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The ‘4 per mille Soils for Food Security and Climate’ was launched at the COP21 with an aspiration to increase global soil organic matter stocks by 4 per 1000 (or 0.4 %) per year as a compensation for the global emissions of greenhouse gases by anthropogenic sources. This paper surveyed the soil organic carbon (SOC) stock estimates and sequestration potentials from 20 regions in the world (New Zealand, Chile, South Africa, Australia, Tanzania, Indonesia, Kenya, Nigeria, India, China Taiwan, South Korea, China Mainland, United States of America, France, Canada, Belgium, England & Wales, Ireland, Scotland, and Russia). We asked whether the 4 per mille initiative is feasible for the region. The outcomes highlight region specific efforts and scopes for soil carbon sequestration. Reported soil C sequestration rates globally show that under best management practices, 4 per mille or even higher sequestration rates can be accomplished. High C sequestration rates (up to 10 per mille) can be achieved for soils with low initial SOC stock (topsoil less than 30 t C ha− 1), and at the first twenty years after implementation of best management practices. In addition, areas which have reached equilibrium will not be able to further increase their sequestration. We found that most studies on SOC sequestration only consider topsoil (up to 0.3 m depth), as it is considered to be most affected by management techniques. The 4 per mille number was based on a blanket calculation of the whole global soil profile C stock, however the potential to increase SOC is mostly on managed agricultural lands. If we consider 4 per mille in the top 1m of global agricultural soils, SOC sequestration is between 2-3 Gt C year− 1, which effectively offset 20–35% of global anthropogenic greenhouse gas emissions. As a strategy for climate change mitigation, soil carbon sequestration buys time over the next ten to twenty years while other effective sequestration and low carbon technologies become viable. The challenge for cropping farmers is to find disruptive technologies that will further improve soil condition and deliver increased soil carbon. Progress in 4 per mille requires collaboration and communication between scientists, farmers, policy makers, and marketeers.

Plants under salt stress require additional energy supply to fuel salt tolerance mechanisms and growth. Bandehagh and Taylor (2020) establish that plants must strike a balance between energy supply and demand to maintain growth and development during salt stress. This review (1) summaries how salt stress affects different physiological and biochemical process altering the abundance of different metabolites that are feeding into regular and alternative respiratory pathways and shunts; (monomeric complex I, dimeric complex III and I + III2 supercomplex) found to be higher in halophyte mitochondria in comparison with glycophyte, implying efficient electron transfer from complex I to complex III in halophyte mitochondria. Further, the stability of ATP synthase (complex V) also found to be higher in halophyte suggesting halophyte mitochondria better equipped to supply additional ATP required to support salt stress response.Synthesis of organic compatible solutes is an important component for plant salt stress tolerance. In this regard, proline plays an important role in protecting plants from under salinity conditions and showed that salt tolerance is associated with changes in lipid metabolic processes. They also discovered the important role of phosphatidylserine (PS) in mediating enzyme activity, and exogenous application of PS alleviated the effects of NaCl tissue toxicity. The results showed that the superior K + retention ability in both mature and elongation zone of rice root is the key trait conferring its differential salinity stress tolerance. They suggested that besides the superior ability to activate root H + -ATPase pump operation, this key trait is also related to the reduced sensitivity of K + efflux channels to reactive oxygen species and the lower upregulation in OsGORK and higher upregulation of OsAKT1.A key trait long recognized to improve salinity tolerance in many plants is the maintenance of a low Na + /K + ratio. Transient expression experiment showed that JcHDZ07 is a nuclear-localized protein.In improving Na + exclusion ability to maintain root ion homeostasis to ensure a relatively 9 low shoot Na + concentration under saline conditions; 2) maintaining a high shoot sugar content under saline conditions which is enabled by protecting photosystems structures, enhancing photosynthetic performance and sucrose synthetase activity, and inhibiting sucrose degradation. Further, authors suggested that targeting the key genes related to the regulatory mechanisms could provide opportunities to breed more salt tolerant sweet sorghum.Overall, we hope this special issue of benefit to plant breeders and land managers by delivering novel information and insights on the salinity stress response, signalling and adaptive mechanisms operating in plants.

Pathogens represent a significant threat to human health leading to the emergence of strategies designed to help manage their negative impact. We examined how spiritual beliefs developed to explain and predict the devastating effects of pathogens and spread of infectious disease. Analysis of existing data in studies 1 and 2 suggests that moral vitalism (beliefs about spiritual forces of evil) is higher in geographical regions characterized by historical higher levels of pathogens. Furthermore, drawing on a sample of 3140 participants from 28 countries in study 3, we found that historical higher levels of pathogens were associated with stronger endorsement of moral vitalistic beliefs. Furthermore, endorsement of moral vitalistic beliefs statistically mediated the previously reported relationship between pathogen prevalence and conservative ideologies, suggesting these beliefs reinforce behavioural strategies which function to prevent infection. We conclude that moral vitalism may be adaptive: by emphasizing concerns over contagion, it provided an explanatory model that enabled human groups to reduce rates of contagious disease.

AbstractChanges in soil fertility during pedogenesis affect the quantity and quality of resources entering the belowground subsystem. Climate governs pedogenesis, yet how climate modulates responses of soil food webs to soil ageing remains unexplored because of the paucity of appropriate model systems. We characterised soil food webs along each of four retrogressive soil chronosequences situated across a strong regional climate gradient to show that belowground communities are predominantly shaped by changes in fertility rather than climate. Basal consumers showed hump‐shaped responses to soil ageing, which were propagated to higher‐order consumers. There was a shift in dominance from bacterial to fungal energy channels with increasing soil age, while the root energy channel was most important in intermediate‐aged soils. Our study highlights the overarching importance of soil fertility in regulating soil food webs, and indicates that belowground food webs will respond more strongly to shifts in soil resources than climate change.