The Current Status of Cultivation and Soil Fertility of Coconut Plantations in Vinh Long Province, Vietnam

Vinh Long has about 120,000 ha (equivalent to about 22 million coconut trees), ranking first and accounting for over 50% of the country’s coconut area. Many studies showed that coconut yield, whether high or low, is influenced by numerous factors.

This study conducted a survey of 400 coconut-growing households and directly assessed soil fertility in 198 coconuts gardens to identify factors affecting the yield of copra coconut, drinking coconut and Sap coconut in Vinh Long province.

The results showed that two-thirds of coconut growers were middle-aged, between 36–55-year-olds, with education levels at or above high school, accounting for 61.1%. Household coconut planting areas were small, ranging from 0.3 to 1.0 ha, accounting for 90.5%. The planting density for copra coconut and Sap coconut ranged from 233–254 trees ha^-1, with an average yield of 42.1-47.5 fruits/ tree/year; drinking coconuts averaged 317 trees ha^-1 with an average yield of 76.7 fruits/tree/year. No strong correlation was found between tree age and coconut yield. Factors such as electrical conductivity (EC) and temperature suitable for coconut growth, as well as the correlation between soil moisture and pH with coconut yield, were very low. However, prolonged low moisture averaging 13.9% can affect coconut growth and reproduction. Only 12.1% of the coconut gardens had readily available nitrogen at good to rich levels (>120 mgN kg^-1), but 85.4% of the gardens were rated from rich to very rich in readily available phosphorus (>21 mgP kg^-1) and 51.5% from medium to very rich in available potassium (>100 mg K kg^-1). No strong correlation was found between the readily available nitrogen, phosphorus and potassium in the soil at the time of survey and coconut yield. It is necessary to increase soil nitrogen levels by increasing the dosage and splitting fertilization events or using nitrogen in organic forms.