Metodologia di rilievo della rugosità superficiale del suolo con Pole Aerial Photography (PAP)

La valutazione della rugosità superficiale del suolo è importante in agricoltura sotto molteplici aspetti: nello studio delle relazioni tra le rugosità della superficie e volume massimo di stoccaggio di acqua nelle depressioni della superficie per lo sviluppo di modelli idrologici da utilizzare nelle strategie di conservazione del suolo e dell'acqua; ogni qualvolta occorra definire lo stato di amminutamento delle zolle determinato dagli strumenti agricoli di lavorazione del suolo in relazione all'umidità e alle caratteristiche fisiche del suolo. Lo scopo di questo lavoro è stato quello di calibrare una nuova metodologia di misura della Rugosità Superficiale del Suolo (Random Roughness), basata sull'analisi di immagini stereoscopiche ricavate con Metodologia PAP (Pole Aerial Photography). La nuova metodologia si pone due obbiettivi innovativi fondamentali: misurare la Rugosità superficiale su ampie aree campionarie, al fine di una migliore rappresentazione delle superfici; ricavare i valori di rugosità con una tecnologia speditiva a basso costo.</p

Effects of waterlogging on the soil structure of some Italian soils in relation to the GAEC cross-compliance standard Maintenance of farm channel networks and field convexity

The aim of this work is to assess the effectiveness of the cross-compliance standard Maintenance of farm channel networks and field convexity with respect to the environmental objective to maintain soil structure through appropriate measures indicated in Annex IV of REG. EC 1782/03. This GAEC standard concerns arable land and obliges the farmer to maintain the farm channel network and the convex shape of fields with a view to the management and preservation of temporary drainage ditches and permanent channels along the edges of the fields, in order to ensure their efficacy and function in draining away water. Experiments have confirmed that maintaining the farm channel networks and giving fields a convex shape has a positive effect in predisposing the soil to ideal conditions for the preservation of its structure. In particular, we have used the data of a newly conducted laboratory study on the effects of the duration of waterlogging on the stability of soil structure, as well as the results of several studies carried out in the past with the following goals: i) assessment of the effects of soil moisture various levels on the stability of the structure; ii) assessment of the effects of several wetting and drying cycles on aggregate stability; iii) determination of aggregate stability under the influence of freezing and thawing under different soil moisture conditions; iv) determination of aggregate stability with an increasing number of freeze/thaw cycles (0, 1, 3, 5, 11 cycles) at field capacity moisture. The tests during which the soil was subjected to freezing and thawing were carried out taking into account the fact that during winter waterlogged soil may freeze, leading to a structure breakdown, due to the expansion of water into the pores during the freezing phase. In general, the results showed that in soils that are sandy and rich in rock fragments, rapid moisture penetration leads to significant disaggregation phenomena compared with soils with higher silt and clay contents. The results also showed that the least extensive disaggregation of the structure occurred with three wetting/drying cycles. This behaviour was more obvious in soils with a greater silt and clay content compared with sandy loam soils. After the third wetting/drying cycle, disaggregation increased with the cycles number increasing. In particular for moisture contents of 50%, this test confirms that maintaining the farm channels efficacy has a beneficial effect on soil structure, as good draining of water, which is ensured by well-functioning ditches, prevents waterlogging and fights the dispersion of clay and silt (when the soil is dry, these two components form a surface crust that disturbs the water and gas exchange as well as plant growth). Disaggregation due to freezing and thawing is linked very closely to the matrix potential (and hence to the moisture) of the aggregates before treatment. In general it can be said that a water content between saturation and field capacity predisposes the soils to a much higher level of disaggregation compared to soil that is air-dry or at the wilting point. The tests that examined the effect of an increasing number of freeze/thaw cycles showed a logarithmic degradation of structural stability in relation to the number of cycles. However, most of the disaggregation occurred after three freeze/thaw cycles. This experiment showed that only few freeze/thaw cycles are necessary to cause a significant structural degradation of soils with high water content and with a texture ranging from loamy to clayey. The results of the studies allow us to deduce that the Standard is efficient in contributing to the preservation of the soil structure. In fact, maintaining the water drainage network in efficient conditions and giving the fields a convex shape are elements that contribute to the removal of excess water, which results in a decrease of both of the possibility of the dispersal of silt+clay microaggregates and of the risk of structural damages due to freezing and thawing

Effectiveness of the GAEC cross-compliance standard Short-term measures for runoff water control on sloping land (temporary ditches and grass strips) in controlling soil erosion

The agronomic measures made obligatory by the cross-compliance Standard Temporary measures for runoff water control on sloping land included in the Ministry of Agricultural, Food and Forestry Policies (MiPAAF) decree on cross compliance until 2008, and by Standard 1.1 Creation of temporary ditches for the prevention of soil erosion in the 2009 decree, certainly appear to be useful for the control of soil erosion and runoff. The efficacy of temporary drainage ditches and of grass strips in controlling runoff and erosion has been demonstrated in trials conducted in field test plots in Italy. When level temporary drainage ditches are correctly built, namely with an inclination of not more than 2.5% in relation to the maximum hillslope gradient, they allow the suspended sediment eroded upstream to settle in the ditches, retaining the material carried away on the slope and, as a result, reducing the quantity of sediment delivered to the hydrographic network. In particular, among all the results, the erosion and runoff data in a trial conducted in Guiglia (Modena) showed that in corn plots, temporary drainage ditches reduced soil erosion by 94%, from 14.4 Mg ha-1 year-1 (above the limit established by the NRCS-USDA of 11.2 Mg ha-1 year-1) to 0.8 Mg ha-1 year-1 (within the NRCS limit and also within the more restrictive limit established by the OECD of 6.0 Mg ha-1 year-1). With respect to the grass buffer strips the most significant research was carried out in Volterra. This research demonstrated their efficacy in reducing erosion from 8.15 Mg ha-1 to 1.6 Mg ha-1, which is approximately 5 times less than the erosion observed on bare soil. The effectiveness of temporary drainage ditches was also assessed through the application of the Revised Universal Soil Loss Equation (RUSLE) erosion model to 60 areas under the control of the Agency for Agricultural Payments (AGEA) in 2009, comparing the risk of erosion in these sample areas by simulating the presence and absence of drainage ditches at a distance of 80 metres from each other as required by the Standard. The results of the scenario analysis showed that the presence of ditches on average decreases erosion by 67%. To sum up, the Standard was found to be effective from a hydraulic point of view, as the results have demonstrated the adequacy of temporary ditches for the control of runoff water. Another important result of this study was the production of a simple equation that can be directly used by farmers or, more realistically, by the farm advisory system to provide farmers with the information necessary for the realisation of temporary drainage ditches (depth and section that can be obtained with the most widespread types of ditch diggers) so that these ditches are effective and maintain their hydraulic efficacy throughout the entire cropping period. This equation would also be useful for cross-compliance control by the AGEA and regional control bodies

Validation of Soil Erosion Risk Assessments in Italy.

Abstract not availableJRC.H-Institute for environment and sustainability (Ispra

Morphological and molecular characterization of a Steinernema carpocapsae (Nematoda Steinernematidae) strain isolated in Veneto region (Italy)

Veneto region (North-East Italy). This new strain was named ItS-CAO1. Molecular and morphological analyses were performed. The ITS region and the 18S rRNA gene were amplified and sequenced. The ITS products were then digested with six restriction enzymes in order to unequivocally identify this species. Nematode virulence was tested against last instar of Galleria mellonella (L.) using different laboratory assays. Insect mortality of this new strain is very high in penetration (100%) and sand column assay (93.3%) and the percentage of penetrating infective juveniles was 57.6 and 42.9, respectively. Larval mortality in one-on-one quality assay was 50% and in exposure time assay it was 50% at 19 minutes. With the results of infectivity assays we can evaluate the possibility to use this new strain in biological control programs

Monitoraggio della biodiversità in relazione all'applicazione degli standard di condizionalità: 4.2c, 4.6, 4.3 (olivo)

Nel presente lavoro vengono riportati i risultati relativi ai monitoraggi della diversità faunistica per i seguenti standard: 4.2c, 4.3 (olivo), 4.6. I risultati ottenuti sono nel complesso interessanti sia dal punto di vista metodologico sia per quanto concerne gli aspetti conservazionistici e gestionali. Emerge l'importanza di utilizzare più indicatori o gruppi tassonomici che comprendano taxa ecologicamente e funzionalmente diversi per valutare la "biodiversità". Relativamente allo sfalcio è stato osservato che una "blanda gestione" dei ritirati dalla produzione può favorire un certo incremento di biodiversità sia per quanto riguarda gli Artropodi, sia per quanto riguarda i Rettili. Risultati concordi sono stati osservati anche negli oliveti dove la gestione della vegetazione al suolo (sfalcio) sembrerebbe incrementare la diversità. Tuttavia è opportuno ricordare che l'effetto monitorato, almeno nei ritirati dalla produzione, non è quello immediatamente successivo all'azione meccanica che invece provoca danni diretti e immediati alla fauna (ferimento e uccisione). Emerge con evidenza dai dati raccolti anche l'importanza della presenza, all'interno degli agro-ecosistemi, di aree a minor disturbo antropico, naturali e semi-naturali: fasce ecotonali e ripariali, ma anche bordure dei campi. Viceversa l'uniformità del paesaggio e la presenza di grandi estensioni coltivate a monocoltura rappresentano elementi sfavorevoli alla biodiversità animale. Nel monitoraggio attraverso l'utilizzo della tecnica di fototrappolaggio è emersa l'importante funzione svolta dai muretti a secco, "presenze" tipiche e diffuse nel paesaggio agricolo tradizionale del nostro territorio italiano. Per molti taxa animali detti manufatti assolvono a funzioni ecologiche diverse, quali: rifugio, aree di foraggiamento, passaggio o sosta nonché punti ottimali per la termoregolazione.</p

Monitoraggio quantitativo della valenza sul paesaggio degli elementi caratteristici, dei livellamenti e degli sbancamenti del suolo in un’area a vocazione vitivinicola, in relazione agli Standard di condizionalità 1.1 e 4.4 (Decreto MiPAAF n° 30125/2009)

Nell'attuale  periodo di  programmazione della PAC la  protezione  e  il  miglioramento  delle infrastrutture  gestite dalle aziende agricole e  che  contribuiscono grandemente alla determinazione della qualità del  paesaggio  rurale,  compreso  quelle  ad  alta  valenza  ecologica,  sono  state  rese  possibili  rispettivamente dall'applicazione dello Standard di Condizionalità 4.4: “Mantenimento degli elementi caratteristici del paesaggio” e dall’adesione alla Misura agroambientale 323: “Tutela e riqualificazione del patrimonio rurale”  implementata dai PSR.In questo studio, che ha riguardato la valutazione paesaggistica di un’area del Comune di Conegliano, si è inteso fornire uno strumento su base geografica  che, insieme ad altri strumenti di valutazione, consenta la redazione di carte tematiche di “monitoraggio  quantitativo” della valenza degli elementi caratteristici del paesaggio e dell’impatto dei livellamenti, consentendo anche di rappresentarne la percezione dinamica. Il monitoraggio quantitativo può consentire alle Amministrazioni locali di trarre elementi di  giudizio e di scelta idonei a tutelare gli aspetti paesistici dei distretti rurali ove l’attività vitivinicola gioca un ruolo fondamentale fra le attività economiche. Sulla base di tali elementi di  giudizio e di scelta sarà possibile predisporre i regolamenti di governo del territorio, efficaci nella tutela del paesaggio, da far rispettare per l’ottenimento della concessione dell’autorizzazione, cui lo Standard di Condizionalità 1.1.b fa riferimento. Le metodologie proposta non sono alternative all’Approccio di Valutazione Storico Culturale (AVASC) proposto da Agnoletti (2010) che valuta la dinamica dell’uso del suolo e i cambiamenti avvenuti in un ampio arco temporale al fine di definire come “caratteristico” un elemento del paesaggio.

Measurement of rill erosion through a new UAV-GIS methodology

Photogrammetry from aerial pictures acquired through micro Unmanned Aerial Vehicles (UAV), integrated by post-processing is a promising methodology both in terms of speed of data acquisition, degree of automation of data processing and cost-effectiveness. The new UAV-GIS methodology has been developed for three main purposes: i) for a quick measurement of rill erosion at a field scale with the aim of combining the simplicity of field survey to reliability of results, at an affordable price; ii) to calibrate the RUSLE model to make it suitable for the purposes of the CAP common indicator; iii) to provide an easy evaluation tool to Regions and to non-research professionals who use the very popular ESRI ArcGis software for assessing the effectiveness of soil conservation measures adopted under CAP and to calibrate the common indicator “soil erosion by water”. High-resolution stereo photos pairs, acquired close to the soil, are of crucial importance in order to produce high resolution DEMs to be analysed under GIS. The GIS methodology consists of the measurement of rill erosion that occurred in a plot from the total volume of the incisions, regardless of internal sediment redeposition, based on Plan Curvature analysis and Focal Statistics analysis, described in detail, as they are the essential constituents of the new methodology. To determine the effectiveness and reliability of the new methodology a comparison between rill depth measured manually on field of 51 rill points and depth measured by UAV-GIS methodology was done. The best calibration equation was obtained by using 30 cm radius in the Focal statistics analysis. The linear regression equation resulted highly significant with R2 =0.87. Two case studies are presented, solved step by step, in order to help the user to overcome possible difficulties of interpretation in the application of the GIS procedure. The first solved exercise concerns a heavily eroded plot where only one DEM, derived from post erosion UAV photos, was used to calculate rills erosion. In this case, incisions due to tillage tools and wheel tracks (false rills) which were present on the soil surface before soil erosion had occurred were no longer present at flight time, as they have been fully incorporated (absorbed) by rills. The second exercise concerns a less rilled plot, where the diachronic analysis of DEMs was deemed necessary to subtract from the rill volume the false rill volume which was still present on the soil surface before soil erosion has occurred. In this case rill erosion increased the volume of preexisting mechanical incisions that are still distinguishable (with the naked eye on the field) from the incision forms due to runoff water. A solved exercise to assess interrill erosion from the calculated value of rill erosion, according to a previous study of 1989, is also reported. A comparison between UAV-GIS measured and RUSLE predicted erosion rates is also reported, which gives a first confirmation of validity of the new methodology

Modeling sediment yields in Italian catchments.

Sediment yield observations, derived from 40 long-term sedimentation records in Italian reservoirs, were used to calibrate and validate the spatially distributed sediment delivery model WaTEM/SEDEM using the best data available at national scale. The sediment yield data set includes records from semi-natural catchments in northern Italy as well as agricultural and semi-natural basins in central and southern Italy. The average size of the catchments is 150 km2 with mean annual sediment yields ranging from 0.20 to 20 t ha−1 year−1. WaTEM/SEDEM estimates mean annual sediment fluxes to permanent river channels. Depending on the local transport capacity, the sediment flux is detachment-limited or transport-limited. The optimal transport capacity parameters for Italian conditions were derived via automatic calibration procedures. A global model calibration procedure taking into account all catchments in the dataset led to an overestimation of the sediment yield for the mountain catchments and an underestimation for the non-mountain catchments. Sediment yield estimates are more reliable when calibration procedures are applied separately for mountain and non-mountain catchments. The model performance of WaTEM/SEDEM is rather poor in the mountain catchments (R=0.25), which suggests that the model structure is too simplified to come to an adequate description of the sediment fluxes. The model performance for the non-mountain catchments, which are more important from a management point of view, is significantly better (R=0.51). Considering the fact that data layers with a 75×75 m resolution were used, the results are encouraging the further development and application of spatially distributed sediment yield models at regional and national scale levels

Effectiveness of the GAEC standard of cross compliance retain terraces on soil erosion control

The GAEC standard retain terraces of cross compliance prohibits farmers the elimination of existing terraces, with the aim to ensure the protection of soil from erosion. In the Italian literature there are not field studies to quantify the effects of the elimination or degradation of terraces on soil erosion. Therefore, the modeling approach was chosen and applied in a scenario analysis to evaluate increasing levels of degradation of stone wall terraces. The study was conducted on two sample areas: Lamole (700.8 ha, Tuscany) and Costaviola (764.73 ha, Calabria) with contrasting landscapes. The Universal Soil Loss Equation model (USLE) was applied in the comparative assessment of the soil erosion risk (Mg . ha-1 . yr-1), by simulating five increasing intensity of terrace degradation, respectively: conserved partially damaged, very damaged, partially removed, removed, each of which corresponding to different values of the indexes of verification in case of infringement to GAEC standard provided for by the AGEA rules which have come into force since December 2009 (Agency for Agricultural Payments). To growing intensity of degradation, a progressive loss of efficacy of terraces was attributed by increasing the values of the LS factor (length and slope) of USLE in relation with the local modification of the length and steepness of the slope between adjacent terraces. Basically, it was simulated the gradual return to the natural morphology of the slope. The results of the analysis showed a significant increase in erosion in relationship with increasing degradation of terraces. Furthermore, it is possible to conclude that the GAEC standard retain terraces is very effective with regard to the primary objective of reducing erosion. A further statistical analysis was performed to test the protective value of terraces against soil erosion in areas where agriculture was abandoned. The analysis was carried out by comparing the specific risk of erosion (Mg . ha-1 . yr-1) of polygons with land uses: forest and abandoned, with natural vegetation in evolution. In both areas, forest on totally degraded terraces is able to decrease erosion well below the tolerance threshold of 11.2 Mg . ha-1 . yr-1, in the same manner as conserved terraces do for other soil uses. At Lamole, the natural vegetation in evolution on completely degraded terraces is able to decrease erosion below the tolerance threshold. On the contrary, at Costaviola on the same soil use and level of terrace degradation, soil erosion remained above the tolerance threshold. This difference can be explained by considering that the average gradient of hillslopes (considered without terraces) is 65.4 % for Costaviola and 35.0 % for Lamole. From these findings it is possible to argue that terraces, although degraded, continue to play a role in the protection of soil against erosion in abandoned areas. Thus, they continue to exert a valuable environmental function in terms of production of public goods and services; in particular, in the decrease of hydrogeological risk