Mr SUNIL MANDI¹, Dr. Yashbir Singh Shivay²

¹Division of Agronomy, ICAR-IARI, New Delhi, India, ²Division of Agronomy, ICAR-IARI, New Delhi, India

Basmati rice-wheat cropping system is covered considerable area in Indo-Gangetic plain zone due to its climatic suitability. Globally, basmati rice demand is increasing due to its special characteristics i.e. long-grain, soft texture and extreme elongation in nature. Nutrients requirement of organic Basmati rice and wheat can be fulfilled by the application of different organic materials. The present study was conducted to assess the physical properties and carbon build–up in different depth as affected by the long–term application of organic material in the organic farming system under Basmati rice-wheat cropping system. The results indicate that application of Sesbania green manure (SGM) + farmyard manure (FYM) @ 10 t ha-1 + blue-green algae  applied to rice and Leucaena green leaf manuring (LGLM) + FYM @ 10 t ha-1 + Azotobacter  applied to wheat  (SFB-R+LFA-W) was recorded reduced soil pH, electrical conductivity and soil bulk density in different soil depth. However, aggregate stability and mean weight diameter was recorded significantly higher in SFB-R+LFA-W than rest of the treatments. The large macroaggregates were recorded dominates in all treatments up to a 30cm depth of soil. However, small macroaggregates were dominates in lower depths. Carbon build-up in upper soil surface (0-15cm) was  42.80 t C ha-1 in SFB-R+LFA-W. However, carbon build-up in FYM @ 10 t ha-1  applied to both rice and wheat was recorded 34.46 t C ha-1 which was comparable to treatment SGM + FYM @ 10 t ha-1 treatment applied to rice and LGLM + FYM @ 10 t ha-1 applied to wheat.  The maximum carbon held by small macroaggregates in different treatments. This might be due to carbon was protected by small macroaggregates from microbial decomposition. Thus, integration of different nutrient sources along with FYM of organic materials in the organic farming system enhanced the carbon build-up, which may improve soil physical properties and sustained crop productivity under basmati rice-wheat cropping system.

Biography: Mr. Sunil Mandi is an agricultural research scientist, posted at ICAR-Central Tobacco Research Institute Rajahmundry, AP India. Presently he is doing Ph.D. as In-service in ICAR-Indian Agricultural Research Institute, New Delhi India. His working area long-term trial on organic and inorganic fertilizers on soil health,  soil fertility and  weed science.