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999			_c26512 _d26512
003			OSt
005			20220827102237.0
008			140128s9999 xx 000 0 und d
082			_a634.9 _bVIM/SO
100			_aVimal M
245			_aSoil-Plant Nuyritional Status Of Tectona Grandis L.f. In Relation To Age and Site Quality
260			_aVellanikkara _bDepartment of Silviculture and Agroforestry, College of Forestry _c1999
502			_bMSc
520	3		_aA study was conducted at College of Forestry, Vellanikkara, KAU, during the period 1994-1996 to identify and assess the nutritional factors limiting productivity of teak plantations, of different age groups belonging to different site qualities, spread through out the State of Kerala. The study was aimed to find out the influence of nutrient status of soil and leaf on the growth as represented through volume and current annual increment in basal area per tree. Another objective was to find out the influence of soil characteristics like pH, organic carbon and nutrient contents on foliar nutrient concentration of teak. The leaf samples were analysed for N, P, K, Ca, Mg, Fe, Mn and Zn concentrations. The soil samples were analysed for pH, organic carbon, available P, total N and exchangeable K, Ca, Mg, Fe and Zn. The whole set of 300 trees was divided into three age groups as < = 20 years, > 20 and < = 40 years and > 40 years and stepwise regression was carried out by taking volume as dependent variable for each group separately. The resultant equations in stepwise regression were utilized to characterize the nature of response surface and to find the optimum levels of soil attributes and foliar nutrient elements. For analysing the relationship between soil attributes and foliar nutrient concentrations a technique called canonical correlation analysis was used. The relation between leaf nutrient status and tree volume was feeble in all the three age groups. In all the three age groups, the critical nutrient concentrations with respect to tree volume do not seem to be attained by the levels of nutrients available in the present data set, indicating a increase in tree volume by adequate supply of the appropriate nutrient elements. 2 The relation between tree growth and nutrient status of soil was stronger compared to the relation between the tree growth and nutrient status of soil. For the first two age group selected, the models were linear in nature. For the older plantations (Age > 40 years), almost 50 per cent of the variation in tree volume was explained by the soil nutrient levels. For this age group soil phosphorus had a quadratic term in the model and the point of maximal response for phosphorus was predicted at P = 26.66 ppm. The relationship between current annual increment in basal area per tree and nutrient status of leaves and soil was also linear. Age related change in current annual increment is positively modified by the level of soil nitrogen. To find out the relationship between the leaf attributes and soil attributes canonical correlation analysis was used. For the younger age group (age < = 20 years) soil organic carbon had a significant positive influence on leaf nitrogen and leaf potassium concentrations while it had a negative effect on leaf Fe and leaf Mg concentrations. Also significant positive correlation was seen between leaf Ca and soil Ca for all the age groups. The canonical correlation analysis showed that as the age of the plantations increases and the canopy closure occurs, the leaf nutrient contents influence the soil fertility attributes to a greater extend due to the effect of litter fall.
700			_aSudhakara K (Guide)
856			_uhttp://krishikosh.egranth.ac.in/handle/1/5810103713
942			_2ddc _cTH