Book of Extended summaries ISDA

International Conference on Reimagining Rainfed Agro-ecosystems: Challenges &
Opportunities during 22-24, December 2022 at ICAR-CRIDA, Hyderabad
Martínez M.L., Intralawan A., Vázquez G., Pérez-Maqueo O., Sutton P., Landgrave R. 2007. The
coasts of our world: Ecological, economic and social importance. Ecol. Econ. 63(2-3): 254-
272. https://doi.org/10.1016/j.ecolecon.2006.10.022.
T4-04R-1217
Impact of Long- Term Fertilization and Manuring on Aggregate Stability
and Biochemical Characterization of Aggregate Associated C in the Alfisols
Suvana Sukumaran 1* , T. J. Purakayastha 2 , Bidisha Chakrabarti 2 ,
K. K. Bandyopadhyay 2 , ThulasiViswanathe 3 , K. K. Rout 4 , K. Sammi Reddy 1 and
A.K. Indoria 1
1 ICAR-Central Research Institute for Dryland Agriculture, Hyderabad, India,
2 ICAR- Indian Agricultural research Institute, New Delhi,
3 Regional Agricultural Research Station, Pattambi, Kerala,
4 Orissa University of Agriculture and Technology, Bhubaneswar, Odisha
* suvana.sukumaran@icar.gov.in
Different land use and land cover management practices affect soil aggregation, which inturn
affect soil C retention. The SOC in the profile can be stabilised by three mechanisms mainly-
physical protection by organo-mineral complexes, biochemical stability to decomposition and
chemical protection by adsorption to clay surfaces. The decomposition rate of C is directly
proportional to the size of aggregates. Chemical association of SOC with silt and clay
particles can also impose a limit to the soil’s C stabilization potential due to a limit in the
surface area of the silt-plus-clay fraction in a given soil. Biochemical stabilization of SOM in
the soil matrix is a strong function of the inherent chemical and structural stability of the
organic biomolecules. Soil aggregate dynamics and SOM decomposition are closely linked.
The present study was undertaken to study the effect of long-term manuring and fertilization
on the physical and biochemical stability of aggregates and the associated carbon in the ricerice
cropping system of the Alfisols of Bhubaneswar (BHNS) and Pattambi (PTMB).
Methodology
This study was carried out in two long term fertilizer experiments continuing in Bhubaneswar
(Orissa) and Pattambi (Kerala), where rice- rice was the main cropping system. The
experimental site at Bhubaneswar has tropical and sub-humid climate, whereas that at
Pattambi has perhumid. The soils at Bhubaneswar were acidic sandy loam and at Pattambi
were acidic sandy clay loam. The following treatments were considered for the study:T1-
control, T2- 50 % NPK, T3- 100%NPK, T4- 150 % NPK, T5- 100%NPK+ FYM ( 10 t ha -1 ),
T6- 100%NPK + Lime. The soil samples were collected from 0-15 and 15-30 cm depth. The
aggregate size distribution was done using wet sieving method. The total carbon content in
the sample was determined by dry combustion in CHNS analyser (Eurovector, model Euro
Sustainable soil management for resilient rainfed agro-ecosystem: conservation agriculture, organic farming,
INM, soil-microorganisms-plant interactions
443 | Page