Efficiency of Land Use in Longan E-Dor Farming (Dimocarpus longan Lour.) in Thai Lai District, Can Tho City, Vietnam

Abstract

The study was conducted to evaluate the economic efficiency and
environmental characteristics of the E-dor longan (Dimocarpus
longan Lour.) farming model. Economic efficiency and chemical use
related issues were assessed by interviewing farmers field survey. Soil
samples were collected in the longan fields and the rice paddy field
for comparison. Soil samples were collected in the longan models with
different land conversion times (>5 years, 3-5 years, <1 year). The
soil quality indicators including pH, organic matters (OM), total
nitrogen (TN), total phosphorus (TP), total potassium (K) and heavy
metals (Fe, Mn, Ni, Cr, Cu, Zn, Pb, and As) were analyzed. The
average total income from longan cultivation was higher than that of
rice, with about 92.6 million VND/ha, the profit/capital ratio from
longan cultivation was 1.48 (excluding the labor) and 1.31 (including
the labor). The longan model was evaluated using more fertilizers and
pesticides than rice cultivation. Soil analysis results showed that pH
was not suitable for the development of longan. The levels of OM,
TKN, TP, and K in longan cultivation were lower than those in rice
cultivation. Heavy metals such as Mn, Fe, Cu, Zn, Pb, Ni, Cr and As
were still within the permissible limits of QCVN 03-MT: 2015/BTNMT
and FAO (2001), but Fe, Mn, Zn, Cr were found to tend to be higher
in longan model and accumulated over cultivated time. The initial
research results showed that the yield of E-dor longan was still low,
so it has not brought about high economic efficiency, the soil quality
was not suitable for the development of longan; Therefore, it is
necessary to have appropriate cultivation and soil improvement
measures to improve longan crop. This study provides preliminary
information on the economic efficiency and environmental problems
of switching from rice cultivation to E-dor longan farming.