Indo-Gangetic Plains Of India Research Articles

Cumulative Effect of Organic and Inorganic Sources of Nutrients on Yield, Nutrients Uptake and Economics by Rice–Wheat Cropping System in Indo-Gangetic Plains of India

ABSTRACTField experiments were conducted for 2 years in sandy loam soil, to study the direct effect of organic manures i.e. sewage sludge (SS), vermicompost (VC) and sesbania (SB) and chemical fertilizers on rice (Oryza sativa) and their residual effect on wheat (Triticum aestivum) grown in sequence in winter (Rabi) and summer (Kharif) season during 2015–2016 to 2016–2017 at Varanasi, Uttar Pradesh. Residual effect of organic sources of nutrients as SS, VC and SB were monitored up to fourth crop (II wheat) in sequence applied in conjunction with 75% recommended dose of fertilize (RDF). Among the nutrient sources, the maximum grain yield in I rice (4.89 t ha−1), II rice (4.95 t ha−1), was recorded in treatment T3 (100% RDF with S, Zn, B) whereas in I wheat (4.68 t ha−1) and II wheat (4.59 t ha−1), it was recorded in T4 (customized fertilizer). The maximum straw yield during all four crops was recorded in T3 (100% RDF with S, Zn, B) in rice and T4 (customized fertilizer) in wheat crop, which showed 25, 32, 23 and 28% increase over 100% RDF (T2). Application of 100% RDF along with S, Zn, B and customized fertilizer increased the total uptake of N, P, K, S and B and also in net returns and B:C ratio followed by organic treatments.

Sustainable Intensification of Rice-Based Systems with Potato in Eastern Indo-Gangetic Plains

In many parts of Asia food security and poverty remain issues even though arable land is available to produce nutritious food. Sustainable intensification of agricultural systems has been proposed to produce more outputs on same land area whilst minimizing environmental degradation. Tradeoffs, however, are inevitable and evidence thereof is scant. In this study, we analyze effects of sustainable intensification of rice-based systems with potato and focus on the Eastern Indo-Gangetic Plains of India and Bangladesh. A literature review, expert consultation, and an economic surplus exercise are used to address our objective. We find that sustainable intensification has a huge potential and positive welfare effects. Socio-economic tradeoffs, especially for labour, need to be considered and balanced out. Increasing input efficiency for instance by improving farming practices may reduce negative environmental effects.

Identifying optimum rates of fertilizer nitrogen application to maximize economic return and minimize nitrous oxide emission from rice–wheat systems in the Indo-Gangetic Plains of India

ABSTRACT Rice–wheat (RW) cropping system in India is a major source of N2O emissions. In such system, defining N rates that deliver minimal N2O emissions and economically optimum yield would benefit both food production and the environment. We measured yield and N2O fluxes from RW systems in Northwest IGP under two tillage systems and five N rates (0, 75, 150, 225 and 300 kg N ha−1) for both rice and wheat using static chamber method. Seasonal pattern of N2O emission was mainly influenced by fertilizer and water application events with no significant effect of tillage systems. Mean annual N2O emission from RW system was 1.49 kg N ha−1 in N75 plot and 2.97–3.04 in the plots receiving ≥150 kg N ha−1. On average, the yield-scaled N2O emissions of rice and wheat were 0.25 and 0.52 kg N2O–N mg−1, respectively. Our finding suggests that N rates between 120–200 kg N ha−1 in rice and 50–185 kg ha−1 in wheat provide the most economical returns and application rates beyond these ranges would be both economically and environmentally unsustainable. Within the range of N rate studied, fertilizer-induced N2O-EF for rice and wheat were 0.41% and 0.79%, respectively.

Seasonal Variation of Potential Source Locations of Atmospheric Particulates over the Indo-Gangetic Plain of India

Ambient particulate matter (PM2.5 and PM10) concentrations were measured during two different seasons (summer and winter) at three different locations of Gurugram which is located in the Indo-Gangetic plain of India. The ambient concentrations of both PM2.5 and PM10 were higher during winter season (PM2.5: 261 μg·m-3; PM10: 440 μg·m-3) when compared to summer period (PM2.5: 114 μg·m-3; PM10: 202 μg·m-3). Potential Source Contribution Function (PSCF) analysis suggests significant seasonal variation in potential contributing locations of ambient PM2.5 over the study area. The PSCF analysis suggests that cross country transport of PM2.5 from Pakistan and Afghanistan significantly attributed to higher concentrations of PM2.5 at the study locations; whereas, PM2.5 emitted from locations in the south-western direction of the study sites attributed to the ambient PM2.5 concentrations at the study site during summer seasons. Further study is required to measure percentage contribution from different sectors and locations to the ambient particulate concentrations at the study site to develop sector specific mitigation plan.

Potato (<em>Solanum tuberosum</em> L.) seed tuber production as influenced by intra-row spacing, dehaulming time and nutrient management in lower Indo-Gangetic plains of India

Potato (<em>Solanum tuberosum</em> L.) seed tuber production as influenced by intra-row spacing, dehaulming time and nutrient management in lower Indo-Gangetic plains of India

Responses of tropical tree species to urban air pollutants: ROS/RNS formation and scavenging

Air pollution in an urban environment is the major stress factor for vegetation due to the direct generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). To quantify urban air pollution-induced ROS/RNS formation, damage and detoxification, nine different biochemical parameters related to free radical formation, scavenging and membrane damage were estimated in twelve tropical tree species. The experiment was performed in three different seasons at four distinct urban environments in Varanasi city located in the Indo-Gangetic plain of India. Redundancy analysis was performed to statistically assess the relationship between air pollutants (PM2.5, NO2, SO2 and O3) and temperature with ROS/RNS generation and their detoxification. Significant effects of air pollution exposure and temperature on ROS/RNS formation, scavenging and membrane damage were recorded with increasing pollution load in the city for all the tree species. The extent of variability (47–87%) in responses of different tree species was due to their intrinsic ability to scavenge free radicals which minimized the membrane damage. PM2.5, NO2 and O3 were identified as major pollutants that influenced trees to different extents in regulating ROS/RNS. However, the response was maximum against NO2 (34–72%) followed by PM2.5 (16–64%) and O3 (3–31%), indicating that under urban environment, trees are considerably sensitive to the combined effects of both particulate and gaseous pollutants. Reactive oxygen intermediate release, total free radical scavenging activity, NO scavenging activity and membrane stability index were identified as major parameters which showed distinct responses with increasing pollution load. Caesalpinia sappan, Ficus religiosa and Albizia lebbeck were identified as most tolerant tree species having higher ROS/RNS scavenging potential resulted in lower membrane damage. Thus responses of urban trees to air pollution are governed by their intrinsic defence mechanisms to scavenge ROS/RNS by maintaining the membrane integrity through integrated cross-talk between different antioxidative pathways.

Assessment of Low Intensity Solar Radiation Susceptibility in 20 Wheat Varieties under Field Conditions Grown in Indo-Gangetic Plains of India

Wheat productivity declines under agro-ecosystems and areas exposed to aerosols due to decline in quality and quantity of solar radiation. Identification of low light-tolerant wheat varieties (Triticum sps.) will help in enhancing the sustainability and productivity of the agroforestry systems as well as areas exposed to aerosol pollution. The field study was conducted to assess the effects of low intensity solar radiation (LR) on 20 wheat varieties in terms of growth, stay green, gaseous exchange, yield attributes, and tolerance indices. Results indicate the increase in plant height and leaf area, reduction in photosynthesis (Pn), stomatal conductance (gs), and transpiration (Tr) in all the varieties grown under LR compared to normal radiation. The varieties, K68 and HD2643, exhibited maximum stay green compared to other varieties. LR caused reduction in biological (35%) and economic (46%) yield of wheat. Among the indices, mean productivity (MP), geometric mean (GM), stress tolerance index (STI), and yield index (YI) were positively correlated (P ≤ 0.05) with grain yield under LR (Ys) and NR (Yp). Cluster analysis indicated that varieties–HD2643, K68, Kalyansona, and C306 varieties were most LR tolerant, while DL1266-1, DL1266-2, and Moti were moderately tolerant and rest of the varieties exhibited LR susceptibility.

Nitrous oxide emission and mitigation from maize–wheat rotation in the upper Indo-Gangetic Plains

Due to its lower water requirement, methane emission and soil degradation, a maize–wheat rotation (MWR) may be a more attractive alternative to rice–wheat rotation (RWR), in the upper Indo-Gangetic plains (IGP) of India. However, N2O emission from MWR needs to be quantified to propose management practices for N2O mitigation. A field experiment was conducted at the Indian Council of Agricultural Research-Indian Agricultural Research Institute (ICAR-IARI), New Delhi, to assess the impacts of various N sources on N2O emission and its mitigation from the MWR. Six treatments –N0 (control), urea, urea + farmyard manure (FYM), FYM, urea + nitrification inhibitor (NI) and neem oil coated urea (NOCU) were investigated during 2012–2014. Results show ranges of N2O-N emissions from MWR of 0.59–0.69, 1.82–1.86, 1.81–1.85, 1.71–1.77, 1.38–1.52, 1.57–1.61 during 2012–2013, and of 0.62–0.68, 1.86–1.90, 1.78–1.84, 1.72–1.76, 1.40–1.46, 1.52–1.60 during 2013–2014, for N0, urea, urea + FYM, FYM, urea + NI and NOCU treatments, respectively. The 2-year pooled N2O-N emission of MWR decreased by 23% in urea + NI and by 16% in NOCU with higher grain yield as compared to conventional urea application. Application of FYM with urea and FYM alone also reduced N2O-N emission; however, the grain yields of these treatments were decreased. Thus, the study suggests that the application of NOCU and NI with urea can mitigate N2O-N emissions from the maize and wheat crops. Hence, the use of NOCU and application of NI with urea could be a better option to mitigate N2O-N emissions from MWR of the upper IGP of India.

IMPACT OF CANAL RESTRUCTURING ON AGRICULTURAL LAND USE IN 23 DOWN HAIDERGARH CANAL COMMAND SYSTEM, UTTAR PRADESH, INDIA

Abstract. The 23 Down Haidergarh Canal command system of Uttar Pradesh is situated in Indo-Gangetic Plain of India. It has huge potential of crop productivity. The canal system was unlined; due to which a huge amount of water waste as seepage, which results, waterlogging and sodic land development. This leads reduction in the productivity of crop land. To overcome with this problem government started the restructuring/lining of canal in 23 Down Haidergarh canal command system.The present study was an attempt to find out the changes in agricultural land of rabi season because during rabi season canal is important source of irrigation in 23 Down Haidergarh canal command system. Remote sensing and GIS techniques were used to monitor the changes after the restructuring of canal system. The LISS-III data (Linear Imaging Self-Scanner) of Rabi season for the year 2011–12 and 2017–18 was used for mapping of agricultural land use changes in rabi season for 23 Down Haidergarh canal command system. This study is useful to find out the change in agricultural land after the restructuring of canal command system.

Negative impacts of elevated ozone on dominant species of semi-natural grassland vegetation in Indo-Gangetic plain

Increasing tropospheric ozone (O3) concentrations in most regions of the world have led to significant phytotoxicity to all types of vegetation. Indo-Gangetic Plains of India is one of the hot spot areas with high O3 concentrations throughout the year although O3 phytotoxicity on grassland species in this region is not explored. Therefore the present study was conducted to assess the responses of a dominant species, Ischaemum rugosum Salisb, a C4 grass and a co-dominant species Malvastrum coromandelianum (L.) Garcke, a C3 forb under future elevated O3 (non filtered ambient + 20 nl l−1; NFA+) concentration compared to non filtered ambient (NFA; 48.7 nl l−1, 8 h mean) for 9 weeks from 15th May to 15th July 2016 in mix-culture using open-top chambers (OTCs). Plants were assessed for physiological, biochemical and growth parameters including biomass accumulation during vegetative and reproductive stages to assess the O3 induced responses. Under NFA+, higher reductions were observed in physiological parameters, growth and total biomass accumulation in M. coromandelianum compared to I. rugosum while both the species suffered membrane damage. Enhancement in contents of ascorbic acid and tannin in I. rugosum while proline and total phenolics in M. coromandelianum led to more protection of former species compared to later from oxidative damage. No significant change in stomatal conductance in I. rugosum while significant increase in M. coromandelianum might have led to more accumulation of O3 inside the plant, thus more negatively affecting the performance of later species. The present study concludes that M. coromandelianum (C3 photosynthetic pathway) will be relatively more negatively affected compared to I. rugosum (C4 photosynthetic pathway) under future O3 concentrations.

Antagonistic potential of bacterial endophytes and induction of systemic resistance against collar rot pathogen Sclerotium rolfsii in tomato

A diverse pool of 310 bacterial endophytes isolated from tomato plants growing in the Indo-Gangetic plains of India was evaluated for their antagonistic potential against three soil-borne fungal pathogens causing root rot (Rhizoctonia solani), collar rot (Sclerotium rolfsii) and, fungal wilt (Fusarium oxysporum f. sp. lycopersici). Preliminary screening indicated that most of the isolates could inhibit R. solani and F. oxysporum f. sp. lycopersici to the greater extent but failed to reduce mycelia growth of S. rolfsii by more than 50 percent. The only exceptions were 1PR7a, 2P2, and 2PR9b which were further characterized and evaluated against S. rolfsii. Molecular identification of 15 isolates based on 16s rRNA gene sequence similarity indicated the presence of three genera viz. Bacillus, Lysinibacillus, and Stenotrophomonas. In planta trial in tomato challenged with pathogen S. rolfsii in presence and absence of endophyte inoculation revealed that Bacillus sp. 2P2 showed the highest protection against S. rolfsii. These strains elicited induced systemic resistance of plant and significantly higher activity (p ≤ 0.05) of phenylalanine ammonia lyase, peroxidase, polyphenol oxidase, and ascorbate oxidase indicating the further strengthening of cell wall barrier through lipid peroxidation, cross linking of cell walls, lignifications, suberization and other cell wall strengthening processes. It was further confirmed by confocal scanning laser micrographs of upper collar region. It was evident that the inoculation of endophyte inhibited the colonization and movement of the pathogen. In addition, endophytes upregulated the expression of three pathogenesis-related genes PR1a, PR2a, and PR3, which are responsible for production of glucanases and chitinases contributing to pathogen inhibition. Further, oxidative stress alleviation was evident from decreased superoxide accumulation and enhanced dry matter content. Results of the present study indicated suppressive potential of endophyte Bacillus sp. 2P2 against S. rolfsii which could be useful in collar rot management in the nursery as well as after transplantation.

Impact of sowing dates and cutting management on productivity and profitability of dual purpose barley (Hordeum vulgare L.) in Indo-Gangetic Plains of India

Impact of sowing dates and cutting management on productivity and profitability of dual purpose barley (Hordeum vulgare L.) in Indo-Gangetic Plains of India

Differential response from nitrogen sources with and without residue management under conservation agriculture on crop yields, water-use and economics in maize-based rotations

Under the present scenario of resource degradation, shortage of water & labour, growing production cost, falling water tables as well as farm profitability and climate-change; the sustainability of traditional rice-wheat (RW) system became a major challenge in Indo-Gangetic Plains (IGP). Therefore, to address these issues in India’s, north-western IGP, RW system need to be diversified with conservation agriculture (CA) based profitable and sustainable systems. Full CA based crop production technologies may furnish more yield, reduce water need and enhance farm profitability, without hampering the sustainability of natural resources. So in an established on-going long term study (since 2012), we assessed the medium term-impact of four different nitrogen management practices [Un-fertilized, N through Prilled urea (PU), N through Sulphur coated urea (SCU) and N through Neem coated urea (NCU)] in residue retained permanent bed (PB + R) vs. residue removed permanent bed (PB-R) plots under maize-mustard-mungbean (MMuMb) and maize-wheat-mungbean (MWMb) crop rotations. Results showed that, the maize, wheat and mustard yields were statistically similar in first year of study irrespective of residue retention or removal, whereas during subsequent years, yields of maize, wheat and mustard were significantly (P < 0.05) higher by 10.1–16.7%, 9.3–23.6% and 13.6–21.9% under residue retained plots (full CA) than residue removed plots (partial CA), respectively. However, the mungbean yield was significantly (P < 0.05) greater by 12.4–24.3% in residue retained plots right from first year onwards. In permanent bed plots, residue retention reduced the water requirement by 50–55 ha-mm, and improved water productivity by 9.4–27.6%, 17.7–30.4%, 21.7–42.6% and 33–57.2% in maize, wheat, mustard and mungbean, respectively compared to no residue plots. Economic profit for MMuMb (from 2nd year onward) and MWMb rotations (in all the 5-years) was significantly (P < 0.05) higher by 220–464 and 165–474 US$/ha/year, respectively in residue retained plots compared to residue removed plots. Among N management practices, application of neem and sulphur coated urea significantly improved the individual crops yield, water productivity and system profitability compared to un-fertilized both under residue retained and removed plots. However, across the cropping systems the effectiveness of different N sources varied with residue management, as the annual increment in system productivity of SCU treated and residue retained plots under MMuMb system was about thrice than the residue removed plots. Whereas, in MWMb system the annual increment in system productivity was double in NCU treated and residue retained plots as compared to residue removed plots. Effectiveness of PU was not increased with residue retention in maize and mustard, whereas in wheat both the coated and uncoated urea application increased the annual yield by manifolds. Findings of this study support differential opportunity of residue management and suggest that a combination of full CA-based MMuMb/MWMb system with use of proper N sources [like slow release coated fertilizers (NCU/SCU)] could augment the system productivity, resource-use efficiency, farm profitability, while sustaining the natural resources in Western IGP in India and other similar agro-ecologies.

Effects of sowing dates and mulching on growth and yield of wheat and weeds (Phalaris minor Retz.)

Weed infestation, particularly Phalaris minor Retz. is a serious threat for increasing wheat productivity in Indo-Gangetic Plains of India. The primary objective of this research was to study the effect of sowing dates and mulching on the growth of wheat and weeds. In general, early sowing (November-25) exhibited less growth of P. minor, but increased weed biomass and lower wheat yields than the delayed (December-10) sowing date. Application of paddy straw, jute mat, and black polythene mulches positively increased the height, tiller count, yield of wheat; and drastically reduced weed infestation, especially the growth of P. minor. Moreover, under no weed management, delayed sowing increased the wheat yield, over earlier sowing. It was concluded that organic mulches can sustainably manage the weed infestation, particularly P. minor and increase the wheat yield.

Exposure assessment of pulmonary functions of school going children due to agriculture crop residue burning practice in Indo-Gangetic plains of India

Agriculture crop residue burning is a serious issue in Northern India due to ineffective control policies. An epidemiological study has been done on school going children to evaluate the trends in their physiological parameters due to crop residue burning activity in the affected area. Total 600 children were recruited and continuously inspected for three years at three different sites. Season wise, the level of fine particulate matter (PM10 and PM2.5) was higher in rice crop residue burning seasons than in wheat crop residue burning seasons. As per dose–response relationship, maximum degradation was observed in FVC (−7.62%) and PEF (−6.23%) parameters from their baseline values due to burning activities. With adjustment of socioeconomic, anthropometric parameters of selected subjects and meteorological parameters in multivariate mixed effect model, prediction equations have been purposed to observe the future trends in physiological parameters of children. Based on Tiffenue index, an unrecoverable effect has been observed in lung parameters. Trends were alarming and may cause serious complications in early age of human subjects.

Soil carbon pools and enzyme activities in aggregate size fractions after seven years of conservation agriculture in a rice–wheat system

Decline in soil organic carbon (SOC) due to intensive tillage and removal or burning of crop residues is considered a major threat to maintaining soil quality and meeting future challenges of food production at national and global scales. Adoption of conservation-agriculture practices (no till and residue retention) is necessary to promote soil structural stability and increases in SOC content and enzyme activities. We evaluated the impact of tillage and residue-management practices on yield, soil labile-C pools, aggregate stability and soil enzyme activities after seven cycles of a rice (Oryza sativa L.)–wheat (Triticum aestivum L.) system on the Indo-Gangetic Plain of India. Treatments included four combinations of tillage and crop establishment in rice (main plots), and three combinations of tillage and residue management in wheat (subplots). Irrespective of rice-establishment method, mean grain yield of no-till wheat with rice-residue mulch (NTW+RR) was 9% and 22% higher, respectively, than of conventional-till (CTW) or no-till wheat with no rice-residue mulch. Soil C pools (very labile, labile, less-labile and non-labile) were significantly higher under a no-till dry-seeded rice (NTDSR)–NTW+RR cycle than conventional-till puddled transplanted rice–CTW. Macro-aggregates (&amp;gt;0.25 mm) had higher labile C pools, glomalin content and enzyme activities than micro-aggregates. NTW+RR significantly increased soil C pools within both macro- and micro-aggregates. Compared with CTW, NTW+RR increased soil dehydrogenase, cellulase and alkaline phosphatase activities by 23%, 34% and 14%, and water-soluble organic C by 31%, and increased water-stable aggregates and mean-weight-diameter. NTDSR–NTW+RR increased SOC, enzyme activity, aggregate stability and wheat grain yield. Results indicated that soil labile-C pools across aggregate fractions were the most sensitive indicators of soil quality when determining the effects of changes in management practices. Furthermore, adoption of no till and residue retention may improve sustainability in rice–wheat systems of the Indo-Gangetic Plain.

Analyzing Spatial Pattern of Weather Induced Yield Variability in Indian Mustard for Formation of Homogeneous Zones in North Western Himalaya and Indo-Gangetic Plains of India

Yield prediction plays an important role to decide the economy of farmer as well as the country. It avoids the under and over cropping of the particular crop. The production of not only mustard crop but all the agricultural crops is mainly affected by the weather variables. The changing weather condition affects the growth and development of crop causing intra seasonal yield variability. In addition, with weather variations, the spatial variability and crop management practices also plays a decisive role. As a result, yield forecasting represents an important tool for optimizing crop yield and to evaluate the crop-area insurance contracts. Considering yield variability and importance of rapeseed-mustard for farmers an attempt has been made to develop a homogeneous zone in respect to inter annual weather induced variability with help of this large region yield prediction could be done easily. For this study the 33 districts of erstwhile Uttar Pradesh has been selected and rapeseed-mustard data have been collected for the year 1997-2016. In this study a three steps approach has been adopted;1) the prediction of trend yield, 2) estimation of yield deviation and cluster formation and 3) mapping of the clusters in GIS and creation of homogeneous zones. Then these homogeneous zones created on basis of weather induced variability were used for yield forecasting of mustard in this region.

Phosphorus skipping effect on productivity, profitability and sustainability of rice-wheat cropping systems in Indo-Gangetic plains of India

ABSTRACTA field experiment was conducted for eight years at ICAR-Indian Institute of Wheat and Barley Research, Karnal, Haryana, India to study the skipping effect of P application on productivity, profitability and sustainability of rice-wheat cropping system. Rice yield and biomass were 8.35% and 6.6% higher where cowpea was grown after wheat compared to rice-vegetable pea-wheat crop sequence, respectively. Phosphorus application to rice or wheat or both crops exhibited at par rice grain yield, biomass, harvest index. Phosphorus application to both crops or only in rice crop produced maximum and significantly higher wheat yield (4.62 t ha−1) as compared to P application only to wheat (4.48 t ha−1). Eight years growing of green gram, cowpea and vegetable pea increased the organic carbon content 42.89, 16.38 and 4.57 %, respectively compared to the initial level. Skipping of P to either crop, by considering 13.5 million ha rice-wheat area, will save approximately Rs 40,500 million (Rs = Indian rupee) or US $ 623 million ($ = Rs 65) per year. Air pollution may be checked, due to saving on diesel in transportation of P fertilizer, to the tune of 60,383 tonnes of CO2 per year by reducing emission of one of important global warming gas.

Ten years of conservation agriculture in a rice–maize rotation of Eastern Gangetic Plains of India: Yield trends, water productivity and economic profitability

In recent years, scarcity of water, energy and labour, increasing production cost, decreasing farm profitability and climate-change-induced variability are major challenges faced by the farmers in the Indo-Gangetic Plains (IGP) of South Asia. Conservation agriculture (CA) based best-bet crop management practices may increase crop productivity and profitability, while conserving natural resources. In a 10-year (2007–2017) field study, we assessed the effects of four combinations of tillage and, crop establishment (TCE), and residue (R) management options for the crop and water productivity and profitability of rice-maize (RM) system in Eastern IGP of India. The treatments consisted of zero-till direct seeded rice followed by zero tilled maize (ZTDSR/ZTM); ZTDSR followed by maize both on permanent raised beds with residue (PBDSR/PBM (+R)); PBDSR followed by PBM without residue (PBDSR/PBM (-R)) and conventional till puddled transplanted rice followed by conventional till maize (PTR/CTM). Overall, mean rice grain yield was similar under ZTDSR/ZTM, PBDSR/PBM (+R) and PTR/CTM, but 5.0–7.9% higher than PBDSR/PBM (-R). However, the maize yield was significantly (P < 0.05) higher by 6–82% in CA-based PBDSR/PBM (+R) RM system compared to PTR/CTM and PBDSR/PBM (-R) right from first year onwards. The RM system productivity (rice equivalent yield, REY) was higher by 1.5–38% in CA-based systems [ZTDSR/ZTM; PBDSR/PBM (+R)] than in the PTR/CTM and PBDSR/PBM (-R) systems. APSIM model predicted yield of rice and maize under different TCE and residue management practices with cumulative probability distribution plots was higher and consistent in PBDSR/PBM (+R) and ZTDSR/ZTM compared to PBDSR/PBM (-R) and PTR/CTM, suggesting that CA plots has lower probability of low yield than CT. CA-based ZTDSR/ZTM and PBDSR/PBM (+R) practices reduced the total system water use by 151–341 mm and 212–423 mm, and resulted enhanced system water productivity (WP) by 27–57% and 39–68%, respectively compared to CT (PTR/CTM) system. Economic profit for RM system was always significantly (P < 0.05) higher (225–1028 US$/ha/year) in CA-based systems than in CT system. Our study shows that CA-based system under RM rotation is one of the ways for improving crop and water productivity and farm income, as well as sustaining the natural resources in smallholder production systems of Eastern IGP in India and other similar agro-ecologies of South Asia.

The influence of urban stress factors on responses of ground cover vegetation.

A comprehensive study was conducted to evaluate the effects of ambient air pollution, land use, and soil properties on ground cover vegetation in the urban area of Varanasi city, situated in the Indo Gangetic Plain of India. Twelve leaf functional traits were assessed on eight most dominant herbaceous species belonging to four angiospermic families in three different land uses with varying air pollution loads and soil properties. Particulate matter (PM10 and TSP), gaseous pollutants (SO2, NO2, and O3), land uses (built-up area, shrub, and grass cover), and soil properties showed significant variability among the land uses. Air pollution was identified as the major stress factor which influenced leaf functional traits of ground cover vegetation followed by soil properties and land uses. Among the plants, Croton sparsiflorus was found to be the most responsive plants to all the factors. Plants responded differently under varying environmental factors as Euphorbia hirta was maximally influenced by air pollution, whereas the effect of land use was maximum in C. sparsiflorus. Influence of soil properties was highest in Digitaria ciliaris and Scoparia dulcis. All the environmental factors in combination maximally influenced non-enzymatic antioxidants (ascorbic acid and polyphenolics) followed by photosynthetic pigments among the different leaf functional traits. Among the environmental factors, NO2 and PM were identified as the most influencing factors regulating leaf functional traits followed by K level in soil and shrub cover. It can be concluded that responses of different leaf functional traits of ground cover vegetation varied with different environmental factors and responses were mostly species specific.