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Getting the Most Out of Commercial Fertilizer Applications

Important Terms

Table 5.1.1 Key words and Definitions

Term Definition

Ammonia Toxicity

This occurs when the free ammonia ion (NH

3

+ ) is released when urea-N fertilizer converts to the ammonium form (NH

4

+ ). A high concentration of the free ammonia ion causes germination and seedling damage. Highly calcareous soils are more susceptible to ammonia toxicity than non-calcareous soils. Banding

Any application method where the fertilizer is applied in concentrated strips, either on the surface or sub-surface.

Broadcast Application Fertilizer applied on the soil surface. Dribble Banding Surface banding of liquid fertilizer.

Fertigation Applying fertilizer using irrigation water and equipment. Foliar Application Applying liquid fertilizer to the leaf surface. Knifing or “Knifing in” Band application below the soil surface.

Broadcast and Incorporation Incorporation of broadcast fertilizer using conventional tillage equipment. Seed-Placed (in row) Fertilizer placed in the same furrow as the seed. Pre-Plant Application Fertilizer application prior to seeding of the crop.

Salt Effect

The osmotic pressure or “pull” that fertilizers have on soil water. This osmotic pressure will prevent soil moisture, which is near the seed, from being accessed by the germinating seed and young seedling. This can be a major cause of germination and seedling damage. Salt effects are most severe when soil moisture is limited.

Seedbed Utilization (SBU)

The width of fertilizer and seed spread, relative to the row spacing, reflects the relative concentration of fertilizer in the seedrow. The higher the SBU, the more fertilizer that can safely be applied with the seed. For example a 7.5 cm spread with a 15 cm row spacing is 50% SBU (7.5/15 x 100 = 50%).

Side Banding Fertilizer placed in a row near the seed during the one-pass seeding operation. Side-Dressing Fertilizer application in a row adjacent to the crop row. Split Application Fertilizer application is split into two or more applications. Starter Fertilizer Fertilizer applied when planting, usually in or near the seed row.

The balance of nutrients in manure does not match the nutrient requirements of crops. Strategic use of commercial fertilizers can address this imbalance by helping to optimize the use of manure nutrients and minimize the accumulation of nutrients (e.g., P) in soils that can occur with long–term, repeated applications of manure. As such, the judicious and efficient use of

commercial fertilizer is an environmentally responsible management practice.

This chapter will introduce important terms and concepts related to optimizing commercial fertilizer application including: fertilization, product placement methods, and the timing of commercial fertilizer applications.