We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Polypropylene microplastics exacerbate microbial phosphorus limitation and disrupt organ-specific nutrient homeostasis in maize-soil systems
Summary
Tiny plastic particles from common plastics like polypropylene (found in packaging and textiles) are building up in farm soil, and this study found they throw off the balance of nutrients that crops need, particularly phosphorus. A little plastic contamination actually helped corn seedlings grow bigger roots, but higher amounts stunted growth overall—suggesting there's a tipping point where microplastic pollution starts harming crops. Since phosphorus and other nutrients are essential for plant health and our food supply, this research is an early warning sign that ongoing plastic pollution in farmland could eventually affect crop yields and the nut
This study examined how pristine polypropylene microplastics (PP-MPs) affect carbon (C), nitrogen (N), and phosphorus (P) stoichiometry across the soil-maize continuum. Under PP-MPs stress, soil organic C increased, soil total N first increased and then decreased with increasing PP-MPs concentration, while soil total P did not change significantly, leading to increased soil C:N and decreased N:P, indicating microbial P limitation. Microbial biomass C increased and biomass P decreased, while biomass N was unchanged, raising the microbial C:N:P ratio and reinforcing exacerbated microbial P limitation. Enzyme activities shifted from C- to N- and P-acquisition, and vector analysis confirmed that PP-MPs alleviated microbial C limitation but sustained P limitation. Maize growth exhibited a concentration-dependent biphasic response, low PP-MPs levels (≤2%) promoted root biomass and root-to-shoot ratio, whereas high levels (≥5%) strongly inhibited both shoot and root growth. Notably, the R/S ratio remained elevated even at inhibitory concentrations, suggesting a preferential allocation of biomass to root under PP-MPs stress. Root showed sensitive homeostasis for N and N:P, whereas shoot maintained strict homeostasis for P and N:P, indicating a strong regulatory capacity of photosynthetic tissues to buffer against microbially mediated soil P limitation under PP-MPs stress. Structural equation modeling identified that PP-MPs affect maize growth through integrated pathways, directly via phytotoxicity and indirectly by modifying soil physical properties, microbial biomass, and enzyme activities. These findings establish a chemometric framework linking microplastic pollution to nutrient remodeling and seedling adaptability in maize, providing mechanistic insights into the risks posed by microplastics to soil-plant systems during early growth stages.