large portion of sequences not yet ascribed to species, thereby emphasizing a need to intensify AMF identification in cropping systems.

Assessment of energy crops alternative to maize for biogas production in the Greater Region.

The biomethane yield of various energy crops, selected among potential alternatives to maize in the Greater Region, was assessed. The biomass yield, the volatile solids (VS) content and the biochemical methane potential (BMP) were measured to calculate the biomethane yield per hectare of all plant species. For all species, the dry matter biomass yield and the VS content were the main factors that influence, respectively, the biomethane yield and the BMP. Both values were predicted with good accuracy by linear regressions using the biomass yield and the VS as independent variable. The perennial crop miscanthus appeared to be the most promising alternative to maize when harvested as green matter in autumn and ensiled. Miscanthus reached a biomethane yield of 5.5 ± 1 × 10(3)m(3)ha(-1) during the second year after the establishment, as compared to 5.3 ± 1 × 10(3)m(3)ha(-1) for maize under similar crop conditions.

Assessment of factors influencing the biomethane yield of maize silages.

A large set of maize silage samples was produced to assess the major traits influencing the biomethane production of this crop. The biomass yield, the volatile solids contents and the biochemical methane potential (BMP) were measured to calculate the biomethane yield per hectare (average=7266m(3)ha(-1)). The most influential factor controlling the biomethane yield was the cropping environment. The biomass yield had more impact than the anaerobic digestibility. Nevertheless, the anaerobic digestibility of maize silages was negatively affected by high VS content in mature maize. Late maturing maize varieties produced high biomass yield with high digestibility resulting in high biomethane yield per hectare. The BMP was predicted with good accuracy using solely the VS content.