Correlation between soil physico-chemical properties and available micronutrients in salt affected soils

Transcription

1 Symposium no. 33 Paper no Presentation: poster Correlation between soil physico-chemical properties and available micronutrients in salt affected soils MALI V.S., ZENDE N.A. and VERMA U.K. Vasantdada Sugar Institute, Manjari (Bkk), Tal. Haveli, Dist. Pune, PIN , India Abstract Twentyfour surface soil samples (0-30 cm) collected from salt affected area of Vasantdada Sugarcane Research and Development farm Manjari(Bkk.), Pune, Maharashtra (India) were studied for the Cu, Zn, Fe and Mn status in relation to important soil factors. All the soil samples had adequate amount of Cu, Zn, Fe and Mn. Iron and Maganese are significantly positively correlated with organic carbon, available nitrogen and phosphorus. However, they are negatively correlated with ECe, they are also positively correlated with ph, calcium carbonate and potassium, but the values are not significant. Zinc and Copper are negatively correlated with calcium carbonate, organic carbon, available nitrogen, phosphorus and potassium. but the 'r' values are not significant. However, available phosphorus is significantly negatively correlated with zinc and copper. Keywords: correlations, micronutrients, salinity and soil properties Introduction Maharashtra covering an area M ha accounts for 10 percent of the total geographical area of the country. About 3.4 percent (1.06 M ha) soils are degraded by the problems of salinity and sodicity (NBSS, Publ. No. 54, 1995). Most of the sugarcane growing soils are Vertisols (13-15%), facing the same problems in the command areas of canals. Harmful effects of high alkalinity are manifested through non-availability of nutrients like iron, manganese, zinc and copper in salt affected soils. It would be of practical importance to identify and reclaim the soils. Necessary steps to be taken in time to prevent the deterioration of soil and insure increase in crop yields. Realizing the seriousness of problems and considering the decreasing productivity the present investigation was undertaken to study the micronutrients in salt affected soils and work out the relationship of some important properties with micronutrients. Material and Methods Twenty four surface soil samples (0-30 cm) were collected from salt affected area of Vasantdada Sugarcane Research and Development farm Manjari (Bkk.). It lies between ' to ' N latitudes and ' to ' E longitudes. The soils were very deep, black in color with leveled plain representing Vertisols. The processed soil samples were analyzed for some important soil characteristics viz. ph, ECe, ESP, Bulk Density, Maximum Water Holding Capacity, cations and anions using standard procedures given in USDA Handbook no. 60. The soil sample were extracted with DTPA solution was analyzed for available Fe, Mn, Zn and Cu by using Inductive Coupled Plasma Emission spectrophotometer. Correlation coefficients between various

2 soil parameters and available macro and micronutrients were estimated by method of Panse and Sukhatme (1967). Table 1 Simple correlation coefficients(r) between available micronutrients and soil characteristics. Soil characteristics Fe (mg kg -1 ) Correlation coefficient Mn Zn (mg kg -1 ) (mg kg -1 ) Cu (mg kg -1 ) ph ECe (dsm -1 ) CaCO 3 (%) Saturation percent ** ** Organic carbon (%) 0.66 ** 0.67 ** Avail. N (kg ha -1 ) 0.72 ** 0.64 ** Avail. P 2 O 5 (kg ha -1 ) 0.72 ** 0.49 ** ** ** Avail.K 2 O (kg ha -1 ) * * Significance at 5 % level. Results and Discussion Chemical properties of salt affected soils The properties of soils are presented in Table 2, 3, 4 and 5. Soils were in alkaline range of ph (saturation paste extract), electrical conductivity of saturation paste extract (ECe) varied from 1.03 to 8.29 dsm -1. The exchangeable sodium percent was varied from 5.93 to percent. The calcium carbonate was in the range of 6.1 to 11.2 percent. The organic carbon content was very low to medium (0.16 to 0.57%), while available nitrogen content was also very low to medium (28.6 to kg/ha). The soils were very low to very high (12.6 to 45.1 kg/ha) in available phosphorus, while very high (374.7 to 1,049.2 kg/ha) in available potassium content. Micronutrient status in salt affected soils The available Cu content of the soils was ranged from 0.7 to 7.4 mg kg -1. Considering 0.20 mg kg -1 (Lindsay and Norvell, 1978) or even 0.66 mg kg -1 (Sakal et al., 1984) as the critical limit of DTPA-extractable Cu for normal growth of plant, it may be inferred that all the soils contain adequate amount of available Cu. The available Zn content of the soils ranged from 0.8 to 4.6 mg kg -1. Lindsay and Norvell (1978) suggested the critical limit of DTPA-extractable Zn as 0.5 to 1.0 mg kg -1 for Indian soils. According to which all samples are quite sufficient in available Zn. The available Fe content of the soils widely varied from 4.2 to 17.6 mg kg -1. According to Arora and Sekhon (1981) 2 mg kg -1 of DTPA-extractable Fe is considered as the critical limit for normal growth. Lindsay and Norvell (1978) suggested the critical limit of Fe as 4.5 mg kg -1. Considering even the highest value of critical limits of Fe (4.5 mg kg -1 ), the soils of the farm appeared to be quite sufficient in available Fe

3 Table 2 Physical and morphological characteristics of soils. Sample no. Saturation Max.W. H. Bulk Density (%) Cap. (%) (Mg m -3 ) Soil color R 3/ R 3/ R 3/ R 5/ R 4/ R 3/ R 4/ R 3/ R 2.5/ R 3/ R 3/ R 4/ R 5/ R 5/ R 4/ R 6/ R 5/ R 4/ R 4/ R4/ R 3/ R 3/ R 3/ R 5/1 The available Mn content of the soils ranged from 6.2 to 27.6 mg kg -1. The variation in the available Mn in these soils is also wide. Lindsay and Norvell (1978) and Arora and Sekhon (1981) reported 1 mg kg -1 of DTPA-extractable Mn as the critical limit for available Mn. Higher standards, such as, 3 mg kg -1 and 4.7 mg kg -1 of DTPA extractable Mn been reported by Shukla and Gupta (1975) and Anoymous (1976), respectively. Accordingly, The soils of the farm appears to be sufficient in available Mn (considering the critical limits suggested by different workers)

4 Table 3 Chemical characteristics of soils. Sample CEC ECe SAR No. (meq/lit) ph (ds m -1 ) ESP % Soil type Normal Alkali Normal Alkali Alkali Alkali Alkali Saline-alkali Alkali Saline-alkali Alkali Alkali Saline-alkali Saline-alkali Normal Alkali Alkali Alkali Saline-alkali Saline-alkali Normal Alkali Saline-alkali Saline-alkali Relationship between micronutrient status and soil properties in salt affected soils Available Fe Simple correlation studies between available Fe and ph of the soil paste did not show any relationship. Negative correlation of Fe with electrical conductivity of soil paste extract was found (r = -0.33) but it was not statistically significant. Available Fe content in soil found to be positively correlated with organic carbon and available N content. It indicates that soils with high organic carbon in soil are rich in available Fe content. Chattergee and Khan (1996) reported similar correlations between Fe and organic carbon. High degree of correlation (0.72) was observed between available Fe and available phosphorus, while it was non-significant positive with available potassium (0.30). Among the micronutrient contents Fe was not shown any definite correlation

5 with Zn and Cu, however it was significant positive with Mn (0.77). Similar relationship of different forms of Fe and exchangeable Mn observed in seirozem soils, reported by Shukla and Singh (1969) and Takkar et al. (1969). Table 4 Chemical characteristics of soils. Sample CaCO 3 O.carbon Av. N Av.P 2 O 5 Av.K 2 O Fe Mn Zn Cu No. (%) (%) kg/ha mg kg Available Mn Simple correlation studies between available Mn with ph and ECe of the soil paste did not show any relationship. The results are in conformity with the findings of Chattopadhay et al. (1996) in the soils of Vindhyan Scarplands of Rajasthan and also with Vadivelu and Bandopadhyay (1995). Negative correlation of Mn with electrical conductivity of soil paste extract was found (r = -0.27) but it was not statistically significant. Available Mn content in soil found to be positively correlated with organic carbon (0.67) and available N (0.64) content. It indicates that available Mn content increases with the organic carbon level in soil. Badhe and Naphade (1969), Chattergee and Khan (1996), reported similar correlation between Mn and organic carbon.a significant positive correlation (0.49) was observed between available Mn and available phosphorus, while it was non significant positive with available potassium (0.21)

6 Among the micronutrient contents Mn was shown negative correlation with Zn and Cu. but, it is non significant. However, it shows significant positive correlation with Fe. Table 5 Chemical composition of saturation extracts of the soils. Sample Exchangeable cations (meq/l) Total cations No. Ca 2+ Mg 2+ Na + K + (meq/l) HCO 3 2- Exchangeable anions (meq/l) SO 4 2- Cl 2- Total anions (meq/l) Available Zn Available Zn content in soil did not show any significant correlation with ph and ECe of the soil. Non significant negative correlation was observed between Zn and organic carbon, available N and available potassium. Similar Relationship was observed between organic carbon with Zn by Rajgopal et al. (1974). However, it was significant negative with available phosphorus. It indicates that soils with high phosphate are low in available Zn. Similar relationship of available phosphorus and Zn observed in coastal soils of Sundarbans, West Bengal reported by Maji et al. (1993). Available Cu There was no any significant correlations were observed between available Cu and ph, ECe, CaCO 3, organic carbon, available N and K 2 O. Similarly Neelkanthan and Mehta (1962) found no relationship between organic carbon and available Cu in Gujarat soils. They also pointed out that copper is less susceptible to changes in ph than other

7 micronutrients. Such divalent relationships between ph and available Cu also been reported by a number of investigators, (Agrawal and Motiramani, 1966) and Mishra (1967). Similar relationship of Cu with ph and ECe was reported by Sakal et al. (1986) and (1988). The negative correlation between Cu and organic carbon also observed by Kanwar (1954) and Rai et al. (1972).The significant negative correlation was observed with available phosphorus (-0.42). Similar relationship of available phosphorus and Cu observed in coastal soils of Sundarbans, West Bengal.reported by Maji et al. (1993). Conclusion The available micronutrients, viz. copper, iron, manganese and zinc did not show any significant positive or negative correlation with ph and ECe. The organic carbon, available nitrogen showed positive significant correlation with Fe and Mn, however it was non significant negative with Zn and Cu. Available phosphorus showed significant negative correlation between Zn and Cu. References Agarwal, H.P. and D.D. Motiramani J. Indian Soc. Soil Sci. 14:162. Anonymous Annual Progress Report of All India Coordinated Project of Micronutrients in Soils and Plants. ICAR, New Delhi. Arora, C.L. and G.S. Sekhon J. Indian Soc. Soil Sci. 29:453. Chattopadhyay, T., A.K. Sahoo, R.P. Singh and R.L. Shyampura J. Indian Soc. Soil Sci. 44:678. Kanwar, J.S J. Indian Soc. Soil Sci. 2:73. Lindsay, W.L and W.A. Norvell Soil Sci. Soc. Am. J. 42:421. Maji,B., S. Chatterji and B.K. Bandyopadhyay J. Indian Soc. Soil Sci. 41:468. Neel Kanthan and Mehta J. Indian Soc. Soil Sci. 32:39. Panse,V.G. and P.V. Sukhatme Statistical Methods for Agricultural Workers. I.C.A.R., New Delhi. Richards, L.A.(ed.) Agric. Handbook U.S.Dep. Agric. 60. Rai, M.M., A.R. Pal, B.P. Chimania, D.B. Shitole and P.Vakh J.Indian Soc. Soil Sci. 20:128. Rajgopal, C.K J.Indian Soc. Soil Sci. 22:347. Shukla, R. and Singh Private communication. Shukla, U. C. and B.L.Gupta J. Indian Soc. Soil Sci. 23:357. Soil Survey Staff Soil Taxonomy,A Basic System of Soil. Singh, M. and K.S. Singh Ann. Arid Zone. 20:77. Sharma, B.K., R.P. Dhir and D.C. Joshi J. Indian Soc. Soil Sci. 33:50. Singh, K., R.L. Ahuja and M. Singh J. Indian Soc. Soil Sci. 36: 828. Sakal, R., A.P. Singh and S.P. Singh J. Indian Soc. Soil Sci. 36:59. Singh, R.R. and S.N. Choudhary J.Indian Soc. Soil Sci. 38:317. Takkar, P.N., D.R. Bhumala and B.R. Arora Agrochimica. 13: Vadivelu, S. and A.K. Bandopadhyay J. Indian Soc. Soil Sci. 43: