Soil aggregate stability and POM occlusion are integral markers for soil quality. Besides physico-chemical interactions, biofilms are considered to aggregate primary particles, but experimental proof is still missing. In our experiment, soil aggregate samples were treated with biofilm degrading enzymes and showed a reduced POM occlusion and an increased bacteria DNA release compared with untreated samples. Thus, biofilms are assumed to be an important factor of POM occlusion in soil aggregates.

Enhancing soil health is key to providing ecosystem services and food security. There are often trade-offs to using a particular practice, or it is not fully understood. This work aimed to identify practices beneficial to soil health and gaps in our knowledge. We reviewed existing research on agricultural practices and an expert panel assessed their effectiveness. The three most beneficial practices used a mix of organic or inorganic material, cover crops, or crop rotations.

Dedicated bioenergy crops are required for future energy production; however the effects of land use change from traditional crops to biofuel crops on soil microbial communities, which drive greenhouse gas production, are largely unknown. We used quantitative PCR to enumerate these microbial communities to assess the sustainability of different bioenergy crops, including miscanthus and corn. We found that miscanthus may be a suitable crop for bioenergy production in variable Ontario conditions.

Investigation of a Dutch sandy profile demonstrated that buried soils provide beneficial growth conditions for plant roots in terms of nutrients. The intense exploitation of deep parts of the soil profile, including subsoil and soil parent material, by roots of the modern vegetation is often underestimated by traditional approaches. Potential consequences of deep rooting for terrestrial carbon stocks, located to a relevant part in buried soils, remain largely unknown and require further studies.

For this study we systematically investigated the molecular pattern of leaf waxes in litter and topsoils along a European transect to assess their potential for palaeoenvironmental reconstruction. Our results show that leaf wax patterns depend on the type of vegetation. The vegetation signal is not only found in the litter; it can also be preserved to some degree in the topsoil.

Soils store more than 3 times as much carbon than the atmosphere, but global carbon models still suffer from large uncertainty. We argue that this may be due to the fact that soil animals are not taken into account in such models. They dig, eat and distribute dead organic matter and microorganisms, and the quantity of their activity is often huge. Soil animals affect microbial activity, soil water content, soil structure, erosion and plant growth – and all of this affects carbon cycling.

Modern agriculture is dominated by monoculture crop production, having negative effects on soil biology. We used a 12-year crop rotation experiment to examine the effects of increasing crop diversity on soil microorganisms and their activity. Crop rotations increased microbial biomass by up to 112 %, and increased potential ability to supply nitrogen as much as 58 %, compared to monoculture corn. Collectively, our findings show that soil health is increased when crop diversity is increased.

Legacy effects of increased temperature on both nitrogen (N) transformation rates and nitrous oxide (N₂O) emissions from permanent temperate grassland soil were evaluated. A new source-partitioning model showed the importance of oxidation of organic N as a source of N₂O. Gross organic (and not inorganic) N transformation rates decreased in response to the prior soil warming treatment. This was also reflected in reduced N₂O emissions associated with organic N oxidation and denitrification.

Soil thermal conductivity in wet conditions can be retrieved together with the soil quartz content using a reverse modelling technique based on sub-hourly soil temperature observations at three depths below the soil surface. A pedotransfer function is proposed for quartz, for the considered region in France. Gravels have a major impact on soil thermal conductivity, and omitting the soil organic matter information tends to enhance this impact.

The review paper surveys the state of the art with respect to water in the critical zone, taking a broad view that concentrates on the global range of natural soils, identifying some areas of currently active research.

We do not understand processes by which soil bacteria and fungi feed on soil organic matter (SOM). Previous research suggests the location of SOM in aggregates may influence whether bacteria can feed on it more easily. We did an experiment to identify the distribution of SOM on very small scales within nine soil aggregates. There was no clear evidence that the distribution of organic matter influenced how easily the organic matter was fed upon by bacteria.

In this study we evaluated CO₂ emissions during composting of green wastes with clay and/or biochar in the presence and absence of worms, as well as the effect of those amendments on carbon mineralization after application to soil. Our results indicated that the addition of clay or clay–biochar mixture reduced carbon mineralization during co-composting without worms by up to 44 %. In the presence of worms, CO₂ emissions during composting increased for all treatments except for the low clay dose.