Book of Extended summaries ISDA

International Conference on Reimagining Rainfed Agro-ecosystems: Challenges & Opportunities
during 22-24, December 2022 at ICAR-CRIDA, Hyderabad
Methodology
The experimental site was located at Gungal Research Farm (GRF) of ICAR-Central Research
Institute for Dryland Agriculture, Hyderabad, Telangana, India. The duration of the experiment
was 2012-2018.The treatments comprised of the three tillage practicesviz., conventional tillage
(CT), reduced tillage (RT) and conservation agriculture (CA), and four nitrogen levels viz., N0=
no nitrogen application (control), N75= 75% of RDN (recommended dose of nitrogen),
N100=100% of RDN and N125=125% of RDN of maize and pigeonpea crops on yearly rotation
basis. The soil totalcarbon was determined by using the CHNS Analyzer, Vario EL, bulk density
was measured by core methodand porosity was calculated by using the formula: Total porosity
(%) = (1-bulk density/particle density).
Results
Effect on soil total carbon content
From the view point of soil total carbon content, the order of soil depth was as follows: 0-
7.5>7.5-15>15-30>30-45 cm., irrespective of tillage and nitrogen levels. There were 28.1, 20.1,
15.6 and 2.5% increase in the soil total carbon contentin CA, and 13.9, 9.9, 7.7 and 0.8%
increase in soil total carbon contentin RT, in 0-7.5, 7.5-15, 15-30 and 30-45 cm, respectively as
compared to the CT. The nitrogen fertilizer levels in relation to the total soil carbon content
follow the order: N125>N100>N75>N0 in all the depths studied. There were 13.5, 18.7 and 23.7%
increase in soil total carbon contentin 0-7.5cm soil depth,9.4, 16.1 and 20.6% increase insoil total
carbon content in 7.5-15 cm, 6.0, 12.7 and 17.4% increase in soil total carbon content in 15-30
cm soil depth and 0.8, 3.0 and 6.4% increase insoil total carbon content in 30-45 cm soil in N75,
N100 and N125, respectively.
Effect on soil bulk density and soil total porosity
620 | Page Resource conservation and rainfed agriculture