C. Buvaneswaran , M. George , S. Mohan

Abstract

Investigations carried out on stemflow, throughfall and interception in a 30-year-old Teak plantation (density 620 trees/ha) at Coimbatore Forest Division, Tamil Nadu have shown that, out of the annual rainfall of 1966.7 mm, 7.54% was accounted as stemflow and 51.20% as tbroughfall. Remaining 41.26% was accounted as interception. While maximum stemflow (8.68% of rainfall) and throughfall (56.71%) and minimum interception loss (34.61%) was recorded during the month of November; minimum stemflow (0.25% of rainfall) and throughfall (5.0%) and maximum interception (94.75%) was recorded during March, It was also found that the seasonal variation of rainfall influenced the stemflow and throughfall. Interception during South-West monsoon (June-August) was almost at par with average annual interception. But during North-East monsoon (September-November) the interception was much below the annual average. The results of the present study show that the interrelationship between rainfall, stemflow and throughfall in Teak is similar to that of broad leaved species like Shorea robusta. It was also found that the interception depends on parameters like crown form, density of the species, external structural features like bark characteristics and branching nature as well as rainfall pattern and other meteorological factors which influence the evaporation.

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S. Mohan

Abstract

Inorganic Fertilizer application is known to augment the fertility of soils depleted of nutrients due to various reasons. An experiment to study the response of N, P and K fertilizers on the growth and biomass yield of Terminalia myriocarpa (Hollock) seedlings, which is a common timber species of Arunachal Pradesh was conducted in greanhouse conditions. It is seen that applications of 336 kg/ha of nitrogen, 336 kg/ha of phosphorus and 112 kg/ha of potash increases the growth (height and diameter) and also biomass production (fresh weight and dry weight). This dosage is recommended for application in fields with similar soil conditions as in the experimental soil types.

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S. Mohan , K. G. Prasad , G. N. Gupta

Abstract

Pot culture experiment using sand,loam and clay textured solis was conducted to see the effect of texture and nutrient application (50 ppm each of N, P and K) on Acacia lenticularis, Acacia pJanifrons, Albizia amara, Albizia lebbek, Azaduachta indica, Eucalyptus teretieornis, Hardwickia binata, Peltaphorum pterocarpum and Tamarindus indica. It was observed that A.lebbek, P.pterocarpum and E. tereticornis are highly responsive to clay texture and nutrient application. All species produced higher above and below ground biomass in clay soli except A. amara which produced higher biomass under sandy soil. A.lenticularis, A.amara, A.indica, H.binata and T.indica showed decrease in biomass due to nutrient application. Further studies are suggested.

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G. N. Gupta , S. Mohan

Abstract

A field experiment on skeletally, degraded forest land of a semi-arid region revealed that adoption of water harvesting technique coupled with preplant applicafion of 25 g each of urea and single superphosphate per plant increased the early growth of tree species of the 11 tree species tried, 7 responded dramatically to management. The increase in biomass yield varied from 5 times to 22 times The most suitable tree species, in order of their performance, on these wastelands were P. pterocarpum, E comaldulensis, A. planifrons, A. nilotica, C. pentandra, A. lebbek and A. leucnophloea. Root growth of these tree species also increased many folds owing to the management treatment.

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Balvinder Singh , G. N. Gupta , K. G. Prasad , S. Mohan

Abstract

Field experiments at three locations, namely Bolampatti, Pethikuttai and Coimbatore (Coimbatore Forest Division, Tamil Nadu) having different rainfall pattern and soils were conducted in 1985-86. Coir pith mulch was used on heavier soils of Bolampatti and Coimbatore, while gravel mulch was used on medium soil of Pethikuttai. Height of A. planifrons (113%), A. nilotica (96%), P. pterocarpum (85%), A. indica (60%) and E. camaldulensis (57%) increased due to coir pith mulch treatment. Response to mulch treatment was not so marked in case of A. leucophloea (27%) and T. indica (13%). A. lebeek, E. cuminii and P. pinnata did not respond to treatment. At Pethikuttai, use of gravel mulch increased height of E. camaldulensis (53%), A. indica (59%) C. pentendra (47%), A. leucophloea (68%) and A. nilotica (96%), A. planifrons (51%), P. pterocarpum (91%) A. lebbeck (122%). Growth of E. cuminii, C. equisetifolia, P. pinnata and T. indica was not significant due to mulch. At Coimbalore, where additional water was also given during severe moisture stress, plant height of C. equisetifolia increased from 115 to 147 cm E. camaldulensis from 102 to 120 cm in 6 months after planting. T. indica did not respond to mulch application at this site. Use of coir pith mulch maintained significantly higher moisture regime at all the locations throughout the growth period. Coir pith mulch reduced the surface soil temperature by 3 to 5°C at Coimbatore.

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G. N. Gupta , K. G. Prasad , S. Mohan , P. Manivachakam

Abstract

In a pot culture study varying levels of salinity were Simulated in clay, loam and sand textured soils. Based on plant survival, height, leaf weight, stem weight total plant weight, ischolar_main length and ischolar_main/shoot ratio, it was concluded that Acacia nilotica and Eucalyptus camaldulensis could be grown with less than 50% growth reduction upto 5 ds/m salinity. Acacia nilotica withstood salinity of as high as 15 dS/m. Casuarina equisetifolia was moderate in salt tolerance. Ceiba pentandra and Acacia auriculaeformes were highly sensitive tree species and did not survive beyond 2.5 ds/m.

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K. G. Prasad , Dnesh Kumar , T. J. Chandrashekharan Nair , S. Mohan , J. Madav Nair , A. D. Deo

Abstract

A factorial experiment with four levels (0.25, 50 and 75 g/plant) eacb of Urea and Superphosphate was carried out witb E. grandis grown on a severely truncated (Lithic Dystropept) soils at Minmutti, Idukki District, Kerala. Height, collar circumference, crown diameter and volume of E. grandis plants Increased with the application of N ferlilizer alone or in combination with P. However, P application alone was inferior to control treatment. Considering tbe growth parameters, relative treatment elfecllveness (RTE) and relative economic effecliveness (REE), treatment N₇₅ P₇₅ was the best followed by N₇₅ P₅₀ and N₅₀ P₇₅ treatments.

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K. G. Prasad , G. N. Gupta , S. B. Singh , S. Mohan , J. Madhavan Nair , A. D. Doe

Abstract

Biomass production of different components (ischolar_main, stem, twig and leaf) of one year old Eucalyptus grandis due to different doses of urea and superphosphate application at Minmutti, Kerala, was assessed. Application of nitrogen and phosphorus increased biomass production of all tree components. Though, response was greater due to urea appliclltion than superphosphate application, combined application of N and P increased biomass production of all plant parts tremendously. Similar to biomass production fertilizer use efficiency was also better due to N and P application alone or in combination. Considering biomass production and fertilizer use efficieney, the treatment receiving 75 g urea along witb 73 g superphosphate found to be the most efficient treatment.

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K. G. Prasad , O. N. Gupta , S. Mohan , V. Subramaniam , P. Manivachakam

Abstract

Nutrient content and uptake by different components (ischolar_main stem, twig and leaf) of one year old Eucalyptus grandis as affected by urea and superphosphate application at Minmutti, Kerala was estimated. In general, N, and K concentration decreased due to N and P fertiliser application either alone or in combination. However, uptake of N, P and K increased with each dose of application of N and P fertilisers and generally uptake values were maximum in N₇₅ P₇₅ treatments. Percent recovery of N was greater (79.1%) in N₇₅ P₇₅ treatment and P recovery (18.8%) In N₇₅ P₇₅ treatment.

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