R. C. Kaushik , I. M. Qureshi , J. S. P. Yadav , Jai Prakash

Abstract

The paper describes the results of an investigation undertaken in November, 1967 and June, 1968, in connection with the All-India Eucalyptus Study Tour and Symposium, in the States of Haryana and Punjab respectively to study the soil conditions supporting good as well as poor growth of Eucalyptus hybrid (Mysore gum) plantations where water was applied in the initial stages. The plantations ranged from one to six years of age (1962-1967) as listed in Table 1. This species fails to grow on the saline alkali soils which have p^H>10 and soluble salt content >0.7% and possess compact indurated sub-soil due to impervious pan, mostly kankar pan. Such sites should not be planted with this species unless soil conditions are reclaimed to the desired level and/or suitable planting method and soil working technique including perforation of impervious pan are adopted to overcome the adverse factors. Prolonged water-logging is also highly detrimental. The growth is arrested on the soils which are non-saline but have p^H>9 and also on the scils which have p^H<8.5 but with a salt content exceeding 1.0%. The species tolerates moderately calcareous soils and is able to grow satisfactorily on the soils having p^H < 9 and a soluble, salt content up to 0.3%. but still better growth is attained on a soil having p^H < 8.5 and soluble salt content <0.2%. The growth is also quite good on a light-textured alluvial soil which has adequate moisture supply as a result of high water table in the vicinity of a river. Provision of water in the initial stages of establishment is beneficial for the growth of this species under the local conditions. Systematic experiments are however required to be conducted to determine the most suitable watering or irrigation regime, soil-working and planting techniques and fertilizer application.

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I. M. Qureshi , J. S. P. Yadav , Jai Prakash

Abstract

The results of a soil investigation conducted in some bamboo forests of Assam in December 1963 have been reported in this paper. The soils of the different bamboo species show wide variations in many physical and chemical characteristics and assume greater significance on account of the shallow ischolar_main system of the species. The soils under Bambusa tulda and Dendrocalamus hamiltonii occurring in the semi-evergreen forests contain higher amounts of clay and silt than those under Melocanna bambusoides, Teinostachyum dullooa and Oxytenananthera nigrociliata occurring in the Cachar evergreen forests. The soil under B.tulda possesses the highest clay fraction, organic matter, nitrogen, calcium, potassium and phosphorus, whereas the soil under T.dullooa and O.nigrociliata exhibits the highest amount of sand and lowest reserve of magnesium, potassium, phosphorus and nitrogen. The data indicate that the latter species are capable of growing satisfactorily even on coarse-textured soils provided sufficient moisture is available. In view of immense potentiality for industrial utilisation and extensive area occupied by several bamboo species in Assam, the need for more systematic intensified studies to know precisely the relationship between soils and bamboos has been suggested.

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J. S. P. Yadav , Jai Prakash

Abstract

The result of a soil investigation undertaken in 1967-68 in Tarai and Bhabar and Bijnor Plantation Divisions to evaluate the soil conditions supporting good and inferior growth of Eucalyptus hybrid (Syn. E. tereticornis or Mysore gum) of Chickbalapur origin bave been reported. The morphological characteristics of soil profile particularly its texture, stoniness and drainage together with the associated effect on moisture regime and aeration are of great importance in influencing the growth of this species. A bhabar soil with coarse texture and excessive bouldery sub-soil having deficient moisture supply is not favourable for good growth, but the situation is improved where a bhabar soil has silty loam texture and is associated with somewhat higher water table. On the other hand, a tarai soil without stones but having adequate moisture availability and satisfactory drainage provides a more congenial environment. This species however, appears to exhibit inferior growth on a tarai soil which has impeded sub-soil drainage. Calcareous soil with slight alkaline reaction and presence of lime nodules in a diffused form does not appear to be harmful under the local conditions. The nutrient supply in the soil is moderate and is not critical in this area. In view of varied soil conditions met with in the region, the importance of a proper selection of sites for raising successful Eucalyptus hybrid plantations capable of adequate economic returns has been emphasized, utilising remaining sites for other species and purposes including retention of unplanted belts of unsuitable areas for preservation of indigenous flora and fauna as an additional measure towards nature conservation.

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