Agricultural abandonment in Mediterranean reclaimed peaty soils: Long-term effects on soil chemical properties, arbuscular mycorrhizas and CO2 flux

In the last century, most peatlands were reclaimed for agricultural purposes, which led to peat degradation and to severe subsidence, and thus too wet conditions for crops. In some areas this has therefore led to wide agricultural abandonment. However, studies on the effect of agricultural abandonment as a potential restoration tool are lacking. In this study, the effectiveness and the restoration potential of agricultural abandonment in reducing peat degradation and in improving soil microbial biodiversity were evaluated. The main chemical parameters, arbuscular mycorrhizal (AM) fungal diversity and soil respiration partitioning were used to assess the long-term effect of 15 years of agricultural abandonment (Aband) in a Mediterranean reclaimed peatland. An intensive maize cultivation (Cult) in the same area was used as a comparison. Multivariate analyses showed that 15 years of agricultural abandonment: did not affect the main soil chemical parameters, except for NH4+ which was lower in the Aband than in the Cult; increased AM fungal root colonization and the diversity in terms of number of families of AM fungi retrieved in roots, but decreased soil AM fungal richness; reduced total soil respiration and its autotrophic component but increased respiration by heterotrophs; determined a lower fluctuation of soil CO2 flux response to air temperature than the Cult. Thus, although some soil quality parameters were significantly improved, 15 years of agricultural abandonment may not lead to an effective restoration. Consequently, alternative and sustainable solutions for the protection and preservation of Mediterranean peatlands need to be develope

Land-use intensity and host plant simultaneously shape the composition of arbuscular mycorrhizal fungal communities in a Mediterranean drained peatland

Land-use change is known to be a major threat to biodiversity and ecosystem services in Mediterranean areas. However, the potential for different host plants to modulate the effect of land-use intensification on community composition of arbuscular mycorrhizal fungi (AMF) is still poorly understood. To test the hypothesis that low land-use intensity promotes AMF diversity at different taxonomic scales and to determine whether any response is dependent upon host plant species identity, we characterised AMF communities in the roots of 10 plant species across four land use types of differing intensity in a Mediterranean peatland system. AMF were identified using 454 pyrosequencing. This revealed an overall low level of AMF richness in the peaty soils; lowest AMF richness in the intense cropping system at both virtual taxa and family level; strong modulation by the host plant of the impact of land-use intensification on AMF communities at the virtual taxa level; and a significant effect of land-use intensification on AMF communities at the family level. These findings have implications for understanding ecosystem stability and productivity and should be considered when developing soil-improvement strategies in fragile ecosystems, such as Mediterranean peatlands

Frumenti teneri toscani: caratteri nutrizionali e nutraceutici di varietà iscritte al repertorio regionale

Il libro illustra il valore della biodiversità in agricoltura, il sistema di conservazione dell’agrobiodiversità in Toscana e le ricerche promosse dalla Regione per valorizzare le proprietà nutrizionali e nutraceutiche del patrimonio dell’agrobiodiversità regionale. Gli aspetti morfologici, tecnologici, nutrizionali e nutraceutici delle varietà di frumento tenero iscritte al Repertorio Regionale sono descritti insieme alle moderne tecniche di coltivazione finalizzate al miglioramento della qualità della granella, come la biofortificazione agronomica e la biofertilizzazione. Alcune ricette tipiche della tradizione toscana a base di frumento completano il libro

Molecular and Physiological Effects of Magnesium–Polyphenolic Compound as Biostimulant in Drought Stress Mitigation in Tomato

Plant biostimulants are being recognized as innovative tools to improve sustainable agricultural practices to mitigate the drastic effects of climate change, which is leading to a severe reduction in agricultural yields. In this work, a new biostimulant (EnNuVi® ALPAN®) was evaluated for its effectiveness on tomato (Solanum lycopersicum Mill. cv. Rio Grande) plants subjected to water deficit conditions. The molecular effects were elucidated through transcriptomic RNA-seq and gene expression qPCR analysis and the physiological responses were evaluated through qualitative analysis of pigments and proline content, membrane stability, and lipid peroxidation. ALPAN® was shown to adjust the transcriptional response by upregulating genes involved in source to sink carbohydrate metabolism and translocation, stomatal closure, and cell homeostasis. ALPAN® was shown to mitigate the deteriorating effects of water deficit on the physiological status of the plants by stabilizing the levels of the photosynthetic pigments, regulating the accumulation of osmo-protectants, and preserving the cell wall lipid bilayer from oxidation. In conclusion, transcriptomic and physiological analysis provided insightful information on the biostimulant effects, indicating a positive role of ALPAN® foliar application in alleviating the negative costs of water deficit

TILLAGE INTENSIFICATION AFFECTS AMF DIVERSITY, SOC AND ENZYMATIC ACTIVITIES WITHIN SOIL AGGREGATES AT VARIOUS SCALES

Long-term agricultural management may change soil C sequestration and alter soil organic matter content, structure and biological activity. The objective of this study was to investigate the impact of tillage and N fertilization within a field experiment with a soybean/ wheat rotation, originally established in 1982 in Central Italy. Treatments were ploughing at 30-cm depth (P30) and minimum tillage (MT) in combination with two N fertilizer rates to wheat, 0 (N0) and 200 kg N ha-1 (N200). In spring 2016, soil samples were collected from the 0–15 and 15–30 cm soil layers. Bulk density (BD), NH4-N and NO3-N concentration were assessed. After wet-sieving fractionation, SOC, total N and available P, enzymatic activities and AMF diversity were assessed in both bulk soil and microaggregates within macroaggregates (mM). AMF diversity was characterized by SSU-ITS-LSU fragment. At both soil layers, BD did not vary between tillage intensities, but was 7% higher in N200 than N0. At 15-30 cm depth, the proportion of mM was 21% higher in MT than P30, while no differences were detected in the surface layer. Tillage did not change soil total N and available P, whereas N fertilization affected NH4-N (15%) and NO3-N (28%) concentration at both soil layers. SOC, enzymatic activities and AMF diversity in bulk soil and in mM changed in P30 respect to MT. Our results showed co-occurrence patterns in SOC, enzymatic activities and AMF diversity of bulk soil and mM fraction, suggesting that the contribution of soil biota to C sequestration within aggregates varied with tillage