Dr Dinesh Kumar1, Dr Yashbir Singh Shivay1
1Icar-indian Agricultural Research Institute, Pusa Campus, New Delhi, India
During recent years, a significant slowdown in the yield growth rate of rice-wheat cropping system (RWCS) has been observed. Key issues include decline in soil organic matter (SOM), lack of adequate rotations, negative nutrient balances and decline in the groundwater table, etc. Overcoming these constraints requires adoption of practices that build-up SOM and need less water. Adoption of organic farming practices and inclusion of legumes may build-up the SOM in RWCS. Thus, a long-term field experiment evaluated the effect of including mungbean (Vigna radiata L.) in RWCS and addition of organic nutrient sources on SOM and microbial activity. Excluding the conversion period of 3 years, the truly organic experiment started in 2006 and continued till 2016 at ICAR- Indian Agricultural Research Institute, New Delhi. 1 Kg soil had 5.1 mg organic at beginning. Experiment was laid out in strip plot design with 3 replications. Treatments consisted of 2 rice-based cropping systems (basmati rice-wheat and basmati rice-wheat- mungbean) in columns, six combinations of different organic materials and biofertilizers [farmyard manure equivalent to 60 kg N ha-1 (FYM), vermicompost equivalent to 60 kg N ha-1 (VC), FYM + crop residue of preceding crop @ 3 t ha-1 for each rice, wheat and mungbean (CR), VC + CR, FYM + CR + biofertilizers and VC + CR + biofertilizers] and control in rows. Levels of organic carbon increased significantly due to inclusion of mungbean in RWCS. Simultaneously, the soil microbiological properties, viz., microbial biomass carbon, microbial biomass nitrogen and enzymatic (alkaline phosphatase, acid phosphatase, dehydrogenase, glucosidase, FDA hydrolysis, etc.) activities were also significantly higher in soils of RWMCS than in RWCS. All the nutrient management practices increased the SOM contents substantially over the control. The increase was most when biofertilizers and crop residues were combined either with farmyard manure (FYM) or vermicompost (VC).
Dr Dinesh Kumar is Principal Scientist at ICAR-Indian Agricultural Research Institute, New Delhi. Joined Agricultural Research Service of ICAR in 1995. Post-doctoral research (2001-02) at South China Agricultural University, University of Newcastle Upon Tyne (2009) and University of Aberdeen (2017), UK. Attended several International conferences in UK, China, Thailand, Turkey, Iran, Singapore, etc. Authored/ co-authored many research papers (110), popular articles (170), books, book chapters, bulletins and manuals. Delivered over 150 lectures, 160 TV talks and 75 radio talks for farmers. Awards – JRF (ICAR), SRF (IARI), Dr. P.S. Deshmukh Young Agronomist Award of ISA (2000), Chinese Government Scholarship (2001-02), Commonwealth Academic Staff Fellowship (2008), Dr D.N. Puri Memorial Award for the Biennium 2007-2008, Fellow-Indian Society of Agronomy (2012), Dhiru Morarji Memorial Award for Best Article 2013-2014, IARI Best Teacher Award 2015 and NEWS India-UK Fellowship 2016-17. Dr. Kumar has guided three MSc and five PhD students in Agronomy. Handled 9 externally funded projects as PI or Co-PI. He specializes in Organic Agriculture, Soil Fertility & Nutrient Management and Rice Agronomy.