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Effects of different rates of N and FE fertilisation on the growth of Tifdwarf Bermudagrass (Cynodon Dactylon x C.Transvaalensis L.Burtt-Davey) and Zoysiagrass (Zoysia Japonica Steud) grown on sand media of different particle sizes
Author
Tan, Ching Wei
Supervisor
Lee, Sing Kong
Abstract
The management of turfgrass in Singapore has received much attention in recent years. It was given greater emphasis with the construction of more new golf courses. With higher expectations for quality of turfgrass management and the need to reduce maintenance cost, there arises a requirement to have better knowledge in maintaining good quality turfgrasses under local conditions and at a relatively low cost. As fertiliser programme, in particular nitrogen(N) and iron(Fe), constitutes the key factor in determining the quality of the turfgrass, this study was conducted to determine their optimal rates of applications under local conditions to achieve good quality turfgrass.
An experiment using specially designed and built lysimeters, was conducted to investigate the effects of different rates of N and Fe fertilisation on the growth of Tifdwarf bermudagrass (hybrid, Cvnodon dactvlon L. X C.transvaalensis L. BurttDavey) and Zoysia iavonica Steud. under local field conditions. Three N levels investigated for their effects on the growth of these two turfgrasses were NO = 4 g/m2, N1 = 8 g/m2 and N2 = 12 gm2 while the Fe lcvcls investigated were Fe0 = 0.1 g/m2, Fe1 = 0.3 g/m2 and Fe2 = 0.5 g/m2.
The effects of two sand particle sizes used as the rootzone media, on the rate of leaching of these two nutrients, were also studied. The sand particle size ranges were. P1 = 0.2 mm to 1.0 mm in diameter with 50% of thc sand at 0.5mm and P2 = 1.0 mm to 2.5mm in diameter with 50% of the sand at 1.5mm. The growth parameters measured were dry weight of the leaf clippings(DW), % N and Fe in the leaf tissue, relative chlorophyll content and visual ratings.
At the end of the experiment, the root length and density, the total biomass of the turf over the 1 m2 plot and the organic layer accumulated were also measured. For N effects in Tifdwarf bermudagrass, the amount of DW of leaf clippings, % N in the tissue, biomass, relative chlorophyll content, organic layer and root density were all significantly increased at higher rates of application (N = 8 g/m2 to 12 g/m2). For comparisons, DW were recorded as 68.24±8.58g under high N level, compared to 52.07±3.70g under low N level. % N in the tissue was 4.75±0.17% and 4.05±0.06% for high and Low N level respectively. Chlorophyll content was increased from 4.26±0.10 mg/g DW under low N level to 4.43±0.15 mgjg DW under high N level. There was an inverse relationship between N levels and root length, and there were no significant N effect on visual ratings.
Similarly for Zoysiagrass, the DW of leaf clippings, % N in the tissue, organic layer and root density were also increased with higher N fertilisation (N = 8 g/m2 to 12 g/m2). There were significantly more DW under high N level at 69.48±7.42g compared to 58.01±3.11g under low N level. The % N in the tissue was higher at 3.02±0.17% under high N level compared to 2.73±0.05% under low N level. The relative chlorophyll content, biomass and root length however were different in terms of their response as compared to Tifdwarf bermudagrass, in that, no respouse towards different levels of N fertilisation was noted.
Generally the Fe effects were insignificant on the growth parameters measured for Tifdwarf bermudagrass. DW of leaf clippings, % N in the tissue, biomass, root length, organic layer, root density and visual ratings were not affected by the increased levels of Fe fertilisation.
Only the amount of Fe in the tissue and the relative chlorophyll content of Tifdwarf bermudagrass were significantly increased with higher levels of Fe fertilisation after 16 weeks. Relative chlorophyll content for turf under high Fe fertilisation (0.5 g Fe/m2) reached 4.42±0.11 mg/g DW at the end of the experiment as compared to 4.28±0.10 mg/g DW under low Fe fertiilisation (0.1 g Fe/m2).
Zoysiagrass was not affected by the different Fe levels, and showed similar response to Tifdwarf bermudagrass in the DW of leaf clippings, % N in the tissue, biomass, root length, organic layer and relative chlorophyll content. Amount of Fe in the tissue was increased with higher levels of Fe applications. Root density and visual ratings for Zoysiagrass were also significantly improved with the increased of Fe level from 0.1 g/m2 to 0.5 g/m2 . The Fe effect on visual ratings was significant for plots grown under medium N (8 g/m2) fertilisation but it was insignificant at the low N(4 g/m2) and high N (12 g/m2) fertilisation.As for leaching, the larger the sand particle size, the more leachate were observed to percolate through the sand profile. At commencement of the experiment, up to 5 1.97±0.68% of the total N applied, under the larger particle size range(P2) were lost through leaching compared to 49.29±0.74% under the smaller particle size range(P1). This effect were reduced with time from application of fertiliser as available nitrate and Fe within the soil were depleted or absorbed by the grass. The N effects on leaching for both Tifdwarf bemudagrass and Zoysiagrass werc noted to be insignificant after 16 weeks. Similar results were obtained for the percentage of Fe lost through leaching under the same conditions, for both Tifdwarf bermudagrass and Zoysiagrass.
An experiment using specially designed and built lysimeters, was conducted to investigate the effects of different rates of N and Fe fertilisation on the growth of Tifdwarf bermudagrass (hybrid, Cvnodon dactvlon L. X C.transvaalensis L. BurttDavey) and Zoysia iavonica Steud. under local field conditions. Three N levels investigated for their effects on the growth of these two turfgrasses were NO = 4 g/m2, N1 = 8 g/m2 and N2 = 12 gm2 while the Fe lcvcls investigated were Fe0 = 0.1 g/m2, Fe1 = 0.3 g/m2 and Fe2 = 0.5 g/m2.
The effects of two sand particle sizes used as the rootzone media, on the rate of leaching of these two nutrients, were also studied. The sand particle size ranges were. P1 = 0.2 mm to 1.0 mm in diameter with 50% of thc sand at 0.5mm and P2 = 1.0 mm to 2.5mm in diameter with 50% of the sand at 1.5mm. The growth parameters measured were dry weight of the leaf clippings(DW), % N and Fe in the leaf tissue, relative chlorophyll content and visual ratings.
At the end of the experiment, the root length and density, the total biomass of the turf over the 1 m2 plot and the organic layer accumulated were also measured. For N effects in Tifdwarf bermudagrass, the amount of DW of leaf clippings, % N in the tissue, biomass, relative chlorophyll content, organic layer and root density were all significantly increased at higher rates of application (N = 8 g/m2 to 12 g/m2). For comparisons, DW were recorded as 68.24±8.58g under high N level, compared to 52.07±3.70g under low N level. % N in the tissue was 4.75±0.17% and 4.05±0.06% for high and Low N level respectively. Chlorophyll content was increased from 4.26±0.10 mg/g DW under low N level to 4.43±0.15 mgjg DW under high N level. There was an inverse relationship between N levels and root length, and there were no significant N effect on visual ratings.
Similarly for Zoysiagrass, the DW of leaf clippings, % N in the tissue, organic layer and root density were also increased with higher N fertilisation (N = 8 g/m2 to 12 g/m2). There were significantly more DW under high N level at 69.48±7.42g compared to 58.01±3.11g under low N level. The % N in the tissue was higher at 3.02±0.17% under high N level compared to 2.73±0.05% under low N level. The relative chlorophyll content, biomass and root length however were different in terms of their response as compared to Tifdwarf bermudagrass, in that, no respouse towards different levels of N fertilisation was noted.
Generally the Fe effects were insignificant on the growth parameters measured for Tifdwarf bermudagrass. DW of leaf clippings, % N in the tissue, biomass, root length, organic layer, root density and visual ratings were not affected by the increased levels of Fe fertilisation.
Only the amount of Fe in the tissue and the relative chlorophyll content of Tifdwarf bermudagrass were significantly increased with higher levels of Fe fertilisation after 16 weeks. Relative chlorophyll content for turf under high Fe fertilisation (0.5 g Fe/m2) reached 4.42±0.11 mg/g DW at the end of the experiment as compared to 4.28±0.10 mg/g DW under low Fe fertiilisation (0.1 g Fe/m2).
Zoysiagrass was not affected by the different Fe levels, and showed similar response to Tifdwarf bermudagrass in the DW of leaf clippings, % N in the tissue, biomass, root length, organic layer and relative chlorophyll content. Amount of Fe in the tissue was increased with higher levels of Fe applications. Root density and visual ratings for Zoysiagrass were also significantly improved with the increased of Fe level from 0.1 g/m2 to 0.5 g/m2 . The Fe effect on visual ratings was significant for plots grown under medium N (8 g/m2) fertilisation but it was insignificant at the low N(4 g/m2) and high N (12 g/m2) fertilisation.As for leaching, the larger the sand particle size, the more leachate were observed to percolate through the sand profile. At commencement of the experiment, up to 5 1.97±0.68% of the total N applied, under the larger particle size range(P2) were lost through leaching compared to 49.29±0.74% under the smaller particle size range(P1). This effect were reduced with time from application of fertiliser as available nitrate and Fe within the soil were depleted or absorbed by the grass. The N effects on leaching for both Tifdwarf bemudagrass and Zoysiagrass werc noted to be insignificant after 16 weeks. Similar results were obtained for the percentage of Fe lost through leaching under the same conditions, for both Tifdwarf bermudagrass and Zoysiagrass.
Date Issued
1996
Call Number
QK495.G74 Tan
Description
Pg. xiii, 141, 142 and 143 are missing
Date Submitted
1996