Fertilizers

Choice of fertilizers

Nitrogen: In Oil Palm plantations, fertilizers like urea, ammonium sulphate and diammonium phosphate may be used as a source of nitrogen as per their availability in the market. However, urea is found to be cheaper. There is a strong interaction between N and P fertilizers as applied N fertilizer will not be efficiently utilized unless adequate P fertilizer is applied.

Phosphorus: Fertilizers like single super phosphate, rock phosphate and diammonium phosphate can be applied as a source of phosphorus nutrition.  Rock phosphate is generally profitable in oil palm as compared to super phosphate.  However, under high pH conditions, application of rock phosphate is not recommended.

Potassium: Potassium may be applied as chloride or sulphate according to availability and price.   Potassium chloride (Muriate of potash) is found to be cheaper and available in local market. 

Magnesium: Magnesium sulphate can be applied as a source of Mg to oil palm.

Frequency of fertilizer application

It is advised to apply fertilizer in four equal splits at three months interval under irrigated conditions. Irrigation should be given immediately after fertilizer application. Under rainfed conditions, fertilizer application should be made shortly before the onset of the rainy season and not before or during the dry season or in the middle of the rains, and are generally given in two splits.

Methods of fertilizer application

All the fertilizers should be evenly broadcasted over the clean weeded circles about 1 m away from the palm base and incorporated into the soil with the help of forks. The area of application should be extended as the weeded palm circles become progressively enlarged as the palm gets older. Under normal circumstances, N and K fertilizers should be applied in close sequence followed by Mg, P and B fertilizers. Fertilizers can be mixed in water when drip irrigation method is followed.