Nitrogen management in rainfed castor: a comprehensive analysis of productivity, nutrient use efficiency, economics, energy flow, and carbon footprint
- 1University of Agricultural Sciences
- 2ICAR - Central Coastal Agricultural Research Institute
Abstract
Introduction: Nitrogen (N), an essential plant nutrient characterized by the lowest use efficiency and multiple loss pathways, challenges its management in rainfed castor. Therefore, a field experiment was conducted over three consecutive Kharif seasons (2022-2024) to develop an adoptable N management strategy for rainfed castor cultivation.
Methodology: The study investigated the impact of eight N management modules viz. , Recommended rate of fertilizer (RRF) (40-40–25 kg N-P ₂ O ₅ -K ₂ O ha ⁻¹ ), 50% recommended rate of basal N (RRBN) +2 ml l ⁻¹ Nano Urea at 30 and 60 days after sowing (DAS), 50% RRBN + 2% Urea spray at 30 and 60 DAS, 75% RRBN + 2 ml l ⁻¹ Nano Urea at 30 and 60 DAS, 75% RRBN + 2% Urea spray at 30 and 60 DAS, 100% RRBN + 2 ml l ⁻¹ Nano Urea at 30 and 60 DAS, 100% RRBN + 2% Urea spray at 30 and 60 DAS, and recommended rate of phosphorous and potassium (RRPK) (00-40–25 kg N-P ₂ O ₅ -K ₂ O ha ⁻¹ ) and were arranged in randomized complete block design with three replications.
Results and discussions: The study found that the combined soil and foliar application of N had a promising effect on crop productivity than soil-only N application. Aqueous solution of urea (2%) proved effective than Nano-Urea (2 ml L ⁻¹ ) for foliar fertilization of N. Specifically, application of 100% RRBN through soil (20 kg ha ⁻¹ ), followed by foliar sprays of 2% Urea at 30 and 60 DAS, improved growth and yield traits of castor. Consequently, it produced significantly higher seed yield (1546 kg ha ⁻¹ ), oil content (42.7%), and N uptake in castor (34.9 kg ha ⁻¹ ). Due to inverse relationship, N substituted via foliar fertilization enhanced the partial factor productivity (67.8–106 kg kg ⁻¹ ) compared to soil-only N application (32.5 kg kg ⁻¹ ). Foliar fertilization depletes the soil N pool as observed through +ve N balance index (10.7-12.1). Furthermore, 100% RRBN + foliar sprays of 2% Urea at 30 and 60 DAS found to be remunerative, besides enhancing energy (58,726 MJ ha ⁻¹ ), carbon (C) output (1,947 kg-CE ha ⁻¹ ), net energy and C-gain. These findings highlight that partial N substitution through foliar applications optimizes castor productivity, economics, energy, and environmental security in rainfed castor.
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BibTeX
@article{kumar2026nitrogen,
title = {{Nitrogen management in rainfed castor: a comprehensive analysis of productivity, nutrient use efficiency, economics, energy flow, and carbon footprint}},
author = {Revappa Mohan Kumar and Yamanura Madival and Venkatesh Paramesha and Ganiga Jadesha and Gopalaswamy Ranganath},
journal = {Frontiers in Plant Science},
year = {2026},
month = oct,
doi = {10.3389/fpls.2026.1969600},
url = {https://www.frontiersin.org/articles/10.3389/fpls.2026.1969600/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Nitrogen management in rainfed castor: a comprehensive analysis of productivity, nutrient use efficiency, economics, energy flow, and carbon footprint
AU - Revappa Mohan Kumar
AU - Yamanura Madival
AU - Venkatesh Paramesha
AU - Ganiga Jadesha
AU - Gopalaswamy Ranganath
PY - 2026
DA - 2026/10/28
JO - Frontiers in Plant Science
DO - 10.3389/fpls.2026.1969600
UR - https://www.frontiersin.org/articles/10.3389/fpls.2026.1969600/full
AB - Introduction: Nitrogen (N), an essential plant nutrient characterized by the lowest use efficiency and multiple loss pathways, challenges its management in rainfed castor. Therefore, a field experiment was conducted over three consecutive Kharif seasons (2022-2024) to develop an adoptable N management strategy for rainfed castor cultivation. Methodology: The study investigated the impact of eight N management modules viz. , Recommended rate of fertilizer (RRF) (40-40–25 kg N-P ₂ O ₅ -K ₂ O ha ⁻¹ ), 50% recommended rate of basal N (RRBN) +2 ml l ⁻¹ Nano Urea at 30 and 60 days after sowing (DAS), 50% RRBN + 2% Urea spray at 30 and 60 DAS, 75% RRBN + 2 ml l ⁻¹ Nano Urea at 30 and 60 DAS, 75% RRBN + 2% Urea spray at 30 and 60 DAS, 100% RRBN + 2 ml l ⁻¹ Nano Urea at 30 and 60 DAS, 100% RRBN + 2% Urea spray at 30 and 60 DAS, and recommended rate of phosphorous and potassium (RRPK) (00-40–25 kg N-P ₂ O ₅ -K ₂ O ha ⁻¹ ) and were arranged in randomized complete block design with three replications. Results and discussions: The study found that the combined soil and foliar application of N had a promising effect on crop productivity than soil-only N application. Aqueous solution of urea (2%) proved effective than Nano-Urea (2 ml L ⁻¹ ) for foliar fertilization of N. Specifically, application of 100% RRBN through soil (20 kg ha ⁻¹ ), followed by foliar sprays of 2% Urea at 30 and 60 DAS, improved growth and yield traits of castor. Consequently, it produced significantly higher seed yield (1546 kg ha ⁻¹ ), oil content (42.7%), and N uptake in castor (34.9 kg ha ⁻¹ ). Due to inverse relationship, N substituted via foliar fertilization enhanced the partial factor productivity (67.8–106 kg kg ⁻¹ ) compared to soil-only N application (32.5 kg kg ⁻¹ ). Foliar fertilization depletes the soil N pool as observed through +ve N balance index (10.7-12.1). Furthermore, 100% RRBN + foliar sprays of 2% Urea at 30 and 60 DAS found to be remunerative, besides enhancing energy (58,726 MJ ha ⁻¹ ), carbon (C) output (1,947 kg-CE ha ⁻¹ ), net energy and C-gain. These findings highlight that partial N substitution through foliar applications optimizes castor productivity, economics, energy, and environmental security in rainfed castor.
SN - 1664-462X
ER -