Comparative Assessment of Panchakavya and DAP-Based Nutrient Management on Soil Properties, Yield Attributes and Grain Elemental Composition of Selected Pulse Crops in Tamil Nadu, India

Abstract

Nutrient management practices can influence the mineral composition and
safety of pulse grains. A three-year field study (2022–2024) was conducted
in Ottapidaram, Thoothukudi, Tamil Nadu, to compare organic
(Panchakavya) and conventional inorganic (DAP) nutrient-management
practices in red cowpea, horse gram, black gram, and green gram. Grain
elemental composition (25 elements) was determined using ICP-MS, while
soil properties, germination, seed count, and 50-seed weight were evaluated
annually. Grains from the DAP-treated plot generally showed lower
concentrations of several potentially hazardous elements, including As, Cd,
Cr, Mn, Mo, Pb, and Tl, along with lower K, Na, and Fe. Green gram from
the organic plot showed markedly higher Cd levels, highlighting the
importance of verifying the quality of organic inputs. A significant difference
across the 25-element profile was observed for red cowpea, but not for the
other crops. Overall, neither nutrient-management system was consistently
superior in terms of grain safety or nutrient density. The findings emphasize
the need for source verification of organic inputs and replicated studies to
assess their effects on pulse grain quality and safety.