Carbon sequestration and relationship between carbon addition and storage under rainfed soybean–wheat rotation in a sandy loam soil of the Indian Himalayas

• Published in: Soil & tillage research Vol. 92; no. 1; pp. 87 - 95
• Main Authors: Kundu, S., Bhattacharyya, Ranjan, Prakash, Ved, Ghosh, B.N., Gupta, H.S.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 2007; Elsevier
• Subjects: Agronomy. Soil science and plant productions; animal manures; Biological and medical sciences; carbon; Carbon addition and storage; Carbon sequestration; crop rotation; crop yield; Farmyard manure; fertilizer application; Fundamental and applied biological sciences. Psychology; Glycine max; grain yield; mineral fertilizers; NPK fertilizers; rain; Sandy loam soil; sandy loam soils; soil depth; soil organic carbon; Soil science; soil-atmosphere interactions; soil-plant interactions; soybeans; Soybean–wheat cropping; Sub-temperate Indian Himalayas; Triticum aestivum; wheat; India; Asia; Himalayas; South Asia; Soybean–wheat cropping; Farmyard manure; Carbon addition and storage; Carbon sequestration; Sandy loam soil; Sub-temperate Indian Himalayas; Monocotyledones; Soybean-wheat cropping; Rainfed agriculture; Carbon; Glycine max; Cereal crop; Grain legume; Storage; Leguminosae; Mountain; Gramineae; Dicotyledones; Crop rotation; Angiospermae; Spermatophyta; Soil science; Triticum aestivum
• ISSN: 0167-1987; 1879-3444
• DOI: 10.1016/j.still.2006.01.009

Soil organic matter (SOM) contributes to the productivity and physical properties of soils. Although crop productivity is sustained mainly through the application of organic manure in the Indian Himalayas, no information is available on the effects of long-term manure addition along with mineral fertilizers on C sequestration and the contribution of total C input towards soil organic C (SOC) storage. We analyzed results of a long-term experiment, initiated in 1973 on a sandy loam soil under rainfed conditions to determine the influence of different combinations of NPK fertilizer and fertilizer + farmyard manure (FYM) at 10 Mg ha −1 on SOC content and its changes in the 0–45 cm soil depth. Concentration of SOC increased 40 and 70% in the NPK + FYM-treated plots as compared to NPK (43.1 Mg C ha −1) and unfertilized control plots (35.5 Mg C ha −1), respectively. Average annual contribution of C input from soybean ( Glycine max (L.) Merr.) was 29% and that from wheat ( Triticum aestivum L. Emend. Flori and Paol) was 24% of the harvestable above-ground biomass yield. Annual gross C input and annual rate of total SOC enrichment were 4852 and 900 kg C ha −1, respectively, for the plots under NPK + FYM. It was estimated that 19% of the gross C input contributed towards the increase in SOC content. C loss from native SOM during 30 years averaged 61 kg C ha −1 yr −1. The estimated quantity of biomass C required to maintain equilibrium SOM content was 321 kg ha −1 yr −1. The total annual C input by the soybean–wheat rotation in the plots under unfertilized control was 890 kg ha −1 yr −1. Thus, increase in SOC concentration under long-term (30 years) rainfed soybean–wheat cropping was due to the fact that annual C input by the system was higher than the required amount to maintaining equilibrium SOM content.