<p>The periodic recycling and subsequent biodegradation and physicochemical decomposition of crop residues in paddy ecosystems may temporarily generate a large quantity of straw colloids - very fine, charged particles. However, little is known about the fate of these colloids or the extent to which they influence the soil colloid system, particularly in relation to nutrient and pollutant mobilization. To address this gap, laser dynamic light scattering, coupled with a test-tube method, was employed to simultaneously monitor the electrophoretic and colloidal properties of microsized straw particles (<i>mSPs</i>) derived from engineered straw powder. Experiments were conducted both in the presence and absence of soluble organic compounds (acetate, oxalate, citrate, humic acid), nutrient ions (NH₄⁺, NO₃⁻, K⁺, PO₄³⁻, Ca²⁺, Mg²⁺), heavy metal ions (Pb²⁺, Cu²⁺, Zn²⁺, Mn²⁺, Fe²⁺, Cr⁶⁺, As⁵⁺), antibiotics (oxytetracycline, ciprofloxacin, sulfapyridine), and cosmetic ingredients (PolyDADMAC, PC11). The results revealed that <i>mSPs</i> are natural composites consisting of organic matter interwoven with a silica phase, and they generally carry negative surface charges. In aqueous environments, <i>mSPs</i> function as colloids capable of adsorbing a range of external substances; however, their surface charge and colloidal stability are notably influenced by the presence of highly charged compounds, particularly humic acid and PolyDADMAC. Notably, interactions between <i>mSPs</i> and soil colloids (e.g., clays) indicated that <i>mSPs</i> can act as dispersive agents. These findings highlight the potential for <i>mSPs</i> to influence soil colloidal transports, and underscore the need to consider their seasonal effects under field conditions.</p>