Assessment of Long‐Term Soil Erosion in a Mountain Vineyard, Aosta Valley (NW Italy)

Gyasi‐Agyei

et al. 2018

IJGI

In vineyards, especially on steep slopes like the Ruwer-Mosel Valley, Germany, soil erosion is a well-known environmental problem. Unfortunately, some enterprises and farmers are not aware of how much soil is being lost and the long-term negative impacts of soil erosion. The non-invasive technique of the stock unearthing method (SUM) can be used for a quick assessment of soil erosion in vineyards. SUM uses the graft union as a reference elevation for soil surface changes since the time of plantation commencement, which is modelled with the help of a geographic information system. A shortcoming of SUM is that the areas between the pair-vine cross sections are not surveyed, hence it is not accurate enough to identify erosion hot-spots. A structure-from-motion (SfM) photogrammetric technique is adopted to complement SUM to fill this data gap. Combining SUM (only measuring the graft unions) and SfM techniques could lead to an improved, easy and low-cost method with a higher accuracy for estimation of soil erosion based on interpolation by projection, and contact and gapless measuring. Thus, the main aim of this paper was to map the current soil surface level and to improve the accuracy of estimation of long-term soil mobilisation rates in vineyards. To achieve this goal, the TEPHOS (TErrestrial PHOtogrammetric Scanner), a static five camera array, was developed on a 20 m2 plot located in a steeply sloping vineyard of the Ruwer-Mosel Valley, Trier, Germany. A total soil mobilisation of 0.52 m3 (9.14 Mg ha yr−1) with soil surface level differences in excess of 30 cm in the 40 years since plantation commencement were recorded. Further research is, however, needed to reduce the number of photos used for the point cloud without loss of accuracy. This method can be useful for the observation of the impacts of other factors in vineyards, such as tillage erosion, runoff pathway detection or the trampling effect on soil erosion in vineyards.

Section: Soil Surface Level Assessment and Soil Mobilisation Ratessupporting

confidence: 92%

Section: Soil Surface Level Assessment and Soil Mobilisation Ratesmentioning

confidence: 99%

Combining the Stock Unearthing Method and Structure-from-Motion Photogrammetry for a Gapless Estimation of Soil Mobilisation in Vineyards

Remke

Gyasi‐Agyei

et al. 2018

IJGI

“…This method allows estimation of soil depletion and accumulation at temporal scales sufficiently long to assess the cumulative effects of agricultural practice impacts, but also to demonstrate the spatial mobilization of sediment detachment, transport and deposition under the natural conditions (Chevigny et al ., ; Biddoccu et al ., ). However, in addition to acquiring much more accurate erosion rates with ISUM, we also found that the maps created with the ISUM technique can be used to provide insights about sediment connectivity (Rodrigo‐Comino and Cerdà, ).…”

Section: Introductionmentioning

confidence: 97%

Connectivity assessment in Mediterranean vineyards using improved stock unearthing method, LiDAR and soil erosion field surveys

Earth Surf Processes Landf

Keesstra

Cerdà

2018

The interaction between processes and landforms is accelerated in vineyards due to bare tilled soils that enhance splash, runoff, and erosion. Traditionally, in order to assess these processes, the stock unearthing method (SUM) is considered a useful methodology that uses the graft union of the vine plant as passive bio-indicator of the topsoil level changes. However, SUM assumes that the topography between the rows is planar when development of a model of the current micro-topography is performed. Thus, we consider that there is a need to develop a new methodology (ISUM: improved SUM) that, by adding new measurements in the inter-row areas (at least 3), allows inclusion of the absent micro-topographical information of SUM. In this way, the main aim of this research was to estimate the micro-topographical changes and soil transport at three different slope positions (upper, middle and lower parts) in a 25-years-old vineyard in eastern Spain. LiDAR data were used to compare the connectivity processes at the catchment with the pedon scale. We obtained maps that showed topsoil level changes and detected soil depletion and accumulation signals. We estimated soil displacement rates of -1.6 Mg ha yr -1 (depletion), +2.8 Mg ha yr -1 and +13.3 Mg ha yr -1 (accumulation) at upper, middle and lower slope positions, respectively. The total average soil erosion rates in the inter-rows were -5.7 Mg ha -1 yr -1 . In the row areas, deposition of +10.5 Mg ha yr -1 was measured. Field erosion marks surveyed after each rainfall event gave insights to the connectivity at the inter-row and the slope scale. It was found that at the row scale there were sinks of sediments underneath the vines and sources in the inter-row parts, although they are the highest and lowest local topographical terrain, respectively. This is due to tillage erosion that redistributed the sediments. At the slope scale, the lower part of the slope collected sediments from the upper slope positions, which were transported along the middle part of the slope, as the measurement of ISUM and the field survey after intense rainfall events demonstrated. Connectivity of the flows along the whole slope were rare (twice), and along individual slope parts connectivity was found eight times, and 19 at the inter-row scale after 8 years of field observations.

“…To assess changes in soil level, stock unearthing method (SUM) has been a useful method because: i) it is relatively easy to be applied; ii) it generates accurate data which are representative of longterm periods of soil erosion rates; and, iii) it is an easily reproducible tool which can generate the production of a very high actual DEM resolution (cm) without drones or planes. The papers published by Brenot et al (2006Brenot et al ( ,2008, Casalí et al (2009), Paroissien et al (2010, Chevigny et al (2014) and Quiquerez et al (2014) as well as the most recent by Rodrigo-Comino et al (2016b) and Biddoccu et al (2017) have not only provided estimates of soil erosion rates and identified the main factors responsible for intra-plot variability, but have generated new information for the education of the stakeholders about the environmental issues.…”

Section: Introductionmentioning

confidence: 99%

“…The most recent studies have tested the SUM accuracy by comparing SUM results with digital elevation models, GPS, orthophotography (Biddoccu et al, 2017;Chevigny et al, 2014;Quiquerez et al, 2014) or with data generated from sediment collectors (Rodrigo-Comino et al, 2016b). However, all of these studies assumed the main limitation of this method: the surface between the vines (inter-row) remains planar.…”

Section: Introductionmentioning

confidence: 99%

Improving stock unearthing method to measure soil erosion rates in vineyards

Cerdà

2018

Ecological Indicators

A B S T R A C TVineyard soils experience high erosion rates compared to soils from other agricultural land uses. The high soil losses in vineyards limits the sustainability of traditional production schemes and warrants comprehensive research aimed at thwarting the main erosion processes affecting vineyard systems. However, long-term measurements, which include spatial variability of soil erosion rates at the plot scale, are uncommon, as most of the measurements have taken place either at the hillslope or watershed scales. Against this background, the stock unearthing method (SUM) can be considered a useful methodology. However, the current method falls short because it assumes that the topography between the vine lines (inter-rows) remains planar. Therefore, we propose a new methodology (ISUM: improved stock unearthing method) that includes three measurements between in the inter-row areas. By taking inter-row measurements, we hypothesized that the spatial patterns of sediment detachment, transport and deposition features in the inter-rows would be detected. The ISUM costs 20% more time to conduct than the SUM, but greatly improved the utility of the field survey. ISUM allowed for: i) the creation of maps that identified linear soil erosion features and accumulation sites; ii) measures the amount of soil accumulated under the vines; iii) estimation of soil erosion rates with higher accuracy at long-term periods in a specific moment. This study compared the ISUM with the SUM in a vineyard in Spain. Soil erosion rates with ISUM were −2.5 Mg ha yr −1 while the SUM calculated rates of +4.9 Mg ha yr −1.Results showed that the traditional method underestimated soil rates a −25.7%. Maps created with the ISUM technique could also be used to provide insights about sediment connectivity.