There is only a limited understanding of how the intensity of tillage affects soil biota and its ability to trigger the formation of soil aggregates, which is an important soil property for erosion control, especially in agricultural soils. In our study we focused on soil bacteria that are able to produce exopolysaccharides (EPS) and lipopolysaccharides (LPS) that “glue” soil particles together. A high-throughput shotgun sequencing of DNA extracted from conventionally and reduced tilled soils from three long-term field trials (Frick, Moškanjci and Juchovo) showed that the influence of tillage intensity on soil aggregates is site-specific, most likely related to soil texture. Furthermore, significantly improved aggregate stability under reduced tillage was linked with an increased absolute abundance of genes involved in EPS and EPS production and can be explained by the increased microbial biomass. Further research is needed to unravel the complicities of bacterial responses to disturbances in soils with different textures.
COBISS.SI-ID: 9459577
In this paper, we discussed the differences in weed cover and in the upper-soil seed bank abundance between the plowed treatment, treatment under reduced tillage and the no-till treatment, all in the organic type of crop production. Due to the non-use of herbicides, large weed cover were shown, especially in summer crops of corn and soybeans, and less so in rye, which has a known allelopathic effect. Weed cover and weed soil seed bank were significantly lower on the plowed plot. Weed species composition was also investigated showing significat differences between soil cultivation types both in aboveground vegetation and soil seed bank.
COBISS.SI-ID: 9154425
In this contribution, for the Moškanjci field experiment we combined the new data obtained within this project with the data from previous years, including the period of transition from conventional to organic crop production. For the fifteen-year period of former conventional production, a pronounced depth stratification of soil organic matter (SOM) with higher SOM contents in the upper soil occurred in the conservation tillage treatment (MT). This is due to the reduction of soil interventions and presence of organic residues on the soil surface. In plowing treatment (CT), SOM is evenly distributed within the plough depth. In MT, we also found better stability of soil aggregates and better water retention in the upper soil compared to CT. After transition to organic production, we observed an increase in microbial biomass in both types of tillage, which is possibly due to higher inputs of plant biomass due to greening of stubble and higher weed abundance due to non-use of herbicides. The improved soil quality demonstrated in MT in this study can be a good incentive for the introduction of conservation tillage into both conventional and organic production systems, as it represents a mitigation measure against erosion, drought and nutrient losses.
COBISS.SI-ID: 9154169