Home Scientific Staff / Faculty

Dr. Ashok Kumar Patra

E-mail Print PDF


Dr. Ashok Kumar Patra

Dr. Ashok Kumar Patra
Principal Scientist
Division of Soil Science & Agricultural Chemistry
Indian Agricultural Research Institute, New Delhi 110 012
Tel (Office): 011-25841494, Cell 09811733465
Email: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Joining date in ICAR : 05 October, 1989

Discipline and specialization: Soil Science- Soil Chemistry/Fertility/Microbiology: Nitrogen cycling, soil ecology and biodiversity, carbon sequestration, nanoparticles.

Training/advance exposure in the area

  1. Post Doctoral Fellowship on "Measurement of nitrogen losses from the soils of the Indian semi-arid tropics", ICRISAT, Hyderabad, India (1991-1993).
  2. Visiting Scientist for research on "Nitrogen dynamics in grasslands", Institute of Grassland and Environmental Research, Exeter, UK (1996).
  3. INRA Postdoctoral Fellowship on "Nitrogen cycling – activity, abundance and diversity of functional communities", Claude Bernard University, Lyon, France (2001-2003).
  4. Short term training on “Recent Techniques in Plant Genetic Engineering and Molecular Breeding” at NRCPB, IARI, New Delhi, under the Project “Team of Excellence on HRD” sponsored by the NATP (ICAR), from 18 Oct. – 7 Nov. 2004.
  5. Visiting Scientist for research on "Nanoparticles-microbial interactions", University of Notre Dame, USA (2008-2009).

Contribution to the scientific advancement
  • Using lysimeters and tracers, identified the mechanisms, critical periods and extent of nitrogen losses from agro-ecosystems of India.
  • Quantified the contribution of macro and micro-organic fractions and soil particles to the potential nitrogen mineralization in soils.
  • Showed for the first time that intensive grassland management has a strong negative effect on the functional communities involved in N cycling, particularly the nitrifying communities.
  • Impact of long term fertilization and manuring and land use systems have revealed that continuous use of manures and balanced fertilizers for more than three decades has improved soil quality particularly the soil biological indicators.
  • Established the mechanism that C2H2, which slowly released from encapsulated calcium carbide and inhibits activity of ammonia mono-oxygenase, is associated with reducing population of the ammonia oxidizing bacteria
  • Developed integrated soil quality index for different cropping and land management systems.

Future Planning of research
  • Linking soil biodiversity with soil health and processes/functions for enhancing nutrient use efficiency and C sequestration.
  • Use of nanoparticles and novel approaches for enhancing nutrient supply and their ecological impacts.
  • Nutrient transformations, uses and C sequestration at elevated CO2 and temperature

Selected publications
  • Patra, AK., Le Roux, X, Grayston, SJ, Loiseau, P., Louault, F. (2008). Unraveling the effects of management regime and plant species on soil organic carbon and microbial phospholipid fatty acid profiles in grassland soils. Bioresource Technology 99: 3545-3551.

  • Patra AK, Chhonkar PK and Khan, MA (2006). Effect of green manure Sesbania sesban and nitrification inhibitor encapsulated calcium carbide (ECC) on soil mineral -N, enzyme activity and nitrifying organisms in a rice-wheat cropping system. European Journal of Soil Biology 42 (3): 173-180.

  • Patra, AK, Clays A, Degrange V, Grayston, SJ, Guillaumaud N, Loiseau P, Louault F, Mahmood S, Nazaret S,  Philippot L, Poly F, Prosser JI, and Le Roux X (2006). Effects of management regime and plant species on the enzyme activity and genetic structure of N-fixing, denitrifying and nitrifying bacterial communities in grassland soils. Environmental Microbiology 8 (6): 1005-1016.

  • Patra AK, Abbadie L, Clays A, Degrange V, Grayston SJ, Loiseau P, Louault F, Mahmood S, Nazaret S,  Philippot L, Poly F, Prosser JI, Richaume A and Le Roux X (2005). Effect of grazing on microbial functional groups involved in soil N dynamics. Ecological Monographs 75(1): 65-80.

  • Patra AK, Chhonkar, PK and Khan MA (2004). Nitrogen loss and wheat (Triticum aestivum L.) yields in response to zero-tillage and sowing time in a semi-arid tropical environment. Journal of Agronomy & Crop Science 190: 324-331.

  • Patra AK, Jarvis SC, and Hatch D (1999). Nitrogen mineralization in soil layers, soil particles and macro-organic matter under grassland. Biology and Fertility of Soils 29(1): 38-45.

Other relevant activities
  • Teaching PG Courses (SSAC 506 Soil Biology & Biochemistry; SSAC 605 Soil Resource Management; SSAC 509 Radiotracer Techniques in Soil and Plant Studies).
  • Guiding Ph.D. and M.Sc. Students as Chairperson or as Advisory Committee Member.
  • Members/Chairman of several committees


British Council TCT Award 1996; Royal Society-IPNC Travel Award, 1997; DBT Overseas Associateship Award 2008; Editor, Range Management and Agroforestry 1996-1998; Councillor of ISSS 2005-2006; Member, Nature's Reader Panel 2008-2009; FAI-Dhiru Morarji Memorial Award 2011; Editor, ISRN Agronomy 2012-; Associate Chief Editor, International Journal of Bioresource & Stress Management 2012-; President, Delhi Chapter of the Indian Society of Soil Science 2012-, Bharat Jyoti Award 2012.

Fellow: National Academy of Agricultural Sciences; Range Management Society of India