~ 237 ~ Journal of Pharmacognosy and Phytochemistry 2018; 7(1): 237-247 E-ISSN: 2278-4136 P-ISSN: 2349-8234 JPP 2018; 7(1): 237-247 Received: 12-11-2017 Accepted: 14-12-2017 RK Naresh Department of Agronomy; Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut, U.P., India SP Singh Department of Soil Science; Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut, U.P., India RK Gupta Borlaug Institute for South Asia (BISA), New Delhi, India Arvind Kumar Rani Lakshmi Bai Central Agricultural University, Jhansi- U.P., India Ashok Kumar Department of Soil Science; Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut, U.P., India RS Rathore Uttar Pradesh Council of Agricultural Research, (UPDASP), Lucknow- U.P., India SS Dhaliwal Department of Soil Science’ Punjab Agricultural University, Ludhiana, Punjab, India Vivak Kumar Department of Agri. Engg. Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut, U.P., India Vivek Department of Agronomy; Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut, U.P., India PK Singh K.V.K.Beghra; Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut, U.P., India SP Singh K.V.K.Baghpat, Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut, U.P., India Nihal Chandra Mahajan Department of Agronomy; Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut, U.P., India Yogesh Kumar Department of Soil Science; Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut, U.P., India Correspondence RK Naresh Department of Agronomy; Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut, U.P., India Long term effects of tillage and residue management on soil aggregation, soil carbon sequestration and energy relations under rice – wheat cropping system in Typic Ustochrept soil of Uttar Pradesh RK Naresh, SP Singh, RK Gupta, Arvind Kumar, Ashok Kumar, RS Rathore, SS Dhaliwal, Vivak Kumar, Vivek, PK Singh, SP Singh, Nihal Chandra Mahajan and Yogesh Kumar Abstract A field experiment was conducted to investigate the influence of different combinations of tillage and residue management on carbon sequestration in different sized soil aggregates and also on crop yield after 4 years of continuous rice–wheat cropping system on Typic Ustochrept soil of Uttar Pradesh. Compared to conventional tillage, macro-aggregates in conservation tillage in wheat coupled with unpuddled transplanted rice (RT-TPR) was increased by 50.13% and micro-aggregates of the later decreased by 10.1% in surface soil.50% surface residue retention caused a significant increment of 15.65% in total aggregates in surface soil (0–5cm) and 7.53% in sub-surface soil (5–10 cm). In surface soil, the maximum (19.2%) and minimum (8.9%) proportion of total aggregated carbon was retained with >2mm and 0.1–0.05mm size fractions, respectively. WBed-TPR combined with zero tillage on permanent wide raised beds in wheat (with residue) (T9) had the highest capability to hold the organic carbon in surface (11.57g kg -1 soil aggregates).From the study, it has been proved that higher SOC content of 8.14 g kg -1 of soil was found in reduced tilled residue retained plots followed by 10.34 g kg -1 in permanently wide raised bed with residue retained plots. Whereas, the lowest level of SOC content of 5.49 g kg -1 of soil were found in puddled transplanted rice followed by wheat planted under conventionally tilled plots. Conservation agriculture practices secure good soil health by improving soil aggregation (53.8%) and increased energy output with respect to the conventional tillage puddle transplanted rice (T10) after four years of continuous rice–wheat cropping system in a Typic Ustochrept soil of Uttar Pradesh. Keywords: Conservation tillage, Carbon sequestration, Residue management, Aggregate stability, Rice– wheat cropping system 1. Introduction Any change in the productivity of rice–wheat cropping systems of the Indo-Gangetic Plains (IGP) would have crucial food security implications, as the region provides staple food for more than 20% of the global population (Chauhan et al., 2012) [4] . Even though the enhancement of cereal productivity in this tract accomplished the Green Revolution in the 1960s and 1970s in South Asia (Kumar et al., 2002) [20] , the rate of productivity growth has come down lately, with a sluggish pace registered over the last two decades (GoI, 2009) [11] . Alongside other factors, degradation of the natural resource-base as a result of intensive farming and inappropriate use of inputs has been widely documented as the root-cause of the problem (Hira, 2009) [15] . This has compelled many agricultural scientists and policy makers to look toward a more sustainable path of cereal production viz., conservation agriculture (CA) and the associated resource conservation technologies (RCTs) (Erenstein et al., 2008a) [8] . The growth conditions required by rice are quite different from those required by upland crops. Rice will grow best under puddled, reduced, and anaerobic soil conditions; where as upland crops require unpuddled aerobic and oxidized soil conditions. Furthermore, because of long- term submergence and mineral fertilizer application, paddy soils experience degradation of soil quality, such as breakdown of stable aggregation and deterioration of soil organic matter, which negatively affects agricultural sustainability (Das et al., 2013; Naresh et al., 2013) [6, 30] . Currently, puddling induces high bulk density, high soil strength and low permeability in subsurface layers (Singh et al., 2014) [39] .