Research on tree growth of acacia and Eucalyptus plantation on embankment at Hon Dat district, Kien Giang province

Abstract

Research on the effect of planting density and fertilizer on growth and
productivity of acacia hybrid, Acacia auriculiformis and eucalyptus hybrid
planted on the embankment in Hon Dat district, Kien Giang province,
conducted from 2016 - 2020. The study was evaluate the characteristics
of soil condition befor establish experiments. The experiments design full
randomized block, with 3 replicates, including 4 planting density levels and
5 fertilizer treatments, area of each experimental plot 300 m
2
. The research
results have shown that: (i) The soil in the study area is strongly acid sulphate soil with low pH,
high levels of iron and aluminum toxins, low pirite level, so the excavation
of canals to make embankment for plantations have to limit digging to the
pirite layer, which has the potential to affect the growth of the plantation and
adversely affect the environment; (ii) Planting density did not significantly
affect survival rate, but had a great influence on growth and productivity
of A. hybrid, A. auriculiformis and E. hybrid plantations. The appropriate
density of afforestation on the embankment is 2,000 - 3,333 trees/ha for MAI
get 28.4 - 33.8 m
3
/ha/year for A. auriculiformis; from 38.0 - 47.0 m
3
/ha/year
for A. hybrid and from 37.3 - 44.1 m
3
/ha/year for E. hybridafter 4.5 years
old; (iii) Phosphate and NPK fertilisers have an effect on survival and growth
of young plantation. For A. hybrid and A. auriculiformis,there is no obvious
effect, but there is a very clear effect on growth and productivity of E. hybrid
plantations. Planting acacia on the embankment should apply fertilize 100-200 g phosphate/tree and planting E. hybrid should apply fertilize 100-200 g
phosphorus + 100 g NPK/tree; (iv) Proposing the application of afforestation
techniques of acacia, eucalyptus on acid sulfate soil in Hon Dat district, Kien
Giang province and other places with similar site conditions, must be planted
on high beds and embankments with-out flooding, using new clones that are
technically advanced, planting density and reasonable fertilizing from the
results of this study will bring high benefit to forest growers.