In this paper we present effects of four paired agricultural management practices (organic matter (OM) addition versus no organic matter input, no-tillage (NT) versus conventional tillage, crop rotation versus monoculture, and organic agriculture versus conventional agriculture) on five key soil quality indicators, i.e., soil organic matter (SOM) content, pH, aggregate stability, earthworms (numbers) and crop yield. We have considered organic matter addition, no-tillage, crop rotation and organic agriculture as “promising practices”; no organic matter input, conventional tillage, monoculture and conventional farming were taken as the respective references or “standard practice” (baseline). Relative effects were analysed through indicator response ratio (RR) under each paired practice. For this we considered data of 30 long-term experiments collected from 13 case study sites in Europe and China as collated in the framework of the EU-China funded iSQAPER project. These were complemented with data from 42 long-term experiments across China and 402 observations of long-term trials published in the literature. Out of these, we only considered experiments covering at least five years. The results show that OM addition favourably affected all the indicators under consideration. The most favourable effect was reported on earthworm numbers, followed by yield, SOM content and soil aggregate stability. For pH, effects depended on soil type; OM input favourably affected the pH of acidic soils, whereas no clear trend was observed under NT. NT generally led to increased aggregate stability and greater SOM content in upper soil horizons. However, the magnitude of the relative effects varied, e.g. with soil texture. No-tillage practices enhanced earthworm populations, but not where herbicides or pesticides were applied to combat weeds and pests. Overall, in this review, yield slightly decreased under NT. Crop rotation had a positive effect on SOM content and yield; rotation with ley very positively influenced earthworms’ numbers. Overall, crop rotation had little impact on soil pH and aggregate stability - depending on the type of intercrop; alternatively, rotation of arable crops only resulted in adverse effects. A clear positive trend was observed for earthworm abundance under organic agriculture. Further, organic agriculture generally resulted in increased aggregate stability and greater SOM content. Overall, no clear trend was found for pH; a decrease in yield was observed under organic agriculture in this review.
COBISS.SI-ID: 8984953
Climate change causes droughts, which in turn cause significant physiological stress for soil microorganisms. In this study, we investigated how the abundance of total bacterial, crenarchaeal and fungal communities and the abundance of N-cycling microbial guilds responded to a severe agricultural drought event in a long-term experiment of minimum tillage (MT) and conventional ploughing (CT) at two soil depths. Drought, defined as a reduction of soil water content and increased soil temperature, significantly decreased the abundance of all the studied microbial communities. The data showed linear relationships between all dependent variables and soil water content and soil temperature for the examined range of soil water content (WHC 13–76%) and examined range of average daily soil temperature at 5 cm depth (17–30 °C). Thus, we found that the abundance of most studied microbial communities decreased by about 2% when water content decreased by 1 mass % and by about 10% when temperature increases by 1 °C. When comparing communities at average soil water content and average soil temperature, MT had higher average abundances of total bacterial and crenarchaeal 16S rRNA and fungal ITS genes in the 0–10 cm soil layer than did CT (1.9, 2.9 and 2.5 times, respectively), as well as AOA and AOB amoA (3.9 and 1.7 times, respectively), nirK, nirS, nosZI and nosZII genes (2.0, 1.8, 1.8 and 2.3 times, respectively); while significant differences between MT and CT in the 10–20 cm soil layer were found only in the average abundance of crenarchaeal 16S rRNA and crenarchaeal amoA genes (3.5 and 2.7 times greater under MT than CT). Regardless of the weather conditions during our study, the abundances of all communities were greater under MT 0–10 than under CT 0–10. After three weeks of severe drought, the greatest decrease in the abundance of all communities, bacterial and archaeal N-cycling guilds as well as total prokaryotes and fungi, was observed under MT 0–10. However, after only a few rainfall events, all communities under both tillage systems reached their initial abundance, demonstrating a high resilience.
COBISS.SI-ID: 8956537
Mofettes are often investigated in ecology, either as extreme sites, natural analogues to future conditions under climate change, or model ecosystems for environmental impact assessments of carbon capture and storage systems. Much of this research, however, inadequately addresses the complexity of the gas environment at these sites, mainly focusing on aboveground CO2-enrichment. In the current research, the gaseous environment of Norway spruce (Picea abies (L) Karst.) trees growing at the Stavešinske slepice mofette (NE Slovenia) were studied by measuring both soil ([CO2]soil) and atmospheric CO2 concentrations ([CO2]air). Within the studied site (800%m2), soil CO2 enrichment was spatially heterogeneous; about 25% of the area was characterized by very high [CO2]soil ()40%) and hypoxic conditions. Aboveground gas measurements along vertical profiles not only revealed substantially elevated [CO2]air close to the ground (height up to 1.5%m), but also in the upper heights (20%25%m; crown layer). On the basis %13C of CO2, it was shown that elevated CO2 relates to a geogenic source. Trees grown in high [CO2]soil were characterized by decreased radial growth; the %13C of their wood was less negative than in trees growing in normal soil. Unfavorable gaseous soil conditions should generally be accepted as being by far the most important factor affecting (i.e. disturbing) the growth of mofette trees.
COBISS.SI-ID: 5047718