## 3 Results
### Biophysical Opportunities for Low ILUC Risk Crops
#### 3.1.3 Sustainable Agricultural Practices  
The low-ILUC risk status for feedstocks involves the cultivation of crops that meet additional conditions and can be produced through smart, sustainable, and low input agricultural practices, which in return are expected to contribute to climate change mitigation and soil quality [28]. These include carbon sequestration through carbon farming. The term 'carbon farming' refers to land practices in agriculture and forestry leading to the storage of carbon from the atmosphere in biomass, organic matter, soils, and vegetation. Carbon farming is one of the mechanisms for the removal of carbon from the atmosphere that are proposed in the EU Communication on Sustainable Carbon Cycles [29]. Such practices include, among others, intercropping, cover crops, rotational cropping, and soil enrichment with biochar [30; 31] that improve soil carbon stocks, organic fertilization, agroforestry that stores carbon in vegetation [32; 33; 34], and restoration of degraded land with perennial crops. Five types of practices that support biomass production, carbon storage, and soil quality are addressed in this review, based on their occurrence in policy instruments of the EU. Each of these will now be discussed in turn. Intercropping refers to a crop grown amidst a main crop or in between the planting rows of that main crop and intended to be harvested or to be supportive to the harvest of the main crop [35]. Cover cropping refers to a crop grown in between two main crop seasons [36]. A review of meta-studies on soil improving cropping systems reported that intercropping, mixed crops, and cover crops can increase yields [37; 38; 39]. Effects on nutrient cycling and resilience to stress were less clear. Legume cover crops could be a substitute for N-fertilisers, whereas other cover crops could decrease loss of N by leaching. The input of carbon to soils from cover crops depends on the biomass yield of the crop, which is determined by the species, time of seeding, winter hardness, and availability of water [40]. Cover crops were reported to increase the soil organic matter content compared to fallow soils [39]. Data indicate that cover crops reduce soil penetration resistance by 0 to 29%. Cover crops also improve wet aggregate stability by 0 to 95% and cumulative infiltration by 0 to 190% but have insignificant impacts on bulk density, dry aggregate stability, saturated hydraulic conductivity, unsaturated hydraulic conductivity, and plant available water. The soils under the cover crop can be warmer in winter and colder in spring, summer, and autumn. Daytime soil temperature decreased by an average 2 \({}^{\circ}\)C, whereas night-time soil temperature increased by 1 \({}^{\circ}\)C, which also can induce changes in the soil organic carbon concentration [39; 40]. Ten-year field trials using cover crops showed that the observed improvement in soil hydraulic function could be based on a more compensated distribution among macro to micropores, reducing soil compaction and increasing soil water retention and crop available water. The result could be less prone to runoff and drainage losses, compensating for the water competition [39; 40; 41]. Rotational cropping refers to the temporal alternation of different crop types (mown vs. lifted, monocots vs. dicots, annual vs. perennial) on a piece of farmland. Crop rotation is the practice of growing a series of different types of crops in the same area in sequential seasons. Crop rotation gives various nutrients to the soil and replenishes nitrogen, for example, through the use of green manure, legumes, or cover crops in sequence with cereals and other crops. Crop rotation also helps to battle against erosion. Rotating crops helps to improve soil stability by alternating between crops with deep roots and those with shallow roots. Crop rotations can help prevent the accumulation of crop-specific pests and reduce the risk of pests developing resistance to ingredients used for crop protection [40; 41].