Fertilization

Arbuscular mycorrhizal fungi are root symbionts that play a key role in plant growth. Agronomists Van Geel et al. show that a broad range of crops highly benefit from the inoculation with arbuscular mycorrhizal fungi. They also found that there is no ‘one-size-fits-all’ arbuscular mycorrhizal fungus for all plants. On the contrary, the fungus species should be adapted to the plant partner. Also they observed that the plant should be coupled with only one fungus species, not with a mixture of several fungal partners.

Rapeseed is the second most important oilseed crop worldwide. Intensive cultivation of rapeseed induces leaching of fertilizers in waters, less efficient fertilization and pollution. There is therefore a need for rapeseed varieties that are more efficient in the use of fertilizer nitrogen. Agronomists Bouchet et al. review new knowledge on rapeseed nitrogen physiology and relevant traits that could be used for plant breeding.

Biochar is a charcoal made by pyrolysis of biomass. Biochar is applied to soils to enhance fertility, carbon sequestration and water retention. Biochar may thus solve actual issues of soil erosion and nutrient depletion. Agronomists Ding et al. review published literature on the use of biochar for soil fertility.

Nitrogen fertilizers used for growing oil palms are costly and are a source of pollution by nitrates and gases. Therefore there is a need to optimize nitrogen management. Pardon et al. review the literature to identify the key unknowns of nitrogen fluxes in oil palm plantations.

Microorganisms such as bacteria are used to help food crops by providing plant nutrients such as phosphorous. Peat moss is presently the most common carrier used to add bacterial inoculants to the soil. However peat moss is a limited natural resource. Therefore Glodowska et al. show that biochar is an alternative inoculant carrier for bacteria. They tested corn growth using the phosphorous-solubilizing bacterium Pseudomonas libanensis.

Food production in Africa is difficult due to poor soil fertility and limited farmer access to inorganic fertilizer. This issue is exacerbated by climate change. A potential solution is to improve sorghum farming because sorghum is tolerant of both drought and water logging. Agronomist Tonitto and Ricker-Gilbert reviewed sorghum management scenarios. They found inorganic fertilizer amendment increased yield by 47-98 %, while organic nutrient amendment increased yield by 43-87 %. Therefore, facilitating access to fertilizers and diversified rotations should increase grain yield in Africa, a recommendation in line with current Integrated Soil Fertility Management (ISFM) techniques promoted by the Alliance for a Green Revolution in Africa (AGRA) .

Industrial agriculture has favoured almost solely the production of for-profit high-yield crops by selecting high-yield cultivars, and adding massively mineral NPK fertilisers and pesticides. Such an approch has led to many negative consequences, such as food and water contamination, pest- and climate-sensitive crops, and food depleted in micronutrients (and taste). Dimkpa et al. review the role of micronutrients such as iron (Fe), manganese (Mn) and Zinc (Zn), for crop protection against pest and drought.

Legume farming has many benefits such as natural fertilisation by fixation of air nitrogen. However, grain legume production is decreasing in Europe, whereas Europe imports legumes, mainly soybean, to meet protein needs. To understand why farmers stop producing legumes in Luxemburg, Zimmer et al. surveyed farmer knowledge and issues of grain legume cultivation.

Inorganic phosphorus (P) is a non-renewable and strategic resource for plant growth in agriculture. Most soil P is not used efficiently by plants because we do not fully understand the mechanisms of P availability and P uptake by roots. Agronomists Recena et al. uncover the role of soil organic P and root activity for P fertilisation.

Producing wine is expected to be tough in the next years due to climate changes such as increasing droughts and pest occurrence. French agronomists Trouvelot et al. report the benefits of mycorrhiza in viticulturefound an unexpected ally, the so-called arbuscular mycorrhiza, a plant-fungus team located in the vine roots. They detail the benefit of these microbial friends in their report.