Application of chelated fertilizers to mitigate organic-inorganic fouling in brackish water drip irrigation systems

Organic-inorganic fouling in brackish water drip irrigation systems (BWDIS) reduces the irrigation and ferti-gation uniformity, resulting in decreased crop yield and quality. This study investigates the effect of chelated fertilizers on organic-inorganic fouling. Compared with control group (CK), application of Fe-ethylenediamine-di (o-hydroxy phenyl acetic acid (EDDHA-Fe) effectively prevented the multiple fouling by reducing the deposition of inorganic (precipitate and particulate) and organic fouling. Fulvic acid chelated iron fertilizer (FA-Fe) alle-viated multiple fouling by drastically decreasing the precipitate and particulate fouling, although organic fouling was slightly increased. Conversely, amino acid chelated iron fertilizer (AA-Fe) slightly decreased the precipitate fouling while drastically accelerated the particulate and organic fouling, leading to severe clogging. Accordingly, EDDHA-Fe and FA-Fe prevented the BWDIS fouling by 32.6-41.8% and 16.1-29.0%, while AA-Fe accelerated by 36.9-45.4%. Moreover, chelated fertilizers (FA-Fe, AA-Fe and EDDHA-Fe) demonstrated better anti-fouling than inorganic iron fertilizer (FeSO4). However, EDDHA-Fe would have negative environmental impact, hence FA-Fe is strongly recommended from the perspectives of fouling mitigation and soil environmental health improvement efficiency. These results may provide a new guideline for applying chelated fertilizers in BWDIS to prevent organic-inorganic fouling and overcome agricultural pollution.

Automated summary

This study investigated the effect of chelated fertilizers on organic-inorganic fouling in brackish water drip irrigation systems (BWDIS). It was found that EDDHA-Fe effectively prevented multiple fouling, whereas FA-Fe reduced precipitate and particulate fouling and slightly increased organic fouling. AA-Fe decreased precipitate fouling but accelerated particulate and organic fouling. Chelated fertilizers demonstrated better anti-fouling effects compared to inorganic iron fertilizer, with FA-Fe being recommended for fouling mitigation and improving soil environmental health.