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M. N. Jha , Padmakar Pande , T. C. Pathak

Abstract

The effect of shifting cultivation Jhuming on the changes in the physico-chemical properties of soils was studied in the Jhumed and Non-jhumed areas of Tripara state. The Jhumed plot was selected in an area where Jbaming was done about two years back. The Non Jhumed plot was selected in an area where Jhuming was discontinued for about fifteen years and the natural vegetation got re-established. The stady reveals that Jhuming caused an appreciable change in organic matter content which resulted in nutrient imbalance. The burning of the debris after clearfelling depleted the organic matter content of the soil under Jhumed condition which led to low field and water holding-capacity. Total Sesuqioxideos, Iron, Aluminium, Calcium, Potassium, Phosphorus and Cation Exchange Capacity were found to be low in Jhumed plot, The availability of Phosphorus, Potassium, Calcium and Magnesium also decreased as a result of Jhuming. Total Nitrogen content was recorded to be slightly high under Non-jhumed plot in comparison to Jhumed plot. The presence of more organic mattet in Non jhumed plot resulted in a wider C:N ratio ( 15:1 on surface), C:N ratio in Jhumed plot was foand to be 8:1 (on surface which should be due to destruction of organic matter. Increaae in p^H value under Jhumed plot was due to lack of organic matter and microbial activity. The lower p^H values obtained under Non-jhumed plot resulted in an overall increase in the availability nutrients.

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R. C. Ghosh , R. M. Singhal , T. C. Pathak

Abstract

The conditions of Eucalyptus monoculture has promoted the formation of humic acids in soils with a clearly expressed aromatic rings as comapared to surrounding sal. Correspondingly the number of peripheral chains has decreased and the hydrophillic nature is less marked; humic acids are only slightly dispersed and coagulate even with small amounts of electrolyte.

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R. M. singhal , T. C. Pathak , S. P. Banerjee

Abstract

A considerable difference in the nature or humus was observed in the two typical sal forest soils of Doon Valley. The humus of the soils obtained from Asarori is predominantly humic in nature with greater condensation of aromatic rings and thus more mature as compared to that of Jhajra which is more lignious and fulvic in nature, containing more of side chains. Greater hydrolysability, oxidisability and mobility of humus of Asarori have been responsible for better soil conditions from the point or view of site quality and also nutrient cycling.

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P. Ramachandra Rao , P. S. B. Naidu , T. C. Pathak

Abstract

A method has been worked out for obtaining Copper Chlorophyll of a tinctorial value of 270-290.

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P. Ramachandra Rao , P. S. Balaraman Naidu , T. C. Pathak

Abstract

The preparation of water-soluble copper chlorophyll from copper chlorophyll has been described. The results of analysis of the product have been compared with those reported for a commercial sample.

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P. S. Rao , Kuldip Bhatia , T. C. Pathak

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J. S. P. Yadav , T. C. Pathak

Abstract

Details of a preliminary soil study undertaken in some of the evergreen forests in Brahmaputra valley of Assam in 1960 are given. The soils are highly acidie deep alluvial and show certain differences in their chemical composition. However, the variations in the physical and morphological characteristics exhibited are of greater significance in influencing the growth and regeneration of important species. Thus, the coarse-textured soil with poor moisture regime and higher reaction carries mixed evergreen forest without Dipterocarpus macrocarpus, and Shorea assamica. On the other hand, the finer textured acidic soils having satisfactory drainage and good moisture retentive power support these evergreen species. Again, a soil with a sandy layer at the bottom restricting moisture retention or with impeded sub-soil drainage retards natural regeneration of D. macrocarpus. The highly clayey soil rich in organic matter, nitrogen and sesquioxides with higher moisture holding power appears to be more favourable for the development of Shorea assamica as compared to D. macrocarpus. In view of these striking observations a need for systematic studies on the soil-vegetation complex in this region bas been emphasized.

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J. S. P. Yadav , T. C. Pathak , G. S. Mahi

Abstract

The results of a soil investigation conducted in 1960 in some evergreen forests of Western Ghats in the States of Mysore, Madras and Kerala are described. The soils show wide variations in depth, texture, stoniness, moisture regime, drainage, topographical situation, etc., but in general they are formed in situ and are acidic in reaction, poor in bases and lateritic in nature with a fair supply of organic matter and nitrogen. The intensive mineral weathering and rapid turn over of the nutrients under the local conditions facilitate easy supply of the nutrients to the vegetation. However, the soils which are shallow, coarse-textured, stony, liable to heavy erosion or with hard compact laterite sub-soil and possess low moisture and nutrient status, carry semi-evergreen forest often without Dipterocarpus indicus. The deep clayey fertile soils with good drainage and adequate moisture supply favour evergreen forest with D. indicus and such other species. On the other hand, deep sandy soil in a valley with somewhat high water table support evergreen forest dominated by Vateria indica, whereas the soil having swampy sub-soil is occupied by Myristica swamp forest. The necessity for conducting more intensified soil studies and for taking utmost care in carrying out heavy working in these forests has been indicated.

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R. M. Singhal , S. P. Banerjee , T. C. Pathak

Abstract

Trend in the changes in peroxidisable, alkali-extractable, and acid-hydrolysable fractions of the soil organic matter under Eucalyptus monoculture and surrounding natural sal in the course of a quinquennium reveals that the former humifies easier and faster. Oxidisability of resistant organic matter of the surface samples increases under both but the non-peroxidisable carbon decreases in all the layers under Eucalyptus as compared to surrounding sal. Optical densities of the alkali- extractable organic fraction, in general, increases and more so in the surface layers, reflecting certain changes in the nature of the organic matter returned during this period. Translocation of the humified material is more pronounced under Eucalyptus although to a limited depth. Soil organic matter under Eucalyptus is more hydrolysable, and non-hydrolysable fractions decrease very significantly under sal as compared to Eucalyptus.

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