Nutrient Cycling

Agroecosystems make up a significant portion of terrestrial ecosystems and receive a disproportionally high amount of terrestrial nitrogen inputs from fertilizer, leading to nitrogen loss and associated environmental problems. Integrated crop livestock systems, such as pasture-integrated crop rotations, may be more environmentally sustainable however the long-term effects of this management practice on soil microorganisms and nitrogen transformations are not well understood.
Elsevier, Soil Biology and Biochemistry, Volume 149, October 2020
Fire is an ecological disturbance that alters soil microbiomes and the functions they mediate in terrestrial ecosystems. Soil microbial diversity in Mediterranean Basin ecosystems shows resilience to fire following the restoration of plant-soil feedbacks. We hypothesised that microbial functions related to organic matter decomposition and nutrient cycling might show similar patterns of recovery.
As a response to the worldwide challenge raised by soil degradation, Conservation Agriculture (CA) was proposed to help restoring the three main soil functions, i.e. carbon transformation, nutrient cycling and structure maintenance. However, there is still a lack of integrative studies that assess the overall impact of CA on soil health. To fill the gap, Biofunctool®, a set of in-field indicators, was developed to monitor changes in soil biological functioning.
Anthropogenic climate change is altering the functioning of terrestrial ecosystems. Agricultural systems are particularly vulnerable to climate change as they are frequently disturbed by intensified management practices. This also threatens belowground organisms that are responsible for providing crucial ecosystem functions and services, such as nutrient cycling and plant disease suppression. Amongst these organisms, earthworms are of particular importance as they can modulate the effects of climate change on soil organisms by modifying the biotic and abiotic soil conditions.
When biochar (BC) ages in soil, its properties change substantially: cation exchange capacity (CEC), surface area and porosity increase and water repellency decreases, consequently affecting the interactions with soil microorganisms. Activation of BC by organic acids may be regarded as artificial aging. Here, we study the effect of acid-activated BCs on soil microbial enzyme activities (EA) in comparison to several different control treatments without activated BC. A greenhouse pot experiment was conducted using a vineyard soil treated with multiple soil additives (four replications).
Non-vascular plants such as mosses, lichens and especially microalgae are widespread in terrestrial ecosystems, but their contribution in the nutrient cycling and energy budget of soil food webs is generally neglected. Despite a relatively low total biomass, soil microalgae can be very productive and contribute to the diet of many soil decomposers such as Collembola. Using 15N/14N ratios we showed that phycophagy is of particular importance for Collembola in extreme habitats like rock surfaces, or seasonally during the wintertime.