Soil health hinges more on how agricultural land is managed than whether the farming system is organic or conventional, according to a new study showing that farms with more intensive management have lower overall soil functionality. The findings argue that optimizing yield whilst lowering management intensity – what the authors call "productive deintensification" – may be a more sustainable path forward that could boost soil health across diverse farming practices. Soils play a critical role in supporting both human well-being and ecological stability. In agricultural soils, efforts to maximize crop yields can come at the cost of essential soil functions such as water retention and nutrient cycling. Intensive farming practices often degrade soil health by reducing organic carbon content and biodiversity, which are key to maintaining soil functionality. Organic farming is often considered to be more sustainable than conventional farming and is seen as a way to enhance soil health. However, benefits to soil health are likely driven by specific management practices – such as crop diversification, reduced tillage, and manure use – rather than by the overarching organic or conventional system used. Given the complexity of real-world farming, simply comparing these systems is insufficient. According to the authors, measuring management intensity as a continuous variable offers a more accurate and useful framework for promoting sustainable agriculture.

 

Here, Sophie van Rijssel and colleagues assessed how both farming type (organic vs. conventional) and management intensity affect soil multifunctionality (soil’s ability to perform multiple ecological functions) and the potential drivers underlying the effects. Sampling soils from 53 organic and conventional agricultural fields from across the Netherlands, van Rijssel et al. measured and combined various soil health and function indicators into a single score tailored to each soil type. Additionally, farm management intensity was quantified through farmer interviews and reflected practices like fertilizer use, tillage, and crop rotation. The analysis revealed that management intensity is a better predictor of soil multifunctionality than whether a farm was labeled organic or conventional. According to the findings, higher management intensity was associated with reduced multifunctionality, particularly in organic systems. The authors show that specific practices – particularly reduced use of inversion tillage and increased use of grass-legume cover crops – were key drivers of improved soil multifunctionality, with total soil organic carbon and bacterial biomass identified as the primary mechanisms underlying these effects.

The spread of highly pathogenic avian influenza (HPAI) in U.S. dairy cattle can be traced to a single spillover event from a wild bird, researchers report, raising concern over growing pandemic risks as the virus evolves and leaps between species. HPAI viruses pose serious threats to animal health, agriculture, and potentially human health due to their ability to cross species barriers. A specific strain, H5N1 clade 2.3.4.4b, has spread globally, infecting wild birds, poultry and, mammals – including a small number of humans – underscoring its pandemic potential. Notably, in 2024, this strain was detected in dairy cattle across multiple U.S. states, marking an unusual and concerning expansion into a previously uncommon host. Here, Thao-Quyen Nguyen and colleagues investigated how this H5N1 strain evolved and spread following its arrival in North America in late 2021. Nguyen et al. analyzed genetic data from over 100 virus variants that emerged through mixing with local, low-pathogenicity bird flu strains. By combining these data with newly sequenced genomes and outbreak information from infected U.S. dairy cattle, the authors discovered that the outbreak originated from a single spillover from an avian source – likely in mid-to-late 2023 in Texas – followed by several months of undetected cow-to-cow transmission. The movement of infected or presymptomatic dairy cattle facilitated the rapid spread of the virus from Texas to several other states, including North Carolina, Idaho, Michigan, Ohio, Kansas, and South Dakota. According to the findings, after the avian influenza virus was introduced into cattle, it not only persisted but also spread from cattle to other species, including poultry, raccoons, cats, and wild birds such as grackles, blackbirds, and pigeons. Moreover, genetic analysis revealed mutations associated with mammalian adaptation, some of which have already become fixed in the viral population. “Our study demonstrates that [influenza A virus] is a transboundary pathogen that requires coordination across regulatory agencies and between animal and public health organizations to improve the health of hosts and reduce pandemic risk,” Nguyen et al. write.

The team will work to identify about how many people have been affected by H5N1 and who they are, as well as to understand the workplace factors involved so they can reduce transmission.