Crops need nutrients to make them grow strong and healthy, just like humans. Each nutrient plays a different, but important role in crop growth and development. If crops do not receive the nutrients they need, the result could be weak crop growth and low yield.
Nutrients do exist in the soil, but as the plants grow they use the nutrients up. Farmers need to apply new nutrients every year to replenish the soil. Farmers test their soil to know which nutrients they are low in.
There are four main crop nutrients:
All plants need nitrogen, phosphorus, potassium, and sulfur to grow healthy and strong.
Phosphorus (P) comes from ancient sea life. All living organisms require phosphorus, especially plants. Plants need phosphorus to:
- Help the plant grow healthy roots
- Store and transport nutrients throughout the plant
- Grow normally and produce fruit/seeds at the right time
- Resist disease (because all the plant parts are well developed)
- Convert energy from the sun into food (photosynthesis)
- Help pulse crops fixate nitrogen (turn nitrogen from the air into a useable form)
If there is not enough phosphorus, the crop will have reduced growth, weak roots, thin shoots, and dark leaves. Too much phosphorus does not harm plants, but will cause it to be lacking in other nutrients.
Sulfur (or Sulphur)
Sulfur comes from fossil hydrocarbons which are often found in areas with high volcanic activity. Sulfur is sometimes called the 4th essential nutrient and is very important for plant growth. Plants need sulfur to:
- Help to make the building blocks of proteins
- Turn the energy from the sun into food, which is called photosynthesis
- Make oil
- Use nitrogen best
- Produce healthy flowers
- Grow healthy roots and nodules
Sulfur is a bright yellow crystal in its natural state.
Oilseed crops, forage crops, and legume crops require more sulfur than other crops such as wheat, barley, or oats.
Plants absorb sulfur from the soil with their roots. Sulfur does not move throughout the plant, so plants need constant access to it throughout the growing season from the time the plant starts to grow, to flowering, to maturity.
These legume crops all require more sulfur than many other crops.
These oilseeds crops all require more sulfur than many other crops.
Crops require just 10% as much sulfur as they do nitrogen. If there is not enough sulfur, plants will have short or thin steams, yellow new leaves, delayed and longer flowering, small pods, and reduced yield.
Sulfur and nitrogen work together and a careful balance of both is needed to produce the healthiest crops.
Sulfur helps the plant to be more resistant to the cold, which gives it some frost tolerance.