Farm Journal Test Plots demonstrate starter fertilizer’s role in young plant growth
The concept of starter fertilizer is no stranger to the Farm Journal Test Plots program. Farm Journal Field Agronomist Ken Ferrie has conducted starter fertilizer trials since 1991. This past spring, the team advanced their research by studying the response to dual starter placement and evaluating the role of the environment when incorporating additives to starter blends.
Ferrie suggests using a hierarchy in decision-making to nail your timing and placement. Timing is determined by the environment and sets the scene for placement. Placement then dictates the source.
The two keys to proper placement are putting the nutrients where the plant can access them and never disrupting the seed. Based on past data, on average, there is a 7 bu. to 10 bu. response to starter placed 2" to the side and 2" down from the surface (2x2) and 3 bu. to 5 bu. response to in-furrow application. If you put the two together using dual placement, there is a 15 bu. to 20 bu. increase.
“It’s like the fertilizer positions are handing off a baton, so the roots find the nutrients as they need them,”
Ferrie explains. “This is why we call it the relay effect.”
However, he cautions the risk of starter burn. To avoid starter burn, limit in-furrow rates to reduce the
potential harm from putting too much salt around the seed, which can affect germination and ear count.
|The combine yield monitor is calibrated, and the grain cart weighs each pass with a verified scale to collect, weigh and evaluate by management zones.
In 2014, Ferrie launched a new study to evaluate the relay effect and the addition of sulfur to starter blends. The crew used a Kinze 8-row planter outfitted with the Schaffert Generation 2 fertilizer disk and Keeton seed firmers for the in-furrow application. The Schaffert attachment cuts a trench 2" away from the seed and uses an injection nozzle to apply fertilizer (see photo on page 12). The plot field stretches more than 70 acres and has natural variance across the field with four soil types (Hartsburg silty clay loam, Sable silty clay loam, Catlin silt loam and Ipava silt loam), which are divided into multiple management zones. Keeping the variables consistent across the plot, including the
hybrids, weather environment and planting dates, allows the opportunity to collect, weigh and evaluate the plot by management zones.
The different blends of starter fertilizer, some with sulfur, were applied across the field and replicated more than eight times to study the yield response across management zones. This particular field had 24 lb. of sulfur broadcast with pot ash the fall before planting.
Much like a typical field, Ferrie and crew experienced unexpected conditions due to excessive rainfall in early June. This left the low-lying ground sitting in water and the high ground relatively dry.
Similar to nitrates, sulfur can gas off. As a result, sulfur deficiency was quickly apparent in the low ground where the sulfur gassed off. Although troublesome, this provided a unique opportunity to learn how the added sulfur in the starter mix would play a role in sulfur-deficient areas. In some parts of the field, ammonia nitrate was aerially applied in mid-July to help rescue those areas.
Due to the wet conditions, the management zones with low-lying areas, including the Hartsburg silty clay loam, showed a greater response to the dual placement of starter with a sulfur additive. This soil has naturally high pH levels of 7.5 to 8.2 and was expected to respond to the sulfur additive. Compared to dual placement alone, this application had nearly a 11 bu. yield increase, which resulted in $26.49 more per acre, as shown in the chart at bottom left.
In the areas that did not experience the effects of ponding the various management zones had little response to the added sulfur. In the Sable silty clay loam, there was only a 1 bu. yield increase (again shown in the chart at left), which does not pay for the sulfur additive.
The plots discovered when dealing with early season sulfur deficiencies, you’ll make money putting sulfur in the starter. Other areas that weren’t hit as hard didn’t pay.
If you have early season nitrogen deficiencies, nitrogen in the starter along with phosphorus will make money. For example, in the Catlin silt loam soils, which has low organic matter, the 20 lb. of nitrogen jumped yield by 10 bu. This area had experienced ongoing nitrogen deficiency problems early on, which triggered the strong response to the high rate of nitrogen in the starter. The soil type did experience water damage, which caused further nitrogen deficiency issues. To rescue the field, ammonia nitrate was applied in mid-July.
“This observation and knowledge of environmental and field conditions results in yield,” Ferrie adds. “If you plant in an environment that struggles in the first six growth stages, you will lose yield that you can never recover.”
The cooler, wetter years often have a bigger response in early growth to starter, phosphorus and placement.
“If planting into cool, wet conditions, you might have trouble with phosphorus availability,” Ferrie says. “In soils with low fertility or high pH, you may put most of your phosphate into a starter band to reduce nutrient tie-up issues.”
Looking for the one mix that can do it all can get costly in down commodity markets. Don’t just include any
additive in your starter blend, choose the right additive conducive to field environments and conditions. FJ