In our previous blog, we spoke about the vital role secondary and micronutrients (SMNs) play in cultivating a healthy crop. Most fertilizers are already designed to provide the foundational elements for growth (nitrogen, potassium and phosphorus), but many fail to include SMNs such as iron and zinc. For a plant to truly flourish, it must have a balanced application of nutrients.

Trying to grow food in degraded soil is like trying to ride a bike with a rusted chain. You can still reach your destination, but it’s not going to be a pleasant ride. Any seed, no matter its nutrient value, will fail to reach its potential if placed in depleted soil.

Just like you can grease the chain of a rusted bike, a malnourished plant can be supplemented with SMNs. Typically, there are two fertilizer-based methods used to accomplish this: foliar spray and SMN fertilizer blends.

Foliar Spray

The foliar spray method coats a plant’s leaves with liquid fertilizer. By applying solutions directly to the leaves, farmers bypass the traditional root-uptake method usually required to supply a crop with its essential micronutrients. The foliar spray method offers many benefits, including increased yield, better produce flavor and longer shelf life.

Foliar spray must be applied frequently to maintain adequate levels of micronutrients. This costs farmers much more money. Large producers can usually afford the extra cost, but smallholder farmers often lack the resources needed to maintain this method. Therefore, liquid fertilizer is typically only recommended either when traditional fertilizer is unable to reach a plant’s roots or when extra income allows farmers to supplement existing methods.

SMN Fertilizer Blends

Unlike foliar spray, application of SMN fertilizer blends can nourish a crop while remaining cost-effective to smallholder farmers. There are several ways to accomplish this.

Bulk blending involves mixing traditional NPK fertilizer with small amounts of SMNs. While all the required elements are present using this method, they tend to segregate when applied in the field, creating a poor distribution of nutrients.

Coating granules of fertilizer can solve the problem of segregation. Through coating, powdered SMNs are applied directly to the surface of fertilizer using adhesives. As a result, the product forms a stronger bond between its components.

Nutrients can also be incorporated during the manufacturing stage. Combining SMNs during the fertilizer production phase can help ensure a more even distribution. Just as with coating, this prevents the negative effects of segregation.

Regardless of which method is used, adding SMNs into soil-applied NPK fertilizers is a sustainable solution that can ensure more nutritious staple crops become part of healthy diets.