Seeds are the most important input for every business, because without them we will not have the harvest we want. While there are several factors that affect seed germination and seedling survival, we will focus on the effects of nutrition in the furrow on the culture. Early feeding of the developing seedlings is important, however, if we are unaware of the risks associated with feeding in the furrow, we can find ourselves in an “too much of a good” situation. Some of the most important factors to consider when applying fertilizer with your seeds include seedbed use (SGE), soil texture, soil moisture, and fertilizer source.
A soil test is a good starting point for planning a fertility program. When developing a 4R (correct rate, location, time, source) fertility program, we look at each nutrient individually and how we manage its use in our program. Mobile nutrients like nitrogen and sulfur work well for banded applications like fall or spring bands, side band or center row banding operations away from the young seedlings as they move around in the soil solution to reach the roots of the crop. Non-mobile nutrients such as phosphate and potassium are best suited for placement in close proximity to the seed and at the time of sowing, taking into account safe quantities in the row of seeds.
Phosphate is perhaps the most important nutrient in the furrow or near the seed furrow (sideband) as it is critical to the plant’s energy production and is relatively immobile in the soil so proximity to the root zone is paramount. We often talk about the “pop-up” effect when using phosphate fertilizers, which is important for the young plants to get off to the best possible start. Our main sources of dry phosphate in Western Canada are either monoammonium phosphate (MAP) or products that use MAP in their primary composition. MAP has a low salt index and low toxicity to seedlings compared to other nutrients such as potassium chloride or urea. Guidelines for the maximum safe rate have been established in each province using MAP and based on a set SBU and using good to excellent soil moisture conditions.
When using the seedbed, it is taken into account how wide your opener is divided by the row spacing of your attachment. For example, a 1-inch opener with a 10-inch gap would use 10% of your potential seedbed. A wider row spacing with narrow openers concentrates your seed and fertilizer band, which can lead to an increased potential for crop reduction compared to wider openers with narrow row spacing. Soils with a higher clay content can better buffer the “salt effect” of fertilizers, and with higher seedbed moisture we will have less negative effects on our germinating seeds.
Ultimately, it is difficult to say that there is a perfect formula for “safe” fertilization with the seed. Every farm differs in its land characteristics, the moisture situation from year to year and of course in terms of equipment. Breeders would be well advised to evaluate their stand facility with their current program and assess the impact their current practices are having on their operation. Consulting with your local plant advisor can help you work through the variables to determine your best path for your fertility plan.
For more information, visit ProvenSeed.ca
