• Authors:
    • Jat, M. L.
    • Jat, H. S.
    • Saharawat, Y. S.
    • Kumar, A.
    • Sharma, P. C.
    • Singh, M.
    • Kumar, V.
    • Gathala, M. K.
    • Humphreys, E.
    • Sharma, D. K.
    • Ladha, J. K.
    • Sharma, S.
  • Source: Agriculture Ecosystems and Environment
  • Volume: 177
  • Year: 2013
  • Summary: Increasing scarcity of resources (labour, water, and energy) and cost of production, along with climate variability, are major challenges for the sustainability of rice-wheat system in the northwesten Indo-Gangetic Plains (IGP). We hypothesized that adopting the principles of conservation agriculture together with best crop management practices would improve system productivity and overall efficiency, resulting in a higher profitability. To test this hypothesis, we evaluated the performance of four cropping system scenarios (treatments), which were designed to be adapted to current and future drivers of agricultural changes. The treatments including farmers practices varied in tillage and crop establishment methods, residue management, crop sequence, and crop management. Zero-tillage direct-seeded rice (ZT-DSR) with residue retention and best management practices provided equivalent or higher yield and 30-50% lower irrigation water use than those of farmer-managed puddled transplanted rice (CT-TPR). Overall, net economic returns increased up to 79% with a net reduction in production cost of up to US$ 55 ha -1 in ZT-DSR than CT-TPR. Substituting rice with ZT maize was equally profitable but with 88-95% less irrigation water use. Avoiding puddling in rice and dry tillage in maize with residue retention increased yield (by 0.5-1.2 t ha -1) and net economic returns of the succeeding wheat crop. Inclusion of mungbean in the rotation further increased system productivity and economic returns. In summary, our initial results of 2-year field study showed positive effects of CA-based improved management practices on yield and system efficiencies with greater benefits in the second year. There is a need of longer term monitoring to quantify cumulative effects of various interventions and to eventually make recommendations for wider dissemination.
  • Authors:
    • Mahanta, D.
    • Tuti, M. D.
    • Gupta, H. S.
    • Bhatt, J. C.
    • Bisht, J. K.
    • Pandey, S. C.
    • Bhattacharyya, R.
    • Mina, B. L.
    • Singh, R. D.
    • Chandra, S.
    • Srivastva, A. K.
    • Kundu, S.
  • Source: Agronomy Journal
  • Volume: 105
  • Issue: 1
  • Year: 2013
  • Summary: Carbon retention is a critical issue in arable farming of the Indian Himalayas. This study, conducted from 2001 through 2010 on a sandy clay loam soil, evaluated the effect of tillage alterations (conventional tillage [CT] and zero tillage [ZT]) and selected irrigation treatments (I1: pre-sowing, I2: pre-sowing + active tillering or crown root initiation, I3: pre-sowing + active tillering or crown root initiation + panicle initiation or flowering, and I4: pre-sowing + active tillering or crown root initiation + panicle initiation or flowering + grain filling), applied at the critical growth stages to rice ( Oryza sativa L.) and wheat ( Triticum aestivum L.) on soil organic C (SOC) retention and its pools, soil aggregation, and aggregate-associated C contents in the 0- to 30-cm soil layer. Results indicate that the plots under ZT had nearly 17 and 14% higher total SOC and particulate organic C contents compared with CT (~9.8 and 3.6 g kg -1 soil) in the 0- to 5-cm soil layer after 9 yr of cropping, despite similar mean aboveground biomass yields of both crops on both CT and ZT plots. Tillage had no effect on C pools in the subsurface layers. Irrigation had positive impact on SOC content in the 0- to 5- and 5- to 15-cm layers. Although the labile pools of SOC were positively affected by ZT, the recalcitrant pool was not. Plots under ZT and I4 also had higher large and small macroaggregates and macroaggregate-associated SOC. Thus, adoption of ZT is the better management option for soil C improvement than CT, and irrigation generally enhances the positive impacts.
  • Authors:
    • Vijayasankarbabu, M.
    • Balaguravaiah, G.
    • Singh, A. K.
    • Lal, R.
    • Venkateswarlu, B.
    • Kundu, S.
    • Srinivasarao, C.
    • Vittal, K. P. R.
    • Reddy, S.
    • Manideep, V. R.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 96
  • Issue: 1
  • Year: 2013
  • Summary: Drought stress, uncertain and variable rainfall, low soil quality and nutrient deficiencies are among principal constraints for enhancing and sustaining agronomic productivity in rainfed farming in semiarid tropical regions of India. Therefore, long-term (1985-2004) effects of cropping, fertilization, manuring (groundnut shells, GNS; farmyard manure, FYM) and integrated nutrient management practices were assessed on pod yields, nutrient status and balances for a groundnut (Arachis hypogaea) monocropping system. The five nutrient management treatments were: control (no fertilizer); 100 % recommended dose of fertilizer (RDF) (20:40:40 N, P, K); 50 % RDF + 4 Mg ha(-1) GNS; 50 % RDF + 4 Mg ha(-1) FYM and 100 % organic (5 Mg ha(-1) FYM). All treatments were replicated four times. The experiment was conducted at Anantapur district, Andhra Pradesh on an Alfisol using a Randomized Complete Block design. The gap in pod yields between control and different nutrient treatments widened with increase in duration of cultivation. Use of diverse fertilizer and manurial treatments produced significantly higher yields than control (P < 0.05). Amount and distribution of rainfall during critical growth stages was more important to agronomic yield than total and seasonal rainfall. Thus, the amount of rainfall received during pegging stage (r = 0.47; P < 0.05) and pod formation stage (r = 0.50; P < 0.05) was significantly correlated with the mean pod yields. Whereas, use of diverse fertility management practices improved nutrient status in soil profiles (N, P, K, S, Ca, Mg, Zn, Fe, Mn and B) after 20 years of cropping, yet soil available N, K and B remained below the critical limits. Long-term cultivation also caused deficiency of S, Zn and B, which limited the groundnut productivity. Crop removal of N, P and K during 20 years of cultivation was more in 50 % RDF + 4 Mg ha(-1) GNS at 523, 210 and 598 kg ha(-1), respectively. With the exception of control, there was a positive nutrient balance of NPK in all other treatments. Higher positive balance of N and K were observed in 50 % RDF + 4 Mg ha(-1) GNS (616 and 837 kg ha(-1), respectively), and those of P in 100 % RDF (655 kg ha(-1)) treatment. There was also a net depletion of available S, Zn, Cu and Mn, but a buildup of available Ca, Mg and Fe. Application of equal amount of GNS was as effective as or even better than FYM in terms of pod yields and nutrient buildup in the soil.
  • Authors:
    • Liu, G.
    • Takigawa, M.
    • Zhu, J. G.
    • Tang, H. Y.
    • Kobayashi, K.
  • Source: Global Change Biology
  • Volume: 19
  • Issue: 9
  • Year: 2013
  • Summary: Using a high-resolution (40*40 km) chemical transport model coupled with the Regional Emission inventory in Asia (REAS), we simulated surface ozone concentrations ([O 3]) and evaluated O 3-induced wheat production loss in China and India for the years 2000 and 2020 using dose-response functions based on AOT40 (accumulated [O 3] above 40 ppb) and POD Y (phytotoxic O 3 dose, accumulated stomatal flux of O 3 above a threshold of Y nmol m -2 s -1). Two O 3 dose metrics (90 days AOT40 and POD 6) were derived from European experiments, and the other two (75 days AOT40 and POD 12) were adapted from Asian studies. Relative yield loss (RYL) of wheat in 2000 was estimated to be 6.4-14.9% for China and 8.2-22.3% for India. POD 6 predicted greater RYL, especially for the warm regions of India, whereas the 90 days AOT40 gave the lowest estimates. For the future projection, all the O 3 dose metrics gave comparable estimates of an increase in RYL from 2000 to 2020 in the range 8.1-9.4% and 5.4-7.7% for China and India, respectively. The lower projected increase in RYL for India may be due to conservative estimation of the emission increase in 2020. Sensitivity tests of the model showed that the POD Y -based estimates of RYL are highly sensitive to perturbations in the meteorological inputs, but that the estimated increase in RYL from 2000 to 2020 is much more robust. The projected increase in wheat production loss in China and India in the near future is substantially larger than the uncertainties in the estimation and indicates an urgent need for curbing the rapid increase in surface [O 3] in these regions.
  • Authors:
    • Ghosh, P. K.
    • Hazra, K. K.
    • Venkatesh, M. S.
    • Praharaj, C. S.
    • Kumar, N.
  • Source: CANADIAN JOURNAL OF SOIL SCIENCE
  • Volume: 93
  • Issue: 1
  • Year: 2013
  • Summary: As an important component of crop diversification, pulses/legumes are known to improve soil quality through their unique characteristics of biological N 2 fixation, root exudates, leaf litter fall and deep root system. Changes in the soil organic carbon pool due to the inclusion of pulses in an upland maize-based cropping system were evaluated after seven cropping cycles. The results indicate that inclusion of pulses in an upland maize-based cropping system improved the total soil organic carbon content, being greater in surface soil (0-0.2 m) and declining with soil depth. Of the four carbon fractions of total soil organic carbon ( C frac1 - C frac4 ) measured in the upland maize-based system, the most labile C fraction ( C frac1 ) was dominant. Distribution of the carbon pool varied with depth and the size of the active carbon pool was larger than that of the passive carbon pool in the surface soil, whereas in the subsurface soil depth, the size of the passive carbon pool was larger than that of the active carbon pool. Maize-wheat-mungbean and pigeonpea-wheat systems resulted in significant increases ( P≤0.05), of 11 and 10%, respectively in total soil organic carbon, and 10 and 15% in soil microbial biomass carbon, respectively, as compared with a conventional maize-wheat system. Application of crop residues along with farmyard manure at 5 Mg ha -1 and biofertilizers resulted in greater amounts of carbon fractions and higher carbon management index than in the control and the recommended inorganic (NPKSZnB) treatment, particularly in the system where pulses were included. In plots receiving organic amendments, the variable cumulative carbon input had higher correlation with total organic carbon ( R2=0.997), active pool ( R2=0.934), passive pool ( R2=0.916) and soil microbial biomass carbon ( R2=0.664). Inclusion of pulses in the maize-based system and the organic nutrient management system sequestered more organic carbon and maintained better soil health in Inceptisols of the Indo-Gangetic plains of India.
  • Authors:
    • Managanvi, K.
    • Erayya
    • Makanur, B
    • Jagdish, J.
  • Source: Environment and Ecology
  • Volume: 31
  • Issue: 2
  • Year: 2013
  • Summary: The evidence for climate change is now considered to be unequivocal, and trends in atmospheric carbon dioxide (CO 2), temperature and sealevel rise are tracking the upper limit of model scenarios elaborated in the Fourth Assessment (AR4) undertaken by the International Panel on Climate Change (IPCC). Agriculture directly contributes almost 14% of total Green House Gas (GHG) emissions and indirectly accounts for a further 7% incurred by the conversion of forests to agriculture (mostly conversion to rangeland in the Amazon), currently at the rate of 7.3 million ha/year. It focuses on specific aspects of agriculture and agricultural water management that contribute to greenhouse gas emissions and offer prospects for mitigation. In addition to the impacts of cycles of wetting and drying, the concentration of inorganic and organic fertilizer on land with some form of water management means that the practice of irrigation has scope to mitigate GHG emissions. Global atmospheric temperature is predicted to rise by approximately 4°C by 2080, consistent with a doubling of atmospheric CO 2 concentration. Increased atmospheric concentrations of CO 2 enhance photosynthetic efficiency and reduce rates of respiration, offsetting the loss of production potential due to temperature rise. Early hopes for substantial CO 2 mitigation of production losses due to global warming have been restrained. A second line of reasoning is that by the time CO 2 levels have doubled, temperatures will also have risen by 4°C, negating any benefit.
  • Authors:
    • Govindaraj, M.
    • Prabukumar, G.
    • Arunachalam, P.
    • Kannan, P.
  • Source: African Journal of Agricultural Research
  • Volume: 8
  • Issue: 21
  • Year: 2013
  • Summary: Atmospheric rise of CO 2, N 2O and CH 4 over years, accelerated increase in global temperature, has led to uncertainty in monsoon rainfall and also leading to recurrence of drought, which in turn is severely affecting crop productivity and livelihood security of the farmers in Semi Arid Tropics. Agriculture contributes considerable amount of CO 2, N 2O and CH 4 emission into the atmosphere through different soil and crop management practices. Nevertheless agricultural activities contribute to global warming. The medium of crop production, soil is one of the major sinks of global warming gaseous and it helps to sequester more carbon and cut the N 2O emission by adopting smart soil and crop management techniques. Biochar is one of the viable organic amendments to combat climate change and sustain the soil health with sustainable crop production. It is an anaerobic pyrolysis product derived from organic sources and store carbon on a long term basis in the terrestrial ecosystem and also capable of reducing greenhouse gases (GHG) emission from soil to the atmosphere. Biochar application improved the soil health, increase the carbon capture and storage, reduce the GHG emission and enhance the crop yield with sustained soil health, which enables to meet out the food grain needs of the ever growing population.
  • Authors:
    • Niwa, Y.
    • Mayorga, E.
    • Ito, A.
    • Hartman, J.
    • Bousquet, P.
    • Bhattacharya, T.
    • Wang, T.
    • Chhabra, A.
    • Manjunath, K.
    • Ciais, P.
    • Oh, N.
    • Piao, S.
    • Houghton, R.
    • Canadell, J.
    • Patra, P.
    • Raymond, P.
    • Sarma, V.
    • Lasco, R.
  • Source: Biogeosciences
  • Volume: 10
  • Issue: 1
  • Year: 2013
  • Summary: The source and sinks of carbon dioxide (CO2) and methane (CH4) due to anthropogenic and natural biospheric activities were estimated for the South Asian region (Bangladesh, Bhutan, India, Nepal, Pakistan and Sri Lanka). Flux estimates were based on top-down methods that use inversions of atmospheric data, and bottom-up methods that use field observations, satellite data, and terrestrial ecosystem models. Based on atmospheric CO2 inversions, the net biospheric CO2 flux in South Asia (equivalent to the Net Biome Productivity, NBP) was a sink, estimated at -104 +/- 150 TgCyr(-1) during 2007-2008. Based on the bottom-up approach, the net biospheric CO2 flux is estimated to be -191 +/- 193 TgCyr(-1) during the period of 2000-2009. This last net flux results from the following flux components: (1) the Net Ecosystem Productivity, NEP (net primary production minus heterotrophic respiration) of -220 +/- 186 TgCyr(-1) (2) the annual net carbon flux from land-use change of -14 +/- 50 TgCyr(-1), which resulted from a sink of -16 TgCyr(-1) due to the establishment of tree plantations and wood harvest, and a source of 2 TgCyr(-1) due to the expansion of croplands; (3) the riverine export flux from terrestrial ecosystems to the coastal oceans of +42.9 TgCyr(-1); and (4) the net CO2 emission due to biomass burning of +44.1 +/- 13.7 TgCyr(-1). Including the emissions from the combustion of fossil fuels of 444 TgCyr(-1) for the 2000s, we estimate a net CO2 land-atmosphere flux of 297 TgCyr(-1). In addition to CO2, a fraction of the sequestered carbon in terrestrial ecosystems is released to the atmosphere as CH4. Based on bottom-up and top-down estimates, and chemistry-transport modeling, we estimate that 37 +/- 3.7 TgC-CH(4)yr(-1) were released to atmosphere from South Asia during the 2000s. Taking all CO2 and CH4 fluxes together, our best estimate of the net land-atmosphere CO2-equivalent flux is a net source of 334 TgCyr(-1) for the South Asian region during the 2000s. If CH4 emissions are weighted by radiative forcing of molecular CH4, the total CO2-equivalent flux increases to 1148 TgCyr(-1) suggesting there is great potential of reducing CH4 emissions for stabilizing greenhouse gases concentrations.
  • Authors:
    • Venkateswarlu, B.
    • Srinivasarao, C.
    • Jakkula, V. S.
  • Source: Indian Journal of Fertilisers
  • Volume: 9
  • Issue: 5
  • Year: 2013
  • Summary: Degrading soil health, falling nutrient use efficiency (NUE) and yield plateaus in major food bowl regions of India threatens the food security for the growing population in India in the backdrop of shrinking per capita land availability from 0.48 ha in 1951 to 0.14 ha in 2001. Maintaining soil health is a vital requirement to ensure sustainable food production and to meet future food demands in the country. Soil health cards play a critical role in assessing soil health conditions and providing soil and crop management recommendations to farmers in order to sustain the crop productivity. Based on free in-depth analysis, soil health cards list vital components of a particular patch of land. They provide detailed information on various minerals present in the soil, suitable crops, fertilisers to be used, and also whether the soil is acidic or alkaline. The cards, which are based on the principles of the ration card, provide permanent identification and status of the land to farmers, if linked with Global Positioning System (GPS). Healthy soils provide a range of ecological services including water infiltration, habitat provision besides sustaining crop production and quality of food produce. Soil health cards guide farmers to use right type of fertiliser nutrients, right quantity to right crop by knowing the key production constraints of soil in his field. Thus, in a way soil health card based crop management can improve soil carbon status and reduces Green House Gas (GHG) emissions. This review highlights how prudent utilization of soil health cards in the country can sustain agricultural production with rational fertiliser application and contribute to climate change adaptation and mitigation.
  • Authors:
    • Thomas,Amy R. C.
    • Bond,Alan J.
    • Hiscock,Kevin M.
  • Source: Global Change Biology Bioenergy
  • Volume: 5
  • Issue: 3
  • Year: 2013
  • Summary: Reduction in energy sector greenhouse gas GHG emissions is a key aim of European Commission plans to expand cultivation of bioenergy crops. Since agriculture makes up 1012% of anthropogenic GHG emissions, impacts of land-use change must be considered, which requires detailed understanding of specific changes to agroecosystems. The greenhouse gas (GHG) balance of perennials may differ significantly from the previous ecosystem. Net change in GHG emissions with land-use change for bioenergy may exceed avoided fossil fuel emissions, meaning that actual GHG mitigation benefits are variable. Carbon (C) and nitrogen (N) cycling are complex interlinked systems, and a change in land management may affect both differently at different sites, depending on other variables. Change in evapotranspiration with land-use change may also have significant environmental or water resource impacts at some locations. This article derives a multi-criteria based decision analysis approach to objectively identify the most appropriate assessment method of the environmental impacts of land-use change for perennial energy crops. Based on a literature review and conceptual model in support of this approach, the potential impacts of land-use change for perennial energy crops on GHG emissions and evapotranspiration were identified, as well as likely controlling variables. These findings were used to structure the decision problem and to outline model requirements. A process-based model representing the complete agroecosystem was identified as the best predictive tool, where adequate data are available. Nineteen models were assessed according to suitability criteria, to identify current model capability, based on the conceptual model, and explicit representation of processes at appropriate resolution. FASSET, ECOSSE, ANIMO, DNDC, DayCent, Expert-N, Ecosys, WNMM and CERES-NOE were identified as appropriate models, with factors such as crop, location and data availability dictating the final decision for a given project. A database to inform such decisions is included.