B. D. Sharma

Relationships Between Soil Characteristics and Total and DTPA-Extractable Micronutrients in Inceptisols of Punjab

Abstract During the last three decades agricultural production in Punjab has increased manifolds. These gains in productivity have been confined to the Inceptisols, which cover about 60% of the geographical area of the state. An investigation was carried out to study surface and profile distribution of total and diethylenetriamine pentaacetic acid (DTPA)-extractable micronutrients zinc (Zn), copper (Cu), manganese (Mn), and iron (Fe)] and their relationships with soil properties in nine different sub group of Inceptisols developed in Siwalik and alluvial plains of northwest India. The total contents varied from 39 to 99 mg kg−1 for Zn, 16 to 47 mg kg−1 for Cu, 2.04 to 4.54% for Fe, and 262 to 805 mg kg−1 for Mn. DTPA-extractable contents varied from 0.08 to 1.28 mg kg−1 for Zn, 0.20 to 2.36 mg kg−1 for Cu, 0.91 to 32.0 mg kg−1 for Fe and 1.50 to 43.8 mg kg−1 for Mn. These micronutrients are higher in the fine fractions than in the coarse fraction. The content of total Cu, Fe, and Mn followed the patterns of accumulation, eluviation, and illuviation. Distribution of micronutrients with depth in these soils indicates that parent material and geomorphic and physicochemical processes control total content, and biological processes affect DTPA-extractable content. The total content of micronutrients increased with an increase in clay and silt and cation exchange capacity (CEC), whereas DTPA-extractable micronutrient increased with an increase in organic carbon content and CEC, and decreased with increasing pH, sand and calcium carbonate content. The total reserves of Zn and Cu showed an influence on availability of these respective micronutrients. The available micronutrient contents depended largely on the organic carbon content. The correlation between total amounts of Cu, Fe, and Mn suggested that they occurred together. Among the various micronutrients, deficiency of Zn was widespread followed by Fe in the intensively cultivated Inceptisols.

Distribution of total and DTPA-extractable zinc, copper, manganese, and Iron in vertisols of India

Abstract Vertisols of India are developed over isohyets of 600 to 1500 mm, and their chemical cycles are set by drainage, landforms, and particle size, which results in variable pedogenic development within the otherwise homogeneous soils. The purpose of this study was to identify pedogenic processes in the distribution of total and DTPA‐extractable zinc (Zn), copper (Cu), manganese (Mn), and iron (Fe). The soils are developed over basaltic parent material of Cretaceous age. Soil samples were drawn from genetic horizons of the 13 benchmark profiles and analyzed by using HF–HClO4 acid for total and DTPA extraction. Correlation coefficients were calculated taking all samples together. The total concentration varied from 24 to 102 mg kg−1 for Zn, 21 to 148 mg kg−1 for Cu, 387 to 1396 mg kg−1 for Mn, and 2.36 to 9.50% for Fe. Their variability was proisotropic and haplodized, and their concentrations increased with advancing isohyets. Within the isohyets, hindrance in drainage caused retention of Zn and Cu but loss of Fe. The piedmont soils had more Fe than alluvium soils. The spatial distribution of total contents of Zn, Cu, and Fe was influenced by the pedogenic processes associated with Haplusterts but not with provenance materials. Surface concentrations of the elements by biotic lifting and/or harvest removal were negated by the pedoturbation that further contributed to the irregular distribution of the elements in the profiles. Total Zn and total Cu had positive coefficients of correlations with coarse clay, whereas total Mn and total Fe were positively correlated with fine clay. The DTPA‐extractable forms were functions of isohyets and drainage and showed association with organic carbon content and coarse clay.

Distribution of Forms of Zinc and Their Association with Soil Properties and Uptake in Different Soil Orders in Semi‐arid Soils of Punjab, India

Abstract Profiles of semi‐arid–zone soils in Punjab, northwest India, were investigated for different forms of zinc (Zn), including total, diethylenetriamine penta‐acetic acid (DTPA)-extractable, soil solution plus exchangeable (Zn), Zn adsorbed onto inorganic sites, Zn bound by organic sites, and Zn adsorbed onto oxide surfaces. Irrespective of the different fractions of Zn present, its content was higher in fine‐textured Alfisols and Inceptisols than in coarse‐textured Entisols. In general, the higher content of Zn was observed in the surface horizon and then decreased in the subsurface horizons. However, none of the forms of Zn exhibited any consistent pattern of distribution. Organic matter and size fractions (clay and silt) had a strong influence on the distribution of different forms of Zn. Based upon the linear coefficient of correlation, the soil solution plus exchangeable Zn, adsorbed onto inorganic sites, and DTPA‐Zn increased with increase in organic carbon but decreased with increase in pH and calcium carbonate content. Total Zn increased with increase in clay and silt content. Among the different forms, Zn bound by organic sites, water soluble plus exchangeable Zn and Zn adsorb onto oxide (amorphous surfaces) were all correlated with DTPA extractable Zn. The uptake of Zn was more in recent floodplain Entisols than very fine textured Alfisols and Inceptisols. Among the different forms soil solution +exchangeable and DTPA‐extractable Zn was positively correlated with total uptake of Zn.

Forms of Iron and Their Association with Soil Properties in Four Soil Taxonomic Orders of Arid and Semi-arid Soils of Punjab, India

Profiles of arid and semi‐arid zones soils of Punjab, northwestern India, were investigated for different forms of iron (Fe): total Fe, diethylenetriamine penta‐acetic acid (DTPA)–extractable Fe, soil solution plus exchangeable Fe, Fe adsorbed onto inorganic sites and oxide surfaces, and Fe bound by organic sites. Irrespective of the different fractions of Fe present, its content was higher in the fine‐textured Alfisols and Inceptisols than in the coarse‐textured Entisols and Aridisols. Lower content of total Fe was observed in the surface horizon and then increased in the subsurface horizons, whereas no set pattern was observed in Entisols. Also, irrespective of the soil orders, the contents of different forms of Fe were higher in the surface horizon and then decreased by depth. None of the forms of Fe exhibited any consistent pattern of distribution. Organic matter and the content of clay and silt fractions had a strong bearing on the distribution of forms of Fe. Based on a linear coefficient of correlation, the soil solution plus exchangeable Fe adsorbed onto inorganic sites and DTPA‐extractable Fe increased with increase in soil organic carbon but decreased with increase in soil pH and calcium carbonate content. Total Fe increased with increase in cation exchange capacity (CEC) and clay and silt content. The results also revealed that there was equilibrium in different fractions of this element. Among the different Fe forms, Fe bound by organic sites, water‐soluble plus exchangeable Fe, and Fe adsorbed onto oxides (amorphous surfaces) were positively correlated with the DTPA‐extractable Fe. Though some forms are interrelated, none of the forms had any relationship with the total Fe.

Effect of Continuous Rice–Wheat Rotation on Soil Properties from Four Agro‐ecosystems of Indian Punjab

In Indian Punjab, rice–wheat is a dominant cropping system in four agro‐ecosystems, namely undulating subregion (zone 1), Piedmont alluvial plains (zone 2), central alluvial plains (zone 3), and southwestern alluvial plains (zone 4), varying in rainfall and temperature. Static and temporal variabilities in soil physical and chemical properties prevail because of alluvial parent material, management/tillage operations, and duration of rice–wheat rotation. A detailed survey was undertaken to study the long‐term effect of rice–wheat rotation on soil physical (soil separates, bulk density, modulus of rupture, saturated and unsaturated hydraulic conductivities, soil water content, and suction relations) and chemical (organic carbon, pH, electrical conductivity) properties of different textured soils (sandy clay loam, loam, clay loam, and silty clay loam) in these four zones of Punjab. Soil samples (of 0‐ to 30‐cm depth) from 45 sites were collected during 2006 and were analyzed for physical and chemical properties. The results showed that sand content and pH increased whereas silt and organic carbon decreased significantly from zones 1 to 4. Compared to other textures, significantly greater organic carbon, modulus of rupture, and pH in silty clay loam; greater bulk density in clay loam, and greater saturated hydraulic conductivity in sandy clay loam were observed. Irrespective of zone and soil texture, in the subsurface soil, there was a hard pan at 15–22.5 cm deep, which had high soil bulk density, modulus of rupture, more silt and clay contents (by 3–5%) and less organic carbon and hydraulic conductivity than the surface (0–15 cm) layer. These properties deteriorated with fineness of the soil texture and less organic carbon content. Continuous rice–wheat cropping had a deleterious effect on many soil properties. Many of these soils would benefit from the addition of organic matter, and crop yields may also be affected by the distinct hardpan that exists between 15 and 22.5 cm deep.

Association of soil properties and soil and plant iron to iron deficiency response in rice (Oryza sativa L.)

Abstract Problems are invariably encountered when attempts are made to explain the variability in Bray percent yields or plant response in terms of soil or plant iron (Fe). To resolve this inconsistency, the present investigation was initiated to identify a combination of soil extractable Fe, soil properties and form of plant Fe that may be used as a measure of Fe deficiency. The study involved 16 diverse soils, using upland rice (Oryza sativa L.) as the test crop and Fe‐EDDHA [ferric ethylenediamine di (o‐hydroxyl‐phenyl acetic acid)] as source of Fe. The results showed that Bray percent yields were neither related to DTPA (diethylenetriamine pentaacetic acid) or EDTA (ethylenediamine tetraacetic acid) extractable Fe nor with total plant Fe. Even the inclusion of pH, lime, organic carbon and clay data in the regression equations was of no value. However, Bray percent yields were significantly and positively (r = 0.57* ) associated with ferrous Fe (Fe2+) in 40‐day‐old rice plants. The explanation concerni...

Distribution of different forms of Mn and their association with soil properties in arid zone soils of Punjab, India

Six pedons from arid zones soils of Punjab, north western India, were investigated for different forms of manganese (Mn): total Mn, diethylenetriamine penta-acetic acid (DTPA)-extractable Mn, soil solution plus exchangeable Mn, adsorbed Mn onto inorganic sites, and oxide surfaces, and Mn bound by organic sites. Total Mn content ranged from 241–517 mg kg−1, DTPA-extractable Mn content ranged from 1.40–4.52 mg kg−1, soil solution plus exchangeable Mn content ranged from 0.04–0.30 mg kg−1, Mn adsorbed onto inorganic sites ranged from 34–109 mg kg−1, and that onto oxide surfaces ranged from 28–173 mg kg−1. The Mn bound by organic sites ranged from 14–56 mg kg−1. The forms of Mn did not exhibit any consistent pattern of distribution. Irrespective of the different fractions of Mn their content was higher in the fine textured soils as compared to the coarse textured soils. The soil solution plus exchangeable Mn held onto organic site and oxide surface (amorphous) increased with increase in organic carbon, silt and clay contents. The Mn adsorbed onto inorganic site (crystalline) increased with only silt and clay content. The DTPA-Mn increased with increase in organic carbon content, whereas Mn adsorbed onto oxide surfaces increased with an increase in organic carbon, silt and clay. However, both these fractions decreased with an increase in calcium carbonate and pH. Total Mn was strongly correlated with organic carbon, silt and clay content of soil. Among the forms, Mn held on the organic site, water soluble + exchangeable and Mn adsorbed onto oxide surface were positively correlated with DTPA-extractable Mn. DTPA-extractable Mn and soil solution plus exchangeable Mn seem to be good indices of Mn availability in soils and are helpful for correction of Mn deficiency in the soils of the region.

Micronutrients distribution in salt-affected soils of the Punjab in relation to soil properties

Salt-affected soils in arid and semi-arid tracts of the Indian Punjab are prone to deficiency of micronutrients. Nine profiles from alluvial terraces, sand dunes and palaeochannels in the southwestern Punjab were investigated for total and diethylenetriamine-penta-acetic acid (DTPA) extractable Zn, Cu, Mn and Fe. Soil physiography exerted significant influence on the spatial distribution of micronutrients. Total contents varied from 20–78 for Zn, 8–32 for Cu, and 88–466 mg kg−1 for Mn and 0.82–2.53% for Fe. DTPA-extractable contents varied from 0.10–0.98 for Zn, 0.14–1.02 for Cu, 0.54–13.02 for Fe and 0.82–9.4 mg kg−1 for Mn. Total contents were higher in fine-textured soil than in coarse-textured soils. Concentration of micronutrients in the surface layer was low and there occurred more accumulation in the Cambic horizon. Organic carbon, pH, clay, silt and calcium carbonate exerted strong influence on the distribution of micronutrients. DTPA extractable Zn, Cu, Mn and Fe increased with increasing organic carbon but decreased with increase in pH and calcium carbonate content. Total micronutrient contents increased with increase in clay, silt and calcium carbonate contents and decreased with increase in sand content.

Zinc Adsorption as Affected by Concentration, Temperature, and Time of Contact in the Presence of Electrolytic and Aqueous Medium in Benchmark Soils of Punjab in Northwest India

Adsorption of zinc (Zn) ions by soil colloids is significant because of its greater adsorbing surface, thus making it an important process in controlling Zn availability to plants. The adsorption processes depend upon a number of factors including temperature, pH, time of contact, clay content, and calcium carbonate content. Therefore, adsorption behavior of Zn was studied for eight benchmark soils of Punjab in northwestern India, varying widely in physical and chemical characteristics. The adsorption of Zn was studied at varying Zn concentrations, temperatures, and time of contact in the presence of 0.01 M sodium sulfate (Na2SO4) electrolyte and in aqueous medium. The greatest amount of Zn adsorbed in the presence of electrolyte and in aqueous medium (deionized water) was in arid series (Gahri Bhagi, Jassipauwali), followed by semi-arid series (Fatehpur, Kanjli) and subhumid series (Dhar, Chamror). The results revealed that irrespective of the soils, Zn adsorption increased with an increase in Zn concentration and decreased with an increase in temperature from 25 oC to 35 oC. Zinc adsorption was found to be greater in 0.01 M Na2SO4 solution as compared to aqueous medium. Further adsorption of Zn increased with increase in time of contact. The Zn adsorption data was well fitted to the Langmuir and Freundlich adsorption equations. The values of distribution coefficient Kd and partial molar free energy change ( ) were greater in the presence of 0.01 M Na2SO4 as compared to aqueous medium, suggesting that greater driving force is involved in adsorption of Zn in the presence of 0.01 M Na2SO4 as compared to aqueous medium.

Forms and Uptake of Manganese in Relation to Soil Taxonomic Orders in Alluvial Soils of Punjab, India

ABSTRACT Different forms of manganese (Mn) were investigated, including total, diethylenetriamine penta-acetic acid (DTPA) extractable, soil solution plus exchangeable (Mn), Mn adsorbed onto inorganic sites, Mn bound by organic sites, and Mn adsorbed onto oxide surfaces, from four soil taxonomic orders in northwestern India. The total Mn content was 200–950 mg kg−1, DTPA-extractable Mn content was 0.60–5.80 mg kg−1, soil solution plus exchangeable Mn content was 0.02–0.80 mg kg−1, Mn adsorbed onto inorganic sites was 2.46–90 mg kg−1, and Mc adsorbed onto oxide surfaces was 6.0–225.0 mg kg−1. Irrespective of the different fractions of Mn their content was generally greater in the fine-textured Alfisols and Inceptisols than in coarse-textured Entisols and Aridisols. The proportion of the Mn fractions extracted from the soil was in the order as follows: Adsorbed onto oxide surfaces > adsorbed onto inorganic site > organically bound > DTPA > soil solution + exchangeable. Based on coefficient of correlation, the soil solution plus exchangeable Mn, held onto organic site and oxide surface (amorphous) and DTPA-extractable Mn, increased with increase in organic carbon of the soil. The two forms, adsorbed onto inorganic site (crystalline) and DTPA extractable, along with organic carbon, increased with increase in clay content of the soil. DTPA-Mn and Mn adsorbed onto oxide surfaces and held on organic site decreased with increased with an increase in calcium carbonate and pH. Total Mn was strongly correlated with organic carbon and clay content of soil. Among the forms, Mn held on the organic site, water soluble + exchangeable and adsorbed onto oxide surface were positively correlated with DTPA-extractable Mn. DTPA-extractable Mn seems to be a good index of Mn availability in soils and this form is helpful for correction of Mn deficiency in the soils of the region. The uptake of Mn was greater in fine-textured Inceptisols and Alfisols than in coarse-textured Entisols and Aridisols. Among the different forms only DTPA-extractable Mn was positively correlated with total uptake of Mn. Among soil properties Mn uptake was only significantly affected by pH of the soil.