Typic Haplustert Research Articles

Leaf Chlorophyll Meter Readings as an Indicator for Sugarcane Yield Under Iron Deficient Typic Haplustert

The objective of this study was to assess the feasibility of using a chlorophyll meter for estimating leaf chlorophyll content of sugarcane varieties under iron deficient condition. The SPAD chlorophyll meter readings were used to measure the leaf greenness. Leaf chlorophyll contents were also determined using the acetone extraction method and metabolically active iron content of leaf was analysed by 1,10-orthophenanthroline extract. SPAD readings were significantly correlated with leaf chlorophyll content, active iron content, cane yield, sugar yield and NMC of sugarcane varieties. These results suggest that the readings from a SPAD meter can be used for rapid and non-destructive estimation of leaf chlorophyll and it could facilitate in situ decision making for identifying tolerant varieties to iron deficiency for superior sugarcane yield.

Evaluation of soil characteristics of sunflower growing shrink-swell soils of Eastern Vidarbha

Summary The sunflower growing soils of eastern Vidarbha region have been investigated for assessing the agro environmental suitability. Six pedons from high intensity area of Bhiwapur and Umred of Nagpur district were selected for study. Crop yield data were collected during field survey and other physical and chemical properties were studied in the laboratory and yields were correlated with soil properties. The investigation revealed that high intensity sunflower growing soils belonged to Typic Haplusterts, alkaline in reaction (pH 8.2 to 8.7) and low to medium in organic carbon content (0.24 to 0.79 %) and high cation exchange capacity (47.91 to 58.71 %), calcium carbonate were < 5 per cent, Ca : Mg ratio varied from 1.8 to 2.6 indicating moderate drainability and base saturation (85 to 89 %). Among the DTPA- extractable micronutrients, zinc was low while the soils were medium to high in manganese and iron and low to high in copper content. The sunflower yield when correlated with agro edaphic parameters it was found that rainfall and major soil physical and chemical characteristics influenced the crop yield. The stepwise regression analysis of sunflower yield with agroenvironment properties reveal that Typic Haplusterts distributed over four villages of Bhiwapur and Umred tahsils of Nagpur district that pH, Ca, Na, sum of cations, CEC, ESP, Mn, sand, clay and water retention at 1500 kPa had positive correlation. The high correlation co-efficient obtained with water retention at 33 kPa (0.91), post Kharif rainfall (0.90), clay (0.87) and water retention at 1500 kPa (0.72) indicating yield influencing factors.

Rhizosphere Effect of Kharif Crops on Phosphatases and Dehydrogenase Activities in a Typic Haplustert

In recent years phosphorus crisis is emerging at global level, every country in the world searching for alternative sources and management options for increasing its supply and use efficiency. Increasing cost of cultivation due to phosphatic fertilizers, attracting our mind towards it. In this experiment it was focused on effect of major kharif crops (maize, soybean, sorghum, pearl millet, finger millet and rice) on phosphatases and dehydrogenase activities in soil at different crop growth periods (30, 50, 75, 90 days after sowing and at crop harvest). Acid phosphatase activity varied crop wise and also at different crop growth periods. The maximum acid phosphatase activities were observed at 75 DAT in rice (0.206 mg PNP/g h), 90 DAS in sorghum (0.194 mg PNP/g h) and pearl millet (0.201 mg PNP/g h), 50 DAS in soybean (0.127 mg PNP/g h), and 30 DAS in maize (0.154 mg PNP/g h) and, 50 DAS as well as 75 DAS in finger millet (0.180 mg PNP/g h), respectively. But alkaline phosphatase activities were maximum at 75 days after sowing in all the crops i.e. sorghum (0.533 mg PNP/g h), soybean (0.465 mg PNP/g h), rice (0.440 mg PNP/g h), maize (0.538 mg PNP/g h), pearl millet (0.546 mg PNP/g h) and finger millet (0.530 mg PNP/g h), respectively. The dehydrogenase activities were also higher in 75 days after sowing in all the crops. These enzyme activities associated with higher availability and uptake of phosphorus.

Influence of long term use of farmyard manure and inorganic fertilizer on grain yield and nutrient availability in vertisols under soyabean-safflower sequence cropping

Field experiment was conducted during 2007–08 and 2008–09 on Typic Haplustert to study the effect of inorganic fertilizers and farm yard manure (FYM) applied in combination or alone on productivity and nutrient availability in soil grown with soybean – safflower cropping system. Results showed significantly highest grain yield of soybean (28.4 q ha−1) and safflower (16.3 q ha−1) in the treatment receiving 150% NPK and it was at par with 100% NPK+ FYM. There was overall increase in the soil bacteria, actinomycetes and fungal population in treatment receiving FYM @ 10 Mg ha1 alone and decreased in treatment receiving 150% NPK. Balanced sheet of available N, P and K after harvest of 2nd cycle showed maximum buildup of soil nutrients in treatment 100% NPK + FYM @ 10 Mg ha−1 fallowed by 150% NPK.

Impact of zinc application on its translocation into various plant parts of wheat and its effect on chemical composition and quality of grain

A field experiment was conducted under All India Co-ordinated Research Project on “Micro, secondary nutrients and pollutant elements in soils and plants” during two consecutive years 2010-2011 and 2011-2012 with fallow-wheat cropping sequence on a Typic Haplustert at the Research Farm of Department of Soil Science and Agricultural Chemistry, J.N. Krishi Vishwa Vidyalaya, Jabalpur (M.P.) to study the influence of Zn application on its translocation into various plant parts of wheat and its impact on chemical composition and quality of grain. The recommended dose of N, P and K was applied at 120 N: 60 P2O5: 40 K2O kg ha-1 in combination with Zn at 0, 1.25, 2.5, 5, 10 and 20 kg ha-1 as zinc sulphate. The results revealed that the application of increasing levels of Zn at 5, 10 and 20 kg ha-1 significantly increased the Zn concentration in root, stem, leaves and earhead of wheat over NPK fertilization alone at different growth stages of wheat. The grain and straw yields as well as harvest index increased with the increasing levels of Zn as compared to NPK alone. The maximum pooled grain yield 4.66 t ha-1 was observed in the treatment 20 kg Zn ha-1, while the maximum pooled grain 3.88 t ha-1 in the control plots (100% NPK alone). The Zn, N and K contents in grain and straw of wheat significantly increased with the increasing levels of Zn at 2.5, 5, 10 and 20 kg ha-1. However, the P content in both grain and straw was in decreasing order with increasing levels of Zn. Further, the quality parameters like crude and true protein, wet gluten and total carbohydrate were also increased with increasing levels of Zn as compared to NPK alone. Thus, the present studies indicated that the application of 20 kg Zn ha-1 with 100% NPK on wheat crop enhanced the as well as maintained the quality of produce and its chemical composition. Key words: Zn application, translocation, chemical composition, quality, wheat, Typic Haplustert.

Microbial Biomass Carbon Status in Agro-Ecological Sub Regions of Black Soils in India

The present study was undertaken with an objective to study the impact of pedo-edaphic environments, cropping systems, land use, and management practices on the MBC. Soil samples were collected from seventeen benchmark soils representing different agro-ecological sub regions of black soil region of India. The pooled comparisons of MBC in different bio-climates indicated significant differences (p < 0.001) between the bio-climates. Significantly higher (p < 0.001) MBC was recorded in sub-humid dry bio-climate (267 μg g−1) followed by sub-humid moist and least in arid bio-climate (97.5 μg g−1). In cropping systems, legume-based system (205 μg g−1) had higher MBC. The lowest MBC was recorded in cotton-based system (128 μg g−1). In soil sub-groups, Halic Haplusterts showed higher MBC (209 μg g−1) followed by Typic Haplusterts (208 μg g−1), while the lowest MBC was observed in Gypsic Haplusterts (98.5 μg g−1). Significantly higher (p < 0.05) MBC was recorded in high management and irrigated agro-systems as compared with low management and rainfed agro-systems. The MBC content in the soil is significantly and positively correlated with organic carbon %, total culturable microbial population, nitrogen content, and available water content.

Analysis of Site Formation History and Potential Disturbance of Stratigraphic Context in Vertisols at the Debra L. Friedkin Archaeological Site in Central Texas, USA

Archaeological sites within physically “active” soils, such as Vertisols, are considered suspect by archaeologists because of concern for possible disturbance of stratigraphic context. Pedology, micromorphology, and geochemistry are tools useful for assessing soil mixing. Clay‐rich floodplain soils (Typic Haplusterts) were examined at the Debra L. Friedkin archaeological site along Buttermilk Creek in southwestern Bell County, Texas, USA. The soil contains abundant lithic (mainly chert) artifacts and was assessed for disturbance by vertic soil processes affecting the stratigraphic integrity of the archaeological materials. Vertic features are only weakly to moderately expressed (slickensides and coarse angular blocky peds) in the field, and they are correspondingly weakly expressed in thin section, consisting mainly of stress cutans around detrital grains, microslickensides, and cross‐striated birefringence fabric. Although there is evidence for clay shrink–swell, there has not been significant upward vertical displacement of older materials and no mixing of cultural horizons. Vertical fractures with dark infilling in gilgai microhighs are deep and narrow, and largely preclude downward movement of even small artifacts. Microdebitage is abundant in all levels within the soil profile above culturally sterile layers dated as &gt;15,500 cal. yr B.P. Based on previously published OSL ages and magnetic susceptibility, sedimentation at the site was nearly continuous except for increases during the Younger and Older Dryas, possibly triggered by climate change, and subsequent pedogenesis resulted in uniform element leaching and concentration depth profiles. Vertisols can preserve “undisturbed” Paleoindian archaeological sites and therefore should not be excluded from archaeological surveys and excavations.

Varietal Differences in Chlorosis and Yield of Sugarcane Grown on a Typic Haplustert

A field experiment was conducted to evaluate the resistance and susceptibility of twenty-four sugarcane varieties to iron chlorosis in an iron deficient soil (Typic Haplustert). Marked differences were observed among the investigated varieties in respect of their sensitivity to Fe chlorosis. Among the varieties, Co 8021, Co 86032, Co 86249, Co 94005 and Co 94012 recorded higher cane yield and were identified as most tolerant, and recommended for cultivation. Using resistant genotypes proved to be the most effective treatment in reducing chlorosis severity. Occurrence of the chlorosis was found to be associated with SPAD readings, chlorophyll content, and active Fe content of leaves, cane yield and sugar yield.

Accumulation and Mobility of Salts in Soil as Influenced by Primary Biomethanated Spentwash

A soil column laboratory experiment was carried out at the central campus, Mahatma Phule Agricultural University, Rahuri, India during 2008–2009 to study the accumulation and mobility of salts in Typic Haplusterts as influenced by primary biomethanated spentwash (PBSW). The PBSW was applied in three different levels (0.5, 1.0, and 2.5 cm) and then tap water with low salinity and low sodium hazard (C1S1 class) was used to carry out leaching in four different levels of water at the pore volume of soil (WPVS) (0.5, 1.0, 1.5, and 2.0). The electrical conductivity (EC) in the soil increased significantly with increasing levels of PBSW and decreased with increasing levels of WPVS in surface (0–15 cm deep) and subsurface (15–30 cm deep) soil layers. The exchangeable calcium (Ca2+), magnesium (Mg2+), and potassium (K+) increased, whereas exchangeable sodium (Na+) decreased with increasing levels of PBSW and WPVS in surface and subsurface layers of soil. The organic carbon content increased with increasing levels of PBSW and decreased with increasing levels of WPVS in both the soil layers. The cation exchange capacity (CEC) increased with increasing levels of PBSW and WPVS in both the soil layers. The exchangeable sodium percentage (ESP) decreased with increasing levels of PBSW and WPVS over the initial values of soil in both the layers. The pH of saturated paste (pHs) was reduced and electrical conductivity of extract (ECe) was increased with increasing levels of PBSW and WPVS in both the layers. The Na+ content of saturation paste extract increased significantly with increasing levels of PBSW and WPVS in both the soil layers.

Terrain Characterization for Soil Resource Mapping Using IRS-P6 Data and GIS - A Case Study From Basaltic Terrain of Central India

In the present study, landforms and soils have been characterized in Borgaon Manju watershed of basaltic terrain located in Akola district, Maharashtra, Central India. Terrain characterization using Shuttle Radar Topography Mission (SRTM) elevation data (90 m) and IRS-P6 LISS IV data in conjunction with adequate field surveys shows nine distinct landforms. Soil resource inventory shows fourteen soil series in the study area. Soils formed on gently sloping (3–8 %) subdued plateau are very shallow (23 cm), moderately well drained, moderate (15–40 %) surface stoniness, severely eroded, clayey and slightly alkaline in reaction, whereas, the soils formed on level to nearly level (0–1 %) slope in the main valley are very deep (>150 cm), well drained, very slight (<3 %) surface stoniness, moderately eroded with clayey surface and moderately alkaline in reaction. Soils in the watershed are grouped into Lithic Ustorthents, Vertic Haplustepts, Calcic Haplustepts, Typic Haplustepts, Typic Haplusterts and Sodic Calciusterts. The study demonstrates that the analysis of SRTM elevation data and IRS P6–IV data in Geographic Information System (GIS) with adequate field surveys helps in characterization of landforms and soils in analysis of landscape-soil relationship.

Phytoaccumulation of Lead by Selected Wetland Plant Species

Several anthropogenic activities lead to the production of substantial amounts of aqueous effluents that contain various toxic trace and heavy metals and which pose potential threats to the wild habitat of wetlands. As a part of the remediation of heavy metals, it is necessary to identify some aquatic hyperaccumulator plants. To this end, a greenhouse study was conducted to investigate the phytotoxicity resulting from lead (Pb) and its accumulation in selected plant species. Lead was added from low to very high levels in a swell–shrink clayey soil (Typic Haplustert). Seven levels of Pb (0, 50, 100 200, 400, 600, and 800 mg kg–1 soil) were applied. Typha angustifolia L. of Typhaceae and Behaya plant (Ipomoea carnea L.) of the Convolvulaceae family were taken as test plants. Lead was added at high and low concentrations to determine whether an increase in concentration would Pb to an increased toxicity to the plants. Recorded weight of the Typha crop was reduced (6%) at 600 mg Pb kg–1 soil, and at greater doses of Pb, the dry-matter yield was inhibited considerably. In the case of Ipomoea, no growth retardation from Pb was observed. Most Pb accumulated in roots and then was transported to shoots. The Typha angustifolia L. and Ipomoea carnea L. plants show promise for the removal of Pb from contaminated wastewater because they can accumulate high concentrations of Pb in roots (1200 and 1500 mg Pb kg–1 respectively) and shoots (275 and 425 mg Pb kg–1 respectively). Lead uptake by both the plants increased with the increasing doses of Pb (50 to 800 mg kg–1 soil). Physiological parameters such as photosynthesis, respiration, chlorophyll content, and different enzyme activities including nitrate reductase (NR), peroxidase (POD), and succinate dehydrogenase (SD) were also studied for the evaluation of these plant species. In Typha plants, at greater doses of Pb, the rate of photosynthesis and chlorophyll content decreased whereas POD and SD activities increased to combat oxidative stress.

Suitability of a hydraulic‐conductivity model for predicting salt effects on swelling soils

AbstractMany empirical approaches have been developed to analyze changes in hydraulic conductivity due to concentration and composition of equilibrium solution. However, in swelling soils these approaches fail to perform satisfactorily, mainly due to the complex nature of clay minerals and soil–water interactions. The present study describes the changes in hydraulic conductivity of clay (Typic Haplustert) and clay‐loam (Vertic Haplustept) soils with change in electrolyte concentration (TEC) and sodium‐adsorption ratio (SAR) of equilibrium solution and assesses the suitability of a model developed by Russo and Bresler (1977) to describe the effects of mixed Na‐Ca‐Mg solutions on hydraulic conductivity. Four solutions encompassing two TEC levels viz., 5 and 50 mmolc L–1 and two SAR levels viz., 2.5 and 30 mmol1/2 L–1/2 were synthesized to equilibrate the soil samples using pure chloride salts of Ca, Mg, and Na at Ca : Mg = 2:1. Diluting 50 mmolc L–1 solution to 5 mmolc L–1 reduced saturated hydraulic conductivity of both soils by 66%, and increasing SAR from 2.5 to 30 mmol1/2 L–1/2 decreased saturated hydraulic conductivity by 82% and 79% in clay and clay‐loam soils, respectively. Near saturation, the magnitude of the change in unsaturated hydraulic conductivity due to the change in TEC and SAR was of 103‐ and 102‐fold, and at volumetric water content of 0.20 cm3 cm–3, it was of 1014‐ and 106‐fold in clay and clay‐loam soils, respectively. Differences between experimental and predicted values of saturated hydraulic conductivity ranged between 0.6% and 11% in clay and between 0.06% and 2.1% in clay‐loam soils. Difference between experimental and predicted values of unsaturated hydraulic conductivity widened with drying in both soils. Predicted values were in good agreement with the experimental values of hydraulic conductivity in clay and clay‐loam soils with R2 values of 0.98 and 0.94, respectively. The model can be satisfactorily used to describe salt effects on hydraulic conductivity of swelling soils in arid and semiarid areas, where groundwater quality is poor.

Respuesta de tomate (Solanum lycopersicum L.) a la fertilización con nitrógeno y aplicación de composta.

Por tres años se evaluaron los efectos de composta producida a partir de residuos vegetales y biosólidos, y de nitrógeno inorgánico en el crecimiento, rendimiento y calidad de fruta de tomate en las Subestaciones de Lajas (Typic Haplusterts) y Juana Díaz (Cumulic Haplustolls) (Subestación de Fortuna), Puerto Rico. En Fortuna, la aplicación de 50 t/ha aumentó el rendimiento sobre suelo sin enmendar pero una segunda aplicación de 50 y 100 t/ha redujo los rendimientos. No hubo un efecto residual de la composta en el tercer año. Los niveles de fertilización no incrementaron significativamente los rendimientos excepto en el tercer año, cuando los mayores rendimientos se obtuvieron con la aplicación de 75 kg N/ha en forma de fertilizante inorgánico. En Lajas, hubo respuesta a la fertilización inicial en uno de los dos sitios-años. La adición de composta no mejoró los rendimientos ni los componentes agronómicos del tomate. El uso del medidor de clorofila SPAD puede ser útil para la producción de tomate cultivado en bancos elevados, con plástico y riego por goteo porque los valores máximos de SPAD coincidieron con los mayores rendimientos obtenidos. La medida sirvió para evaluar el efecto de los tratamientos, aunque los resultados dependen de la variedad o híbrido utilizado. El nivel óptimo económico obtenido fue poco sensitivo a los precios de fertilizante y tomate seleccionado. El nivel óptimo de fertilización de N para obtener el 99% de rendimiento máximo fue 143 kg N/ha en áreas que recibieron aplicaciones iniciales de N en Lajas, y 165 kg N/ha en áreas con más de un año bajo el cultivo de tomate en Fortuna, con rendimientos cerca de 54 t/ha.

Potassium Indexing of Crops Grown on Eight Benchmark Soil Series of India

Surface soil (0–15 cm) and foliar samples of wheat, rice, sugarcane, and cotton crops growing in eight intensively cultivated soil series of India were collected from farmers' fields during 2004 and 2005. Analysis of soil and leaf samples indicated widespread potassium (K) deficiency in soils and crops. Potassium deficiency in wheat growing in Lukhi series (Udic Ustocrept) and Akbarpur series (Udic Haplustulf) and in cotton growing in Typic Torrifluvent were comparable to 1N ammonium acetate (NH4OAc)–K (available K) soil test values. Rice cultivated on Udic Ustocrept soils in summer monsoon season showed relatively less K deficiency in comparison to winter wheat, and K deficiency in growing rice did not match 1N NH4OAc‐K soil test values. In the Khatki series, K deficiency in sugarcane was much less than 1N NH4OAc‐K soil test values. In the Arsia series (Typic Haplustert), despite the high 1N NH4OAc‐K status of soils, K deficiency in growing wheat was observed.

Vertisols (cracking clay soils) in a climosequence of Peninsular India: Evidence for Holocene climate changes

Smectitic parent material from the weathering Deccan basalt has been deposited in the lower piedmont plains, valleys and microdepressions during a previous wetter climate. The cracking clay soils (Vertisols) were developed in such alluvium during drier climate of the Holocene period. In India they occur in humid tropical (HT), sub-humid moist (SHM), sub-humid dry (SHD), semi-arid moist (SAM), semi-arid dry (SAD) and arid dry (AD) climatic environments and thus indicate an array of soils in a climosequence. The soils show a change in their morphological, physical, chemical and micromorphological properties in the climosequence. Soils of HT climate are dominated by Ca ++ ions in their exchange complex throughout depth. However, in the sub-humid climates Mg ++ ions tend to dominate in the lower horizons. The sub-humid moist to aridic climatic environments caused a progressive formation of pedogenic calcium carbonates (PC) with the concomitant increase in Na + ions in soil solution. This facilitated the translocation of Na-clay in the soil profile. This is responsible for the increase in pH, decrease in Ca/Mg ratio of exchange sites with depth and finally in the development of subsoil sodicity. The reduction in mean annual rainfall (MAR) from sub-humid moist to arid climates accelerated the formation of PC and thus the soils of semi-arid and arid climates (SAM, SAD and AD) are more calcareous and sodic than soils of other climates (SHM and SHD). Formation of PC, illuviation of clay and the development of subsoil sodicity are concurrent, contemporary and active pedogenetic processes operating during the climate change of the Holocene period. These processes impaired the hydraulic properties of soils in general, and in soils of drier climates in particular. As a result, cracking pattern, chemical composition and plasmic fabric were more modified in soils of the drier climates. Such modifications in soil properties have a place in the rationale of Vertisol order of the US Soil Taxonomy. The soils of wetter climates (HT, SHM and SHD) are grouped in Typic Haplusterts whereas the soils of drier climates (SAM, SAD and AD) are classified as Aridic Haplusterts, Sodic Haplusterts and Sodic Calciusterts. The present study demonstrates how the intrinsic soil properties of the cracking clay soils in a climosequence may help in inferring the change in climate in a geologic period.

DRIS Norms and their Field Validation in Nagpur Mandarin

ABSTRACT Diagnosis and recommendation integrated system (DRIS) norms were computed from the data on leaf mineral composition, soil available nutrients, and corresponding mean fruit yield of three years (1999–2002), collected from the set of 57 irrigated commercial ‘Nagpur’ mandarin (budded on Citrus jambhiri Lush) orchards, representing 26 locations and 3 basalt derived soil orders (Entisols, Inceptisols, and Vertisols) rich in smectite minerals. The DRIS norms derived primarily from spring-cycle index leaves from non-fruiting terminals sampled during August to October (6–8 months old) suggested optimum leaf macronutrient concentration (%) as: 1.70–2.81 nitrogen (N), 0.09–0.15 phosphorus (P), 1.02–2.59 potassium (K), 1.80–3.28 calcium (Ca), and 0.43–0.92 magnesium (Mg). While, optimum level of micronutrients (ppm) was determined as: 74.9–113.4 iron (Fe), 54.8–84.6 manganese (Mn), 9.8–17.6 copper (Cu), and 13.6–29.6 zinc (Zn) in relation to fruit yield of 47.7–117.2 kg tree− 1. Likewise, DRIS indices for soil fertility developed from dripline soil samples collected at 0–20 cm depth corresponding to similar level of fruit yield, the optimum limit of soil available nutrients (mg kg− 1) was observed as: 94.8–154.8 N, 6.6–15.9 P, 146.6–311.9 K, 401.0–601.6 Ca, 85.2–369.6 Mg, 10.9–25.2 Fe, 7.5–23.2 Mn, 2.5–5.1 Cu, and 0.59–1.26 Zn. Primary DRIS indices developed on the basis of leaf and soil analysis revealed deficiency of N, P, K, Fe, and Zn. The nutrient constraints so diagnosed were further verified through fertilizer response studies carried out on a representative Typic Haplustert soil type facing multiple nutrient deficiencies, and accordingly suggested the revised fertilizer schedule.

Uptake of nitrogen, phosphorus and potassium by some promising mid late maturing sugarcane clones

A field experiment was conducted at the ECC farm of Sugarcane Breeding Institute, Coimbatore during 1999–2000 to evaluate promising mid late maturing sugarcane clones for nutrient use efficiency. Twelve clones including three standards were planted in a clay soil (Typic Haplustert). Nitrogen, phosphorus and potassium contents were estimated in dry leaves, green tops and stem on dry weight basis and their uptake in different parts was calculated. Total nutrient uptake and uptake per tonne of cane were also computed. Significant clonal variations in N, P and K uptake by various plant parts viz., dry leaves, green tops and stem, total uptake in above ground parts and uptake per tonne of cane (physiological use efficiency). Total N uptake ranged from 88.55 kg/ha in CoTl 93116 to 148.52 kg/ha in Co 7219. The lowest uptake of 0.88 kg N per tonne of cane was recorded in Co 86032 and the highest uptake of 1.47 kg/tonne of cane was registered in Co 93018. Clones identified for better N use efficiency were Co 94011, Co 94015 and CoTl 93116. Total P uptake by above ground parts ranged from 34.95 kg/ha in CoTl 93116 to 57.97 kg/ha in Co 7219. The uptake of phosphorus per tonne of cane ranged from 0.34 kg in Co 94012 to 0.56 in Co 93018 with a mean of 0.48 kg. Clones Co 94012, Co 94016, Co 94015, Co 94009 and CoTl 93116 were identified for better P use efficiency. The total K uptake in above ground parts varied from 108.55 kg/ha (CoTl 93116) to 305.98 kg/ha (Co 7219) with a mean of 210.25 kg/ha. The K uptake per tonne of cane ranged from 1.44 kg in CoTl 93116 to 2.91 kg in Co 7219 with a mean of 2.09 kg. Clones identified for better potassium use efficiency were CoTl 93116, Co 93018 and Co 94012. Co 86032 was found superior among the standards in nutrient use efficiency.

Morphology, physico-chemical properties and classification of some vertisols of Jabalpur, Madhya Pradesh

There Vertisol pedons in Jabalpur district, were morphologically studied, characterized and classified. The soils are very deep, colour ranges from dark brown (10YR3/1) to very dark grey (10YR4/3) in different horizons. The texture of deep soils clay of all pedons throughout the profile. Crack of 2-3 cm wide extends beyond one meter. Slickensides, wedge shaped aggregates, Fe Mn, and calcrets are observed in all this soils pedons. The soils are imperfectly drained. The soils are calcareous and pH ranged form neutral to mildly alkaline. The organic carbon content in these soils were low to medium in surface and that too decreased with depth. Effervescence was observed in all the soils pedons in lower horizons. The soils are base rich and high in CEC: clay ratio (0.60 to 0.93) and are classified as Typic Haplusterts.

Changes in soil physical properties and organic carbon status at the topsoil horizon of a vertisol of central India after 28 years of continuous cropping, fertilization and manuring

Abstract Balanced application of inorganic fertilizer and organic amendments greatly influence the accumulation of organic matter in soil and also influence the soil physical environment. An investigation was carried out to study the long-term impact of fertilizer and manure application in a soybean–wheat–maize (fodder) crop rotation on soil organic carbon status and physical properties of a vertisol (Typic Haplustert or Pellic Vertisols) in sub-humid sub-tropical India. Five treatments namely, control (no fertilizer and manure), 100% of the optimum rate for nitrogen (100% N), 50% of the optimum rate for nitrogen, phosphorus and potassium (50% NPK), 100% of the optimum rate for NPK (100% NPK) and 100% NPK + farmyard manure at 15 Mg ha −1 (100% NPK + FYM) from a long-term fertilizer experiment continuing at Jabalpur, India, were chosen for this study. Soil samples were collected from the topsoil horizon (0–15 cm) of all the four replications of the selected five treatments in April 2000 after 28 crop cycles and analyzed for physical and chemical properties. The results showed that the soil organic carbon (SOC) content in 100% NPK and 100% NPK + FYM treatments increased, respectively, by 22.5 and 56.3% over the initial level (1.14 kg m −2 ). The electrical conductivity, SOC content, aggregation, water retention, microporosity and available water capacity of the soil were increased while the bulk density was reduced significantly with the 100% NPK + FYM treatment over all other treatments. However, the use of imbalanced (100% N) and suboptimal rate of inorganic fertilizer (50% NPK) as compared to the unfertilized control showed no significant effect on the physical properties of the soil. The study indicates that application of balanced rate of fertilizers in combination with organic manure could sequester soil organic carbon in the surface layer, improve the soil physical environment and sustain higher crop productivity under this intensive cropping system.

Salinity appraisal using IRS images in Shorapur Taluka, Upper Krishna Irrigation Project, Phase I, Gulbarga District, Karnataka, India

Shorapur Taluka, located between 76°15′ and 76°56′ E longitudes and 16°10′ and 16°35′ N latitudes, was the first area to receive irrigation waters from the Krishna left bank canal under the Upper Krishna Irrigation Project in the district of Gulbarga, in the state of Karnataka, India. The soils in Shorapur are extensively affected by the problems of salinity and water logging. Images from IRS ID LISS‐III for 27 March 1999 were interpreted to assess the extent to which salt‐affected soils could be identified and inventoried and mapped. It was found that salinization occurs especially in the valleys and on lower slopes as well as on side slopes of the low granitic hills covered with red soils. Electrical conductivity (EC) and pH could not be related to the DN values on the images and therefore into mapping classes due to the wide variation in the field. Using an accuracy assessment carried out to assess the supervised classification it was possible to identify the severely affected saline‐alkali soils with the greatest accuracy (85% accuracy). Severely affected alkali soils could be identified with 52% accuracy. The other classes identified were not significantly accurate. Based on image characteristics and ground data, salt‐affected soils were designated with classes based on severity as moderately affected, severely to moderately affected, and severely affected in terms of area affected as under <40% affected, 40–75% affected and >75% affected and the brightness on the imagery. The total salt‐affected area surveyed was 21 094 ha, of which severely salt‐affected lands were 33%, severely to moderately affected were 40%, and moderately affected were 27%, respectively and belong to the great groups Sodic Calciusterts, Halic Calciusterts, Aquic Haplustepts, Sodic Haplusterts, Typic Haplusterts and Fluventic Haplusterts. The total area covered and surveyed was approximately 0.12 million ha..