Crop residues exacerbate the negative effects of extreme flooding on soil quality

Could flooding undermine progress in building climate-resilient crops?

Flooding threatens crop productivity, agricultural sustainability, and global food security. In this article I review the effects of flooding on plants and highlight three important gaps in our understanding: (i) effects of flooding on ecological interactions mediated by plants both below (changing root metabolites and exudates) and aboveground (changing plant quality and metabolites, and weakening the plant immune system), (ii) flooding impacts on soil health and microorganisms that underpin plant and ecosystems health, and (iii) the legacy impacts of flooding. Failure to address these overlooked aspects could derail and undermine the monumental progress made in building climate-resilient crops and soil-microbe-assisted plant resilience. Addressing the outlined knowledge gaps will enhance solutions developed to mitigate flooding and preserve gains made to date.

Flooding, Food Security and the Sustainable Development Goals in Nigeria: An Assemblage and Systems Thinking Approach

Food is connected to sustainable development goals in numerous ways, as food security is key to achieving sustainable development. The world is currently not on track to achieve the set sustainable development goals (SDGs). In Nigeria, flooding is a recurrent disaster and constitutes a setback to success with the SDGs and sustainable development. Flooding disasters are a threat to food security due to their impact on the food system. This study is an integrative review that explores the link between Nigeria’s flooding, food security, and the SDGs. It adopts an assemblage and systems thinking approach to analyze the impact of flooding on all components of food security. It finds that, despite the impact of flooding on food security, it is not recognized as a threat by policymakers, as evidenced by the lack of mention of disasters in the current Nigeria Agriculture Promotion Policy (APP). Attention is drawn to this oversight in this work by highlighting the interconnections between flooding, food security, and sustainable development. Recommendations on flood mitigation and adaptive practices that can alleviate the negative impact of flooding on food security to enhance the success rate of the SDGs are proffered. This work contributes to the literature by showcasing the impact of flooding on food security and its connection to sustainable development, which is an area that has not received adequate attention in research. The assemblage and system thinking approach adopted brings novelty and allows for a succinct understanding of how flooding impacts all four aspects of food security. This paper serves as the first time the problem has been explored in this manner.

How Does N Mineral Fertilizer Influence the Crop Residue N Credit?

In no-tillage systems, there is an accumulation of crop residues (CR), which plays an essential role in the availability of soil-N. A study was set up to provide information regarding the N credit and the influence of N mineral fertilizer. There was the addition of a similar rate of residue (10 Mg ha−1; sugarcane, soybean, and brachiaria) and N mineral fertilizer (urea; 120 kg N ha−1) in loam soil. After the stabilization of biological activity (73 days), soil and remaining residues were collected, and C and N monitored. The results showed that the N credit was positive with the application of soybean, sugarcane, and brachiaria. There was a positive balance of the soybean N credit in soil with a reduction from 2.49 to 0.90 g kg−1 of N in remaining residue, and a direct increase of 90% of soil-N. There is no need of N fertilizer to potentialize the soybean N credit, but it is required to potentialize N credit of brachiaria and sugarcane. The urea demonstrated to be an excellent enhancer of brachiaria N credit, but it was not adequate for sugarcane residues. Based on our result, the accumulation and incorporation of CR can be considered as N credit with a positive contribution in soil-N.

How Does N Mineral Fertilizer Influence the Crop Residue N Credit?

In no-tillage systems, there is an accumulation of crop residues (CR), which plays an essential role in the availability of soil-N. A study was set up to provide information regarding the N credit and the influence of N mineral fertilizer. There was the addition of a similar rate of residue (10 Mg ha−1; sugarcane, soybean, and brachiaria) and N mineral fertilizer (urea; 120 kg N ha−1) in loam soil. After the stabilization of biological activity (73 days), soil and remaining residues were collected, and C and N monitored. The results showed that the N credit was positive with the application of soybean, sugarcane, and brachiaria. There was a positive balance of the soybean N credit in soil with a reduction from 2.49 to 0.90 g kg−1 of N in remaining residue, and a direct increase of 90% of soil-N. There is no need of N fertilizer to potentialize the soybean N credit, but it is required to potentialize N credit of brachiaria and sugarcane. The urea demonstrated to be an excellent enhancer of brachiaria N credit, but it was not adequate for sugarcane residues. Based on our result, the accumulation and incorporation of CR can be considered as N credit with a positive contribution in soil-N.