Climate Change Mitigation and Adaptation through Conservation Agriculture and Precise Nutrient Management in Current and Future Cereal-based Cropping Systems of the Indo Gangetic Plains

Research Concept
The Green Revolution has been a global agricultural success story of the second half of the 21^st century. The success has led to food self-sufficiency in the post populous regions of South Asia including India and China. But the real challenges have surfaced in the recent years with ever-increasing food demand due to burgeoning populations, degradation of land and natural resources , degrading soil nutrient status and soil health, changing climatic conditions and yield stagnation. To compound the challenges further, global climate change is likely to impact crop and livestock production, hydrologic balances, input/nutrient supplies and other components of agricultural systems, making production much more variable than at present. The conservation agriculture (CA) involving three key features of i) minimum soil disturbance, ii) retention of crop residues, and iii) appropriate crop rotation have great relevance to restore the degraded ecologies of India, where low farm income and fatigue in crop yield have become major concern. Integrating the précised nutrient management with CA based technologies is the way forward to achieve agricultural and environment sustainability. The precision nutrient management tools and CA is being promoted and adopted by farmers on large scale as an alternative technology to enhance input use efficiency, soil health and environmental quality. The conservation and precision agriculture (CPA) based technologies are being reported to help more efficient use of water under both rainfed and irrigated systems. Soil health is the combined effects of three major interacting components i.e. physical, chemical and biological characteristics of the soil. The physical and chemical characteristics of soil are far better understood than that of the nutrient dynamics and kinetics under different management practices. In the integration of these properties have a significant impact on the nutrient availability and carbon dynamics in soil. Another important change with CA practices is in soil organic matter (SOM), that not only affects sustainability of agricultural ecosystems, but also extremely important in maintaining overall quality of environment by mitigating climate change, as soil contains a significant part of global carbon stock and nutrient efficiency. Most of the cultivated lands in India are poor in organic carbon and fatigued nutritional status. At the same time results of long-term experiments of the country show only a marginal build up of soil organic carbon (SOC) as result of addition of organic manures over a period of four decades. In this context, it will be worthwhile to study both nutrient dynamics & carbon sequestration potential; and its interaction with soil physical properties of CA vis-à-vis dynamics and quality of SOC. But in India, overall CA based scientific documentation shows major research and delivery work on resource conservation technologies. But in full CA based systems scanty information is available on the interactive effect of CA based tillage, moisture and residue retention, nutrient dynamics on soil physical, chemical and microbial properties. Therefore, the wider research gaps and quantum of researchable issues under different nutrient management and CA based systems emphasize an in-depth systematic basic research on soil health, C and Nutrient dynamics to elucidate the sustainability of CA in respect of maintaining soil health, crop productivity and environmental quality. Such endeavor will certainly make CA more meaningful and feasible in the present context.

Goal:
To quantify the soil and environmental health indicators in conservation agriculture and precise nutrient management based targeted cropping systems of India to counteract the changing weather conditions, degrading resource use bases on a long-term basis for a sustainable agricultural production and environment system.

Proposed duration of the Project: 36 months

The proposed field and laboratory studies will be conducted to fill the basic and strategic research gaps on nutrient dynamics interactions with soil physical, chemical and microbial properties under CA vis-à-vis conventional crop production technologies involving different tillage, residue and moisture levels in three different soil types/agro-ecologies with following objectives:

Objectives:

S. No.	Objective		Activities
1.	To study carbon sequestration, and sustainability under different tillage, residue & moisture management in CA systems		(i) Quantification of carbon fractionation, and sequestration under different CA vis-à-vis conventional crop production technologies (ii) Monitoring the carbon sustainability index under conventional and CA
2.	Systematic evaluation of nutrient release kinetics and GHG emissions under different tillage, moisture, and residue management conditions in CA systems		(i) Assessment of soil profile nutrient dynamics, and fractionation under different tillage and residue management conditions (ii) In-season GHG emission studies and their interaction with nutrient management practices and CA systems (iii) Interaction studies on nutrients x moisture x under different tillage and residue management (iv) Development of nutrient management tools and strategies based on availability and dynamics of nutrients in soil
3.	To evaluate crop productivity, energy use efficiency and economics of CA		(i) Evaluating the effect of CA on crop productivity under different tillage and residue management practices (ii) Evaluating the carbon foot prints of CA based technologies for environmental sustainability (iii) Computation of energy input and its use efficiency in conventional agriculture vis-à-vis CA

Study Site

1. IARI New Delhi

Research Status and Gaps
· Persistent use of CT practice with extensive tillage and burning of crop residues have magnified nutrient depletion, degraded soil resource base (Limon-Ortega et al., 2006, Sommer et al., 2007; Lichter et al., 2008, Saharawat et al., 2010), decrease SOM content (Biamah et al., 2000), deteriorates soil physical properties (Gathala et al. 2011, Saharawat et al. 2012, ), as well as are capital- and energy-intensive and in any crop production system resulting to lower economic returns (Labios et al., 1997 and Jat et al, 2006; Saharawat et al, 2010).
· CA systems often result in greater stratification of soil nutrients than CT and higher availability of nutrients especially P & K (Grant and Bailey, 1994; Lupwayi et al., 2006; Jones and Chen, 2007), increase nutrient supply to crops through changes in mineralization and immobilization of nutrients by microbial biomass (Carter and Rennie, 1982; Jansson and Persson, 1982).
· The CA systems increase total carbon by 45%, microbial biomass by 83% and MBC:total Carbon ratio by 23%, increase C and N mineralization by 74% and decrease the metabolic quotient by 32% (Balota et al. 2004, Sainju et al., 2009; Fuentes et al., 2009 ).
· In 20-year-old rice (O. sativa L)–berseem (T. alexandrium L) cropping system expt. with different nutrient management strategies Bidisha et al., (2007) reported decreased SOC over the years due to tillage, while balanced fertilization with NPK maintained the SOC. About 62% of the C applied as FYM was stabilized into SOC. The passive pool (C_frac 3+C_frac 4) constituted about 55% of the C_t.
· Carbon pools like microbial biomass C (Cmic), mineralizable C (Cmin), particulate organic C (Cp) and oxidisable organic C (Coc) are good indicators of soil quality and these get depleted due to CT and cultivation practices (Sherrod et al., 2005). Higher SOM (24%) was recorded in 25 year ZT field than 3 year ZT field by Lafond et al., (2005).
· CA has proved to be improving soil health in terms of its physical, chemical, and biological properties (Zachmann et al., 1987; Sharma and Acharya, 2000; Gan et al., 2007; Bazaya et al., 2009, Gathala et al., 2011, Jat et al., 2011), and in turn improves overall soil fertility, WUE, crop productivity, and farmers’ income (Sen and Sharma, 2002; Gupta and Sayre, 2007; Yaduvanshi and Sharma, 2008, Gathala et al., 2011, Saharawat et al., 2012). A positive relation between SOC and soil aggregation (MWD) has been reported (Verma and Sharma, 2007).
· CA based practices in different cropping systems and soils provide a conducive environment to plant through enhanced root-moisture interaction in root zone for effective capture of plant nutrients and water (Derpsch, 2008), refine soil architecture through macro-aggregation as well as increased fungal growth and hyphae promoting beneficial biological activities, improves SOM and contributes to capture, retention, chelation and slow release of plant nutrients (Kassam et al,. 2009, Saharawat et al. 2010).
· Research gaps on interaction between tillage x soil moisture x nutrients and carbon dynamics in CA based approaches has not been reported in details from cereal based cropping systems in South Asia. In addition to that a wide gap on crop modeling approaches in CA based systems exist in South Asia emphasizing urgent need to refine, develop or calibrate the CA based crop modeling approaches in India.

Expected Outcomes:
• Identified the key nutrient management strategies and tools as well as soil health indicators for sustainable production targeted cropping systems with optimized food production under changing climatic scenarios
• Quantified the effects of CA based technologies on carbon & nutrient dynamics and soil health in rainfed and irrigated cropping systems to adapt and mitigate the climatic variability in current and future cereal systems
• Enhanced the input-use efficiency through CA based practices to mitigate and adapt to changing climatic conditions
• Demarcated the impact of tillage, residue management and intensification on carbon & nutrient dynamics
• Calibrated and validated the nutrient management decision tools CA based technologies in South Asia