Soil carbon-nutrient cycling, energetics, and carbon footprint in calcareous soils with adoption of long-term conservation tillage practices and cropping systems diversification

Biswajit Pramanick; Mritunjay Kumar; Banavath Mahesh Naik; Santosh Kumar Singh; Mukesh Kumar; Shiv Vendra Singh

doi:10.1016/j.scitotenv.2023.169421

Soil carbon-nutrient cycling, energetics, and carbon footprint in calcareous soils with adoption of long-term conservation tillage practices and cropping systems diversification

Sci Total Environ. 2024 Feb 20:912:169421. doi: 10.1016/j.scitotenv.2023.169421. Epub 2023 Dec 19.

Authors

Biswajit Pramanick¹, Mritunjay Kumar², Banavath Mahesh Naik², Santosh Kumar Singh³, Mukesh Kumar², Shiv Vendra Singh⁴

Affiliations

¹ Department of Agronomy, Dr. Rajendra Prasad Central Agricultural University, Pusa 848125, Bihar, India. Electronic address: biswajit@rpcau.ac.in.
² Department of Agronomy, Dr. Rajendra Prasad Central Agricultural University, Pusa 848125, Bihar, India.
³ Department of Soil Science, Dr. Rajendra Prasad Central Agricultural University, Pusa 848125, Bihar, India.
⁴ Department of Agronomy, Rani Lakshmi Bai Central Agricultural University, Jhansi 284003, Uttar Pradesh, India. Electronic address: shiv1992gbpuat@gmail.com.

PMID: 38128664
DOI: 10.1016/j.scitotenv.2023.169421

Abstract

Calcareous soils, comprising vast areas in northern and eastern parts of India, are characterized by low soil organic carbon (SOC) with high free CaCO₃ that results in low nutrient bioavailability with poor soil structure. Improvement of this soil can be achieved with conservation tillage with residue retention coupled with diversification of cropping system including legumes, and oilseeds in the system. Concerning all these, a long-term experiment was carried out in the calcareous soils having low organic carbon and high free CaCO₃ (∼33 %) with varied tillage practices, viz. permanent bed with residue (PB), zero tillage with residue (ZT), and conventional tillage without residue (CT); and cropping systems viz. maize-wheat-greengram (MWGg), rice-maize (RM), and maize-mustard-greengram (MMuGg) during 2015-2021. From this study, it was observed that PB and ZT resulted in ∼25-30 % increment in SOC compared to the initial SOC, while CT showed a 4 % decrease in the SOC. Conservation tillage practices also resulted in better soil aggregation and favourable bulk density of the soil. Furthermore, PB and ZT practice exhibited 10-13 %; 15-18 %; 11-15 %; 40-60 %, 20-36 %, and 23-45 % increments in the soil available N, P, K, soil microbial biomass carbon, dehydrogenase activity, and urease activity, respectively over those under CT. Crop diversification with the inclusion of legume and oilseed crops (MMuGg, and MWGg) over cereal-dominated RM systems resulted in better soil health. Maize equivalent yield and energy use efficiency (%) were also found to be the maximum under PB, and ZT, in combination with the MMuGg system. ZT and PB also reduced the carbon footprint by 465 and 822 %, respectively over CT by elevating SOC sequestration. Hence, conservation tillage practices with residue retention coupled with diversification in maize-based cropping systems with mustard and greengram can improve soil health, system productivity, and energetics, and reduce the carbon footprint in calcareous soils.

Keywords: Carbon footprint; Energy auditing; Permanent bed; Soil health; System productivity; Zero tillage.