INM-A Potential Way of Farming in Reduction of CH4 and CO2 Emission in Rice-sunflower Sequential Cropping System

Aim: To find out the CH4 and CO2 emission pattern and the considerable amount of SOC sequestered by using different organic sources in sandy clay loam soil.

Study Design: Randomized Block Design.

Place and Duration of the Study: The study was conducted in a farmer's field at Ayanathur, which is geographically located at 11°23’N latitude, 79°29'E longitude, and an altitude of +26 m MSL. Duration of the study confined to 2 years cycle from September 2016 to January 2018 I and II crops respectively.

Methodology: Different sources of organic manures viz., Farm Yard Manure @ 12.5 t ha-1, vermicompost, pressmud, poultry manure, and composted coirpith are each @ 5 t ha-1 were applied as basally and incorporated along with Azospirillum and phosphobacteria @ 2 kg ha-1 as a soil application at the time of last ploughing. Fertilizers were applied as per the treatment schedule of 150:50:50 kg N, P, and K ha-1 was followed throughout the period of study through urea, Di Ammonium phosphate and muriate of potash for rice crops. An open path LICOR analyzer 7700 and 7500 for CH4 and CO2 to find the CH4 and CO2 fluxes during the period of study through calibration of eddy covariance fluxes emissions were calculated.

Results: Combined application of a Recommended dose of fertilizers along with Farmyard manure @ 12.5 t ha-1 reduced the CH4 emission by 13.6 and 15 % over other organic sources in rice whereas, the CO2 emission by 54.4 and 53.8% and 61.5 and 53.9 % over other organic sources in rice and sunflower respectively. Concomitantly, the SOC increased by 6.8 and 7.5% in rice and 4,7 and 4.4% in sunflower over other organic sources.