Evaluating plant micronutrient retention using an electric potential around the root zone in Rice (Oryza sativa L.)

Abstract

Gayathree I. Senevirathne, J.A.S. Chathurika, Manju Gunawardana, Asitha S. Siriwardhana, Kosala Purasinhala

Deficiency in micronutrients lead to poor health and performance in plants and hidden hunger in many developing countries. This could be inherited by unavailability micronutrients around the root zone especially, in rice, where water logged conditions are maintained. Hence, adding electric potential around the root zone to retain micronutrients would be a beneficial. Therefore, this study was designed to evaluate the effect of direct electric potential (EP) in retaining soil nutrient around the root zone using iron as an index ion. The experimental setup consisted of two concentric iron mesh pots, inner pot connected to the negative end and outer pot connected to the positive end. An electric potential of 5.0 V was supplied with the direct current of 0.1 A for 8 hours per day. Soil was characterized for available iron (Fe) content around three zones at the time of panicle initiation and time of harvest using ICPMS plant growth and performance was measured. At the time of panicle initiation soil-available Fe content was higher around the negative electrode than the positive electrode in plants supplied with EP (WEP).Plant height, above ground biomass, and paddy yield were significantly lower in WEP plants than the contol plants (P<0.05). WEP plants showed a 45% reduction in paddy yield compared to the NEP plants. Results confirms that Fe provided in the presence of an electric potential increases the Fe concentration around the root zone and enhances the Fe absorption. This underpins the use of electric potential to retain micronutrients especially, cations around the root zone ultimately enhancing their availability for plants.

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