Impact of long-term manuring and cropping system on stability of humus associated with clay-organic complex

ABSTRACT

The objective was to study the impact of ten year’s manuring and fertilization on chemical stability of clay-organic complex (COC) in rice−potato−wheat (R–P–W) and maize−potato−onion (M–P–O) cropping systems. Soil samples were collected from the control, 100% NPK–Fertilizer, 100% N–Vermicompost (VC), 50% NPK–Fertilizer + 50% N–VC, 100% NPK–Fertilizer + crop residue (CR), 100% N–VC + CR. The stability (1/k) of humus C i.e. inverse of humus desorption rate constant (k) in hours (h), in COC was higher in 100% N–VC an1d 00% N–VC + CR in both the cropping systems. The C:N ratio of humic acid (HA) was also higher in the treatments receiving full organics (100% N–VC and 100% N–VC + CR) and showed positive correlation (p < 0.05) with the humus C stability in COC. Long-term manuring treatments created C = N and C–O stretching of aromatic ether in HA extracted from 100% NPK–VC and other selected treatments in both the cropping systems. 100% N–VC and 100%N–VC + CR produced higher stability of humus-C in Inceptisol. The R–P–W imparted higher stability of humus C than M–P–O cropping system.

KEYWORDS:

• Vermicompost
• crop residue
• humus stability
• FTIR spectroscopy
• C:N ratio
• cropping system

Acknowledgements

The first author acknowledges the Junior Research Fellowship (JRF) awarded by the Indian Agricultural Research Institute, New Delhi and logistic support of Central Potato Research Institute Campus, Modipuram, Meerut, Uttar Pradesh, India to carry out this study.

Disclosure statement

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

Credit authorship contribution statement

Rajendra Yadav: Funding acquisition, Investigation, Data curation, Writing – original draft, Formal analysis. Tapan Jyoti Purakayasha: Conceptualization, Investigation, Data curation, Writing – original draft, review, editing. Ruma Das: Investigation, Data curation, Writing – original draft, review, editing. M.A. Khan: Supervision of the experiment, Assist in soil sampling.

Additional information

Funding

This work was supported by the ICAR-Indian Agricultural Research Institute [Fund No.20474].