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Conventional agricultural practices that rely heavily on blanket fertilizer recommendation, eventually leading to deteriorated partial factor productivity and N use efficiency. We investigated the effect of SPAD-based N-management on productivity and N use efficiency of rice and wheat in eastern India. Here, in the experiment three SPAD thresholds (34, 36 and 38 in rice and 38, 40 and 42 in wheat) using three N levels (15, 25 and 35 kg N ha−1) in split were incorporated as real-time N management (RTNM), one fixed-time N management (FTNM), farmers’ fertilizer practice (FFP) and control (No fertilizer) were introduced in wet and dry seasons for rice and wheat, respectively, during the years 2010 to 2012. Topdressing with 25 kg N ha−1 at medium SPAD (S36 in rice and S40 in wheat) increased soil N availability, leaf N content and grain yield of rice (5215 kg ha−1) and wheat (4483 kg ha−1) over the grain yield recorded under a low rate of N topdressing at low SPAD. While saving 33.3% N in rice and 18.8% N in wheat, the agronomic N use efficiency (58.5% in both rice and wheat) and nitrogen recovery efficiency (32.2% in rice and 15.1% in wheat) can be increased when compared with conventional FTNM. The SPAD-based management strategy showed great promise in efficient management of N fertilizer, and we estimated the optimal SPAD threshold for rice and wheat as 37.5 and 41.8, respectively.

In Indian semi-arid tropics (SATs), low water and crop productivity in Vertisols and associated soils are mainly due to poor land management and erratic and low rainfall occurrence. This study was conducted from 2014 to 2016 at the ICRISAT in India to test the effect of broad bed furrows (BBF) as land water management against conventional flatbed planting for improving soil water content (SWC) and water and crop productivity of three cropping systems: sorghum [Sorghum bicolor (L.) Moench]–chickpea (Cicer arientinum L.) and maize (Zea mays)–groundnut (Arachis hypogaea L.) as sequential and pearl millet [Pennisetum glaucum (L.)] + pigeonpea [Cajanus cajan (L.) Millsp.] as intercropping, grown under different nutrients management involving macronutrients (N, P, and K) only and combined application of macro- and micronutrients. The results stated that the SWC in BBF was higher over flatbed by 9.35–10.44% in 0- to 0.3-m, 4.56–9.30% in 0.3- to 0.6-m and 3.85–5.26% in 0.6- to 1.05-m soil depths during the cropping season. Moreover, depletion of the soil water through plant uptake was higher in BBF than in flatbed. Among the cropping systems, sorghum–chickpea was the best in bringing highest system equivalent yield and water productivity with the combined application of macro- and micronutrients. The BBF minimized water stress at critical crop growth stages leading to increase crop yield and water productivity in SATs. Thus, BBF along with the application of macro- and micronutrients could be an adaptation strategy to mitigate erratic rainfall due to climate change in SATs.

Sustainable crop production in sub-tropical countries is severely affected by the unscientific application of fertilizers. The SPAD based N management of the rice–wheat sequence was investigated in eastern India. Topdressing of 25 kg N ha−1 was applied at SPAD 36 and 40 (S36 and S40) for rice (Oryza sativa L.) and wheat (Triticum aestivum L.), respectively, reduced the N requirement by an average of 26.5% (33.3% in rice and 18.8% in wheat) over the fixed-time N management (FTNM) without reducing the grain yield. The 25 kg N ha−1 increased nutrient removal in the system having high agronomic N use efficiency (21.4) and nitrogen recovery efficiency (0.60) with the lower N requirement (62.5 kg N ha−1) over the FTNM. The treatment with medium SPAD (S36 for rice and S40 for wheat) under 25 kg N ha−1 increased the agronomic N use efficiency by 58% in rice and 58.5% in wheat compared to that under FTNM and recorded the highest gross (2106.1$ ha−1 Year−1) and net (1202.5$ ha−1 Year−1) returns from the rice–wheat system. The SPAD-based N management increased the water content in N-treated plots compared to that in the control plots, and the utmost moisture custody was observed when using a moderate (25 kg ha−1) N topdressing at a moderate SPAD (S36 for rice and S40 for wheat) for a given soil suction. This study suggests that using SPAD meter in rice–wheat system can cover the productive N management and profitability and can be dependably used in precision agriculture to manage the spatial variation in farmers’ field.

Elevated CO2 might have differential impact on the growth, development, and yield of wheat under varying nutrient management, especially in a warmer climate when the global atmospheric temperature is already increasing. Field experiments were conducted in subtropical Eastern India during the rabi seasons of 2014–2016 to study the performance of wheat under the elevated CO2 environment with different nitrogen (N) management. Wheat was grown in open field and inside open top chambers (OTCs) with ambient (˜390 μmol mol−1) and elevated (˜585 μmol mol−1) level of CO2 without any fertilizer addition (N0), and with application of N through chemical fertilizer (CF) at normal (100%) recommendation [N100(CF)] and 50% higher dose [N150(CF)] and through integration of organic and chemical fertilizer [N150(OF + CF)]. Results showed that CO2 enrichment had a positive effect on various growth parameters and yield attributes of wheat. Elevated CO2 tended to increase the crop growth rate and the fraction of leaf biomass and leaf N, especially for the N management using chemical fertilizer [N100(CF) and N150(CF)]. Elevated CO2 [+˜200 μmol mol−1] caused 17% increase in wheat grain yield above ambient as averaged over the N fertilized treatments. Application of N at 50% higher dose than normal through CF did not increase the grain yield significantly under the open field and OTC with ambient [CO2] environment, whereas the yield increment was significant under the elevated [CO2] environment. Elevated CO2 also resulted in higher agronomic N use efficiency and nitrogen harvest index with the increased N fertilizer dose. Thus, wheat production under the elevated CO2 environment in Eastern India might be maintained or improved through the normal and increased dose of N fertilizer application.

A comparative study on the effect of elevated CO2 environment on soil nitrogen availability in different rice planting system is needed to develop nutrient management strategies in future climate scenarios. A field experiment was conducted inside open top chambers (OTC) to study the effect of elevated CO2 environment with varying nitrogen management on soil NH4+–N and NO3−–N status in two planting system of rice, direct-seeded rice (DSR) and puddled transplanted rice (PTR). The nitrogen management included chemical fertilizer (CF) at 100% (CF100) and 150% (CF150) of the recommended dose, integrated nitrogen management including organic fertilizer (OF) and CF as CF75+ OF75, and site-specific N management through CF using SPAD meter. The soil NH4+–N content was higher in PTR, but NO3−–N was higher in DSR. The soil NH4+–N and NO3−–N content decreased significantly under elevated CO2 environment as compared to ambient in both planting system, except the NO3−–N content at flowering in DSR. The decrease was around 8% for NH4+–N and 5% for NO3−–N content. Soil nitrogen content in DSR can be maintained by following integrated nutrient management (CF75 + OF75) and SPAD-based nitrogen management for sustainable yield. Grain yield, in general, increased with CO2 elevation in both planting system. Under ambient environment, CF150 increased the grain yield by 23% as compared to CF100 in DSR, but no change was noted in PTR. However, under elevated CO2 environment, CF150 increased the grain yield by 13% in PTR. Under elevated CO2 environment, the yield increase of the hybrid rice to additional N fertilizer application was noted in PTR but not in DSR. This study suggests that for sustainable rice production under increasing CO2 environment in future climate scenarios, higher dose of N fertilizer is recommended in PTR, but normal dose in DSR production system.

Our understanding of crop response to elevated [CO2] concerning its growth and yield has improved significantly. However, little is known about the germination and vigour of seeds harvested from mother plant grown under elevated [CO2], particularly in rice. Since elevated [CO2] influences the physiological functions of crop and seed development process, it is expected that such changes will alter the quality of the seed. To test this hypothesis, rice crop (IR 36) was grown in open top chamber (OTC) with varying [CO2] [410 (ambient), 510, 610 and 720 ppm] and seed quality in terms of germination and vigour [accelerated ageing test (AAT) and electrical conductivity (EC)] was assessed. Elevated [CO2] up to 610 ppm had no effect on seed germination; but, [CO2] at 720 ppm reduced the germination of freshly harvested seeds. Elevated [CO2] at 610 and 720 ppm reduced seed vigour. An increase in abnormal seedlings and dead seeds were symptomatic of the seed physiological deterioration associated with loss of seed vigour. Elevated [CO2] at 720 ppm reduced seed nitrogen content, substrate availability, and its subsequent translocation. Thus, atmospheric [CO2] above 610 ppm reduced seed vigour of rice.

Temperatures have a major effect on potato crop growth and yield attributes during the crop growing season. In this study, the SUBSTOR-Potato model was used to simulate the potato crop growth and yield in a sub-tropical region of West Bengal comprising of three districts, namely West Medinipur, Bankura and Birbhum in India. Also, the effect of temperature and planting dates scenario on potato crop growth was evaluated by using 30 years historical weather data of the aforesaid districts. Field experiments were conducted on potato crops of cultivar Kufri Jyoti under two planting dates (10th and 25th of December) and different fertilizer treatments in the years 2013–2014 and 2014–2015, respectively. The statistical results showed the satisfactory performance of the model with an R2 of 0.82 to 0.98 and d-stat of 0.94 to 0.98 for the year 2013–2014 and an R2 of 0.89 to 0.98 and d-stat of 0.97 to 0.98 for the year 2014–2015. Evaluation of planting dates with past 30 years historical data showed planting dates 20th and 30th of November resulted in average higher yield than planting dates 10th, 25th and 30th of December, respectively, in current climate scenario. Furthermore, the study suggests that amending the planting dates is an effective climate change adaptation strategy for reducing the effect of temperature on the yield of a potato crop in the near future.

Water management technologies under projected climate change will play key role in sustainable rice production. Modeling approach was used to assess the impact of climate change on rice production under drip irrigation (DIR) and conventional puddle transplanted (PTR) in subtropical India. The genotype coefficients of CERES-Rice model (cv. Naveen) were determined and tested using experimental data for the years 2012–2014. Close match between the observed and simulated values was recorded during both the years which led to higher d-index (> 0.95) and lower normalized RMSE (RMSEn) values. Under the projected climate change scenarios (RCP 4.5 and RCP 8.5), grain yield reduced over the period 2020–2080, with higher decline in RCP 8.5. Over the period, higher nitrogen (N) use efficiency in DIR led to lower yield reduction over PTR. Among the different adaptation measures, higher fertilizer N dose was able to mitigate negative impact of temperature rise up to 3.3 °C over base period, beyond which grain yield was significantly reduced. Results of the simulations for the different sowing dates stated higher reduction in grain yield with delayed sowing in DIR as well as in PTR for both (RCP 4.5 and 8.5) climate change scenarios. However, early sowing resulted in better crop establishment in DIR leading to better yield compared to PTR in both the climate change scenarios.

Aerobic or partially-aerobic rice cultivation techniques like direct-seeding of rice (DSR) and system of rice intensification (SRI) are gaining recognition, particularly for water-saving. However, their productivity is often constrained by several deficiencies in the soil-plant system (crop nutrition in particular). The study aimed to assess crop eco-physiology and soil-plant nutrient dynamics in rice-lentil system in an alkaline Fluvisol as influenced by different rice cultivation techniques (RCT) viz., DSR, SRI and conventional transplanted flooded-rice (PTR). The lower (9–11 %) yield of DSR crop compared to PTR crop was attributed to reduced root growth, effective tiller, and panicle and seed weights. Likewise, the SRI crop yield was lower (4–7 %) than the PTR crop. The reduced availability of soil KMnO4-N (7%) and Olsen-P (9%) in the rice seasons caused lower N (12–14 %), P (10 %), K (5–7 %) accumulations in DSR crop as compared to PTR crop (p

Aerobic rice is gaining global recognition for its role in the conservation of water. However, its productivity is often constrained by several deficiencies in the soil-plant system. Particularly, in absence of flood-induced phosphorus (P) desorption, it is likely that P availability in aerobic soils would be reduced thus affecting the productivity. Presently, our understanding of soil P dynamics and its bioavailability in aerobic rice-based system(s) is limited, particularly in alkaline soils. In this study, the impact of sole fertilizer and integrated P management on soil P dynamics, biochemical and biophysical properties and crop yields in direct-seeded rice (DSR)-lentil rotation in alkaline soil was assessed to devise sustainable management option(s). Seven different P treatments in aerobic direct seeded rice-lentil system [subscript value (kg P ha−1)] i.e., P control (P[0−0]), three sole fertilizer-P treatments with variable rate application to component crops (P[22−22], P[33−11], P[11−33]), and three integrated treatments ([P11−11+ phosphate solubilizing bacteria (B)], [P16.5−5.5+ rice residue recycling (RR)+B], [P5.5−16.5+lentil residue recycling (LR)+B]) in aerobic direct seeded rice-lentil system along with a conventional flooded rice-lentil system with the recommended fertilizer-P rate (P[22−22]FR) were studied. Given the recommended sole fertilizer-P rate, the aerobic rice soil (P[22−22]) had lower available-P (8–10 %) compared to the flooded rice soil (P[22−22]FR). The rice residue recycling integrated treatment (P16.5−5.5+RR + B) increased soil available-P in both the rice (5–6 %) and lentil (12–13 %) crop season over the recommended sole fertilizer-P treatment (P[22−22]), and also increased the system productivity by 6–7 %. The higher NaHCO3-Pi (13 %) and dissolved non-reactive P (DNRP) (7%) in the treatment P16.5−5.5+RR + B over the treatment P[22−22] suggested a higher soil P mobilization potential of rice residue recycling integrated treatment. The effect of lentil residue recycling integrated treatment (P5.5−16.5+LR + B) and recommended sole fertilizer-P treatment P[22−22] was similar on soil P and crop yields, and would thus be an option when considering the reduction of P fertilizer use in aerobic rice. Soil aggregation, very-labile carbon, microbial biomass carbon, DNRP exhibited positive correlations with P bioavailability in the aerobic rice soil. Our results suggested that C-stabilization in aerobic rice soil is altered with P input, the lowest rate being recorded in the control treatment. Hence, the study concluded that reduced soil P availability could limit the productivity potential of aerobic rice-lentil system in alkaline soils, and integrated treatments involving in-situ crop residue recycling (rice in particular) and suboptimal fertilizer rate could improve soil P bioavailability, soil quality parameters, and crop yields, thus, recommended for sustainable management.

SUMMARYTopdressing of N fertilizer, whenever leaf greenness, as measured by Chlorophyllmeter (SPAD), falls below the threshold value can be used for site-specific N management in wheat cultivation. Herein, a field experiment was conducted to analyse the effect of SPAD-based N management on wheat productivity and N use efficiency during the dry season of 2010/11 and 2011/12 on acid lateritic soil of eastern India. The experiment had 12 treatments, with nine treatments combining three SPAD thresholds (38, 40 and 42) and three N levels (15, 25 and 35 kg N ha−1) as real time N management (RTNM), one fixed time N management (FTNM), one farmers’ fertilizer practise (FFP) and control (Zero N), with three replications. The grain yield of RTNM ranged from 90 to 113% as that of FTNM, but using considerably less N. Maintaining SPAD threshold of 40 up to heading stage by topdressing 25 kg N ha−1 at each time (N25S40) caused the highest grain yield (4483 kg ha−1). While saving 22.5 kg N ha−1 (18.8%), N25S40 increased agronomic N use efficiency by 58.5%, nitrogen recovery efficiency by 15.1% and partial factor productivity of applied N by 26.4% when compared with conventional fertilizer recommendations (i.e. FTNM). The SPAD-based N management strategy was found very promising in efficiently managing N fertilizer in wheat for improving wheat productivity and N use efficiency.

Location specific adaptation option is required to minimize adverse impact of climate change on rice production. In the present investigation, we calibrated genotype coefficients of four cultivars in the CERES-Rice model for simulation of rice yield under elevated CO2 environment and evaluation of the cultivar adaptation in subtropical India. The four cultivars (IR 36, Swarna, Swarn sub1, and Badshabhog) were grown in open field and in Open Top Chamber (OTC) of ambient CO2 (≈390 ppm) and elevated CO2 environment (25% higher than the ambient) during wet season (June–November) of the years 2011 and 2012 at Kharagpur, India. The genotype coefficients; P1 (basic vegetative phase), P2R (photoperiod sensitivity) and P5 (grain filling phase) were higher, but G1 (potential spikelet number) was lower under the elevated CO2 environment as compared to their open field value in all the four cultivars. Use of the calibrated model of elevated CO2 environment simulated the changes in grain yield of −13%, −17%, −4%, and +7% for the cultivars IR 36, Swarna, Swarna sub1, and Badshabhog, respectively, with increasing CO2 level of 100 ppm and rising temperature of 1 °C as compared to the ambient CO2 level and temperature and they were comparable with observed yield changes from the OTC experiment. Potential impacts of climate change were simulated for climate change scenarios developed from HadCM3 global climate model under the Intergovernmental Panel on Climate Change Special Report on Emission Scenarios (A2 and B2) for the years 2020, 2050, and 2080. Use of the future climate data simulated a continuous decline in rice grain yield from present years to the years 2020, 2050 and 2080 for the cultivars IR 36 and Swarna in A2 as well as B2 scenario with rising temperature of ≥0.8 °C. Whereas, the cultivar Swarna sub1 was least affected and Badshabhog was favoured under elevated CO2 with rising temperature up to 2 °C in the sub-tropical climate of India.

Nutrient management plays an important role in yield and quality of tomatoes. A field experiment was conducted during the years 2008–09 and 2009–10 to analyze the effect of organic and conventional sources of fertilizer on yield and quality of tomatoes in an acid lateritic soil of India. The organic sources of fertilizer were vermicompost (VC), crop residue (CR), vermiwash (VW) and biofertilizer (BF). The conventional input was chemical fertilizer (CF) applied at recommended dose of 100:80:60 kg ha−1 of N:P2O5:K2O for the tomato. The organic source VC was used to supply 100% N recommendation as single source or 50% N recommendation when combined with CF or organic sources. Maximum fruit yield was recorded when CF was applied at full dose, which was on a par with VC at full recommendation. A higher percentage of large-size fruits (>7 cm) was obtained in VC-based treatments compared with CF treatment. Vermicompost at full dose increased ascorbic acid, beta carotene, total soluble solids and color value comp...

The projected adverse impact of climate change on food grain production of tropical and subtropical latitudes necessitates the development of suitable agro-adaptations. We used open top chamber (OTC) experimental facility and simulation analysis to study the effect of elevated [CO2] with varying nutrients management on rice grain yield and to evaluate planting time adjustment as adaptation to climate change. The OTC experiments with ambient [CO2] level ([CO2] ~390 ppm) and elevated [CO2] (25% higher than the ambient) using cultivar ‘Swarna sub1 (140–145 days)’ were conducted during wet season of the years 2011 and 2012 at West Medinipur, India. Using CERES model, we simulated rice grain yield for future climate scenario (A1B) during the years 2020 (2010–2039) and 2080 (2071–2099) at four selected locations of the subtropical India. The elevated [CO2] in OTC increased panicle number, but decreased filled grain number per panicle, 1000-grain weight and grain yield. The increasing [CO2] had smaller adverse impact for integrated nutrients management as compared with chemical fertiliser. The model simulated grain yield reduction of 6.1−13.0% during 2020 and 14.4 −25.0% during 2080 with rising temperature 1.6 and 4.6°C, respectively, compared with the base period (1961–1990). Early planting during 25 June to 25 July received closure favourable temperature and rainfall during the crop growing period, hence had better adaptation to the climate change. Increasing dose of integrated nutrients and early planting is expected to minimise the adverse impact of climate change on rice production of the subtropical India.

Impact of elevated CO2 and temperature on rice yield in eastern India was simulated by using the ORYZA1 and the INFOCROP rice models. The crop and weather data from 10 different sites, viz., Bhubaneswar, Chinsurah, Cuttack, Faizabad, Jabalpur, Jorhat, Kalyani, Pusa, Raipur and Ranchi, which differed significantly in their geographical and climatological factors, were used in these two models. For every 1 °C increase in temperature, ORYZA1 and INFOCROP rice models predicted average yield changes of −7.20 and −6.66%, respectively, at the current level of CO2 (380 ppm). But increases in the CO2 concentration up to 700 ppm led to the average yield increases of about 30.73% by ORYZA1 and 56.37% by INFOCROP rice. When temperature was increased by about +4 °C above the ambient level, the differences in the responses by the two models became remarkably small. For the GDFL, GISS and UKMO scenarios, ORYZA1 predicted the yield changes of −7.63, −9.38 and −15.86%, respectively, while INFOCROP predicted changes of −9.02, −11.30 and −21.35%. There were considerable differences in the yield predictions for individual sites, with declining trend for Cuttack and Bhubaneswar but an increasing trend for Jorhat. These differences in yield predictions were mainly attributed to the sterility of rice spikelets at higher temperatures. Results suggest that the limitations on rice yield imposed by high CO2 and temperature can be mitigated, at least in part, by altering the sowing time and the selection of genotypes that possess higher fertility of spikelets at high temperatures.

A field experiment investigating amendments of organic material including farmyard manure, paper factory sludge and crop residues combined with fly ash, lime and chemical fertilizer in a rice-peanut cropping system was conducted during 1997–98 and 1998–99 at the Indian Institute of Technology, Kharagpur, India. The soil was an acid lateritic (Halustaf) sandy loam. For rice, an N:P:K level of 90:26.2:33.3 kg ha−1 was supplied through the organic materials and chemical fertilizer to all the treatments except control and fly ash alone. The required quantities of organic materials were added to supply 30 kg N ha−1 and the balance amount of N, P and K was supplied through chemical fertilizer. Amendment materials as per fertilization treatments were incorporated to individual plots 15 days before planting of rice during the rainy season. The residual effects were studied on the following peanut crop with application of N:P:K at 30:26.2:33.3 kg ha−1 through chemical fertilizer alone in all treatments, a...

There is a need to increase the rice production in nonwaterstressed rice-growing areas during the wet season in Asia by the use of a suitable combination of a medium- or long-duration variety and appropriate nutrient management strategy. The crop growth simulation model ORYZA 1N was used for variety selection and N optimization in nonwaterstress conditions. Selection was made from 12 released rice varieties of 115 to 150 d duration. The model was calibrated using input data from field experiments that were conducted during the wet season (June–November) of 2001 at the Central Rice Research Institute, Cuttack, India. In the medium-duration varieties (115–130 d), there was good agreement between simulated and observed leaf area index, biomass, and grain yield. The simulated biomass of longduration varieties (135–150 d) showed large deviation from observed biomass at flowering. In the wet season of 2000, the model accurately predicted the grain yield, biomass, and leaf area index of medium- and long-duration varieties. When the ORYZA 1N model was used to simulate the effect of planting dates on rice yield, it predicted the decline in yield with late planting. It was recommended that farmers consider planting new variety Ranjit in the favorable lowlands that do not have water stress during the wet season and should apply 80 kg N ha 21 in four equal splits at transplanting, active tillering, panicle initiation, and flowering. Technology verification trials of this practice conducted during the wet season of 2002 produced 5.51 Mg ha 21 of rice, compared with 4.36 Mg ha 21 grown with the conventional practices of area farmers.

Field experiments were conducted at the village Kasiadihi, Dhenkanal district, Orissa, India during wet seasons 2001, 2002 and 2003 under non water-stressed conditions (0–25 cm standing water) to assess variability in N uptake and utilization by medium and late duration rice varieties. The N rates were 0, 40, 80 and 120 kg N/ha applied as urea in four equal splits at transplanting, active tiller initiation, panicle initiation and flowering stages. The grain yield response was up to 80 kg N/ha. The optimum grain yield attainable by the efficient medium duration varieties was 4·5 t/ha. The N efficient late duration varieties produced optimum grain yield of 5·8 t/ha. The relationship for total dry matter and grain yield production between N fertilized (40, 80 and 120 kg N/ha) and non-fertilized treatments were all significant, suggesting cultivar selection under optimum N fertilized conditions. The difference in optimum yield of the medium and late duration varieties was due to the differences in the amount of N uptake and its use efficiency by the plant for grain production. There was a curvilinear relationship between grain yield and N use efficiency for grain production. The relationship between N use efficiency for grain production and N contents of leaf, stem and grain at maturity was quadratic. The optimum plant N use efficiency of medium duration varieties was 49 kg grain/kg N uptake, achieved with leaf, stem and grain N contents of 10, 8 and 14 g/kg, respectively, at maturity. For late duration varieties, the optimum plant N use efficiency was 68 kg grain/kg N uptake and it was maintained with leaf and stem N content of 4·0 g/kg each and grain N content of 9·0 g/kg at maturity. The N content in plant organs could be the selection guide used to obtain efficient rice varieties.

The present experiment was conducted to evaluate the effect of elevated [CO 2 ] with varying nutrient management on rice–rice production system. The experiment was conducted in the open field and inside open-top chambers (OTCs) of ambient [CO 2 ] (≈ 390 μmol L − 1 ) and elevated [CO 2 ] environment (25% above ambient) during wet and dry seasons in 2011–2013 at Kharagpur, India. The nutrient management included recommended doses of N, P, and K as chemical fertilizer (CF), integration of chemical and organic sources, and application of increased (25% higher) doses of CF. The higher [CO 2 ] level in the OTC increased aboveground biomass but marginally decreased filled grains per panicle and grain yield of rice, compared to the ambient environment. However, crop root biomass was increased significantly under elevated [CO 2 ]. With respect to nutrient management, increasing the dose of CF increased grain yield significantly in both seasons. At the recommended dose of nutrients, integrated nutrient management was comparable to CF in the wet season, but significantly inferior in the dry season, in its effect on growth and yield of rice. The [CO 2 ] elevation in OTC led to a marginal increase in organic C and available P content of soil, but a decrease in available N content. It was concluded that increased doses of nutrients via integration of chemical and organic sources in the wet season and chemical sources alone in the dry season will minimize the adverse effect of future climate on rice production in subtropical India.