Influence of Tillage and Organic Amendments on Terrace Soil Bio-physico-Chemical Properties and Carbon Sequestration Index

ABSTRACT

Two sets of experiments were conducted in Bangladesh for 10 successive growing seasons of transplanted aman and boro rice during 2010–2015 to assess the effects of tillage and organic amendments on properties and carbon sequestration index (CSI) of terrace soil. The experiment 1 comprised of two tillage practices (minimum and traditional) and three rice straw management (zero, incorporation, and mulch). The experiment 2 consisted of five treatments viz. control, poultry manure (PM), cowdung (CD), rice straw (RS), and soil test-based fertilizers. A fixed carbon (C) rate of 2 t ha⁻¹ was ensured from organic amendments in each crop season. Data were collected after harvesting of the 10^th crop in 2015. Traditional tillage and RS mulch were found immensely positive for microbial population and biomass C and nitrogen (N) in soils. Minimum tillage tied with RS incorporation was appeared positive in holding C and nutrients and increasing CSI. Poultry manure contributed to higher quantities of bacteria, fungi, and actinomycetes and attributed to maximum biomass C and N compared to other organic treatments. Organic amendments increased soil aggregate stability, nutrients, and moisture contents. The CSI of RS (0.21–0.29), PM (0.25), and CD (0.22) can be used to predict soil C sequestration.

KEYWORDS:

• Rice straw
• manures
• biomass carbon & nitrogen
• soil health

Acknowledgments

The research was conducted under the ‘Carbon sequestration in soils of Bangladesh’ project (ID # 305) of the National Agricultural Technology Program (NATP), Phase 1 of Bangladesh Agricultural Research Council, Dhaka 1215, Bangladesh.