Papers by Kulasekaran Ramesh
Abiotic Stress Management for Resilient Agriculture
Pollution of soils with heavy metals from various sources has become a common feature across the ... more Pollution of soils with heavy metals from various sources has become a common feature across the globe due to increase in anthropogenic activities and industrial development and has attracted the attention of all stakeholders. In spite of the differential tolerance of plants to heavy metal toxicities, impairment in the productivity of most of the agricultural crops is steadfast throughout the globe. Bio-transfer of these metals remains unabated from polluted sites and even through animal milk and dung. The remediation methods are broadly grouped into engineering, electrokinetics, and bioremediation. These have their own merits and demerits, but the bioremediation is quite effective and the current results are encouraging. Therefore, the sources of heavy metals to soils (including pathways), their effect on soils and plants, and few of the proven phytoremediation methods have been elaborated here.
Frontiers in Plant Science, 2021
Sesame is predominantly cultivated in rainfed and low fertile lands and is frequently exposed to ... more Sesame is predominantly cultivated in rainfed and low fertile lands and is frequently exposed to terminal drought. Sesamum species inhabiting dryland ecosystems adaptively diverge from those inhabiting rainfed habitats, and drought-specific traits have a genetic basis. In sesame, traits associated with drought conditions have not been explored to date, yet studies of these traits are needed given that drought is predicted to become more frequent and severe in many parts of the world because of climate change. Here, 76 accessions from the available Indian core set were used to quantify variation in several traits under irrigated (WW) and terminal drought stress (WS) conditions as well as their association with seed yield over two consecutive years. The range of trait variation among the studied genotypes under WW and WS was significant. Furthermore, the traits associated with seed yield under WW and WS differed. The per se performance of the accessions indicated that the expression o...
Journal of Plant Nutrition, 2021
Abstract Conventional fertilizer nitrogen (N) recommendations for rainfed maize resulted in low N... more Abstract Conventional fertilizer nitrogen (N) recommendations for rainfed maize resulted in low N use efficiency (NUE) due to several reasons. This warrants application of fertilizer synchronous with plant requirements that could aid in improved productivity and NUE. In this backdrop, to optimize N rates for maize, a field experiment was conducted during 2014 to 2016 in Vertisols. Twelve treatments in combinations viz., N omission, skipping basal dose, multi-split topdressing at varying time either as broadcast or band placement, soil test crop response (STCR) based N with target yield 6.0 t ha−1 and biochar application were investigated in a randomized block design (RBD). Late application of N rates (120 kg ha−1) in 2 equal splits at knee high (V8) and tasseling (VT) stages with skipping of basal N, significantly increased grain yield, agronomy efficiency (AE), partial factor productivity (PFP), physiological efficiency (PE) and recovery efficiency (RE) to the tune of 16.3%, 45.1%, 15.3%, 14.0% and 37.9% than conventional recommendations, respectively. The higher yields and NUE with late application of N were ascribed due to positive significant linear relationship between yield and N availability. Factor analysis too revealed the one to one positive function of biomass with N uptake at V8 and VT. Principal component (PC) regression exhibited that PC1 acted as a major predictor for yield and dominated by leaf area index (LAI) and N uptake. Thus, we conclude that the multi-split N, to achieve higher yield and greater NUE, is strongly linked with late splits of N at V8 and VT.
Oryza-An International Journal on Rice, 2021
Potassium (K) is the most neglected nutrient in Indian agriculture and accounts only 10% of the t... more Potassium (K) is the most neglected nutrient in Indian agriculture and accounts only 10% of the total fertilizer use. The increased cropping intensity and use of high yielding cultivars since the green revolution led to heavy withdrawal of K from soil. Persistent K mining over the past six decades has mined soil K level in many cultivated areas and continuously transforming sufficiency into deficiency. A recent soil test a little over 1 lakh samples from 33 states of India have categorized 41.1%, 29.3%, and 29.5% of soil samples as low, medium and high in available K respectively. Further, the trend of soil available K status showed a persistent decline in percentage of area under high and medium soil K. Consequently, the evidence of rice crop responding to K nutrition is increased. This review attempts the nexus of K nutrition in rice for devising strategies for potassium management in rice-based cropping systems in the country.
Communications in Soil Science and Plant Analysis, 2015
Analysis of differential pore-volume distribution (PVD) patterns of commercial clinoptilolite fra... more Analysis of differential pore-volume distribution (PVD) patterns of commercial clinoptilolite fractions [(<125 µ (Z8; fine), 125–250 µ (Z9; medium), and >250 µ (Z10; coarse)] has been conducted experimentally using an analyzer to measure the nitrogen (N2) adsorption isotherms. The differential PVDs of the clinoptilolite fractions were calculated from the hysteresis loop according to the adsorption and desorption curves of the Barret, Joyner, and Halenda (BJH) model. The adsorption and desorption cycles of BJH produced heterogeneous as well as dissimilar differential PVD patterns with assorted peaks. While the adsorption curve has prolonged up to 300 nm, the desorption cycle was confined up to 190-nm pore diameter only. In the adsorption cycle, all the clinoptilolite fractions displayed U-shaped curves and had a differential pore volume in the range of 3 × 10–3 to 8 × 10–3 cm3/g A° in the micropore region with a sole peak at 1.75 nm for the fine fraction (Z8). In contrast, the curves were linear in the mesoporous region for all the fractions, with the fine fraction (Z8) having the greatest differential pore volume, whereas the other two fractions were almost parallel to each other. The desorption cycle has revealed an inverted V-shape curve with no definite patterns for the microporous region. Although the adsorption cycle could ascertain the micropore region, the desorption cycle was unable to do so. It was apparent from the differential PVD of the BJH model that fraction size has a major role in determining the textural properties of clinoptilolite fractions.
Advances in Agronomy, 2015
ABSTRACT The unsustainable exploitation of the inelastic resources for farming has led to a wides... more ABSTRACT The unsustainable exploitation of the inelastic resources for farming has led to a widespread degradation of soil resources, which has forced us to rethink our food production strategies into conservation agriculture (CA). It would be difficult to slow down the intensive-production process keeping in view, the demographic pressure. The present-day systems are posing challenges to land, water, and atmosphere, besides the biodiversity. CA involves minimal disturbance of the land, coupled with good agro-nomic principles such as crop residue management and crop rotation, with the appli-cation of chemicals for weed management. With a view to sustainable development in agriculture, CA is a concept trying to reconcile ecology, economy, and performance. Tillage is practiced since ages, for the preparation offield andmakingweed-free con-ditions and is an integral component of traditional agricultural systems. However, soil erosion was inevitable. The focal theme of CA revolves around reducing tillage opera-tions. From a weed management point of view, soil tillage brought buried seeds to the upper layer and stimulated their germination and the maintenance of crop residues hampered the herbicide efficacy. However, there are reports of shift inweed population due to the adoption of CA as compared to the conventional agricultural practices posing a formidable challenge to the CA concept. The interaction of weed–crop system becomes too complex. Reduced tillage and zero tillage allowed seed to stay on the sur-face so that they become prey to the predators. The crop/cover crop residue may also release some chemicals, which may also reduce weed seed germination process. Understanding the weed seed ecology and weed ecology could aid in devising appro-priate management options for successful implementation of CA. An integrated man-agement encompassing selection of appropriate crop cultivar and cropping system coupled with CA principles would aid in the management of weeds. Understanding weed seed predation would add value to the management issues. Herbicide resistance need to be given due attention for chemical weed management
Applied Agrometeorology, 2010
Natural disturbances play an important role in forest ecology, with effects that are highly depen... more Natural disturbances play an important role in forest ecology, with effects that are highly dependent on characteristics of the specific disturbance. Climate and weather induced risks often interfere with the productivity of forests. Excessive wind, ice, and snow regularly cause major disturbances to forests in many parts of the world. The uprooted trees are susceptible to the risk of secondary damage to the surviving trees. In the last four decades, many European countries have suffered acute forest damage.
Applied Agrometeorology, 2010
Forest risk management for minimizing climate and weather induced damage requires assessing the c... more Forest risk management for minimizing climate and weather induced damage requires assessing the current damage and predicting the future risks as accurately as possible. The main causes of acute forest damage are strong winds, fires, insect attacks, pollution and flooding (FAO 1995), out of which our interest here lies in wind (Box III.4.22), fire and flooding effects. Gadow (2000) has made an excellent review on “Evaluating risk in forest planning models”.
Advances in Agronomy, 2011
Zeolites are natural crystalline aluminosilicates. They are among the most common minerals presen... more Zeolites are natural crystalline aluminosilicates. They are among the most common minerals present in sedimentary rocks. Zeolites occur in rocks of diverse age, lithology, and geologic setting, and represent valuable indicators of the depositional and postdepositional (diagenetic) environments of the host rocks. It was reported that, of the 40 naturally occurring zeolites studied by research groups, the most well-known ones are clinoptilolite, erionite, chabazite, heulandite, mordenite, stilbite, and phillipsite. Structurally, zeolites are tectosilicates exhibiting an open three-dimensional structure containing cations needed to balance the electrostatic charge of the framework of silica and alumina tetrahedral units. Pores and voids are the key characteristics of zeolite
Applied Agrometeorology, 2010
ABSTRACT Climate is a big risk factor impacting on the performance of crop production systems and... more ABSTRACT Climate is a big risk factor impacting on the performance of crop production systems and their management for profitable returns. Stewart et al. (1989) presented an interesting picture of the difficulty of achieving sustainability of an agricultural system because of varying temperature and moisture regimes. As temperatures increase and amounts of rainfall decrease, the development of sustainable cropping systems becomes more difficult. Soil degradation processes such as organic matter decline and soil erosion are generally accelerated as temperatures increase.
Applied Agrometeorology, 2010
Applied Agrometeorology, 2010
Climate is a non monetary input influencing the performance of forest production systems for the ... more Climate is a non monetary input influencing the performance of forest production systems for the efficient use of monetary inputs. (Micro)climatic events also largely determine the efficiency of external inputs in agriculture, forestry, animal husbandry and fisheries. In forestry, climatic information and its application to input management has immense value. From the time seeds are sown and plants establish in the field to final harvest, climatic events have a role to play (e.g. Tewari 1994)
Protoplasma, 2009
The response to molybdenum (Mo) was studied in the metal-tolerant hydrophyte Trapa natans L. Prev... more The response to molybdenum (Mo) was studied in the metal-tolerant hydrophyte Trapa natans L. Previously, it was shown that the plant accumulates Mn in the floating lamina by means of phenolic compounds and responded with acclimation responses of the chloroplast. Since the involvement of phenolics has been proposed also in Mo resistance, we tested the response of T. natans to increasing doses (5, 50, 150, 600 µM) of Mo using the photosynthetic apparatus as an indicator of cellular stress. Only 5 μM Mo did not cause evident modifications with respect to controls. Conversely, 50 to 600 μM Mo induced progressively marked alterations of the lamina morphology. The chloroplast ultrastructure showed disorganisation of the thylakoid system, and correspondingly, the photosynthetic pigment pattern was altered with a fall-down in photosynthesis. Microspectrofluorimetry indicated alterations of photosystem II, with differences among the three cell layers (first and second palisade and spongy tissues). While the highest dose caused plant death, 50 and 150 μM Mo-treated plants underwent partial recovery, and the plant survived up to the end of the vegetative season. However, reproduction was unsuccessful. Mo treatment did not induce increase in total phenolics, but only in anthocyanin. In contrast to Mn, detoxification of Mo by chelation inside vacuoles, possibly by anthocyanins, is suggested to be an insufficient mechanism to reduce Mo toxicity, which probably includes an impairment of nitrogen metabolism. However, the metal was accumulated in the lamina. On the whole, T. natans showed limited capabilities to survive Mo excess as compared with Mn.
Valeriana jafall/ansi Jones (Valeriana wallichii DC), family Valerianacae is a perennial plant wi... more Valeriana jafall/ansi Jones (Valeriana wallichii DC), family Valerianacae is a perennial plant with wide green leaves. Local names of the plant are Tagar (Hindi), Tagara (Sanskrit) and Indian Valerian (Engli sh). The plan t is nati ve to temperate zones of Himalayas and is found abundantly from Kashmir to Bhutan at an altitude of 13003000m, in the Khasia Hills (India) and in Afghanistan and Pakistan . Essential oil for commercial use is extracted from the roots and rhizomes of thi s plant which is used as mild sedative. The derived medicine is used for nervous debility and failing reflexes. It is also used in the treatment of hysteria, hypochondriasis, mental illness and depression etc. Valepotriate and essential oil deri ved from this plant are in high demand in India and European countries. It is multiplied mostly by rhi zomes and is transplanted in field during March to April and October with a spacing of 30 x 30 cm. It bears fl owers in February and seeds are formed in March to ...
Journal of Applied and Natural Science, 2015
A field experiment was conducted to evaluate the influence of organic farming practices on soil h... more A field experiment was conducted to evaluate the influence of organic farming practices on soil health and crop performance of Soybean (Glycine max).The crop cultivar JS-335 of soybean was grown with 30:26.2:16.6 kg ha-1 (NPK) recommended dose of fertilizers under three management practices viz., organic, chemical and integrated (50:50) in randomized block design, replicated three times. Soil organic carbon, available N, P and K, microbial enzymatic activities, total biomass, seed yield and harvest index (HI) were analysed during the study. It was observed that soil organic carbon (11.3 g kg-1), available N (125 mg kg-1), P (49.7 mg kg-1) and soil enzyme activities viz., dehydrogenase (DHA) (98.20 µ grams TPF/g soil/24 h) and alkaline phosphatase (178.2 µ grams p-nitro phenol/g soil/h) were found significantly higher in the plot managed organically while available K (320.1 mg kg-1) was not significant with respect to chemical and integrated practices. The total biomass (1927 kg ha-1...
Crop Protection, 2017
In India, the three staple food crops viz., rice, wheat, and maize, contribute more than four-fif... more In India, the three staple food crops viz., rice, wheat, and maize, contribute more than four-fifths of the total food grain production. Among the several factors limiting their productivity, weeds account for about 40%. In order to meet the requirements of growing population, it is essential to improve productivity by reducing such unwarranted losses. Managing weeds with crop competition is an ecofriendly approach. Once the mechanisms of competition are understood, further improvements in weed control could be gained by manipulating other agronomic practices. The choice of cultivars, crop density, seeding rate, direction of planting, and intercropping could be exploited to enhance crop competitiveness against weeds. The variation in competitiveness and weed suppression among cultivars has been documented in rice, and to a lesser extent in wheat and maize. Research has demonstrated that the integration of crop competitiveness with other methods, such as the use of herbicides and manual weeding, is successful in managing weeds. However, in India, greater efforts are needed to exploit crop competitiveness for managing weeds in rice, wheat and maize. The success of these approaches relies on proper understanding of the biology and ecology of weeds, to identify weak points in their life cycle.
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Papers by Kulasekaran Ramesh