CHOOSING THE RIGHT FERTILIZER PLACEMENT METHOD
When applying nitrogen and phosphorus fertilizers to your crops, there are several approaches you can take. Phosphorus doesn’t leach out of the soil, and it isn’t typically harmful to seeds or seedlings, making it the easier of the two fertilizers to apply. Nitrogen dissipates into the atmosphere quickly, and it is also easily washed away in soil water. In heavy concentrations, nitrogen can also be harmful to your crops. Here is an overview of the various fertilizing techniques used by direct seeding growers to help you choose the best method for your crops.
Seed Placed Fertilization
Seed placed fertilization is the easiest method – the fertilizer simply flows down the seed tube with the seed. It is also the most cost-effective way to fertilize your crops. It only requires one pass over the field as you are seeding, and there isn’t a lot of nitrogen loss. The equipment is easier to pull than banding fertilizers, so you are using less power as you plant the fields. However, applying nitrogen with this method can be dangerous. When applied at rates of more than 25 to 40 pounds per acre, nitrogen can damage seedlings.
This method can be useful in certain situations. If the soil is too wet to be worked properly, you can resort to broadcast fertilization. It is also commonly used in hay fields, or on crops that are already growing. However, the drawback to broadcast application is that a lot of nitrogen will be lost to the atmosphere as you apply it.
Spring or Fall Fertilizer Banding
Fertilizer banding is nice because it places the fertilizer directly into the root zone. By applying banded fertilizer in the fall when prices are lower, you may be able to save on fertilizer costs. However, this method does require an extra pass over the cropland, which will increase the total amount of manpower and fuel invested in your crop. It also means extra tilling, which is a disadvantage in a direct seeding program.
Below-seed fertilization is meant to increase the efficiency of nitrogen fertilizers. In practice, it is often difficult to place the fertilizer accurately and keep it separate from the seed. If the soil isn’t flowing properly around the opener, the seed can be placed directly in the fertilizer. In addition, furrow packing may push the seed closer to the fertilizer than it should be. With the seed placed in loose soil rather than on a firm seedbed, you are reducing your seed to soil contact, which can lead to poor germination rates.
Many growers prefer side-banding because it is a good method to ensure that the seed and fertilizer remain separate. You will also have the advantages of an undisturbed seedbed, and you can control the depth at which the fertilizer is placed. However, equipment that is capable of sidebanding tends to cost more. With the extra openers, seeders with sidebanding capability are more difficult to pull, which will increase your fuel costs.
Paired Row Fertilization
Paired row banding works similarly to side-banding with one key difference: one fertilizer band is placed for every two seed rows. This method provides two advantages over traditional side-banding methods. With fewer openers, paired-row capable equipment is easier to pull, so your fuel costs will be lower. Paired row banding should also result in less soil disturbance than traditional side-banding. Since this is a fairly new fertilization method, make sure you purchase proven equipment. Some paired row openers have inaccurate fertilizer placement, while others cause more soil disturbance than they should.