HomeInternational Rice Research Notesvol. 26 no. 2 (2001)

Relationship between applied potassium and iron toxicity in rice

S.k. Sahu | B. Sandha | G. Dev

Discipline: Agriculture



Highly weathered soils that are acidic, low in bases, deficient in P and K, and rich in sesquioxides occur on 11.7 million ha in India (Prasad and Biswas 2000) and 0.75 million ha in Orissa (Sahu 1993). Rice grown in low- to medium- elevation lands with this type of soil and adjacent to leached uplands often suffers from Fe toxicity associated with interflow of water from the uplands. The mechanism by which interflow exacerbates the toxicity is uncertain, but it appears to involve dilution of plant nutrients and upsetting of the plant's ability to exclude toxic Fe, rather than the inflow of large amounts of dissolved Fe (van Breemen and Moormann 1978). Related to this, the application of liberal doses of K has been found to reduce Fe toxicity in rice and increase yields.