Productivity of ailanthus(ailanthus triphysa) and population densities
By: Naveed Shujauddin.
Contributor(s): Mohankumar B(Guide).
Material type:
BookPublisher: Vellanikkara Department of Sivilculture and Agroforestry, College of Forestry 2001DDC classification: 634.9 Online resources: Click here to access online Dissertation note: MSc Abstract: A split plot experiment involving ailanthus (Ailanthus triphysa
(Dennst.) Alston) at four population densities (3333,2500, 1600 an 1111 tpha) and
four fertiliser regimes (0:0:0, 50:25:25, 100:50:50 and 150:75:75 kg N:P205:K20
ha" yr") was initiated in June 1991. The objectives included evaluating the
biomass production potential of ailanthus grown under different spacing and
fertiliser regimes and estimating nutrient export through whole tree harvesting.
Height, diameter and stand leaf area of ailanthus trees at 8.7 years of age
was greater in the 2500 trees per hectare (tpha) stand than other density levels.
Lower densities recorded higher biomass on a per tree basis whereas on a stand
.basis, the high density stand (3333 tpha) showed greater biomass yield. Fertilisers
applied at 1.2, 2.25 and 5.25 years had no significant effect on biomass
accumulation. Regarding the partitioning of tree biomass, stemwood was the most
important component in all density and fertiliser treatments while foliage
contributed the least. Nonetheless, foliage registered the highest N, P and K
concentration (%). NPK concentration of other fractions decreased in the order:
branchwood > roots> stemwood.
Nutrient accumulation (N, P and K) on a per tree basis was higher in the
lower densities while on a stand basis, greater accumulation was noted in the
higher density stands (3333 and 2500 tpha). Bole fraction accounted for only 56
per cent of total nutrients removed during harvest. Thus leaving other biomass
components (foliage and branches) at the site will greatly reduced the nutrient
export associated with tree harvesting.
Stands with 1600 and 1111 tpha showed higher N and K use efficiencies
whereas for P, the tree population density of 2500 tpha 'showed the highest
efficiency. Regarding fertiliser effect, trees in the control plot (no fertiliser)
exhibited highest efficiencies for N, P and K.
Available soil P, K and organic carbon concentrations declined with
increasing tree population density. However, there was an overall increase in total
N and available K levels compared to the previous. observation at 3 years of age.
Increasing levels of fertilisers in general resulted in higher soil organic carbon, N,
available P and K levels.
| Item type | Current location | Call number | Status | Date due | Barcode |
|---|---|---|---|---|---|
Theses
|
KAU Central Library, Thrissur Theses | 634.9 NAV/PR (Browse shelf) | Available | 171754 |
MSc
A split plot experiment involving ailanthus (Ailanthus triphysa
(Dennst.) Alston) at four population densities (3333,2500, 1600 an 1111 tpha) and
four fertiliser regimes (0:0:0, 50:25:25, 100:50:50 and 150:75:75 kg N:P205:K20
ha" yr") was initiated in June 1991. The objectives included evaluating the
biomass production potential of ailanthus grown under different spacing and
fertiliser regimes and estimating nutrient export through whole tree harvesting.
Height, diameter and stand leaf area of ailanthus trees at 8.7 years of age
was greater in the 2500 trees per hectare (tpha) stand than other density levels.
Lower densities recorded higher biomass on a per tree basis whereas on a stand
.basis, the high density stand (3333 tpha) showed greater biomass yield. Fertilisers
applied at 1.2, 2.25 and 5.25 years had no significant effect on biomass
accumulation. Regarding the partitioning of tree biomass, stemwood was the most
important component in all density and fertiliser treatments while foliage
contributed the least. Nonetheless, foliage registered the highest N, P and K
concentration (%). NPK concentration of other fractions decreased in the order:
branchwood > roots> stemwood.
Nutrient accumulation (N, P and K) on a per tree basis was higher in the
lower densities while on a stand basis, greater accumulation was noted in the
higher density stands (3333 and 2500 tpha). Bole fraction accounted for only 56
per cent of total nutrients removed during harvest. Thus leaving other biomass
components (foliage and branches) at the site will greatly reduced the nutrient
export associated with tree harvesting.
Stands with 1600 and 1111 tpha showed higher N and K use efficiencies
whereas for P, the tree population density of 2500 tpha 'showed the highest
efficiency. Regarding fertiliser effect, trees in the control plot (no fertiliser)
exhibited highest efficiencies for N, P and K.
Available soil P, K and organic carbon concentrations declined with
increasing tree population density. However, there was an overall increase in total
N and available K levels compared to the previous. observation at 3 years of age.
Increasing levels of fertilisers in general resulted in higher soil organic carbon, N,
available P and K levels.
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