357 research outputs found
Improved Beerkan run methodology to assess water impact effects on infiltration and hydraulic properties of a loam soil under conventional- and no-tillage
No full textBeerkan infiltration experiments with three water pouring heights (low, L = 3 cm; intermediate, M = 100 cm; high, H = 200 cm) were performed on both a no-tilled (NT) and a conventionally tilled (CT) bare loam soil to determine the surface soil hydraulic properties by the BEST-steady algorithm. Saturated soil hydraulic conductivity, Ks, significantly and monotonically decreased from the L to the H runs (from 236 to 37 mm h‒1) and lower Ks values were detected under CT (163–23 mm h‒1) than NT (346–51 mm h‒1) for each water pouring height. For both soil management practices, the gravitational potential energy, Ep, of the water used for the infiltration runs, explained most of the variance in the mean Ks values. According to the fitted relationships, an increase of Ep from 50 to 3,327 J m‒2 determined a Ks decrease by a factor of 9.5 in the CT soil and 6.3 in the NT soil. The CT soil was 2.1 and 3.3 times less conductive than the NT soil with the lowest and the highest energy, respectively. The water retention scale parameter, hg, only varied between non-perturbing (L) and perturbing (M, H) runs because |hg| increased from 55 to 93–100 mm. Therefore, water impact can greatly influence hydrodynamic properties of the upper soil layer regardless of the management practice. The tested infiltration methodology looks promising to mimic effects of relatively high energy rainfall events and to determine the hydraulic properties of the exposed soil layer under different management practices
Seasonal and Soil Use Dependent Variability of Physical and Hydraulic Properties: An Assessment under Minimum Tillage and No-Tillage in a Long-Term Experiment in Southern Italy
No full textAbstract: Defining the optimal sampling time across the growing season is crucial to standardize
sampling protocols for soil physical status monitoring and to achieve comparable results under
different experimental conditions and on different sites. In this study, the seasonal variability of soil
physical and hydraulic properties under two conservative soil management strategies, minimum
tillage and no-tillage, was evaluated in a long-term field experiment. On two sampling dates,
autumn 2021 and summer 2022, soil bulk density (BD) and volumetric soil water content at the time
of the experiments (θi) were measured in each experimental unit and Beerkan infiltration
experiments were performed. The soil water retention curve and the hydraulic conductivity
function were then estimated using the Beerkan estimation of soil transfer parameters (BEST)
methodology. In this way, the saturated hydraulic conductivity (Ks) and a set of capacitive
indicators—plant available water capacity (PAWC), soil macroporosity (PMAC), air capacity (AC) and
relative field capacity (RFC)—were obtained. Results underlined the role of soil moisture conditions
as a main factor affecting variability in soil physical properties. Different soil moisture under
autumn and summer samplings significantly affected BD (1.0093 and 1.1905 g cm−3, respectively, in
autumn and summer) and Ks (0.0431 and 0.0492 mm s−1). Relationships observed between BEST derived variables, such as PMAC (or AC) and RFC, and measured variables, such as BD, showed
consistent results, with increases in PMAC to BD decreases. However, a comparison of capacity-based
indicators obtained by BEST with those obtained from measured soil water retention curves, in a
previous year but under comparable soil conditions, highlighted some discrepancies. This finding
drives the focus towards the need to use more robust datasets deriving from experimental
measurements or from coupling information obtained from measured and estimated data. Finally,
this study provided further evidence that, in the long-term field experiment investigated, the two
soil management systems allowed keeping the values of key soil physical quality indicators, such
as bulk density and saturated hydraulic conductivity, within the optimal or near- optimal reference
ranges
Deep Insight on Land Use/Land Cover Geospatial Assessment through Internet-Based Validation Tool in Upper Karkheh River Basin (KRB), South-West Iran
No full textRecently, the demand for high-quality land use/land cover (LULC) information for near real-time crop type mapping, in particular for multi-relief landscapes, has increased. While the LULC classes are inherently imbalanced, the statistics generally overestimate the majority classes and underestimate the minority ones. Therefore, the aim of this study was to assess the classes of the 10 m European Satellite Agency (ESA) WorldCover 2020 land use/land cover product with the support of the Google Earth Engine (GEE) in the Honam sub-basin, south-west Iran, using the LACOVAL (validation tool for regional-scale land cover and land cover change) online platform. The effect of imbalanced ground truth has also been explored. Four sampling schemes were employed on a total of 720 collected ground truth points over approximately 14,100 ha. The grassland and cropland totally canopied 94% of the study area, while barren land, shrubland, trees and built-up covered the rest. The results of the validation accuracy showed that the equalized sampling scheme was more realistically successful than the others in terms of roughly the same overall accuracy (91.6%), mean user’s accuracy (91.6%), mean producers’ accuracy (91.9%), mean partial portmanteau (91.9%) and
kappa (0.9). The product was statistically improved to 93.5% ± 0.04 by the assembling approach and segmented with the help of supplementary datasets and visual interpretation. The findings confirmed that, in mapping LULC, data of classes should be balanced before accuracy assessment. It is concluded that the product is a reliable dataset for environmental modeling at the regional scale but
needs some modifications for barren land and grassland classes in mountainous semi-arid regions of the globe
Different Suitability of Olive Cultivars Resistant to Xylella fastidiosa to the Super-Intensive Planting System
No full textUntil today, only Leccino and Fs-17 (=Favolosa®) olive cultivars proved resistant to Xylella fastidiosa subsp. pauca (Xfp) due to a low presence of bacteria in the xylem. Integrated disease management in olive growing areas threatened by the spread of Xfp is crucial to overcoming the environmental, economic and social crisis. Since the EU Decision allows for the plantation of resistant olive cultivars in infected areas, there is a need to define a suitable plantation system for these cultivars. The adoption of new planting systems, such as intensive and super-intensive (SHD), could compensate for the economic losses and restore the olive agroecosystem. The aim is to ascertain the suitability of the available Xfp-resistant cultivars to SHD planting systems that demonstrate the best economic and environmental sustainability. Hence, a five-year study was established in an experimental SHD olive orchard (Southern Italy) in order to analyse the main vegetative and productive traits of Leccino and Fs-17, together with four other Italian cultivars (Cipressino, Coratina, Frantoio and Urano), compared with the well-adapted cultivars to SHD orchards (Arbequina and Arbosana), by means of the von Bertalanffy function. The results indicated that cv. Fs-17 showed sufficient suitability for SHD planting systems, giving the best-accumulated yield despite some canopy growth limitations, whereas cv. Leccino did not show satisfactory results in terms of both vegetative and yield parameters, confirming its suitability for intensive planting systems. These results are useful for optimizing integrated resistance management in Xfp-infected areas by planting resistant host plants
Managing orchard floor for saving water in a late ripening peach cultivar: a preliminary result
No full textLow humidity conditions occurring in Southern Italy till late summer allow the cultivation of late ripening peach cultivars. However, they are highly water demanding thus the increase of water use efficiency not affecting fruit production and quality is crucial. Four different agronomic managements were evaluated on ‘Redcall’ peach: completely tilled (T), mulched with a plastic film reducing soil evaporation and increasing diffuse light (M), mulching with a Leguminosae cover crop flattened after peach fruit set (F), tilled plot supplying the same volume of M that was supposed to be lower than T (S). Water was supplied till the field capacity when soil humidity reached the threshold of the readily available water. During fruit cell expansion S had leaf net photosynthesis (Pn), stomatal conductance (gs), transpiration (Tr) as well as stem water potential (Ψs) lower than T. Interestingly M and F showed the same low Ψs of S at 120 and 135 DAFB, respectively even if their Pn, gs and Tr were higher than S and comparable with T. Under water stress this peach cultivar behaved in a “conservative” way maintaining its Ψs above a safe threshold against embolism through stomata closure, thus reducing Pn. Few days before the harvest F drastically reduced gas exchanges, fruit growth, Ψs and soil water content albeit it received the same water volume of T. The increase of soil evaporation would be attributable to the disruption of the flattened crop as well as to the onset of soil cracking. Fruit production and size were affected by water stress in S and F, while M showed the highest productivity supplying 43% less water. The “conservative” behaviour of peach suggested that in certain conditions Ψs could not represent the real plant water status. Mulching with plastic film could be a promising practice in semi-arid conditions while the flattening practice should be refined since leaf functionality and fruit growth started to decrease only 15 days before the harvest
Microclimatic Parameters, Soil Quality, and Crop Performance of Lettuce, Pepper, and Chili Pepper as Affected by Modified Growing Conditions in a Photovoltaic Plant: A Case Study in the Puglia Region (Italy)
No full textThe performance of lettuce, pepper, and chili pepper, and the biological soil quality, in a ground-mounted PV system under cultivation conditions typical of the Mediterranean environment of the Puglia region were evaluated. Microclimatic parameters, plant growth and yield response, soil quality assessed using the QBS-ar index, and land equivalent ratio (LER) were determined in three different cultivation areas: a cultivation area outside the photovoltaic plant but immediately adjacent to it ('Control'); the inter-row area closest to the row of panels exposed to sunlight ('Area close PV structure'); the inter-row area distant from the row of panels ('Area distant PV structure'). Cumulated solar radiation, in particular during the summer growing cycles, was only slightly affected in the Area distant PV structure (1616 and 2130 MJ m-2 for pepper and chili pepper, respectively, in the control area, in comparison to 1630 and 2044 MJ m-2, in the Area distant PV structure), while it was strongly reduced in the Area close PV structure (883 and 1091 MJ m-2 for pepper and chili pepper, respectively). In general, a reduction in air temperature and wind speed, as well as an increase in relative air humidity, was observed under PV conditions. On average, the evapotranspirative demand was reduced in the PV growing conditions compared to open field, with a more relevant effect in the sub-zone close to the photovoltaic structures, where cumulative ET0 was 28% and 34% lower than the Control in the pepper and chili pepper growing cycle, respectively. Lettuce growth was impaired by PV cultivation conditions, with an average reduction of 15% in plant height and 37% in marketable yield per plant, with no significant differences between the two sub-zones in the PV system. For pepper, the best growing conditions were observed in open field control compared to PV, but with differences related to the PV sub-zone. The plants grown in the Area distant PV structure were more negatively affected by the modified growing conditions, showing the lowest shoot and fruit fresh weight, the latter reduced by 51% compared to the Control; intermediate values were observed for these parameters in the Area close PV structure, with a less severe tendency to yield reduction. For chili pepper, both shoot and fruit fresh weight were lower in PV conditions, regardless of the sub-zone, with a reduction of 82% in yield per plant compared to the Control. However, despite the yield reductions, the LER was improved (1.60 and 1.40 in case of a lettuce + pepper or lettuce + chili pepper annual cropping program, respectively), highlighting a more efficient use of land, without negative or even ameliorative impacts on biological soil quality and biodiversity in terms of QBS-ar and microarthropods taxa abundance. Knowledge of the response of different crops under cultivation conditions typical of specific environments is necessary to define optimal cropping programs aimed at maximizing resource-use efficiency and land use
Hygienic sustainability of site-location of wastewater treatment plants. I. Estimating odour emission impact
No full textBy reference to the wastewater treatment plant of Taranto (Apulia Region, S. Italy), a typical Mediterranean city, an odour impact assessment has been carried out in order to evaluate the annoyance for the population living in the neighbourhood. In adverse weather conditions ("worst scenario"), the study indicated a limited off-site odour impact at the 300 m setback distance dictated by local regulation
Yield and water use efficiency of early potato grown under different irrigation regimes
No full textPotato grown for early or off-season production plays a crucial role in the economy of several areas in the Mediterranean countries. Irrigation is important for determining yield and earliness, thus a better investigation of plant response under various pedo-climatic conditions can help to improve resource use efficiency and farmer income. A two-year field research (2009-2010) was carried out in Apulia region, southern Italy, on cv Spunta grown under three irrigation regimes: full irrigation (I100), 50% of full irrigation (I50) and rainfed (I0). Treatments were arranged in a randomized complete block design with three replicates. Plant water status, plant growth and, at harvesting, water use efficiency, yield and quality parameters were quantified. Water stress significantly affected yield response: as an average of the two years, a marketable yield decrement of 25.9 and 63.6% was observed in I50 and rainfed compared with I100 treatment, respectively. On the contrary, tuber dry matter and specific gravity increased moving from irrigated treatments to the rainfed one and varied also as a function of experimental year. The results confirmed that irrigation is required for early potato cultivation because rainfall is not sufficient to meet crop water needs. In addition, the study indicated that the irrigation regime reduced by 50% of crop water requirements was able to furnish satisfactory yield, with tuber quality characteristics similar or even better than those obtained under full irrigation
Follow-up a lungo termine della linfangectasia multicistica peripielica renale (LMPR)
No full textRenal peripelvic multicystic lymphangiectasia is a benign disease characterized by multiple cysts arising from the lymphatic vessels of the renal sinus. Cysts, almost always bilateral, surround the profiles of the calices; the biggest cysts can compress pelvis or iuxtapielic ureter and it is difficult to differentiate RPML from hydronephrosis at the Ultrasound. Cysts are asymptomatic, the profiles of calices appear irregular with thin membrane separating each other, the cortical of the kidney is preserved: these are principle elements to distinguish RPML to hydronephrosis at the Ultrasound. Usually it is necessary to confirm the diagnosis at IVP and CT scan evaluation. From 1995 to March 2002, 10 cases of RPML with a long-term follow-up have been studied. IVP in 8 patients and CT scan in 2 have shown compression of the collecting system by multiple cysts. We followed the cases with periodic lab tests of kidney function, ultrasound, IVP, CT scan. In order to valuate the presence of "true obstruction", we tested in over-night urine EGF and MCP-1 as markers of urinary tract obstruction and subsequent renal damage. A valuable data regarding how to differentiate RPML from hydronephrosis at Ultrasound show that RPML does not modify renal function and cyst volume has not changed in the time. In long-term follow-up the prognosis of the RPML is not clear. Particolarly this renal sinus disease has not neoplastic degeneration and the effect of cysts on kidney function is unknown. RPML is an uncommon disease and it can be enclosed in the group of renal sinus pathologies. The absence of symptoms, the hystologic diagnosis, the unchanged dimensions of the cysts confirm the benign prognosis of RPML which does not need a close functional and morphologic monitoring in the long-term follow-up
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