Sustainable Oil Palm Farming / Types of fertilisers

Download: Module 4: Fertiliser Application

Warning! Fake fertilisers are a common problem in many countries. Be careful when buying fertilisers, especially from someone you don’t know.

When buying fertilisers, stick to the following guidelines:

• Buy from a trusted person;
• Do not buy fertilisers that are extremely cheap or from an unclear origin (these are likely to be fake);
• Check if the fertilisers are in good condition (i.e. dry, clean, correct colour);
• Check if the bags look good and have been closed correctly with a straight stitch and the same colour thread for all bags;
• Check if the soluble fertilisers (i.e. all fertilisers other than rock phosphate and dolomite) actually dissolve when a handful is thrown into a bucket of water. If the grains sink to the bottom and don’t dissolve after stirring the fertiliser is probably fake;
• If KCl (MOP) or urea is dissolved when put in water, the water temperature should go down, so the water should get colder;
• Check the smell of KCI—good quality KCl doesn’t have a particular smell.

Advantages and disadvantages of different types of fertilisers

The following tables provide an overview of the key advantages and disadvantages of different types of fertilisers on the market today ^, .

Nitrogen fertiliser

Type	% N	Advantages	Disadvantages
Urea	46	Cheap, easy to store	Loss through leaching and volatilisation, acidifying
Ammonium nitrate (AN)	34	Little volatilisation, non-acidifying	Expensive, difficult to store
Sulphate of ammonium (SA)	20.6	Easy to store	Expensive, very acidifying, induces Mg deficiency

Phosphate fertiliser

Type	% P2O5	Advantages	Disadvantages
Triple Super Phosphate (TSP)	45—47	Very soluble, effective, also contains 20% CaO	Expensive
Diammonium Phosphate (DAP)	46	Very soluble, also contains 18% N and 11% S
Rock Phosphate (RP)	30—34	Inexpensive, effective, also contains 45% CaO	Bulky, slower response, high transport costs

Potassium fertiliser

Figure 17: KCl, also known as potassium chloride or Muriate of Potash (MOP)

Type	% K2O	Advantages	Disadvantages
Muriate of Potash (MOP, KCl)	60	Relatively cheap, effective, also contains 35% Cl
Bunch ash	20—40	Cheap, increased soil pH, effective	Cannot be stored for long, difficult to obtain for smallholders

Compound fertiliser (NPK)

Figure 18: NPK fertiliser with magnesium and trace elements (12-12-17-2 + TE)

Type	% N, P2O5, K2O, MgO	Advantages	Disadvantages
12-12-17-2 + micronutrients	12-12-17-2 + micronutrients	Easy to apply and easy to obtain, containing all required nutrients	Expensive, less suitable for mature plantations

Note: Compound (NPK) fertilisers are usually most suitable for application in nurseries and immature plantations (less than 3 years after planting). In mature plantations, the balance of N, P and K in the compound fertilisers is often not correct, and in most cases it is cheaper to apply single nutrient fertilisers unless the labour costs for application are high.

Magnesium fertiliser

Type	% MgO	Advantages	Disadvantages
Kieserite	26	More soluble, also contains 23% S	Expensive
Langbeinite	18	More soluble, also contains 22% K2O and 22% S
Dolomite	10—18	Reduces soil acidity, also contains ~ 30% CaO	Insoluble, only useful on very acid soils 1, 2

Boron fertiliser

Type	% B	Advantages	Disadvantages
Borax	11.3	Effective	Expensive

Copper and zinc fertiliser

Type	% Cu / Zn	Advantages	Disadvantages
Copper sulfate	25	Also contains 13% S	Expensive, difficult to get
Zinc sulfate (ZnSO4.H2O)	36	Also contains S	Relatively expensive, difficult to get
Zinc sulfate (ZnSO4.7H2O)	22	Also contains S	Relatively expensive, difficult to get

Acknowledgements

The material from Types of fertilisers is sourced from Smallholder Oil Palm Handbook and put together by Lotte Suzanne Woittiez (Wageningen Universit) and Haryono Sadikin, Sri Turhina, Hidayat Dani, Tri Purba Dukan, and Hans Smit (SNV) in August 2016. See Module 4: Fertiliser Application for more information.