prior to the season, Chemical Fertilizer need is assessed by the Department of agriculture base on the agri ecological zones and irrigation system.They will also consider cultivation targets before issuing fertilizer recommendation through the area Agrarian Service.
PRODUCT
CHARACTERISTIC
Nitrogen (N)
Promotes rapid plant growth and improves grain yield and grain quality. N is generally the most limiting nutrient as it is needed in large amounts and is readily lost as a gas (volatilized) and by leaching (washing out of the root zone)
Phosphorus (P)
Essential for root development, tilling, Early flowering and ripening. It is especially deficient in sandy soils with low organic matter, very acidic soils and alkaline soils.
Potassium (K)
Essential for root growth and plant vigor. It also helps fight against lodging and improves the crop resistance to diseases. Potassium can quickly become a yield limiting factor in high yielding rice fields when the straw is removed from the field. Rice paddy straw is rich in K.
*Zinc and sometimes Sulfur deficiencies are much less frequent but can be important locally.