1,721,034 research outputs found
Digestato e stress climatici: effetti sulla dinamica del carbonio e sulla resa colturale nei suoli di risaia
No full textI suoli di risaia rappresentano un agroecosistema di importanza globale, fondamentale per la produzione di riso (Oryza sativa L.) e per la loro capacità di immagazzinare carbonio organico (SOC). Tuttavia, làumento delle temperature e la riduzione della disponibilità idrica, indotti dai cambiamenti climatici, compromettono la fertilità e la resilienza di tali sistemi, con possibili ripercussioni sulla produttività e sulla sostenibilità ambientale. Questo studio ha valutato gli effetti dell'applicazione di digestato anaerobico sulla dinamica della sostanza organica del suolo e sulla resa produttiva del riso, in condizioni di stress termico e idrico simulato. È stato condotto un esperimento in campo che ha considerato tre fattori: ammendamento (digestato, DS; controllo non ammendato, UN), temperatura (ambiente, AM; aumento della temperatura +2 °C, WR) e
regime idrico (inondazione normale, NF; ridotta del 30%, RF). Nel periodo 2023–2024 è stata osservata una riduzione del SOC sia nei suoli DS (da ∼13,8 a 12,0 g/kg) che nei suoli UN (da ∼18,2 a 14,8 g/kg), con perdite fino al 15% superiori nei trattamenti sottoposti a stress termico. L'applicazione di digestato ha tuttavia attenuato parzialmente tali perdite, in particolare in condizioni di inondazione normale. Il rapporto C/N è diminuito, indicando una maggiore disponibilità di azoto, mentre la resa del riso è calata in tutte le condizioni sperimentali, con riduzioni del 40–60% dovute allo stress termico; anche in questo caso, il digestato ha mostrato un certo effetto “tampone”. Nel complesso, i risultati hanno evidenziato che l'impiego del digestato può contribuire all'attuazione delle politiche italiane ed europee per la gestione sostenibile del suolo, quali il Piano Strategico PAC 2023–2027, la Strategia Nazionale per il Suolo e il PNRR,
promuovendo pratiche sostenibili e circolari per il miglioramento della fertilità del suolo e la resilienza climatica dei sistemi agroalimentari
Influence of reduced water flooding and increased temperature on SOM dynamics and crop yield in amended paddy soils
No full textPaddy soils represent a globally significant agroecosystem, not only as the primary environment for irrigated rice (Oryza sativa L.) production, but also as extensive anthropogenic wetlands, playing a key role in soil organic carbon (SOC) sequestration. In the context of climate change, rising temperatures and reduced water availability threaten soil health and fertility, as well as the whole resilience of this agroecosystem.
This study evaluates how anaerobic digestate application influences soil organic matter (SOM) dynamics and crop yield in paddy soils under simulated climate stresses. A factorial field experiment tested three factors: amendment application (digestate, DS; unamended control, UN), temperature (ambient, AM; warming, ~2 °C, WR), and water regime (normal flooding, NF; reduced flooding, -30%, RF). SOM was fractionated into particulate (POM) and mineral-associated (MAOM) pools to assess C stabilization.
Comparing data obtained in 2024 and 2023, a SOC decline has been observed in both DS plots (~13.8 to 12.0 g/kg) and UN plots (~18.2 to 14.8 g/kg), with WR plots losing up to 15% more SOC than AM. At the same time, digestate application under NF conditions partially mitigated SOC losses. The C/N ratio also declined more in DS (11 to 9) than in UN (15 to 11), reflecting enhanced N availability.
Rice yield trends over the two-year period demonstrated clear responses to both organic amendment and climate stresses. In 2023, increased temperature and reduced flooding level resulted in a crop yield loss around 60-70%, whereas digestate application did not seem to mitigate the observed differences. By 2024, yields declined across all treatments, with warming reducing productivity by 40-60% compared to ambient conditions. This highlights the strong negative effect of elevated temperature on rice yield. While digestate improved N availability and supported higher yields under favorable conditions, its benefits were markedly constrained under warming, especially in combination with normal flooding. These findings indicate that digestate can enhance productivity and nutrient cycling under current climates, while its use needs to be integrated with tailored water management to sustain yields under warming scenarios
Influence of digestate application on rice yield and soil organic matter pools in a climate change scenario
No full textIncreasing temperature and decreasing precipitation represent a serious threat to the agricultural sustainability of paddy soils, not only because rice (Oryza sativa L.) is the main irrigated crop worldwide, but also because they represent the largest anthropogenic wetland which, as such, is involved in carbon (C) sequestration. The application of anaerobic digestate represents an enormous potential to increase both soil C accrual, and thus mitigate climate change, and soil fertility. However, there is still a lack of knowledge on the relative distribution of digestate into soil organic matter (SOM) pools under increasing temperatures. The main aims of our research are: a) to investigate the effects of increased temperature (~2°C) and reduced water levels (by 30%) on the amount and quality of SOM pools; and b) to determine how digestate application affects organic C (OC) stability and distribution into SOM fractions, with or without climate manipulation. The ability of digestate to mitigate the negative influence of climate changes on rice yields will be also assessed. The experimental design consists of 3 factors - amendment application (unamended control, UN; digestate, DS), climate manipulation (ambient temperature, AM; warming, WM) and water management (normal flooding, NF; reduced flooding, RF). To capture SOM protection mechanisms, soil samples were fractionated by size following aggregate dispersion, thus resulting in a particulate (POM) and a mineral-associated organic matter (MAOM) fraction. Preliminary results reveal that, in AM and NF conditions, digestate application slightly increased rice yield compared to UN. In general, increased temperature and reduced water supply result in a crop yield loss ranging between 60 and 70%. Moreover, while in UN the water regime (NF vs. RF) seems to have no effect on rice yield in both AM and WM conditions, in DS the NF results in significantly higher rice yield. The main differences in the POM fraction are observed between DS and UN; in particular, reduced flooding conditions in UN decrease the OC content by ca. 3× compared to normal flooding. In the MAOM pool, OC is not significantly affected by flooding level and digestate application, while both digestate application and
warming, as well as their interaction, affect total N content. This research has the potential to generate soil management recommendations required to address global change challenges and recycle organic wastes while improving SOM content
Soil organic carbon stabilization mechanisms along two climo-cronosequences
No full textThe aim of the work is to study the mechanisms of soil organic carbon (SOC) sequestration as a function of time and climate. Two chronosequences located along a climate gradient (i.e., climo-chronosequence) were compared. The first (ADI) consists of river terraces of the Adige river (Veneto region) whereas the second (LED) of river-glacial terraces of Ledro lake (Trentino Alto-Adige region). All sites were grassland. Soil samples were collected (1 profile and 2 cores) for horizon and sub-sampled by depth (5 cm). Sub-samples were characterized by pH, EC, organic C (Corg), total nitrogen, texture, major and trace elements, and horizons were characterized by XRD. Basal soil respiration and enzymatic assays were determined for all sub-samples. Particulate organic matter (POM) and mineral-associated organic matter (MAOM) were also isolated and characterized by elemental (CHNS) and thermal (TGA-DSC) analyses. In the ADI chronosequence, the oldest site (125 ky) had the highest SOC stock, whereas, in LED chronosequence, the highest SOC storage was found in the youngest site (13-11 ky). In LED sites, the contribution of POM on SOC storage was predominant in the first 10 cm. The ratio between Corg in MAOM/POM ranged between 0.7-1.6, and increased with depth. On the opposite, in ADI, the MAOM played a more important role on SOC storage. Obtained data indicate that i) MAOM and POM may play a different role on SOC accumulation in chronosequences, ii) SOC stability generally increases with depth, and iii) the climate plays a major role, compared to time, on SOC sequestration
Soil organic carbon sequestration and dynamics in two fluvial terraces along a chronosequence
No full textMechanisms of soil organic carbon (SOC) sequestration as a function of time and depth are investigated. Two fluvial terraces, showing the same land use, have been selected along a chronosequence (T1, 125 m a.s.l., ca. 125,000 years BP; T2, 15 m a.s.l., early Holocene). From each site, soil samples have been collected (1 profile and 2 cores) by horizon, and each horizon sub-sampled by depth. Five-cm thick sub-samples have been characterized for pH, EC, total organic C, total N, major/trace elements, SOC stability and texture, and particulate organic matter (POM) and mineral-associated organic matter (MAOM) have been isolated. The average organic C content in topsoil (20 cm) is quite constant in both sites (27.4 mg/g), whereas the average total N concentration ranges between 2.7-2.9 mg/g. SOC stock in topsoil is 50% higher in T1 (72±3 MgC/ha) than in T2 (49±5 MgC/ha). Although SOC accumulation decreases with depth, the two sites recorded a similar average C stock at 35 cm (89±9 and 76±8 MgC/ha, respectively). The average content of the MAOM pool is constant along the T2 profile (52%), while increases with depth in T1. Thermal analysis (TGA-DSC) suggests a general increase of the stability of MAOM and POM with depth in both sites, with T1 showing a largest increase of MAOM recalcitrance in deep soil respect to T2. While most of the studies on SOC sequestration and stabilization focuses on topsoils (0-20 cm), our preliminary data show that a significant stock of more recalcitrant organic C in the deeper layers
Soil organic matter dynamics and stability: Climate vs. time
No full textClimate and time are among the most important factors driving soil organic carbon (SOC) stability and accrual in mineral soils; however, their relative importance on SOC dynamics is still unclear. Therefore, understanding how these factors covary over a range of soil developmental stages is crucial to improve our knowledge of climate change impact on SOC accumulation and persistence. Two chronosequences located along a climate gradient were investigated to determine the main interactions among time (age) and climate (precipitation and temperature) on SOC stability and stock with depth. Considering a common depth (0-15 or 0-30 cm), in the drier chronosequence, the older soil showed the highest SOC stock, while the younger exhibited the lowest carbon accumulation. Considering the whole profile, the SOC stock increased with age. In the wetter chronosequence, the younger soil showed the highest SOC stock considering a common depth, whereas, when the entire profile is taken into account, the older one accumulated 2-3 times more SOC than the others. In both chronosequences, significant stocks of SOC (similar to 42 %) were accumulated below 30 cm. Soil organic matter stability, assessed by thermal analysis and heterotrophic respiration, increases with depth and age only in the drier chronosequence. Soils from the wetter chronosequence were instead characterized by a greater quantity of labile and/or not-stabilized SOC; here, the amorphous Fe/Al-rich secondary mineral weathering products showed an essential predictor function of SOC storage, although they do not seem to be involved in SOC stabilization mechanisms. Otherwise, the interaction of SOC with fine particles, short-range order minerals, and organo-metal complexes represent the significant stabilization mechanisms in soils from drier climate. The results highlighted how the age factor plays an unassuming role in geochemical processes influencing SOC dynamics; however, climate determines different trajectories of soil development and SOC dynamics for a given soil age. Thus, soil age shows a key role in SOC stabilization especially in drier climatic conditions, while wetter conditions determine an accumulation of a higher yet more labile amount of SOC
Time and climate as driving factors of SOM pools dynamics
No full textThis study aims at investigating the effect of climate and time on the dynamics of two natural soil organic matter (SOM) pools, i.e., the particulate and the mineral-associated organic matter (POM and MAOM, respectively). Two chronosequences characterized by different climates were investigated; the drier chronosequence (ADI) consisted of fluvial terraces whereas the wetter one (LED) of fluvio-glacial terraces. The age of the ADI soils (ADI125, ADI10, ADI8 and ADI3) ranged from about 125,000 (ADI125) to 3,000 years BP (ADI3), whereas that of the LED soils (LED16, LED14, and LED10) from about 16,000 (LED16) to 10,000 years BP (LED10). All sites were grasslands. Soil samples (1 profile and 2 cores per site) were collected by horizon, and sub-sampled by depth (each 5 cm). From each sample, POM and MAOM were isolated and characterized by elemental and thermal analyses.
Overall, LED soils are characterized by a higher organic carbon (OC) content respect to the ADI ones.
In particular, the concentration of OC in the mineral (MAOC) and the particulate pool (POC) along the whole profiles is ca. 2x and 3x higher, respectively, in LED compared to ADI. The MAOC concentration in drier climate follows the rank of ADI3 [...
Dinamiche e stabilità del carbonio organico in due suoli coevi lungo una climosequenza caldo-temperata del Nord Italia
No full textDue siti lungo una climosequenza caldo-temperata sono stati selezionati all’interno di altrettante cronosequenze al fine di studiare i meccanismi di stoccaggio e stabilizzazione del carbonio organico (OC) in funzione del clima, ma a parità di età (8-11 ky) ed utilizzo del suolo (prato). Il primo sito, ADIQ3, è un terrazzo fluviale, ubicato a Santa Lucia (VR) in Veneto, a 15 m al di sopra dell’attuale livello del fiume Adige, mentre il secondo, LEDQ3, è un terrazzo fluvio-glaciale situato in Ledro (TN), in Trentino Alto-Adige, a 620 m s.l.m. LEDQ3 è caratterizzato da una maggiore piovosità media annua e da una temperatura media annua inferiore rispetto ad ADIQ3, contraddistinto invece da un clima più secco. I rispettivi suoli sono stati campionati (1 profilo e 2 carote) per orizzonte e sub-campionati per profondità (5 cm), e caratterizzati per pH, EC, OC, N totale, mineralogia e contenuto in elementi totali ed estraibili. È stata determinata la respirazione cumulativa (RHCUM) e la biomassa microbica attraverso incubazione e fumigazione. La sostanza organica sia particolata (POM) che associata ai minerali (MAOM) è stata isolata e caratterizzata mediante analisi elementare (CHNS) e termica (TG-DSC). LEDQ3 presenta una concentrazione di OC nei primi 30 cm circa 3 volte superiore rispetto ad ADIQ3. In particolare, LEDQ3 stocca quasi il doppio di OC rispetto ad ADIQ3 sia nel topsoil (0-15 cm; 87 vs. 51 Mg C ha-1, rispettivamente) che tra 0 e 30 cm (138 vs. 77 Mg C ha-1). Il contributo della POM è predominante soprattutto nel topsoil, mentre quello della MAOM aumenta con la profondità in entrambi i siti. In particolare, il rapporto tra OC nella MAOM e quello nella POM nel topsoil è pari a 0.9±0.3 in LEDQ3 e a 3.3±1.4 in ADIQ3. Gli indici termici (i.e., WL400-550/200-400, TG-T50) mostrano un chiaro aumento della stabilità con la profondità in ADIQ3 ma non in LEDQ3. Inoltre, a fine incubazione, e considerando i primi 30 cm di profondità, LEDQ3 presenta una RHCUM circa 3 volte superiore rispetto a quella di ADIQ3 (3.7 e 1.2 mg CO2-C gsoil-1, rispettivamente). I risultati ottenuti suggeriscono un ruolo differente della POM e MAOM nello stoccaggio di OC in funzione del clima, poiché a parità di età ed uso del suolo, un clima più umido favorisce l’accumulo di maggiori quantità di carbonio caratterizzate però da una minore stabilità
Soil organic carbon stabilization mechanisms along two climo-cronosequences
No full textThe aim of the work is to study the mechanisms of soil organic carbon (SOC) sequestration as a function of time and climate. Two chronosequences located along a climate gradient (i.e., climo-chronosequence) were compared. The first (ADI) consists of river terraces of the Adige river (Veneto region) whereas the second (LED) of river-glacial terraces of Ledro lake (Trentino Alto-Adige region). All sites were grassland. Soil samples were collected (1 profile and 2 cores) for horizon and sub-sampled by depth (5 cm). Sub-samples were characterized by pH, EC, organic C (Corg), total nitrogen, texture, major and trace elements, and horizons were characterized by XRD. Basal soil respiration and enzymatic assays were determined for all sub-samples. Particulate organic matter (POM) and mineral-associated organic matter (MAOM) were also isolated and characterized by elemental (CHNS) and thermal (TGA-DSC) analyses. In the ADI chronosequence, the oldest site (125 ky) had the highest SOC stock, whereas, in LED chronosequence, the highest SOC storage was found in the youngest site (13-11 ky). In LED sites, the contribution of POM on SOC storage was predominant in the first 10 cm. The ratio between Corg in MAOM/POM ranged between 0.7-1.6, and increased with depth. On the opposite, in ADI, the MAOM played a more important role on SOC storage. Obtained data indicate that i) MAOM and POM may play a different role on SOC accumulation in chronosequences, ii) SOC stability generally increases with depth, and iii) the climate plays a major role, compared to time, on SOC sequestration
Organic carbon sequestration along a soil chronosequence on fluvial terraces (Adige river, Italy)
No full textThe aim of this work is to investigate the mechanisms of soil organic carbon (SOC) sequestration as a function of two factors, namely climate and time. Two-to-three chronosequences, located along a climate gradient and consisting of 3 sites each, will be investigated. The first chronosequence soils were studied in two orders (T1 and T2) of fluvial terraces of the Adige river (Veneto region, North of Italy). The highest and oldest terrace (T1) is situated at Montalto di Gaium, at an altitude of 125 m above the Adige riverbed level. This terrace was presumably formed during the last interglacial (ca. 125,000 years BP) and was characterized by paleudalf soils. On the opposite, T2, situated at 15 m above the actual riverbed level, represents the youngest order of terrace in this area, and probably formed during early Holocene. These fluvial terraces have different age but a common land use. From each site along this chronosequence, soil samples have been collected (1 profile and 2 cores per site) by soil horizon, and each horizon then sub-sampled by depth (each 5 cm). Five-cm thick sub-samples have been characterized for pH, electrical conductivity (EC), total organic C, total N and texture. Particulate organic matter (POM) and mineral-associated organic matter (MAOM) have been isolated and will be characterized by elemental analysis (CHNS), thermogravimetric analysis (TGA-DSC), X-ray diffraction (XRD) and other spectroscopic techniques (i.e., ICP-MS, FTIR, NMR). The average organic C content in the topsoil (20 cm) is quite constant in the three sites (27.4 mg/g), whereas the average total N concentration ranges between 2.7 and 3.1 mg/g. SOC stock in the topsoil increases with soil age, being 30% higher in soils from T1 than from T2. Although SOC accumulation decreases with depth, soils along the chronosequence recorded approximately the same average C stock around 35 cm (76-85 Mg/ha). At the same time, in the site showing the deepest soil profile, the SOC accumulated between 35 and 80 cm represents ca. 30% of the total. TGA-DSC data suggest that the thermal stability/recalcitrance of SOM generally increases with depth. While most of the studies on SOC sequestration and stabilization focused on topsoils (10-20 cm), our preliminary data highlight the importance of investigating also deeper layers. Future data will help to better understand the effects of climate and time on SOM distribution among different pools and as a function of depth
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