SoCo: European Overview on soil degradation processes related to agriculture

Transcription

1 SoCo Policy Seminar, Brussels, 28 May SoCo: European Overview on soil degradation processes related to agriculture by E. Rusco, L. Montanarella, B. Marechal JRC IES Land management and Natural Hazards Unit Soil Action

2 Legislative framework SoCo Policy Seminar, Brussels, 28 May EU Thematic Strategy for Soil Protection adopted by the European Commission on the 22nd of September 2006 COMMUNICATION COM(2006) 231 on the Thematic Strategy for Soil Protection DIRECTIVE COM(2006) 232 establishing a framework for the protection of soil and amending Directive 2004/35/EC IMPACT ASSESSMENT SEC(2006) 620 of the Thematic Strategy for Soil Protection

3 Legislative framework SoCo Policy Seminar, Brussels, 28 May COUNCIL REGULATION (EC) No 73/2009

4 SoCo Policy Seminar, Brussels, 28 May The impact of human activities on soil Sealing Blocking of soil functions important to the ecology of the landscape Destruction of soil Diffuse input of contaminants as particulates Gradual disappearance of farms Gradual destruction of soils Reduction in soil fertility Persistent substances Soil erosion Decline of Soil OM Changes in the structure of soils Reduction in soil fertility Acids Pesticides & herbicides Accumulation/ Contamination Compaction Salinisation Acidification Manures and fertilisers Sewage sludge Heavy metals Contamination of soils and ground water with applied agrochemicals and atmospheric pollutants Changes in soil composition Adverse impacts on living organisms in the soil Release of toxic substances Gravel extraction Destruction of soil

5 Soil Erosion in Europe SoCo Policy Seminar, Brussels, 28 May

6 Soil Erosion Main effects of agriculture on soil erosion SoCo Policy Seminar, Brussels, 28 May Agriculture and soil erosion - discontinous soil cover

7 Soil Erosion Main effects of agriculture on soil erosion SoCo Policy Seminar, Brussels, 28 May Agriculture and soil erosion - discontinous soil cover - insufficient surface water management

8 Soil Erosion Main effects of agriculture on soil erosion SoCo Policy Seminar, Brussels, 28 May Agriculture and soil erosion - discontinous soil cover - insufficient surface water management - reduced water infiltration rate due to soil compaction

9 Soil Erosion Main effects of agriculture on soil erosion SoCo Policy Seminar, Brussels, 28 May Agriculture and soil erosion - discontinous soil cover - insufficient surface water management - reduced water infiltration rate due to soil compaction - decline in organic matter with changes in hydrological properties of soil

10 Soil Erosion in Europe Soil loss tolerance factor SoCo Policy Seminar, Brussels, 28 May The T factor is the maximum rate of soil erosion that can occurs and still permit crop productivity to be sustained economically. Factors considered in defining the T factor include soil depth, physical properties and other characteristics affecting roots development, gully prevention, on field sediment problems, seeding losses, organic matter decline and loss of plant nutrients.

11 Soil Erosion in Europe Soil loss tolerance factor SoCo Policy Seminar, Brussels, 28 May Agricultural Land with T factor > 2 ton/ha/yr 24,972, % of the total UAA < 2 t ha-1 yr-1 > 2 t ha-1 yr-1 87 % of the total UAA 170,049,166

12 Soil Erosion in Europe Soil loss tolerance factor SoCo Policy Seminar, Brussels, 28 May Agricultural land with T factor 5 t ha-1 yr-1 16,274,386 9% of the total UAA 5 t ha-1 yr-1 5 t ha-1 yr-1 91% of the total UAA 178,747,146

13 Soil Erosion in Europe Soil loss tolerance factor SoCo Policy Seminar, Brussels, 28 May Agricultural land with T factor 10 t ha-1 yr-1 8,690,835 5% of the total UUA 10 t ha-1 yr-1 > 10 t ha-1 yr-1 95% of the total UUA 186,330,697

14 Soil Organic Matter SoCo Policy Seminar, Brussels, 28 May The kinetics of the SOC changes follow an exponential curve that shows a declining rate of SOC accumulation/loss with time when soil approaches either the maximum or minimum SOC content. These kinetics allow for the suggestion that the probability of SOC gain is higher for carbon unsaturated soil; and the risk of the SOC loss is higher for carbon saturated soil. These assumptions are phrased above as the 'risk of SOC loss'. For practical reasons, the threshold intervals are equally distributed and computed as (Max SOC Min SOC)/3.

15 Soil Organic Matter SoCo Policy Seminar, Brussels, 28 May

16 Soil Compaction in Europe SoCo Policy Seminar, Brussels, 28 May Damage due to increasing soil deformation Heavy machinery compacts arable, forest, and pasture soils Effects on the environment Reduced growth, higher uncertainty less Dust emission increased yield Increased fungi deseases, N2O gas emission After rain storm Rapid water table increase in rivers and lakes Consequences for plant production more weeds erosion Surface water runoff increase N - loss due to stagnic water Reduced groundwater recharge Soil quality declines due to - reduced pore volume, - reduced aeration Soil biota suffers Reduced root growth (less dense and deep) Effects on soil management - higher draft energy required, - higher fuel consumption, -Water infiltration - wet and cold soils result in reduced, smaller - soils remain longer wet number of working days, and cold, - more fertilizers needed - more slaking problems, - reduced water storage Source: R. Horn, personal communication

17 Soil Compaction in Europe SoCo Policy Seminar, Brussels, 28 May % of European Soils have high or very high susceptibility to compaction

18 Soil Compaction in Europe SoCo Policy Seminar, Brussels, 28 May % more infiltration

19 Salinisation/sodification SoCo Policy Seminar, Brussels, 28 May Classes of salinity low: ECse < 4 ds/m (decisiemens per metre) medium: 4 < ECse < 15 ds/m high: ECse > 15 ds/m Classes of alkalinity low: ESP < 6 % medium:6 < ESP < 15 % high: ESP > 15 % with ESP: exchangeable sodium percentage.

20 Conclusion SoCo Policy Seminar, Brussels, 28 May Soil Degradation processes are strictly linked with the different types of soil, environmental conditions and management systems It is difficult, if not impossible, to identify soil conservation practices without linking practices and soil types Is absolutely crucial apply management system that take into account the soil degradation processes as a whole A soil monitoring system that evaluates the magnitude of the soil degradation processes needs to be established as a first priority.

21 SoCo Policy Seminar, Brussels, 28 May Thank you for your attention! Farming looks mighty easy when your plough is a pencil and you re a thousand miles from the corn field Dwight David Eisenhower