In each of the study sites the iSQAPER team, together with local farmers or land users, identified the main agricultural management practices used locally. The practices vary according to the climatic zone, soil type and crop produced. Some of them were conventional and designed to maximise yield while other innovative* practices were being used with the explicit purpose of also benefitting or improving soil quality. In the European study sites the most common innovative practices were: manuring & composting, crop rotation and minimum tillage. The most common in China were: manuring & composting, residue maintenance/mulching and integrated pest and disease management (incl. organic agriculture). For more details see: »Impact of promising land managment practices
In two separate field campaigns we compared the effects of the innovative to the conventional practices by assessing soil quality of 132 pairs of neighbouring fields. For more details of the visual assessment methods see: »Visual soil and plant quality assessment
Of the original 132, one or two practices per country were identified as having the best proven effectiveness on improving soil quality in that location. Many of these practices are described in the leaflets below which explain the
- principles of the practice,
- the soil threat it is designed to address,
- the scientific evidence for its effectiveness.
*Note: The use of the word innovative to describe some of these practices may look odd; in the history of agriculture crop rotation and manuring are hardly new. However within the context of iSQAPER's study sites these practices represent an improvement over conventional practice and are generally not widely applied in area.
Study site 1: De Peel, Netherlands
Non-inversion tillage causes less disturbance to the soil, resulting in better structure and more organic matter and soil life in the top soil. It has shown positive effects on the structure of clay soils but hasn't been tested intensively on sandy soils.
Study site 3: Cértima, Portugal
The incorporation of sludge into the soil (as part of a circular economy) increases organic matter content, improving structure and nutrient content. However, long-term application increases the amounts of heavy metals and other trace elements in the soil. Understanding the behaviour of these elements is important to support effective management practices that mitigate contamination.
Study site 4: Southeast Spain
Minimum tillage protects the soil from erosion and compaction. Allowing crop residues to remain on the soil and applying additional manure increases the organic matter content and protects the soil.
Study site 5: Crete, Greece
Extensive sustainable grazing is based on a stable animal density below or equal to the sustainable stocking rate. Extensive grazing protects the land from erosion by maintaining a vegetation cover above 40-50%, the threshold below which accelerated erosion occurs.
Minimum and no tillage belong to the conservation tillage production system where soil cultivation is kept to the minimum necessary for crop establishment and growth. Under olive groves in Crete both minimum and no tillage can decrease soil disturbance, runoff and soil loss and improve soil water conservation, aggregate stability and water infiltration.
Study site 6: Ljubljana, Slovenia
Using an organic farming system with a five year crop rotation cycle, nitrogen is supplied to the soil by organic fertiliser (from livestock) or by using legumes. Nutrient cycling is kept to a maximum within the farm. The use of chisel ploughs and hoes causes less frequent turning of the soil and maintains a continuous soil cover.
Study site 7: Zala County, Hungary
Matured farmyard manure (from cattle, pigs and horses) is applied every 3 years, before maize in the crop rotation. Storing the manure reduces weed infestation and burying it immediately after spreading avoids nutrient loss. The manure application results in higher soil organic carbon and microbial biomass.
Study site 8: Braila County, Romania
Study site 10: Tartuuma, Estonia
Using direct seeding crops are grown from year to year without cultivating the soil. Seeds are injected into the soil beneath the residue of the previous crop without loosening the soil structure. Direct seeding is considered to be environmentally friendly because in general less fuel is used and greenhouse gas emissions are reduced. However, there is a risk that costs pesticides increase as ploughing and tillage help to reduce weeds and the spread of pests. (in Estonian)
Study sites 11 and 14: Qiyang and Gongzhuling, China
Agricultural measures such as the combined application of organic and inorganic fertilizers, green manure, crop rotation and straw return are in line with Chinese national "weight loss and efficiency" principles and can improve fertility while maintaining foor production.
Study site 12: Suining, China