Sulfur

Micronutrients

The four most commonly deficient micronutrients that plants require and that can be supplemented through the use of fertilizer nutrients are: boron, copper, zinc and manganese. Micronutrients are key components of the body’s hormones and proteins. Although the combined weight of the micronutrients in your body is very small, you could not live without them. As is the case with primary nutrients, micronutrients should be applied on an “as-needed” basis to increase yields and quality. Levels can be estimated by a simple soil test. In order to be of value in making fertilizer recommendations, these tests can be further correlated with crop response on similar soils as plant analysis results can be used to confirm micronutrient deficiencies.

• Boron – Boron is an essential nutrient in the growth and development of new cells. It regulates flowering, pollination, seed development and sugar transport in plants. In human nutrition research, boron has recently been linked to the prevention of osteoporosis. Because boron does not translocate within the plant as readily as other nutrients, a constant supply must be available throughout the growing season. There may be sufficient boron early in the season for normal growth, yet an insufficient supply during seed development, resulting in poor grain or seed yields.
  
• Copper – Copper is a critical regulator of several plant enzyme systems and is necessary for protein synthesis and nitrogen metabolism. Plants only require small amounts of copper, which plays an important role in the formation of protein pigments found in red blood cells. Cereal crops are more sensitive to low levels of available copper than most other crops.
  
• Zinc – Zinc is an essential enzyme regulator in the synthesis of protein, starch and growth hormones in plants. Zinc-deficient plants usually mature at a later date than normal plants. The absence of zinc in the human diet can result in slow growth, bone and skin disorders, and even sterility.
  
• Manganese – Manganese is a part of several plant enzyme systems and plays a role in photosynthesis by regulating the formation of plant chlorophyll. It also plays an important role in humans where it is critical in the function of some enzymes and serves as an activator of others.

What's in my bag?

How much N, P and K are in your bag of fertilizer? The analysis found on each bag or bulk shipment of fertilizer tells the farmer or consumer the amount of nutrients being supplied. States have a system of laws and regulations that ensure the fertilizer is properly labeled and delivers the amount of nutrients stated to the farmer or consumer.

The three numbers on your bag of fertilizer are referred to as the "analysis." It is the percentage of nitrogen, phosphate and potash that is available to plants from that bag of fertilizer. In this diagram, this product contains 5 percent nitrogen, 10 percent phosphate and 5 percent potash.

So what's the other 80 percent of what's in this bag? While brands vary, typically the rest will contain some micronutrients and filler material, which allows for even application of the nutrients across the fertilized area.