An Asian Journal of Soil Science Volume 7 Issue 1 June,

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1 An Asian Journal of Soil Science Volume 7 Issue 1 June, 2012 Research Article Distribution of DTPA-extractable and total micronutrients in association with properties of some reclaimed salt affected soils of southwest Punjab, India JAGMOHAN SINGH AND N.S. DHALIWAL MEMBERS OF RESEARCH FORUM : Corresponding author : JAGMOHAN SINGH, Krishi Vigyan Kendra (P.A.U.), MUKTSAR (PUNJAB) INDIA jagmohanpau@gmail.com Co-authors': N.S. DHALIWAL, Krishi Vigyan Kendra (P.A.U.), MUKTSAR (PUNJAB) INDIA Received : ; Revised : ; Accepted : Summary An investigation was carried out to study surface and profile distribution of total and diethylenetriamine penta acetic acid (DTPA) - extractable zinc, copper, manganese and iron in some reclaimed salt affected soils of southwest Punjab. The Southwestern zone of Punjab is deficient in available micronutrients, but has large reserve of micronutrients. These soils were originally salt affected and were found in relatively low-lying terraces at varying stages of deterioration. During the last years, these soils have been reclaimed by the application of gypsum followed by heavy irrigation (flooding) to leach down soluble salts from the solum. In order to study DTPA-extractable and total micronutrients and their association with soil properties, four pedons representing different categories of reclaimed salt affected soils were taken from the Southwest Punjab. Total and DTPA-extractable micronutrients were higher in surface horizons and decreased in subsurface horizons. The total content varied from 26 to 76 mg/kg for zinc, from 9 to 42 mg/kg for copper, from 300 to 475 mg/kg for manganese and from 1.99 to 3.82 per cent for iron. The total content of micronutrients increased with increase in clay content and cation exchange capacity (CEC), whereas DTPA- extractable micronutrient increased with increase in organic carbon content and CEC, and decreased with increasing ph and sand content. The total reserve of Zn and Cu showed an influence on availability of these respective micronutrients. Key words : DTPA-extractable, Micronutrients, Reclaimed, Solum, Leached. How to cite this article : Singh, Jagmoha and Dhaliwal, N.S. (2012). Distribution of DTPA-extractable and total micronutrients in association with properties of some reclaimed salt affected soils of southwest Punjab, India. Asian J. Soil Sci., 7(1):. Introduction Micronutrient deficiency frequently occurs in arid and semi-ard regions of the Indo-Gangetic plains of India and is exhibited mainly in upland crops grown on soils with coarse texture, high ph, high calcium carbonate content and poor retention of water and nutrients (Katyal and Sharma, 1979). These soils are low in organic matter because of the prevailing arid and semi-arid climatic conditions and hence contribution of soil organic matter to available pools of micronutrients (Zn, Cu, Mn and Fe) is limited. Additionally, the emphasis on increasing the crop production using high yielding varieties along with intensive application of chemical fertilizers and limited use of organic manures has accentuated the depletion of micronutrient reserves in the soils (Sharma et al., 2004). In Punjab, it has been estimated that out of the total geographical area of sq. km, a sizeable area had been suffering from various land degradation problems such as soil salinity and sodicity, soil erosion (wind and water), flooding, water logging, shallow soil depth and sand dunes (Sidhu et al., 1994). Salt-affected soils contain excess salts which impair their productivity. The degree of adverse affects depends upon the type and quality of salts, soil texture, type of crop, variety, stage of growth, cultural practices and environment. Development of salinity and water logging is a serious problem in arid and semi-arid regions of the world and is threatening the HIND AGRICULTURAL RESEARCH AND TRAINING INSTITUTE

2 JAGMOHAN SINGH AND N.S DHALIWAL sustainability of irrigated agriculture (Chhabra, 2005). In Punjab, about 0.06 million hectare of land is salt affected. These soils are alkaline in reaction with exchangeable sodium percentage (ESP) more than 50 and are thus, prone to deficiency of one or more micronutrients. Widespread Zn deficiency has been reported in saline-sodic soils and it was associated with high ph and calcareous nature of these soils (Katyal and Sharma, 1979; Sharma et al., 1982). It has been observed that the relationship of soil properties with the profile distribution of total fraction was strong in the soils of the Indo-Gangetic plain (Sharma et al., 2000) and inceptisols and entisols of Punjab (Sharma et al., 2002; 2004). Although efforts are underway to ameliorate these soils by applying inorganic amendments, biofertilizers and by following certain agronomic practices, adequate attention has not been paid to study the distribution of micronutrients in the reclaimed soils. Also not much is known about the relationship between total and available (DTPA-extractable) contents of different micronutrients in surface and sub-surface horizons. The present investigation aims to study the distribution of total and DTPA-extractable contents of Zn, Fe, Cu and Mn in soil profiles of reclaimed soils located in the southwestern regions of Punjab and their association with soil characteristics. Resources and Research Methods The study area covering an area of 5730 km 2 lies between 29 o 50' to 30 o 54' N latitudes and 74 o 15' and 75 o 34' E longitude and forms a part of the Malwa Plain and great Indo-Gangetic alluvial plain. It is bounded by Ludhiana, Ferozepur and Bathinda districts in the east, northwest and southwestern directions, respectively. Soil samples from four pedons representing different categories of reclaimed salt affected soils i.e. severely saline sodic (P 1 ), moderately saline sodic (P 2 ), severely saline (P 3 ) and slightly saline soils (P 4 ) were taken horizon-wise and analyzed for ph (1:2 ratio of soil: water), organic carbon (O.C) by Walkley and Black s wet digestion method (1934), calcium carbonate (CaCO 3 ) content by rapid titration method of Puri (1930), cation exchange capacity (CEC) by saturating the soil with Na after equilibrating it with 1N sodium acetate (ph 8.2). The sodium saturated soil was made salt free by repeatedly washing with 98 per cent absolute alcohol and then extracted with 1N neutral ammonium acetate. Sodium concentration in the extract was determined using systronic flame photometer 128 and cation exchange capacity was calculated and particle size distribution by pipette method (Day, 1965). The plant-available fractions of Zn, Cu, Mn and Fe were extracted with (DTPA) (Lindsay and Norvell, 1978). For total elemental analysis, 0.1 soil (0.149mm, 100 mesh) was digested with a few drops of H 2 SO 4 and 5 ml of HF ml of HClO 4 in a 30-ml-capacity platinum crucible (Page, 1982). Following digestion, the residue was dissolved in 6N HCl, and transferred to a 50-ml volumetric flask made to volume. Analyses for Zn, Cu, Mn and Fe were carried out using an atomic absorption spectrophotometer. Data were recorded on an oven dry-weight basis. Analysis of variance was performed to test the significance of variance in micronutrient distribution and selected soil properties in different pedons. Relationships between the various soil properties and micronutrient distribution were established by using a general linear model. Research Findings and Discussion The results of the present study as well as relevant discussions have been presented under following sub heads: Physical and chemical characteristics : The sand content of pedon I (severely saline sodic soils) varied from 15 to 52.2 per cent (weighted mean, 31.1%), pedon II (moderately saline sodic soils) 13.2 to 84.9 per cent (weighted mean, 62.5%), pedon III (severely saline soils) 24.2 to 68.7 per cent (weighted mean, 43.3%) and pedon IV (slightly saline soils) 14.1 to 60.1 per cent (weighted mean, 34.2%). The clay content varied from 20.8 to 29.6 per cent in Pedon I (severely saline sodic soils), 10.3 to 15.5 per cent in pedon II (moderately saline sodic soils), 17.1 to 29.2 per cent in pedon III (severely saline soils) and 16 to 38.2 per cent in pedon IV (slightly saline soils). Pedon II (moderately saline sodic soils) contain highest amount of sand and lowest amount of clay whereas pedon I (severely saline sodic soils) contain highest amount of clay (Table 1). There was an increase in the clay content with depth in the soil profiles of pedon I (severely saline sodic soils) and IV (severely saline soils) but no definite trend has been observed in pedon II (moderately saline sodic soils) and III (severely saline soils). The soils were saline sodic and saline and ph ranged from and increases with depth. The organic carbon content, varied from per cent, per cent, per cent and per cent in Pedon Fig. 1: Weighted mean (%) of sand, silt and clay of different pedons of reclaimed salt affected soils HIND AGRICULTURAL RESEARCH AND TRAINING INSTITUTE 2 Asian J. Soil Sci., (June, 2012) 7 (1) :

3 DISTRIBUTION OF DTPA-EXTRACTABLE & TOTAL MICRONUTRIENTS IN ASSOCIATION WITH PROPERTIES OF SOME RECLAIMED SALT AFFECTED SOILS Table 1: Some selected properties of reclaimed salt affected soils Property Data specification Pedon 1 Pedon II Pedon III Pedon IV Sand (%) Range(R) (50-200µm) Weighted mean (WM) Silt (%) Range(R) (2-50µm) Weighted mean (WM) Clay (%) Range(R) (<2µm) Weighted mean (WM) CaCO 3 (%) Range(R) Weighted mean (WM) CEC Range(R) (C mol/ Kg) Weighted mean (WM) ph (1:2) Range(R) Weighted mean (WM) EC (ds/ m) Range(R) Weighted mean (WM) OC (%) Range(R) Weighted mean (WM) I, II, III, and IV, respectively. The CaCO 3 content was highest in Pedon II (moderately saline sodic soils) ( %) followed by Pedon III (severely saline soils) ( %), Pedon I (severely saline sodic soils) ( %) and Pedon IV (slightly saline soils) ( %). The cation exchange capacity varied widely and it increased with an increase in finer fractions in the soils. Total reserves of micronutrients : Total Zn: The total Zn content (Table 2) in different soils varied from 26 to 76 mg/kg. These differences may be due to the variation in the weathered ferromagnesian silicates in these soils. Its content was highest in soils of pedon I (severely saline sodic soils) (weighted mean = 46.5 mg /kg) (Table 3) and lowest in pedon II (moderately saline sodic soils) (weighted mean = 40 mg/kg). This may be ascribed to the nature of their parent materials. No systematic pattern of depth distribution of total Zn was observed in these soils. The concomitant increase in clay and CaCO 3 content in these horizons appears to be responsible for the accumulation of Zn resulting from its adsorption and/or fixation by these mineral constituents. Total Zn paralleled increase in CEC, silt and clay content (Table 4). This is consistent with the earlier reports of Katyal and Sharma (1991), who observed that silt and clay contents controlled the distribution of Zn in these soils. The total Zn content also increased with the increase in organic carbon in these soils (Table 4). Numerous reports (Frank et al., 1976) indicate that organic carbon is the dominant factor controlling the total Zn content in soils. In contrast to clay, sand was negatively correlated with Zn (r = ). It may be as a result of presence of quartz in the sand size particles. Total Zn was correlated with DTPA-extractable Zn (r = 0.251) indicating that the amount of Zn extracted by DTPA is a function of the total Zn in the soils. Total Zn also exhibited a significant correlation with the total contents of Fe (r = 0.569), Cu (r = 0.655) and Mn (r = 0.457), indicating their cooccurrence in the mineral frameworks. These results confirm the findings of Sharma et al. (2000;2005). Total Cu: The total Cu content (Table 2) ranged from 9 to 42 mg/ kg. Katyal and Sharma (1991) reported 14.4 to 19.7 mg/kg total Cu in the soils of India. Total Cu was highest in pedon I (severely saline sodic soils) (weighted mean = 30.4 mg kg -1 ) and lowest in pedon II (moderately saline sodic soils) (weighted mean = 14 mg kg -1 ). No specific pattern of distribution of total Cu was observed in any of these soils. The total Cu content was positively correlated with CEC (r = HIND AGRICULTURAL RESEARCH AND TRAINING INSTITUTE 3 Asian J. Soil Sci., (June, 2012) 7 (1) :

4 JAGMOHAN SINGH AND N.S DHALIWAL Table 2: Distribution of DTPA-extractable and total micronutrient content of different categories of reclaimed salt affected soils Horizon Depth (cm) DTPA-extractable Total Zn Cu Mn Fe Zn Cu Mn Fe (mg/kg) % Pedon 1: Severely saline sodic soils A B B B 22Ca B 23Ca B 23Ca Cca Pedon II: Moderately saline sodic soils Ap A B B 2Ca C 1Ca C Pedon III: Severely saline soils A B B B C 1ca Pedon IV: Slightly saline soils Ap B B B 3ca ) and silt (r = 0.645) content of these soils, confirming the results of Sharma et al. (1992). Since total Cu was positively correlated with clay content (r = 0.451), a negative correlation (r = ) was expected with sand content (Table 4). The highest content of total Cu in severely sodic soils may be due to its higher content in parent material. Sharma et al., (2000) observed that total Cu in soils increased with fineness of soil texture. Total Cu was also correlated with DTPA Cu (r = 0.331). Total Fe: The total Fe content in soils from different pedons varied from 1.99 to 3.87 per cent with weighted mean of 2.83 per cent. The soils from pedon IV (slightly saline soils) showed the highest content of Fe (weighted mean = 2.8%), whereas pedon II (moderately saline sodic soils) showed lowest amount of total Fe (weighted mean = 2.42%). Katyal and Sharma (1991) reported 3 per cent of total Fe in some soils, may be due to the Table 3: Total elemental composition of studied pedons (weighted means of sola) Pedon Zn Cu Mn Fe Zn Cu Mn Fe No. (mg/kg) % P P P P HIND AGRICULTURAL RESEARCH AND TRAINING INSTITUTE 4 Asian J. Soil Sci., (June, 2012) 7 (1) :

5 DISTRIBUTION OF DTPA-EXTRACTABLE & TOTAL MICRONUTRIENTS IN ASSOCIATION WITH PROPERTIES OF SOME RECLAIMED SALT AFFECTED SOILS Table 4 : Correlation coefficient (r) based on 22 x 15 (sample x attribute) sets DTPA Total Zn Cu Mn Fe Zn Cu Mn Fe ph CEC OC CaCo3 Sand Silt Cu Mn Fe Zn Cu Mn Fe ph CEC OC CaCo Sand Silt Clay Critical value of r at 5% = absence of Fe bearing minerals, such as Fe oxides, hydroxides and oxyhydroxides (Saini et al., 1995). Important soil factors contributing total Fe distribution were CEC (r = 0.344, clay (r = 0.304) and silt (r = 0.675), which were positively correlated with total Fe content (Table 4). Sharma et al., (2005) also reported similar results. Follet and Lindsay (1970) and Sharma et al. (2000) reported that clay and organic matter exert a strong influence on Fe distribution in moderately saline sodic soils may be due to higher sand content in such soils, and a negative correlation (r =-0.595) among them support the proposition. Total Mn: The total Mn content ranged between 300 to 525 mg kg 1 being highest in pedon III (severely saline soils) (weighted mean = 435 mg kg -1 ) and lowest in pedon II moderately saline sodic soils) (weighted mean = 380 mg kg -1 ). The soils did not show any systematic pattern of total Mn distribution within the profile. Total clay and CEC appeared to be the main factors responsible for the variation in the distribution of total Mn in soils, as observed by the positive correlation of these parameters with total Mn (Table 4). DTPA-extractable micronutrients : DTPA-Zn: The content of DTPA-Zn varied from 0.11 to 0.54 mg/kg soil (weighted mean 0.24 mg/kg soil) and constituted less than 1per cent of the total Zn (Table 2). In general, it was highest in severely saline soils (Pedon III) (weighted mean 0.33 mg/kg), followed by slightly saline soils (Pedon IV) (weighted mean 0.26 mg/kg), severely saline sodic soils (Pedon I) (weighted mean 0.25 mg/kg) and the least in moderately saline sodic soils (Pedon II) (weighted mean 0.14 mg/kg). The content of DTPA-Zn, in general, decreased with depth and coincided with the distribution pattern of organic carbon in the profiles. The probable reason of accumulation of Zn in surface horizon of the soils might be due to its regular turnover by plant residues, as also reported by Sharma et al. (2000). A high coefficient of correlation (r = 0.418) was observed between organic matter and DTPA-extractable Zn. Similar results were reported by Sharma et al. (1999). Organic matter had always been presumed to supply complexing agent that promote the availability of nutrient elements (Hodgson, 1963). Like total Zn, DTPA-Zn was correlated with silt (r = 0.694) and CEC (r = 0.457), confirming the findings of Katyal and Sharma (1991). Negative significant coefficient of correlation between DTPA-Zn and sand (r = ) indicates that Zn availability decreased with an increase in sand content and this was also validated by the results, which showed that soils having maximum sand content had the least available Zn (Table 4). DTPA-Zn was positively correlated with DTPA-Cu (r = 0.274) and Fe (r = 0.216). Follet and Lindsay (1970) attributed the interdependence of micronutrient cations to the soil factor. DTPA-Cu: DTPA-Cu ranged between 0.17 and 0.98 mg/kg soil (weighted mean 0.44 mg/kg). It constituted about 2 per cent of the total Cu (Table 2). The severely saline sodic soils (Pedon I) had the highest concentration of DTPA-Cu (weighted mean 0.67 mg/kg), followed by moderately saline sodic soils (Pedon II) (weighted mean 0.39 mg/kg), severely saline soils (Pedon III) (weighted mean 0.33 mg/kg) and least in slightly saline soils (Pedon IV) (weighted mean 0.29 mg/kg). In general the HIND AGRICULTURAL RESEARCH AND TRAINING INSTITUTE 5 Asian J. Soil Sci., (June, 2012) 7 (1) :

6 JAGMOHAN SINGH AND N.S DHALIWAL content of DTPA-Cu decreased with depth. This again could be due to the accumulation of biomass in the surface horizons of these soils. The DTPA- extractable Cu was correlated with organic matter (r = 0.154), CEC (r = 0.225) and silt (r = 0.076) a relationship similar to that for DTPA-Zn (Table 4). Based on the negative correlation for DTPA-Cu and sand (r = ), availability of Cu in soils is expected to fall as the texture becomes coarser. These results validate the higher incidence of Cu deficiency reported by Arora and Sekhon (1980) in wheat grown in coarse textured alkaline soils low in organic matter. Positive correlation between total Cu and DTPA-Cu (r = 0.331) indicates that its availability is largely dependant on the total copper reserves of the soil (Shuman, 1986). DTPA-Fe: DTPA-Fe ranged between 1.30 and 3.52 mg/kg in the soils (Table 2) (weighted mean 2.43 mg/kg). DTPA Fe was highest in slightly saline soils (Pedon IV) (weighted mean 3 mg/kg), followed by severely saline soils (Pedon III) (weighted mean 2.9mg/kg), moderately saline sodic soils (Pedon II) (weighted mean 2.6mg/kg) and the least in severely saline sodic soils (Pedon I) (weighted mean 1.7mg/kg). In all the profiles it was below the critical level of 4.5-mg/kg soil (Lindsay and Norvell, 1978). The DTPA-Fe generally decreased with soil depth, which may be due to low amounts of organic carbon in the subsurface and sub-soils. The DTPA-extractable Fe exhibited a positive correlation with silt (r = 0.054) and organic carbon (r = 0.385). The organic matter is reported to be the main source of plant-available forms of Fe (Mortvedt et al.,1977). The DTPA-Fe was not correlated with total Fe, which confirmed the vide incidence of Fe deficiency irrespective of total Fe in the soils (Brown, 1977). DTPA-Mn: The content of DTPA-Mn ranged between 1.80 and 8.80 mg/kg soil (Table 2) (Weighted mean 4.29 mg/kg). It constituted about 1.06 per cent of the total Mn. Availability of DTPA-Mn is highest in slightly saline soils (Pedon IV) (weighted mean 5.02 mg/kg), followed by severely saline sodic soils (Pedon I) (weighted mean 5.01 mg/kg), severely saline soils (Pedon III) (weighted mean 3.68 mg/kg) and least available in moderately saline sodic soils (Pedon II) (weighted mean 3.48 mg/kg). Susceptibility of Mn to change from coarse-textured to finetextured soils explains the vide variability of DTPA-Mn among soils. A notable feature of DTPA-Mn distribution was a negative correlation with ph (r = ) and CaCO 3 (r = ) and a positive correlation with organic carbon (r = 0.427) (Table 4). Hodgson (1963) found that the addition of organic matter to soil encourages microorganisms, aid in the liberation of trace elements. From this association between DTPA-Mn and HIND AGRICULTURAL RESEARCH AND TRAINING INSTITUTE 6 Asian J. Soil Sci., (June, 2012) 7 (1) : soil properties, it is inferred that Mn deficiency may be a serious problem in alkaline calcareous coarse textured soils. These findings corroborate the widespread incidence of Mn deficiency in sandy alluvial soils (Nayyar et al., 1985). Conclusion : In general, total micronutrient content was higher in severely saline sodic soils as compared to other soils. Soil factors like ph, calcium carbonate, organic matter and particle size fractions had strong influence on the distribution of total and available micronutrients. Pedogenic processes and parent material control total content, whereas biological processes affect DTPA-extractable content of different micronutrients. Generally, the DTPA-extractable micronutrient content of surface horizons was higher than that of the lower horizons. Accretion of organic matter in surface horizons by biological process associated with natural vegetation and crop production appears to have resulted in relatively higher extractable values. Literature Cited Arora, C.L.and Shekhon, G.S. (1980). The effect of soil characteristics on the zinc-copper interaction in the nutrition of wheat. J. agric.sci., Cambridge, 99: Black, C.A. (1965). In: Methods of soil Analysis. Part I and II American Society of Agronomy, Inc., Madison, Wisconsin, U.S.A Brown, J.C. (1977). Physiology of plant tolerance to alkaline soils. In Crop tolerance to sub-optimal land conditions. (American Society of Agronomy, Inc.: Madison, Wisconsin, USA.) pp Chhabra, R. (2005). Classification of salt-affected soils. Arid Land Res. Manage, 19:69. Day, P.R. (1965). Particle fractionation and particle size analysis. In: Methods of soils analysis Part I.pp C.A. Black et al. (Ed.). American Society of Agronomy, MADISON. Follet, R.H. and Lindsay, W. L. (1970). 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7 DISTRIBUTION OF DTPA-EXTRACTABLE & TOTAL MICRONUTRIENTS IN ASSOCIATION WITH PROPERTIES OF SOME RECLAIMED SALT AFFECTED SOILS Mortvedt, J.J.,Wallace, A. and Curley, R. D. (1977). Iron, the elusive micronutrient. Ferti. Solutions, 21: Nayyar, V. K., Sadana, U. S. and Takkar, P. N. (1985). Methods and rates of application of Mn and its critical level for wheat following rice on coarse textured soils. Ferti. News, 8: Page, A. L. (Ed.) (1982). Methods of soil analysis, Part 2. Chemical and microbiological properties. (2 nd Ed.). (American Society of Agronomy Inc.: Madison, Wisconsin, USA.). Puri, A.N. (1930). A new method of estimating total carbonates in soils. Imp. Agric. Res. Pusa. Bulletin. pp Saini, R.S., Chahal, D. S. and Sharma, B. D. (1995). Distribution of different forms of iron in arid zone soils of Punjab, India. Arid Soil Res. & Rehabilitation, 9: Sharma, B.D. Takkar, P.N. and Sadana, U.S. (1982). Evaluation of levels and methods of zinc application to rice in sodic soils. Fert. Res., 3: Sharma, B.D. Sidhu, P.S. and Nayyar, V. K. (1992). Distribution of micronutrients in arid zone soils of Punjab and their relation with soil properties. Arid Soil Res.& Rehabilitation, 6: Sharma, B.D., Jassal, H.S., Sawhney, J.S. and Sidhu, P.S. (1999). Micronutrient distribution in different physiographic units of the siwalik hills of semiarid tract of Punjab, India. Arid Soil Res.& Rehabilitation, 13: Sharma, B.D., Mukhopadhyay, S.S., Sidhu, P.S. and Katyal, J.C. (2000). Pedosphere attributes of total and DTPA-extractable Zn, Cu, Mn and Fe in Indo-Gangetic plains. Geoderma,56: Sharma, B.D., Aggarwal, V.K., Mukhopadhyay, S.S. and Arora, Harsh (2002). Micronutrient distribution and their association with soil properties in entisols of Punjab. Indian J. Agric.Sci.72: Sharma, B.D., Arora, Harsh, Raj-Kumar and Nayyar, V.K. (2004). Relationships between soil characteristics and total and DTPAextractable micronutrients in inceptisols of Punjab.Comm. Soil Sci. & Plant Anal., 35 : Sharma, B.D., Mukhopadhyay, S.S., Arora, H. (2005). Total and DTPA-extractable micronutrients in relation to pedogenesis in some alfisols of Punjab. Indian Soil Sci., 170: Sidhu, G.S., Walia, C.S., Tarsem-Lal, Rana, K.P.C. and Sehgal, J.L. (1994). Soils of Punjab for optimizing land use. NBBS Publ. 45 (Soils of India Series 4). National Bureau of Soil Survey & Land Use Planning, Nagpur, India, 75p+2 sheets soil map (1:500,00 scale). Shuman, L.M. (1986). Effect of liming on the distribution of manganese, copper, iron and zinc among soil fractions. Soil Sci.Soc. America J., 50: Walkey, A. and Black, I.A. (1934). An examination of the Degtjareff method for determining soil organic matter and a proposed modification of the chromic acid titration method. Soil Sci., 37, ******** ****** **** HIND AGRICULTURAL RESEARCH AND TRAINING INSTITUTE 7 Asian J. Soil Sci., (June, 2012) 7 (1) :