Microplastics (MPs) are an emerging global change factor with the potential to affect key agroecosystem services. Yet, MPs enter soils with highly variable properties (e.g., type, shape, size, concentration, and aging duration), reflecting their heterogeneous chemical compositions and diverse sources. The impacts of MPs with such varying properties on agroecosystem services remain poorly understood, limiting effective risk assessment and mitigation efforts. We synthesized 6315 global observations to assess the broad impacts of microplastic properties on key agroecosystem services, including crop productivity and physiology, soil carbon sequestration, nutrient retention, water regulation, and soil physical and microbial properties. MPs generally caused significant declines in aboveground productivity, crop physiology, water-holding capacity, and nutrient retention. However, the direction and magnitude of these effects varied considerably depending on the specific properties of MPs. The hazards posed by MPs to aboveground productivity, antioxidant systems, and root activity were size- and dose-dependent, with larger particles at higher concentrations inducing greater damage. Prolonged microplastic exposure impaired crop photosynthesis and soil nutrient retention, but most other ecosystem services (e.g., belowground productivity, antioxidant systems, and root activity) showed gradual recovery over time. Fiber-shaped MPs positively influenced crop aboveground and belowground productivity and soil carbon sequestration, potentially due to their linear configuration enhancing soil aggregation and connectivity. Polymer type emerged as the most prominent driver of the complex and unpredictable responses of agroecosystem services to MPs, with biodegradable polymers unexpectedly exerting larger negative effects on crop productivity, root activity, photosynthesis, and soil nutrient retention than other polymers. This synthesis underscores the critical role of microplastic properties in determining their ecological impacts, providing essential insights for property-specific risk assessment and mitigation strategies to address microplastic pollution in agroecosystems.

Global demand for ecosystem services like food and clean water is increasing, and it is crucial to economically value these services for the purposes of environmental conservation, land-use planning, and the implementation of green taxes. Focusing on a monoculture wheat agroecosystem, the economic value of ecosystem services and environmental damage from different farm management types is here compared with natural ecosystems in a semi-arid region in Iran during the 2019-2020 agricultural year. Using field survey data collected from 203 wheat farms with varying management practices, we estimated the economic value of six ecosystem services, along with three environmental damages. The net value of provisioning/regulating services less environmental disservices in wheat agroecosystems was highest for farms with a conservation management system, followed (in rank order) by intensive, traditional, organic, and industrial management types. Wheat agroecosystems recorded net values of 41.94% to 66.92% below those of natural ecosystems in the region. The findings show that converting natural ecosystems into wheat agroecosystems increases the value of provisioning services (food and forage) but also substantially increases environmental costs. These costs rose linearly with the value of increases in provisioning services.

Soil arthropods can affect plant growth and aboveground interactions directly via root herbivory and indirectly through nutrient cycling and interactions with soil microorganisms. Research on these effects of soil arthropods has focused on a few taxa within natural systems, largely neglecting agroecosystems and arthropod community-level effects. This study investigated the effects of soil arthropod communities from cereal-based agroecosystems on wheat plant growth and above-belowground interactions. Nutrient cycling and wheat growth were measured in a greenhouse microcosm experiment using field-collected agricultural soils from two rotational schemes with and without their soil arthropod communities. The effects of soil arthropods on aboveground phytohormones and colony growth of an aphid [Metopolophium festucae cerealium (Stroyan)] infesting the plants were measured. Wheat grown in soils with arthropod communities had significantly greater root (+ Arth mean: 0.15 +/- 0.01 g; - Arth mean: 0.06 +/- 0.01 g; F-1,F-54 = 72.34, p 0.05), was significantly greater on wheat grown in soils with arthropods. Aphids, in turn, modified the effects of soil arthropods on root architecture and increased the abundance of soil arthropods. Wheat grown in soils with arthropods had increased levels of stress- and defense-related phytohormones in response to aphid herbivory, while phytohormones of wheat plants grown in soils without arthropods did not differ with aphid presence. Soil arthropod communities may help plants defend against herbivores aboveground by facilitating phytohormone induction while offsetting costs by increasing soil nutrients and modifying plant growth. By using taxonomically diverse field-collected soil arthropod communities from agroecosystems, this study showed that community-level effects on plant growth are more complex and dynamic than the effects of any single taxon, such as Collembola, illustrating that interactions within communities can produce emergent properties that alter the net effect of soil arthropods on plant growth. The results indicate that community-level effects of soil organisms should be considered as part of sustainable plant production and protection strategies.