Effect of conservation agriculture on stratification of soil organic matter under cereal-based cropping systems

ABSTRACT

Degradation of soil quality caused by conventional tillage practices is a major concern for the sustainability of rice-wheat cropping systems in South Asian region. Therefore, suitable conservation agriculture (CA) practices are required. This study investigates the stratification and storage of soil organic carbon (SOC) and total nitrogen (TN) as affected by eight years of different CA practices in the North-West Indo-Gangetic Plains of India. There were four treatments: (1) conventionally tilled rice-wheat cropping system, (2) reduced-till CA-based rice-wheat-mungbean system, (3) no-till CA-based rice-wheat-mungbean system, and (4) no-till CA-based maize-wheat-mungbean system. The mean stratification ratio (SR) (i.e. a ratio of the concentrations of SOC and TN in the soil surface to those in a deeper layer) of SOC and TN for 0–5:5–10, 10–15, 15–20, 20–25 and 25–30 cm were found higher (> 2) under CA practices compared to intensive tillage-based conventional agricultural practice (< 2). No-till CA-based rice-wheat-mungbean system stored the highest amount of SOC (25.32 Mg ha⁻¹) whereas reduced till CA-based rice-wheat-mungbean system stored highest amount of TN (3.21 Mg ha⁻¹) at 0–30 cm soil depth. This study shows that CA stratifies SOC and TN and helps to enhance SOC sequestration and soil quality.

KEYWORDS:

• Conservation agriculture
• soil organic carbon
• soil total nitrogen
• storage
• stratification ratio
• Indo-Gangetic Plains

Acknowledgment

The first author gratefully acknowledges the financial support provided by the Indian Council of Agricultural Research (ICAR), New Delhi, India, through the Netaji Subhash - ICAR International Fellowship for his doctoral programme. The logistical and scientific assistance received from TU Dresden, Germany, CIMMYT, New Delhi, India, ICAR-CSSRI, Karnal, India, and the UNU - FLORES, Dresden, Germany is gratefully acknowledged. The strategic research platform at ICAR-CSSRI Karnal where the experiment was carried out is supported by CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) funded by the CGIAR Fund Council, Australia (ACIAR), Irish Aid, European Union, International Fund for Agricultural Development (IFAD), Netherlands, New Zealand, Switzerland, UK, USAID and Thailand. The logistical support received from Drs. H.S. Jat and A.K. Yadav (CIMMYT and ICAR-CSSRI, Karnal, India) during the field campaign is thankfully acknowledged. In addition, we acknowledge and thank Ms Claudia Matthias, UNU-FLORES, Dresden, Germany for her help with infographic design of Figure 2.

Disclosure statement

No potential conflict of interest was reported by the authors.