1) Spanish Case Study - reduction in contamination through amendment additions and afforestation

The researchers tested and monitored the efectiveness and duration of amendments to reduce contamination in the Guadiamar corridor.  They also monitored the effects of trees on soil contamination and carbon sequestration.

Reduction of contamination by amendment addition

Afforestation of contaminated land

Final Results

• The main target was to increase pH and thereby reduce the availability of cationic trace elements.

• The addition of amendments increased pH and their effects lasted with time. Sugar beet lime increased pH by 111%, while biosolid compost increment was 43%.

• The available concentration of trace elements showed a strong decrease in the amended plots. In particular, sugar beet lime reduced Cd, Cu and Zn availability by 99%.

• The soil pH under trees ranged from 2.6 up to 6.1 and was negatively and exponentially related with availability of trace elements (see example of Cd in the figure below).

• Ceratonia, Fraxinus, and Populus were the tree species most effective at reducing trace elements availability in the soil underneath them.

Enrichment of soil organic carbon was a second target of remediation measures.

• The initial values of soil carbon were very low, around 1%. The addition of biosolid compost doubled soil carbon.
• Soils underneath trees were richer in organic carbon than those in the treeless sites. The highest values were for Ceratonia and Fraxinus.

Further details about this experiment can be found in the fact sheet HERE (ES) and in the project report HERE.

For more details about this experiment, please contact Teodoro Marañón This email address is being protected from spambots. You need JavaScript enabled to view it.

Scientific articles

Madejón, Paula, María T. Domínguez, Engracia Madejón, Francisco Cabrera, Teodoro Marañón, and José M. Murillo. Soil-plant relationships and contamination by trace elements: A review of twenty years of experimentation and monitoring after the Aznalcóllar (SW Spain) mine accident. Science of The Total Environment 625 (2018): 50-63.  doi.org/10.1016/j.scitotenv.2017.12.277doi.org/10.1016/j.scitotenv.2017.12.277

M.T. Domínguez,J.M. Alegre, P. Madejón, E. Madejón, P. Burgos, F. Cabrera, T. Marañón, J.M. Murillo (2016) River banks and channels as hotspots of soil pollution after large-scale remediation of a river basin  Geoderma Vol 261, 1 January 2016, Pages 133–140 DOI:10.1016/j.geoderma.2015.07.008

María T. Domínguez, , Ignacio M. Pérez-Ramos, José M. Murillo, Teodoro Marañón Facilitating the afforestation of Mediterranean polluted soils by nurse shrubs.Journal of Environmental Management Vol Volume 161, 15 September 2015, Pages 276–286 doi:10.1016/j.jenvman.2015.07.009

María Anaya-Romero,Sameh Kotb Abd-Elmabod, Miriam Muñoz-Rojas, Gianni Castellano, Carlos Juan Ceacero, Susana Alvarez, Miguel Méndez, Diego De la Rosa (2015) Evaluating Soil Threats Under Climate Change Scenarios in the Andalusia Region, Southern Spain. Published in: Land Degradation & Development Volume 26, Issue 5 July 2015 Pages 441–449 http://onlinelibrary.wiley.com/doi/10.1002/ldr.2363/full

For more details about this experiment, please contact Teodoro Marañón This email address is being protected from spambots. You need JavaScript enabled to view it.

2) Romanian Case Study - immobilization of heavy metals using soil amendements

The researchers tested the effectiveness of different soil amendements to reduce the heavy metals mobility in soil and the uptake by plants.

Factory site, Copsca Mica

 Final Results

The main results from the experimental field were:

• The highest increase in pH values was for soil treated with Na-bentonite (7.16) compared with the control (5.18).
• In both experimental years, concentrations of available cadmium, lead and zinc decreased significantly with the application of amendments, and they followed the order (highest to lowest): control > natural zeolite > manure > Na-bentonite > dolomite.

• Compared with the control all treatments had statistically significant effects on metals accumulation in biomass but the highest decrease of metal content in the plant was after dolomite application.

Further details about this experiment can be found in the fact sheet HERE (RO) and in the project report HERE.

For more information about this RECARE experiment, please contact  Mihail Dumitru This email address is being protected from spambots. You need JavaScript enabled to view it.

Scientific References

• Increasing or maintaing soil organic matter

• Increasing organic matter with cover crops and conservation agriculture

1) The Netherlands Case Study - increasing or maintaining soil organic matter

Grass undersowing in maize

Final Results

• Grass undersowing in maize fields is expected to result in 0.5% extra soil organic matter (SOM) after 30 years, and also a little more production of grass in years with grass cropping. But since the measure was only started in 2014, the result is still unknown. Conversations with four farmers revealed that the SOM content has remained stable or slightly increased, and that the bearing capacity of the soil has improved.
• Average nitrate concentration in the upper groundwater in the area fluctuated around the EU-standard of 50 mg/l: in 2014 and 2017 it was above and in 2005 and 2016 below the standard.
• Farmers experienced variable results from grass undersowing, depending strongly on the weather, with good growth of the grass cover in wet years, but competition for water with the maize crop and no grass growth in dry years. Farmers frequently experienced poor grass cover.
• Drawbacks of the measure mentioned by farmers are that the undersowing may cause damage to the standing maize crop and in the headlands of the fields and that the sowing is a difficult task since it needs to be done at the right places and in the right period. It is difficult to perform in small parcels, and the weed control is more difficult.
• Farmers also indicate that grass undersowing is not effective in a grain maize crop, where only the maize cobs are harvested and the rest of the plant is frittered, thereby suffocating the undersown grass.
• Grass undersowing was evaluated by farmers and residents to foster regulating ecosystem services, namely the increase of the buffer function for organic matter and nitrogen and the bearing capacity of the soil. Also, cultural ecosystem services were found to be improved when fields remain green after the harvest of the maize crop, instead of showing brown stubble.
• However, the provisioning ecosystem services that were foreseen as a result of this measure (increase in feed crop yield and groundwater production) were not mentioned by the farmers as a benefit.

Further details about this experiment can be found in the fact sheet HERE (NL) and in the project report HERE

For more information about this RECARE experiment, please contact Simone Verzandvoort This email address is being protected from spambots. You need JavaScript enabled to view it.

2) Italy Case Study - increasing organic matter with cover crops and conservation agriculture

Increasing organic matter content through long-term sustainable agriculture systems

Final Results

Experimental results showed significant differences in crop production between treatments, with lower average yields in CA (5.4 Mg ha^-1) than in CC (7.9 Mg ha^-1) and CV (8.5 Mg ha^-1). Continuous soil cover in CA and CC determined the soil-water balance through increased evapotranspiration and reduced percolation (-30%) relative to CV. On the other hand, CC and CV tillage operations significantly affected NO3-N concentrations, with higher soil solution concentrations in tilled (CV = 74.6 mg l^-1; CC = 58.1 mg l^-1) than in untilled (CA = 14.0 mg l^-1) systems. Model results emphasised that SLM practices responded differently in the short and long 30 terms due to initial inertia to C changes and lower N2O fluxes, followed by higher SOC sequestration, and increased N2O emissions. These results demand time–dependent studies that weigh agro-environmental benefits provided by SLM practices against management alternatives to find a suitable compromise for stakeholders.

Further details about this experiment can be found in this project report HERE.

Scientific articles

Pituello, C., Dal Ferro, N., Francioso, O., Simonetti, G., Berti, A., Piccoli, I., Pisi, A. and Morari, F., 2018. Effects of biochar on the dynamics of aggregate stability in clay and sandy loam soils. European Journal of Soil Science, 69(5), pp.827-842. https://doi.org/10.1111/ejss.12676

Chiara Pituello, Nicola Dal Ferro, Gianluca Simonetti, Antonio Berti, Francesco Morari (2015) Nano to macro pore structure changes induced by long-term residue management in three different soils. Ecosystems and Environment, Vol 217, 1 February 2016, Pages 49–58 doi:10.1016/j.agee.2015.10.029

For more information about this RECARE experiment, please contact Francesco Morari This email address is being protected from spambots. You need JavaScript enabled to view it.

1) Case Study Experiment - decline in organic matter in peat soils

The researchers in The Netherlands tested the effectiveness of infiltration via submerged drains to reduce peat oxidation and so the loss of organic matter.

Submerged drains in peat soils

Final results

Results survey among 30 dairy farmers with submerged drains: 

• About 10% area drained (submerged)
• Aim to increase trafficability and decrease subsidence
• 75% are positive (better trafficability, better grass yield, less drought)
• 25% doesn’t see an improvement
• These 25% have wide distances (> 6 m) or high ditchwater levels (< 50 cm -surface) according to most farmers governments and waterboards lack a vision on submerged drains
• Better insight in costs and benefits is required
• A majority will install more submerged drains if subsidized

Results pilots with infiltration via submerged drains to conserve peat:

Infiltration via submerged drains reduces the subsidence with 50 -70% depending on the ditch water level. Combination of submerged drains with a high ditchwater level of about 20 cm minus surface level reduces subsidence to less than 1 mm per year.

For more information about this RECARE experiment, please contact Jan van den Akker This email address is being protected from spambots. You need JavaScript enabled to view it.

Further information about the case study activities in Dutch can be found on the Stakeholder Platform here.  

2) Sweden Case Study - loss of organic matter in organic soil

The researchers in Sweden are testing different crops, especially reed canary grass and Tall fescue and comparing them with the "ususal" crop timothy, regarding yield and CO2 emissions.

An aeriel view of the case study site. 

Swedish Case Study Experimental site

Final results:

Effects of treatments on soil proprties

Penetration resistance (average of measurements at 10-20 cm depth) in July and October for Reed canarygrass(RCG), Timothy (T) and Tall fescue (TF).

Effect of treatments on soil threat

The N²Oemission was quite low during the growing season and no significant difference between the crops could be found. The total yield from 2 cuts (t DM/ha) of T was 6.6. RCG yielded 9.3 and TF 8.6.

For more information about this RECARE experiment, please contact Kerstin Berglund This email address is being protected from spambots. You need JavaScript enabled to view it.

1) Norway Case Study - Preventing floods and landslides

The researchers in Norway tested flood retention and the impact of vegetation on river bank stability in the Morsa Catchment. They modelled the effect of different sized retention dams in forest areas (upstream agricultural fields) and the root strength of river bank vegetation.

Preventing floods and landslides

Final Results

Water retention ponds

• The flood peak is most likely lowered by the inclusion of a retention area in the catchment. The retention area has a large impact on decreasing soil erosion on the down-slope agricultural fields.  It captures and diverts surface runoff, resulting in less sheet and especially gully erosion on the agricultural land.
• Although the number of floods was not quantified during the experiment, according to the statements of the farmers, the flooding over
  the agricultural land is reduced from 2-3 times a year to once every second year (reduction in local flooding). 

	Example of the modelling results for the area without and with implemented retention pond

Further details about this experiment can be found in the fact sheet HERE (NO) and in the project report HERE

Bank stability 

• The grass and shrub plots showed similar dynamics both in groundwater level and soil water content fluctuation, while clear differences were observed in hydrological responses within the plot containing trees. The trends observed in soil water content variation corresponded to the groundwater level fluctuations. The differences can be explained by different root depths and subsequent root water uptake.
• Soil-root strength changes with time. In all three plots, higher values of shear strength were observed during late spring and summer. This trend stems from two factors: intensity of the vegetation growth (higher root density) and lower soil moisture content. Variation in modelled slope stability corresponds to variation in groundwater levels and stream water levels.   The probability of riverbank failure was higher during spring and early autumn, and lower during the summer. The tree plot was the most stable and shows the highest capacity to accommodate potential shear stress.

Changes in average shear strength with time and with depth, for the three plots
Changes in average shear strength with time and with depth, for the three plots		Frequency of Fs for all simulated scenarios, for min and max slope angles. Stability classes: red – unstable slope; yellow – conditional stability; green – stable slope

Further details about this experiment can be found in the fact sheet HERE (NO) and in the project report HERE.

For more information about this experiment, please contact Jannes StolteThis email address is being protected from spambots. You need JavaScript enabled to view it.

2) Slovakia Case Study - Mitigating muddy floods and soil erosion

The researchers in Slovakia conducted three eperiments 1) tested the effect of rainfall intensity, soil moisture and vegetation cover on generation of overland flow and sediment transport; 2) measurements of gully erosion; and 3) measurements of sediment loads and bed sediments in a small water reservoir.

Mitigating muddy floods and gully erosion

Final results

Experiment	Results
1. Generation of surface runoff	High dependency on the type of soil cover, crop management techniques used, and the stage of vegetation growth on the volume of surface runoff, bare soil together with high initial soil moisture (above 40%) had the most significant impact on the amount of surface runoff, erosion modelling confirmed a good protective effect of winter wheat, which could be planted even on steeper slopes, with no need to plant an excessive number of protective vegetation strips, the simulations with a 100-year rainfall revealed, that when compared to the bare soil, a 42% decrease of surface runoff volume was estimated when the area was used for maize production, and as much as a 90% decrease when used for winter crop production.
2. Changes in erosion gully	Analysis of historical maps identified changes in the position of the gully erosion between the individual years, while the bottom part stayed relatively stable For a detailed analysis of gully erosion, the experiments focused on the assessment of changes in the gully rills volume and selected parameters using a terrestrial laser scanner, UAV technology and GNSS. The measurements show that despite the use of small wooden check dams, the erosion processes are still ongoing Comparison between 2014 and 2015 showed the gully volume had increased by more than 10 %. Between 2015 and 2016 the volume increased by almost 80 m3, which represents an 8% increase Measurements suggest that the geometry of the erosion gully near the wood check dams is somewhat stable. The gully is continuously observed and monitored In two of the existing check dams, an increase in the longitudinal slope was recorded, which was caused by deposits of eroded soil particles.
3. Changes in sediment loads	Over five years, 10.694 m3 of bottom sediments accumulated in the Svacenický Creek reservoir.  Meanwhile, during the same time period, 179m3 of soil on the area above 1,693m2 was eroded.  Results confirmed ideas about ongoing sedimentation processes in Svacenický creek.      Management practices caused significant differences between runoff and the amount of soil loss in the Svacenický creek catchment. In the case of different land management strategies, the most intensive erosion processes were detected on the fallow land cover type as opposed to the winter wheat, where the effect of the net erosion rapidly decreased in the catchment

Further details about the experiment on the generation of runoff can be found in the fact sheet HERE(SK), changes in erosion gully fact sheet HERE (SK) and changes in sediment loads HERE (SK) and in the project report HERE.

Scientific Articles

Michaela Danáčová, Radovan Nosko, Roman Výleta, Beata Randusová, Ján Szolgay (2015) Possibilities of estimating the gully erosion changes on the Myjava Basin Published in: ACTA HYDROLOGICA SLOVACA Ročník 16, Tematické číslo 1, 2015, 167 - 175

Korbeľová, Lenka, and Silvia Kohnová (2017) Methods for Improvement of the Ecosystem Services of Soil by Sustainable Land Management in the Myjava River Basin Published in: Slovak Journal of Civil Engineering 25, no. 1, 2017, 29-36  https://doi.org/10.1515/sjce-2017-0005

Čistý, M., Čelár, Ľ., Minarič, P. (2015) Conversion Between Soil Texture Classification Systems Using the Random Forest Algorithm, Air, Soil and Water Research. Published in: Air, Soil and Water Research. Volume 8, Pages 67-75, ISSN 1178-6221 http://www.la-press.com/conversion-between-soil-texture-classification-systems-using-the-rando-article-a5217

For more information about this experiment, please contact Ján Szolgay  This email address is being protected from spambots. You need JavaScript enabled to view it.