Adsorption of elements in earthworms affected by chemical fertilizers in orchard Soil

Earthworms have been used as adsorption markers to prove the biological availability of chemical fertilizers in soil. This study aimed to determine the amount of nutrient uptake in some earthworm species in an orchard soil. In this study, the uptake of nitrogen, phosphorus, potassium, zinc and iron by the application of different chemical fertilizers urea, ammonium sulfate, diammonium phosphate, solupotas, NPK compound fertilizer, NPK fertilizer with cow manure, zinc chelate and iron chelate in five Earthworm species were studied. Treatments were applied in three replications in a randomized complete block design and data were analyzed by ANOVA. Results showed that epigeic species were more active in the uptake of elements such as nitrogen and phosphorus. Meanwhile, E. fetida was more active in nitrogen uptake of urea (72%) and ammonium sulfate but was not active in uptake of phosphorus from diammonium phosphate fertilizer. On the other hand, the presence of organic matter in the fertilizer treatments caused less nitrogen and phosphorus uptake by the worms and under these conditions, the anecic species have performed poorly in the adsorption process. Chelating of nitrogen and phosphorus in organic compound molecules has reduced their adsorption power. In addition, E. fetida showed a higher tendency to adsorb iron (52%) and zinc (50%) in treated soil than control soil. In order to reduce the negative effects of chemical fertilizers on soil organisms, it is recommended to reduce their consumption in shallow soils.