On the benefits and challenges of blockchains for managing food supply chains.

The expansion of the food industry, within and beyond national borders, has resulted in complex collaborative networks and supply chains. The management culture adopted for food supply chains has an impact on the quality of the end product and the vitality of the businesses involved. In this report, we focus on the use of blockchain technology, and distributed ledgers in general, for managing supply chains in the food and agricultural sectors. We explore the challenges with which typical management systems are faced, such as food safety, food fraud, and inefficient processes, as well as ethical aspects like fair trade, animal welfare, and the environmental impact of food production. The use of blockchain-based systems for managing a supply chain offers significant benefits, such as faster and more reliable traceability. Our analysis, involving small and medium enterprises (SMEs) from Denmark, highlights that SMEs could benefit from blockchain-based systems that encourage fair trade and authenticity documentation, expose good practices, and decrease management costs. However, due to a lack of important policies and standards, and due to the limited understanding of the technology itself, its large-scale adoption is at the moment immature. © 2020 Society of Chemical Industry.

The influence of phosphorus deficiency on growth and nitrogen fixation of white clover plants.

The effects of P deficiency on growth, N(2)-fixation and photosynthesis in white clover (Trifolium repens L.) plants were investigated using three contrasting relative addition rates of P, or following abrupt withdrawal of the P supply. Responses to a constant below-optimum P supply rate consisted of a decline in N(2)-fixation per unit root weight and a small reduction in the efficiency with which electrons were allocated to the reduction of N(2) in nodules. Abrupt removal of P arrested nodule growth and caused a substantial decline in nitrogenase activity per unit root weight, but not per unit nodule mass. Similarly, the rate of photosynthesis per unit leaf area was unaffected by abrupt P removal, whereas CO(2) acquisition for the plant as a whole decreased due to a decline in total leaf area, leaf area per unit leaf weight and utilization of incoming radiation. These changes followed the decline in tissue P concentrations. The ratio between CO(2)-fixation and N(2)-fixation was maintained under short-term P deprivation but increased under long-term low P supply, indicating a regulatory inhibition of nodule activity following morphological and growth adjustments. It is concluded that N(2)-fixation did not limit the growth of clover plants experiencing P deficiency. A low P status induced changes in the relative growth of roots, nodules and shoots rather than changes in N and/or C uptake rates per unit mass or area of these organs.