Potassium nutrition in rice: A review

Potassium (K) is the most neglected nutrient in Indian agriculture and accounts only 10% of the total fertilizer use. The increased cropping intensity and use of high yielding cultivars since the green revolution led to heavy withdrawal of K from soil. Persistent K mining over the past six decades has mined soil K level in many cultivated areas and continuously transforming sufficiency into deficiency. A recent soil test a little over 1 lakh samples from 33 states of India have categorized 41.1%, 29.3%, and 29.5% of soil samples as low, medium and high in available K respectively. Further, the trend of soil available K status showed a persistent decline in percentage of area under high and medium soil K. Consequently, the evidence of rice crop responding to K nutrition is increased. This review attempts the nexus of K nutrition in rice for devising strategies for potassium management in rice-based cropping systems in the country.