Legumes are the future of food and fertilisation

Legumes are plants that do not need nitrogen (N) fertilisation because legumes are plants that are able to fix atmospheric nitrogen (N2). In addition legumes can be used as ‘green’ fertilisers because legumes are N-rich and thus cropping legumes provides the soil with a cheap, sustainable source of N fertiliser. Legumes are also an excellent source of protein for feed and food. Nonetheless legume cropping land in Europe represents only less than 4% of arable land. The grounds for such a low cropping surface are discussed by Voisin et al. who analyse the production of forage and grain legumes in France since 1950. The authors propose changes to improve legume production.

 

Silicon-rich manure for sustainable rice production

Rice is a plant that needs silicon (Si) as a nutrient to grow well. Silicon is an element of silica (SiO2) found commonly in sand. Rice yields decrease when soils are depleted in available silicon. A possible solution is to add silicon-rich manure to soils. Song et al performed a 10-year field experiment and found that adding silicon-rich manure doubled the amount of available silicon in soils. Using manure brings the additional benefit of recycling organic waste and providing other plant nutrients such as nitrogen and phosphorus

 

Benefits and risks of anaerobic digestate fertilisers

Intensive soil fertilization with mineral fertilizers has led to several issues such as high cost, nitrate pollution, and loss of soil carbon. Fertilization with organic wastes such as anaerobic digestates is an alternative for sustainable agriculture. Conflicting results in the literature have questioned the effectiveness of anaerobic digestates as organic fertilizers. The review by Roger Nkoa demonstrates the fertilizer values of anaerobic digestates. However, anaerobic digestates emit amonia (NH3) and contain copper (Cu), Zinc (Zn) and manganese (Mn) that could pollute the soil and the atmosphere upon repeated soil applications.

 

Benefits of compost in agriculture

Climate change and most actual world food issues are linked directly or indirectly to soil loss of carbon and fertility. Here composting appears as a cheap and sustainable solution.The review by Martínez-Blanco et al. presents nine benefits of compost application to the soil. Composting practices are classified into short-term, mid-term, and long-term benefits.