Effect of potassium solubilizing bacteria and waste mica on potassium uptake and dynamics in maize rhizosphere

Abstract

Potassium (K), being the third most important primary macronutrient, plays a significant role in crop production. Due to scarcity of K-bearing ores in the Indian sub-continent the K-fertilizers are imported which increases the cost of cultivation. Hence, the alternative K sources like waste mica along with microbial intervention is needed to be explored. So, a pot experiment was conducted during kharif season of 2015-16 and 2016-17 with ten treatments consisting of T1: Control,T2: Recommended dose of fertilizer (RDF: N:P2O5:K2O: 100:40:40 kg ha-1), T3: Full N and P + 75% K and rest 25% by waste mica, T4: Full N and P + 50% K and rest 50% by waste mica, T5: T3 + KSB1 ( Fraturia aurantia ), T6: T4 + KSB1, T7: T3 + KSB2 ( Bacillus edaphicus ),T8: T4 + KSB2, T9: T3+KSB1+KSB2 and T10: T4+ KSB1+KSB2 was conducted with maize ( Zea mays L) as the test crop (var: SHM 1). The results revealed that the water soluble, exchangeable and non-exchangeable pools of K over different stages, ranged from 3-5%, 9-10% and 85- 88%, respectively. Correlation studies between biomass yield, K uptake and different pools of K showed a significant relationship. Out of the ten treatments used in the experiment, treatment, T10: Full N and P + 50% K and rest 50% by waste mica + KSB1+KSB2 was found to be most superior. Application of waste mica co-inoculated with potassium solubilizing microorganisms also had significant effect on biomass yield as well as K uptake by maize.