Mechanisms underlying cereal/legume intercropping as nature-based biofortification: A review

Abstract

The deficiencies of micronutrients known as hidden hunger are severely affecting more than one-half of the world’s population, which is highly related to low bioavailability of micronutrients, poor quality diets, and consumption of cereal-based foods in developing countries. Although numerous experiments proved biofortification as a paramount approach for improving hidden hunger around the world, its effectiveness is highly related to various soil factors, climate conditions, and the adoption rates of biofortified crops. Furthermore, agronomic biofortification may result in the sedimentation of heavy metals in the soil that pose another detrimental effect on plants and human health. In response to these challenges, several studies suggested intercropping as one of the feasible, eco-friendly, low-cost, and short-term approaches for improving the nutritional quality and yield of crops sustainable way. Besides, it is the cornerstone of climate-smart agriculture and the holistic solution for the most vulnerable area to solve malnutrition that disturbs human healthy catastrophically. Nevertheless, there is meager information on mechanisms and processes related to soil-plant interspecific interactions that lead to an increment of nutrients bioavailability to tackle the crisis of micronutrient deficiency in a nature-based solution. In this regard, this review tempted to (1) explore mechanisms and processes that can favor the bioavailability of Zn, Fe, P, etc. in soil and edible parts of crops, (2) synthesize available information on the benefits and synergic role of the intercropping system in food and nutritional security, and (3) outline the bottlenecks influencing the effectiveness of biofortification for promoting sustainable agriculture in sub-Saharan Africa (SSA). Based on this review SSA countries are malnourished due to limited access to diverse diets, supplementation, and commercially fortified food; hence, I suggest integrated research by agronomists, plant nutritionists, and agroecologist to intensify and utilize intercropping systems as biofortification sustainably alleviating micronutrient deficiencies. Graphical Abstract

Maize/soybean intercropping increases nutrient uptake, crop yield and modifies soil physio-chemical characteristics and enzymatic activities in the subtropical humid region based in Southwest China

“…Below-ground complementarity, nutrient sharing via interspecific root interactions, and rhizosphere modification in maize-soybean intercropping could also impact crop growth, development, and yield, either directly or indirectly [ 26 , 53 ]. Adequate N fertilization could further increase the yield of crops under such intercropping system where N is a primary element required for plant growth and development.…”

Maize/soybeans intercropping increases nutrient uptake, crop yield and modifies soil physio-chemical characteristics and enzymatic activities in a subtropical humid region based in Southwest China

“…Below-ground complementarity, nutrient sharing via interspeci c root interactions, and rhizosphere modi cation in maize-soybean intercropping could also impact crop growth, development, and yield, either directly or indirectly [26,53]. Adequate N fertilization could further increase the yield of crops under such intercropping system where N is a primary element required for plant growth and development.…”

“…For example, maize-common bean intercropping considerably enhanced the maize crop yield by 12.5% and biomass dry matter (shoots and root) by 31.5% when compared with its mono-cropping system [61]. Several other intercropping studies have shown that the complementarity or facilitative interactions that occur both above and below ground between intercrops consequently improve the soil nutrient availability and increase plant nutrient content and their uptake, which ultimately enhances the crop yield [53,62,63], and that con rmed our results.…”

Crop diversification effects on soil organic carbon and nitrogen storage and stabilization is mediated by soil management practices in semiarid woody crops

“…In light of the ongoing discussion on the post-2020 European Common Agricultural Policy, and the current sustainability agenda (e.g., Paris Climate Agreement, European Strategy of Biodiversity and the European Mission of Soil, Sustainable Development Goals), there is a need to promote sustainable agricultural management practices that contribute to SOC sequestration while reducing external inputs such as fertilizers and pesticides (Pe'Er et al, 2019). In this regard, crop diversification (either adding more crops into an existing crop rotation scheme or inter-cropping, i.e., growing annual or perennial crops in the inter-tree-rows of woody crops) is a promising strategy to mitigate climate change and land degradation through soil carbon sequestration while ensuring food security and maintaining natural resources (soil, water and biodiversity), particularly in dry regions (Francaviglia et al, 2017;Sanz et al, 2017;Yang et al, 2021;Ebbisa, 2022).…”