Agricultural land in Norway

Soils are the basis for food- and biomass production and delivering a range of additional important ecosystem services. Later years the importance of soil resources for human wellbeing is increasingly recognized both nationally and globally.

Important reasons for the increased awareness are yield stagnations, soils ability to drain and retain excess water is often poor, and increasing losses of organic matter and organic carbon. In addition to decreasing soils’ production capacity, these trends are also resulting in increased emissions and inputs of sediments and nutrients to water bodies.  In Norway only 3 % of the land area consist of agricultural land, and only 1 % is suited for cultivation of food grains, so the soil resources are limited and important to conserve to ensure future production.

Challanges for this land type

The challenges to agricultural land can vary, particularly with the type of agricultural system and soil type. On mineral soils challenges to Norwegian soils are mainly related to decreasing concentrations of soil organic matter, reduced soil biodiversity and poor soil structure. The levels of soil organic matter in Norwegian arable soils have been reduced substantially the last 60-70 years (primarily areas of cereal-, potato- and vegetable production). Mineral soils of high soil organic matter concentrations or organic soils are more susceptible to soil compaction, particularly in areas of high precipitation, and low biological activity.

There are several potential threats that can reduce soils’ ability to function and deliver ecosystem services. These threats can be grouped as biological, physical and chemical soil threats. Erosion, soil compaction, loss of organic matter and organic carbon, loss of biodiversity, floods and landslides, contamination, soil sealing, desertification and salinization are examples of threats that might degrade soil resources and their ability to deliver functions and ecosystem services.

These threats might be amplified by additional drivers such as climate and agricultural practices. Climate change resulting in changed precipitation patterns, such as droughts and intensive precipitation events and extreme weather that can increase the risk of erosion and losses of organic matter and biomass. More precipitation can also lead to higher risk of soil compaction if the soil water content is higher during periods of field operations and harvesting.

Some possible solutions

Improving or maintaining soil health is important for soil functionality. The suitability and effect of measures to improve soil health varies largely with soil type, climate conditions and type of production. There are, however, several measures associated with good agronomic practice that can contribute to improving soil health. More emphasis on implementing one or more agricultural practices or measures on the individual farm could be one possible approach. Developing guidelines or principles for good soil health is another approach that could be useful to develop better practices for improving soil health. Examples of such principles are to minimize soil disturbance, maximize biodiversity, maximize soil cover and maximize presence of living roots (from the National Resources Conservation Service (NRCS)).

The expert group that developed the Norwegian soil health programme (appointed by the Norwegian Agriculture Agency) evaluated these principles and concluded that they are a useful basis for evaluating current soil health measures and methods. The principles are complimentary, and the highest benefit for soil health will be achieved if all four principles are considered in a farming system. Other interests should, however, also be considered, balancing the principles and the need to produce sufficient yields. Measures and practices that aim to enhance soil health are also believed to reduce the impact of soil threats.

Examples of such measures are drainage, liming, remediation of soil compaction damage (biologically by deep roots or mechanically), addition of manure, organic matter, biochar, and biological waste products (e.g., sewage sludge, fish sludge), reduced/no tillage, measures to reduce soil compaction (e.g., lighter machinery, reduced air pressure in tires, larger tires).

Still, more knowledge about how soil health can be improved and maintained while yields are maintained or increased is still needed.

The Norwegian government has decided that the rate of soil sealing should not exceed 4 km2 per year by 2020.