Impact of long term integrated nutrient management (INM) practice on aluminium dynamics and nutritional quality of rice under acidic Inceptisol

ABSTRACT

Applications of enriched compost (ECM) with reduced doses of inorganic fertilizers over ten consecutive years reduced phytotoxic aluminium (Al) fractions, whereas, improved nutritional quality of rice in acid soil. The long-term field trial with integrated nutrient management (INM) practices was initiated in kharif–2006 at Instructional-cum-Research (ICR) farm under rice mono-cropping system. Treatments consisted of T₁; absolute control, T₂; 100% recommended doses of nitrogen (N), phosphorus (P) and potassium (K), T₃; 50% recommended doses of NP + 100% K + biofertilizer, T₄; 50% recommended doses of NP + 100% K + ECM at 1 tonne ha⁻¹ and T₅; 25% recommended doses of NP + 100% K + ECM at 2 tonne ha⁻¹. Exchangeable Al (~31%) and strongly organically bound and interlayer Al (~26%) fractions decreased with an increasing dose of ECM application at all soil depths. However, weakly organically bound Al (~25%), amorphous Al (~7.3%), and free Al (~13%) significantly increased over 100% NPK. Long-term use of ECM had a significant positive impact on micronutrient content in post-harvest soil. Micronutrient accumulation (Zn, Fe, Cu, Mn and Ni) in rice increased with continuous application of manuring and fertilization, while the accumulation of Al decreased significantly.

KEYWORDS:

• Acidic soil
• aluminium dynamics
• organic manure
• long term integrated nutrient management
• nutritional quality

Acknowledgements

The first author is grateful to the ICAR-Indian Agricultural Research Institute, New Delhi for financial assistance to conduct this study. He also acknowledges the fellowship given by the Indian Council of Agricultural Research.

Disclosure statement

The authors declare that they do not have any conflict of interest.