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D K Pal - One of the best experts on this subject based on the ideXlab platform.
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Clay Illuviation and Pedoturbation in SAT Vertisols
Simple Methods to Study Pedology and Edaphology of Indian Tropical Soils, 2018Co-Authors: D K PalAbstract:For a long time the apparent uniform distribution of clay throughout Vertisols was considered to be effect of haploidisation within the pedon caused by pedoturbation and in some cases the observed gradual increase in clay content with depth was thought to be due to inheritance from parent material. Recent systematic pedological studies on Vertisols that have no stratification in the parent material and no clay skins, indicated that their Bss horizons contain clay even up to 20%; an increase from the eluvial horizon. Such depth distribution of clay is due to clay illuviation process was confirmed by micro-morphological investigation of the thin sections, which indicated the presence of >2% impure clay pedofeatures. Thus the clay enriched Bss horizons in Vertisols suggests that pedoturbation was too much favoured as an important pedogenic process in Vertisols by the past researchers till early nineties, who envisaged pedoturbation would obliterate all evidence of illuviation. But in reality, pedoturbation in Vertisols is only a partially functional process, which cannot overshadow the more significant long-term clay illuviation process. Although the micro-morphological study of soil thin sections is a unique analytical tool to confirm clay illuviation process, for many of the national soil science laboratories it is truly a very distant facility. In its absence some simple analytical data are of much help in ensuring the clay illuviation process with certainty as major pedogenic process in Indian Vertisols, which are described in this chapter.
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Vertisols of tropical Indian environments: Pedology and edaphology
Geoderma, 2012Co-Authors: D K Pal, S.p. Wani, K L SahrawatAbstract:Vertisols in the tropics occur in a range of climates and are used in a range of production systems. This review is a synthesis of the recent developments in pedology of Vertisols achieved via high-resolution micro-morphology, mineralogy, and age-control data along with their geomorphologic and climatic history. This knowledge has contributed to our understanding of how the climate change-related pedogenic processes during the Holocene altered soil properties in the presence or absence of soil modifiers (Ca-zeolites and gypsum), calcium carbonate and palygorskite minerals. These state-of-the-art methods have established an organic link between pedogenic processes and bulk soil properties; the review also considers the need to modify the classification of Vertisols at the subgroup level. We hope this review will fulfil the need for a handbook on Vertisols to facilitate their better management for optimising their productivity in the 21st century
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significance of the formation of calcium carbonate minerals in the pedogenesis and management of cracking clay soils Vertisols of india
Clays and Clay Minerals, 2002Co-Authors: P Srivastava, T Bhattacharyya, D K PalAbstract:Micromorphological studies were performed in order to understand the factors and processes involved in the formation of calcium carbonate (CaCO3) in twenty three soil series of Vertisols representing sub-humid, semi-arid and arid climatic regions of Peninsular India. The study indicates that Vertisols contain both pedogenic calcium carbonate (PC) and non-pedogenic calcium carbonate (NPC) irrespective of the ecosystems to which they belong. The NPCs are part of the parent material of Vertisols. Dissolution of NPCs and recrystallization of dissolved Ca2+ ions are responsible for the formation of PCs. Vertisols of arid and semi-arid climates contain more PC in their soil control section (SCS) than those of sub-humid climates. Formation of PC is the prime chemical reaction responsible for the increase in pH, the decrease in the Ca/Mg ratio of exchange site with depth and in the development of subsoil sodicity. Petrographic and scanning electron microscopic (SEM) examination of quartz, feldspars and micas indicate little or no alteration, discounting the possibile formation of smectite during Vertisol formation. X-ray diffraction (XRD) analysis of clays indicates that smectites of Vertisols are fairly well crystallized and do not show any sign of transformation except for hydroxy interlayering. The preservation of the crystallinity of smectite and the lack of transformation of primary minerals thus validate the hypothesis of positive entropy change during the formation of Vertisols.
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significance of the formation of calcium carbonate minerals in the pedogenesis and management of cracking clay soils Vertisols of india
Clays and Clay Minerals, 2002Co-Authors: P Srivastava, T Bhattacharyya, D K PalAbstract:Micromorphological studies were performed in order to understand the factors and processes involved in the formation of calcium carbonate (CaCO3) in twenty three soil series of Vertisols representing sub-humid, semi-arid and arid climatic regions of Peninsular India. The study indicates that Vertisols contain both pedogenic calcium carbonate (PC) and non-pedogenic calcium carbonate (NPC) irrespective of the ecosystems to which they belong. The NPCs are part of the parent material of Vertisols. Dissolution of NPCs and recrystallization of dissolved Ca2+ ions are responsible for the formation of PCs. Vertisols of arid and semi-arid climates contain more PC in their soil control section (SCS) than those of sub-humid climates. Formation of PC is the prime chemical reaction responsible for the increase in pH, the decrease in the Ca/Mg ratio of exchange site with depth and in the development of subsoil sodicity. Petrographic and scanning electron microscopic (SEM) examination of quartz, feldspars and micas indicate little or no alteration, discounting the possibile formation of smectite during Vertisol formation. X-ray diffraction (XRD) analysis of clays indicates that smectites of Vertisols are fairly well crystallized and do not show any sign of transformation except for hydroxy interlayering. The preservation of the crystallinity of smectite and the lack of transformation of primary minerals thus validate the hypothesis of positive entropy change during the formation of Vertisols. The precise cause-effect relationship between CaCO3 of pedogenic and non-pedogenic origin, and exchangeable Mg, Na and Ca percentages (EMP, ESP and ECP) has been established in the study. This indicates that impoverishment of Ca2+ ions on the exchange sites of Vertisols needs to be controlled by rehabilitation methods that can replenish Ca2+ ions, and thus the study provides relevant information for future land resource management programmes not only on Vertisols of India but also on similar soils occurring elsewhere.
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Microtopography as a factor in the degradation of Vertisols in central India
Land Degradation & Development, 2002Co-Authors: P. H. Vaidya, D K PalAbstract:Earlier studies on soil degradation in Vertisols of the Purna Valley of central India indicated that the semiarid climate characterized by a mean annual rainfall (MAR) of 875 mm and a tropustic moisture regime is responsible for the development of calcareous sodic soils. Recent observations, however, indicate that in the adjacent east upland of the Purna Valley, namely in the Pedhi Watershed, Vertisols have drainage problems, although the area receives a higher MAR than the Purna Valley, the total MAR being 975 mm. The Pedhi Watershed covers an area of 44 321 ha, and is characterized by a tropustic moisture regime and a hyperthermic temperature regime. Vertisols of the Pedhi Watershed are deep, calcareous, clayey and very dark greyish-brown to dark yellowish-brown in colour. Vertisols occur on both microhigh (MH) and microlow (ML) positions. The distance between the MH and ML positions is approximately 6 km and the elevation difference is 0.5–5 m. Cracks > 1 cm wide extend down to the slickenside zones in soils of ML whereas they cut these zones in some soils in MH positions. The soils of the MH positions are strongly alkaline and those of ML are mildly alkaline. The present study attempts to relate the distinctly different morphological and chemical properties of Vertisols in the MH and ML positions to pinpoint the prime factor responsible for the impairment of drainage on the basis of physical, chemical, mineralogical and micromorphological data. These data were obtained from 13 Vertisol pedons of methodically selected sites in the Pedhi Watershed. Despite their similar coefficient of linear extensibility (COLE), volumetric shrinkage potential (VSP), clay contents and amounts of fine smectite clay, the plasmic fabric of the slickenside horizons in soils of ML is porostriated, whereas in soils of MH it is stipple speckled to mosaic speckled, indicating weak plasma separation. The soils have both pedogenic and non-pedogenic calcium carbonates (CaCO3). The semiarid climate induces the precipitation of CaCO3 with a concomitant development of subsoil sodicity. The degree of development of sodicity (Exchangeable sodium percentage (ESP) ≥ 5) is more in soils of MH as evidenced by the higher amount of pedogenic CaCO3 (PC). The lack of water in soils of MH position is the reason for weak swelling of smectite, for larger amounts of PC, for higher alkalinity and sodicity, and for cracks cutting through the slickenside zones. Formation of sodic Vertisols in MH alongside non-sodic Vertisols in ML positions is a unique phenomenon. It develops because of microtopographic differences which modify distribution of water across the landscape and facilitate greater penetration of rainwater in ML positions. The development of sodicity due to microtopographic differences assumes a great importance when a future land resource management programme on Vertisols in the higher MAR zone of overall a semiarid climate is considered. Copyright © 2002 John Wiley & Sons, Ltd.
M Mohanty - One of the best experts on this subject based on the ideXlab platform.
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soil carbon sequestration potential in a vertisol in central india results from a 43 year long term experiment and apsim modeling
Agricultural Systems, 2020Co-Authors: M Mohanty, Nishant K Sinha, J Somasundaram, Sonali Shukla Mcdermid, A K Patra, Muneshwar Singh, A K Dwivedi, Sammi K Reddy, Ch Srinivas Rao, M PrabhakarAbstract:Abstract Soil organic matter dynamics in terrestrial ecosystems are controlled by complex interactions between various factors such as climate, soil, and agricultural management practices. We utilized a process-based crop model, APSIM, to simulate long-term soil organic carbon (SOC) dynamics for a soybean-wheat cropping system under nitrogen (N) and farmyard manure management (FYM) practices for a 43-year old experimental dataset in India. The APSIM was parameterized and validated to predict grain yield and SOC stock. The validated model was then used to evaluate the impacts of different management practices on SOC dynamics in the top 30 cm of soil through scenario modeling. The results of the APSIM simulations demonstrated that improved N and FYM management practices had great potential to increase SOC sequestration in these Vertisols. The equilibrium SOC concentration under different N management practices increased with a higher N application rate, with the integrated application of N with FYM showing the maximum rate. The optimum N (Nopt) rate for maximum SOC sequestration was estimated to be 155 kg ha−1 for wheat in the studied Vertisol and the time to reach steady-state of the site was 104 years. The Nopt increased SOC by about 28.6% over the initial concentration. We found that the APSIM was robust in predicting long-term changes in SOC stock (Index of agreement = 0.79 and root mean square error = 3.33 Mg ha−1, R2 = 0.92, mean bias error = −1.08) for a Vertisol soil of central India, in this case under a soybean-wheat cropping system. The study results highlighted that balanced fertilization is the key to sustaining SOC stock in the long-term for Vertisols.
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soil and nutrients losses under different crop covers in Vertisols of central india
Journal of Soils and Sediments, 2020Co-Authors: R K Singh, M Mohanty, Nishant K Sinha, J Somasundaram, A K Patra, K M Hati, R S Chaudhary, I Rashmi, S K Chaudhari, Rattan LalAbstract:Accelerated erosion removes fertile top soil along with nutrients through runoff and sediments, eventually affecting crop productivity and land degradation. However, scanty information is available on soil and nutrient losses under different crop covers in a vertisol of Central India. Thus, a field experiment was conducted for 4 years (2010–2013) to study the effect of different crop cover combinations on soil and nutrient losses through runoff in a vertisol. Very limited information is available on runoff, soil, and nutrient losses under different vegetative covers in a rainfed vertisol. Thus, the hypothesis of the study was to evaluate if different crop cover combinations would have greater impact on reducing soil and nutrient losses compared to control plots in a vertisol. This experiment consisted of seven treatment combinations of crop covers namely soybean (Glycine max) (CC1), maize (Zea mays) (CC2), pigeon pea (Cajanus cajan) (CC3), soybean (Glycine max) + maize (Zea mays) − 1:1 (CC4), soybean (Glycine ma x)) + pigeon pea (Cajanus cajan) −2:1 (CC5), maize (Zea mays) + pigeon pea (Cajanus cajan) − 1:1 (CC6), and cultivated fallow (CC7). The plot size was 10 × 5 m with 1% slope, and runoff and soil loss were measured using multi-slot devisor. All treatments were arranged in a randomized block design with three replications. Results demonstrated that the runoff and soil loss were significantly (p < 0.05) higher (289 mm and 3.92 Mg ha−1) under cultivated fallow than those in cropped plots. Among various crop covers, sole pigeon pea (CC3) recorded significantly higher runoff and soil loss (257 mm and 3.16 Mg ha−1) followed by that under sole maize (CC2) (235 mm and 2.85 Mg ha−1) and the intercrops were in the order of maize + pigeon pea (211 mm and 2.47 Mg ha−1) followed by soybean + maize (202 mm and 2.38 Mg ha−1), and soybean + pigeon pea (195 mm and 2.15 Mg ha−1). The lowest runoff and soil loss were recorded under soybean sole crop (194 mm and 2.27 Mg ha−1). The data on nutrient losses indicated that the highest losses of soil organic carbon (SOC) (25.83 kg ha−1), total nitrogen (N), phosphorus (P), and potassium (K) (7.76, 0.96, 32.5 kg ha−1) were recorded in cultivated fallow (CC7) as compared to those from sole and intercrop treatments. However, sole soybean and its intercrops recorded the minimum losses of SOC and total N, P, and K, whereas the maximum losses of nutrients were recorded under pigeon pea (CC3). The system productivity in terms of soybean grain equivalent yield (SGEY) was higher (p < 0.05) from maize + pigeon pea (3358 kg ha−1) followed by that for soybean + pigeon pea (2191 kg ha−1) as compared to sole soybean. Therefore, maize + pigeon pea (1:1) intercropping is the promising option in reducing runoff, soil-nutrient losses, and enhancing crop productivity in the hot sub-humid eco-region. Study results highlight the need for maintenance of suitable vegetative cover as of great significance to diffusing the erosive energy of heavy rains and also safe guarding the soil resource from degradation by water erosion in Vertisols.
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effect of contrasting tillage and cropping systems on soil aggregation carbon pools and aggregate associated carbon in rainfed Vertisols
European Journal of Soil Science, 2018Co-Authors: J Somasundaram, M Mohanty, Nishant K Sinha, K M Hati, R S Chaudhary, Awanish D Kumar, A K Biswas, Pramod Jha, M Sankar, A K PatraAbstract:Worldwide, conservation agriculture practices involving minimal soil disturbances and retention of crop residue (>30%) have been practised increasingly and recognized to enhance soil health by optimizing key soil attributes. However, little information is available on the short-term effects of conservation agriculture practices on soil properties under rainfed Vertisols of Central India. Thus, our aim was to study the short-term effects of contrasting tillage treatments and cropping systems on soil aggregation, aggregate-associated carbon (C), carbon pools and crop productivity. This study comprised three tillage systems (TS), reduced tillage (RT), no tillage (NT) with retention of crop residue and conventional tillage (CT), together with four cropping systems (CS), namely soya bean (Glycine max L.)+pigeon pea (Cajanus cajan L.) (2:1), soya bean-wheat (Titricum durum L.), maize (Zea mays L.)+pigeon pea (1:1), and maize-chickpea Cicer arietinum L.). The experiment was laid out in a split-plot design with three replicates. Soil samples were collected at four depths: 0-5, 5-15, 15-30 and 30-45cm from the experimental field after completion of four crop cycles. Results indicated that at depths 0-5 and 5-15cm, tillage and cropping system had a significant effect on aggregate mean weight diameter (MWD). The MWDs of 0.97 and 0.94mm were larger for NT than CT (0.77 and 0.83mm) at 0-5- and 5-15-cm depths, respectively. Water-stable aggregates (WSAs) were also larger for NT (70.74%) and RT (70.09%) than CT (59.50%) at 0-5cm. Tillage practice, cropping system and their interaction had a greater effect (P very labile >less labile >labile for 0-5- and 5-15-cm depths after four crop cycles. Less labile and non-labile C fractions contributed >50% of TOC, indicating a more recalcitrant form of carbon present in the soil. Tillage had no significant effect (P>0.05) on crop yields after four crop cycles. Conservation agriculture can have a positive effect on aggregate stability, aggregate-associated C and different carbon pools in a Vertisol. Highlights: Does conservation agriculture affect soil aggregation, aggregate stability and carbon pools more than conventional tillage? The SOC concentration increases with aggregate size and provides physical protection and stabilization of carbon (C). Aggregate-associated C content was significantly affected by tillage practices and cropping system. Less labile and non-labile C fractions contribute >50% TOC in the rainfed Vertisols of central India.
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soil quality effects of tillage and residue under rice wheat cropping on a vertisol in india
Soil & Tillage Research, 2007Co-Authors: M Mohanty, D K Painuli, A K Misra, P K GhoshAbstract:Abstract Soil quality in rice ( Oryza sativa L.)–wheat ( Triticum aestivum L.) cropping systems is governed primarily by the tillage practices used to fulfill the contrasting soil physical and hydrological requirements of the two crops. The objective of this study was to develop a soil quality index (SQI) based on bulk density (BD), penetration resistance (PR), water stable aggregates (WSA) and soil organic matter (OM) to evaluate this important cropping system on a Vertisol in India. Regression analysis between crop yield and SQI values for various tillage and crop residue management treatments indicated SQI values of 0.84–0.92, 0.88–0.93 and 0.86–0.92 were optimum for rice, wheat and the combined system (rice + wheat), respectively. The maximum yields for rice and wheat were 5806 and 1825 kg ha −1 occurred at SQI values of 0.85 and 0.99, respectively. Using zero tillage (ZT) for wheat had a positive effect on soil quality regardless of the treatments used for rice. Regression analyses to predict sustainability of the various tillage and crop residue treatments showed that as puddling intensity for rice increased, sustainability without returning crop residues decreased from 6 to 1 years. When residue was returned, the time for sustainable productivity increased from 6 to 15 years for direct seeded rice, 5 to 11 years with low-intensity puddling (P 1 ) and 1 to 8 years for high-intensity (P 2 ) puddling. For sustainability and productivity, the best practice for this or similar Vertisols in India would be direct seeding of rice with conventional tillage and residues returned.
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influence of tillage practices and nutrient management on crack parameters in a vertisol of central india
Soil & Tillage Research, 2003Co-Authors: K K Bandyopadhyay, M Mohanty, D K Painuli, A K Misra, K M Hati, K G Mandal, P K Ghosh, R S Chaudhary, C L AcharyaAbstract:Abstract The frequency, size and rate of development of cracks influence the transport of water, nutrients and gases in the soil profile and plant growth processes in Vertisols. Despite their importance, studies on characterising cracks in Vertisols of India are limited. This study attempts to evaluate the influence of different tillage practices, nutrient management and cropping systems on cracking behaviour of a Vertisol in central India. The length, depth, width, area and volume of cracks were recorded after the harvest of the wet season crops, i.e. soybean ( Glycine max L.) and rice ( Oryza sativa L.) from three ongoing tillage experiments with three different cropping systems, i.e. soybean–wheat ( Triticum aestivum L.), soybean–linseed ( Linum usitatissimum L.) and rice–wheat. The results revealed that all the crack parameters were significantly negatively correlated with the water content of the 0–15 cm soil layer and, crack width and crack volume were significantly positively correlated with the bulk density of the 0–15 cm soil layer. Gravimetric water content and bulk density of the 0–15 cm soil layer together explained 79% variation in the crack volume. The crack volume was significantly negatively correlated ( r =0.86, P =0.01) with the root length density of the previous soybean crop. Rice grown under puddled condition significantly enhanced different crack parameters viz., length, depth, width, surface area and volume of the cracks over nonpuddled direct seeded rice. Sub-soiling practised in soybean under the soybean–linseed system significantly reduced the width, depth, length and surface area of cracks by 12.5, 10, 5 and 12%, respectively, over conventional tillage. No tillage practised in soybean under soybean–wheat system resulted in significant increase in width, depth and volume of the cracks but decrease in length and surface area of cracks over conventional tillage and mould board tillage practice. Application of manure reduced the magnitude of different crack parameters in soybean–linseed cropping system. Thus cracking in Vertisols can be favourably managed by the selection of proper tillage practice, cropping system and organic manure amendments.
Balesh Tulema - One of the best experts on this subject based on the ideXlab platform.
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the prospects of reduced tillage in tef eragrostis tef zucca in gare arera west shawa zone of oromiya ethiopia
Soil & Tillage Research, 2008Co-Authors: Balesh Tulema, Jens B Aune, Fred H Johnsen, Bernard VanlauweAbstract:Abstract Soils in Ethiopia are traditionally ploughed repeatedly with an oxen-drawn plough before sowing. The oxen ploughing system exposes the soil to erosion and is expensive for farmers without oxen. This study was undertaken to assess agronomic and economic impacts of alternative, reduced tillage methods. Field experiments were carried out on a Vertisol and a Nitisol for 2 years to study the effect of zero tillage, minimum tillage, conventional tillage, and broad bed furrows (BBF) on the yield of tef (Eragrostis tef Zucca). No significant differences in tef biomass and grain yields were observed between the treatments on both soils in the first year. In Nitisol in the second year, yield was lower in the zero tillage treatment as compared to the other treatments. No difference in yield was observed between single plough, conventional, and BBF. On Vertisol, the yields were higher in BBF as compared to the other treatments. The yields on Vertisol were 1368, 1520, 1560 and 1768 kg ha−1 for the zero tillage, minimum tillage, conventional tillage and BBF treatments respectively. More than twice as much grass weed was observed on zero tillage treatment as compared to the BBF treatment on both soils. Zero tillage gave the lowest gross margin on both soils whereas BBF gave the highest gross margin. The gross margin on Nitisols for the zero tillage and BBF treatments were −108 and 1504 Birr/ha respectively and corresponding numbers for the Vertisol were 520 and 1924 Birr ha−1. On Vertisol there were no significant difference in gross margin between minimum tillage and conventional tillage. Minimum tillage is an interesting option on Vertisols, particularly for female-headed households as it reduces the tillage cost. It may also improve overall productivity of the farming system because it allows partial replacement of oxen with cows and reduces soil erosion.
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n fertilisation soil type and cultivars effects on n use efficiency in tef eragrostis tef zucc trotte
Nutrient Cycling in Agroecosystems, 2005Co-Authors: Balesh Tulema, F Zapata, Jens B Aune, Bishal K SitaulaAbstract:Tef [Eragrostis tef (Zucc.) Trotte] is a major staple crop in Ethiopia and a large proportion of the imported fertiliser is being applied to tef fields. However, since the 1980s the yield on farmers’ fields has stagnated. Response of the crop to applied fertiliser is influenced by several factors. We aimed to study the fertiliser N use efficiency (FNUE) of four tef varieties from ammonium sulphate and urea on different soil types with the help of the 15N isotopic dilution technique. Three experiments were conducted under greenhouse and field conditions. On a typic Eutrocrept soil, higher percent N derived from fertiliser (% Ndff) and % FNUE were obtained for all the tested tef varieties when the N source was urea, while percent N derived from soil (% Ndfs) was higher for ammonium sulphate. The mean % FNUE for urea and ammonium sulphate was 49 and 34%, respectively. When the varieties were grown on a Nitosol or a Vertisol and ammonium sulphate was applied, the % Ndff, the total and fertiliser N yield and % FNUE of the tef varieties were higher on a eutric Nitosol compared to the Vertisol. The mean % FNUE was 61.3 for the Nitosol and 27.8 for the Vertisol. In an ‘on farm’ experiment, relatively higher FNUE (33.3%) was obtained on an Andosol compared to Vertisols (17 and 27%). The tested varieties showed no difference in FNUE. As tef is the most important crop grown on Vertisols in Ethiopia, the low FNUE has a direct negative implication for the livelihood of the farmers and the environment.
A K Patra - One of the best experts on this subject based on the ideXlab platform.
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soil carbon sequestration potential in a vertisol in central india results from a 43 year long term experiment and apsim modeling
Agricultural Systems, 2020Co-Authors: M Mohanty, Nishant K Sinha, J Somasundaram, Sonali Shukla Mcdermid, A K Patra, Muneshwar Singh, A K Dwivedi, Sammi K Reddy, Ch Srinivas Rao, M PrabhakarAbstract:Abstract Soil organic matter dynamics in terrestrial ecosystems are controlled by complex interactions between various factors such as climate, soil, and agricultural management practices. We utilized a process-based crop model, APSIM, to simulate long-term soil organic carbon (SOC) dynamics for a soybean-wheat cropping system under nitrogen (N) and farmyard manure management (FYM) practices for a 43-year old experimental dataset in India. The APSIM was parameterized and validated to predict grain yield and SOC stock. The validated model was then used to evaluate the impacts of different management practices on SOC dynamics in the top 30 cm of soil through scenario modeling. The results of the APSIM simulations demonstrated that improved N and FYM management practices had great potential to increase SOC sequestration in these Vertisols. The equilibrium SOC concentration under different N management practices increased with a higher N application rate, with the integrated application of N with FYM showing the maximum rate. The optimum N (Nopt) rate for maximum SOC sequestration was estimated to be 155 kg ha−1 for wheat in the studied Vertisol and the time to reach steady-state of the site was 104 years. The Nopt increased SOC by about 28.6% over the initial concentration. We found that the APSIM was robust in predicting long-term changes in SOC stock (Index of agreement = 0.79 and root mean square error = 3.33 Mg ha−1, R2 = 0.92, mean bias error = −1.08) for a Vertisol soil of central India, in this case under a soybean-wheat cropping system. The study results highlighted that balanced fertilization is the key to sustaining SOC stock in the long-term for Vertisols.
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soil and nutrients losses under different crop covers in Vertisols of central india
Journal of Soils and Sediments, 2020Co-Authors: R K Singh, M Mohanty, Nishant K Sinha, J Somasundaram, A K Patra, K M Hati, R S Chaudhary, I Rashmi, S K Chaudhari, Rattan LalAbstract:Accelerated erosion removes fertile top soil along with nutrients through runoff and sediments, eventually affecting crop productivity and land degradation. However, scanty information is available on soil and nutrient losses under different crop covers in a vertisol of Central India. Thus, a field experiment was conducted for 4 years (2010–2013) to study the effect of different crop cover combinations on soil and nutrient losses through runoff in a vertisol. Very limited information is available on runoff, soil, and nutrient losses under different vegetative covers in a rainfed vertisol. Thus, the hypothesis of the study was to evaluate if different crop cover combinations would have greater impact on reducing soil and nutrient losses compared to control plots in a vertisol. This experiment consisted of seven treatment combinations of crop covers namely soybean (Glycine max) (CC1), maize (Zea mays) (CC2), pigeon pea (Cajanus cajan) (CC3), soybean (Glycine max) + maize (Zea mays) − 1:1 (CC4), soybean (Glycine ma x)) + pigeon pea (Cajanus cajan) −2:1 (CC5), maize (Zea mays) + pigeon pea (Cajanus cajan) − 1:1 (CC6), and cultivated fallow (CC7). The plot size was 10 × 5 m with 1% slope, and runoff and soil loss were measured using multi-slot devisor. All treatments were arranged in a randomized block design with three replications. Results demonstrated that the runoff and soil loss were significantly (p < 0.05) higher (289 mm and 3.92 Mg ha−1) under cultivated fallow than those in cropped plots. Among various crop covers, sole pigeon pea (CC3) recorded significantly higher runoff and soil loss (257 mm and 3.16 Mg ha−1) followed by that under sole maize (CC2) (235 mm and 2.85 Mg ha−1) and the intercrops were in the order of maize + pigeon pea (211 mm and 2.47 Mg ha−1) followed by soybean + maize (202 mm and 2.38 Mg ha−1), and soybean + pigeon pea (195 mm and 2.15 Mg ha−1). The lowest runoff and soil loss were recorded under soybean sole crop (194 mm and 2.27 Mg ha−1). The data on nutrient losses indicated that the highest losses of soil organic carbon (SOC) (25.83 kg ha−1), total nitrogen (N), phosphorus (P), and potassium (K) (7.76, 0.96, 32.5 kg ha−1) were recorded in cultivated fallow (CC7) as compared to those from sole and intercrop treatments. However, sole soybean and its intercrops recorded the minimum losses of SOC and total N, P, and K, whereas the maximum losses of nutrients were recorded under pigeon pea (CC3). The system productivity in terms of soybean grain equivalent yield (SGEY) was higher (p < 0.05) from maize + pigeon pea (3358 kg ha−1) followed by that for soybean + pigeon pea (2191 kg ha−1) as compared to sole soybean. Therefore, maize + pigeon pea (1:1) intercropping is the promising option in reducing runoff, soil-nutrient losses, and enhancing crop productivity in the hot sub-humid eco-region. Study results highlight the need for maintenance of suitable vegetative cover as of great significance to diffusing the erosive energy of heavy rains and also safe guarding the soil resource from degradation by water erosion in Vertisols.
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effect of contrasting tillage and cropping systems on soil aggregation carbon pools and aggregate associated carbon in rainfed Vertisols
European Journal of Soil Science, 2018Co-Authors: J Somasundaram, M Mohanty, Nishant K Sinha, K M Hati, R S Chaudhary, Awanish D Kumar, A K Biswas, Pramod Jha, M Sankar, A K PatraAbstract:Worldwide, conservation agriculture practices involving minimal soil disturbances and retention of crop residue (>30%) have been practised increasingly and recognized to enhance soil health by optimizing key soil attributes. However, little information is available on the short-term effects of conservation agriculture practices on soil properties under rainfed Vertisols of Central India. Thus, our aim was to study the short-term effects of contrasting tillage treatments and cropping systems on soil aggregation, aggregate-associated carbon (C), carbon pools and crop productivity. This study comprised three tillage systems (TS), reduced tillage (RT), no tillage (NT) with retention of crop residue and conventional tillage (CT), together with four cropping systems (CS), namely soya bean (Glycine max L.)+pigeon pea (Cajanus cajan L.) (2:1), soya bean-wheat (Titricum durum L.), maize (Zea mays L.)+pigeon pea (1:1), and maize-chickpea Cicer arietinum L.). The experiment was laid out in a split-plot design with three replicates. Soil samples were collected at four depths: 0-5, 5-15, 15-30 and 30-45cm from the experimental field after completion of four crop cycles. Results indicated that at depths 0-5 and 5-15cm, tillage and cropping system had a significant effect on aggregate mean weight diameter (MWD). The MWDs of 0.97 and 0.94mm were larger for NT than CT (0.77 and 0.83mm) at 0-5- and 5-15-cm depths, respectively. Water-stable aggregates (WSAs) were also larger for NT (70.74%) and RT (70.09%) than CT (59.50%) at 0-5cm. Tillage practice, cropping system and their interaction had a greater effect (P very labile >less labile >labile for 0-5- and 5-15-cm depths after four crop cycles. Less labile and non-labile C fractions contributed >50% of TOC, indicating a more recalcitrant form of carbon present in the soil. Tillage had no significant effect (P>0.05) on crop yields after four crop cycles. Conservation agriculture can have a positive effect on aggregate stability, aggregate-associated C and different carbon pools in a Vertisol. Highlights: Does conservation agriculture affect soil aggregation, aggregate stability and carbon pools more than conventional tillage? The SOC concentration increases with aggregate size and provides physical protection and stabilization of carbon (C). Aggregate-associated C content was significantly affected by tillage practices and cropping system. Less labile and non-labile C fractions contribute >50% TOC in the rainfed Vertisols of central India.
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characterization of breeding sites of phlebotomus orientalis the vector of visceral leishmaniasis in northwestern ethiopia
Acta Tropica, 2014Co-Authors: Aviad Moncaz, Oscar David Kirstein, Araya Gebresellassie, Wossenseged Lemma, Asrat Hailu, Solomon Yared, Teshome Gebremichael, Moshe Shenker, Alon WarburgAbstract:We studied breeding sites of Phlebotomus orientalis (Diptera: Psychodidae) the vector of visceral leishmaniasis in northern Ethiopia. Although numbers were rather small, 165 sand flies were captured emerging from vertisol cracks. The most productive breeding sites were cracked Vertisols, dry river banks and close to trees. No sand flies were caught emerging from sandy clay loam soils in peri-domestic habitats but a few were captured emerging from gaps in a stone wall. Abiotic parameters in Vertisols close to trees and in open field from which P. orientalis had emerged, were compared. Soil pH was slightly alkaline and salinity was low. Organic matter contents were similar in both sites. Temperatures and RH remained relatively stable near trees from the end of the rainy season through mid dry season, yet fluctuated markedly at the shallower depth in the open field. During the rainy season, cracks in the soil were sealed resulting in significant lowering of the oxygen concentrations near the tree. Gravimetric water content of soil near trees was lower than open field at shallow depth but similar deeper down. We conclude that ambient conditions suitable for sand fly larvae at shallow depths (45cm) are restricted to areas close to trees. However, deeper in Vertisols (90cm) suitable conditions are apparently maintained throughout the dry season even in open fallow fields.
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Sergentomyia spp.: breeding sites in Vertisols and peri-domestic habitats in North West Ethiopia.
Acta Tropica, 2014Co-Authors: Aviad Moncaz, Oscar David Kirstein, Araya Gebresellassie, Wossenseged Lemma, Teshome Gebre-michael, Meshesha Balkew, Shewaye Belay, Asrat Hailu, Alon WarburgAbstract:Sand flies belonging to the genus Sergentomyia Franca & Parrot, 1920, are hematophagous insects feeding mostly on reptiles and birds, but some species feed also on mammals including humans. Sergentomyia spp. frequently comprise the vast majority of sand flies trapped along with Phlebotomus spp., the vectors of mammalian leishmaniasis. Within the framework of a project on the ecology and transmission of visceral leishmaniasis in Ethiopia, putative breeding sites of phlebotomine sand flies were studied. Large horizontal sticky traps (LHSTs) covered with sand fly-proof mesh were deployed over cracked vertisol and related habitats for up to 3 nights, and emerging sand flies were collected daily. Emergence traps (ETs) were also adapted to sample other putative breeding sites including tree trunks, termite mounds, rock piles and vertical river banks. Productive breeding sites were identified in the trunks and roots systems of trees, vertisol fields, cracks and burrows in vertisol dry river banks and termite mounds. Emerging flies were also collected form a stone wall and a rock pile situated inside a village. Significantly more Sergentomyia spp. were trapped in Vertisols by ETs deployed over root system than in open fields. Similarly, more sand flies emerged from cracks in the vertisol in fallow Sorghum than in fallow sesame fields. Productive breeding sites were characterized by stable micro-climatic conditions. Species composition of emerging sand flies varied with habitat, season and geographical location.
