Rosetree Consulting LLC

06/03/2026

Nitrogen Is Too Expensive for Guesswork
Tool #2: Penn State's Nitrogen Support Tool (G*T)

Yesterday, we talked about nutrient management planning and mass balance calculations. It's where we start every nitrogen recommendation.

Today, let's look at a situation where another tool challenged our original recommendation.

This scenario is built from a Berks County corn field with very little manure history. However, this field did receive 4 tons/acre of poultry litter this spring. Based on our traditional mass balance calculation, we planned for:

• 69 lbs manure nitrogen
• 6 lbs starter nitrogen
• 119 lbs nitrogen from pre-emerge UAN (40 gal 28%)

Total planned nitrogen: 194 lbs/A

At today's fertilizer prices, that's a significant investment.

Before making the application, we ran Penn State's Nitrogen Support Tool (Graphical Analysis Tool, or G*T). Unlike a traditional mass balance calculation, the G*T incorporates soil texture, cover crop management, and the soil's ability to mineralize nitrogen throughout the growing season.

The result?

The tool suggested the field may only need about 64 lbs of nitrogen to achieve the target yield — an amount already supplied by the poultry litter application.

That's a big difference.

Did we eliminate the planned UAN application entirely? No.

While the data was compelling, both the grower and agronomist felt reducing the entire field to zero supplemental nitrogen was too much risk for a single season. Instead, the field received 20 gallons of UAN rather than 40 gallons, reducing nitrogen costs while still maintaining a level of comfort with the recommendation.

The lesson isn't that a computer model is always right.

The lesson is that tools like the Penn State G*T can help challenge assumptions, quantify nitrogen cycling, and identify opportunities to improve nitrogen use efficiency. Building confidence in these tools takes time, which is why we'll continue to pair them with in-season observations, tissue sampling, cornstalk nitrate testing, and yield data.

As nitrogen prices remain high, that's a conversation worth having.

Tomorrow we'll look at another tool we're using to bring weather, soil conditions, and crop management together to fine-tune nitrogen recommendations.

06/02/2026

Nitrogen Is Too Expensive for Guesswork: Start with the Basics (MBC)

Before we get into advanced modeling tools and in-season testing, we start with the basics: a mass balance calculation (MBC).

The concept is simple. Estimate crop nitrogen demand, then account for every nitrogen source available to the crop.

For this Berks County corn field, our 235 bu/A yield goal required approximately 235 lbs of nitrogen.

Here's where that nitrogen came from:
• Spring-applied heifer slurry: 51 lbs
• Residual manure credit: 35 lbs
• Soybean rotation credit: 40 lbs
• Pre-emerge UAN: 45 lbs
• In-season topdress: 66 lbs

Total nitrogen available: 237 lbs

On paper, that's almost exactly 1 pound of nitrogen per bushel of expected yield.

But the interesting part is what happened next.

This field has averaged 247 bu/A corn over the past five years while consistently using less than 1 pound of nitrogen per bushel produced. Why? Deep limestone soils, annual manure applications, cover crops, and continuous no-till all contribute to improved nitrogen cycling and efficiency.

The lesson: before adding more nitrogen, make sure you're accounting for ALL of the nitrogen already available to the crop.

Tomorrow we'll look at a field where Penn State's Nitrogen Support Tool challenged our original recommendation and reduced planned nitrogen applications significantly.

06/01/2026

Nitrogen Is Too Expensive for Guesswork

Last week, we talked about how nitrogen decisions are moving beyond "what we've always done" and toward using field-specific data and actual growing conditions to fine-tune recommendations.

This week, we're going to show you what that looks like in practice.

Nitrogen is on the mind of many Rosetree clients right now, and it may be on yours too. Fertilizer prices remain high, and while we want to set the crop up for success this fall, we also want to make sure every pound of nitrogen is delivering a return on investment.

The challenge? There is no one-size-fits-all nitrogen plan.

Soils vary in their ability to retain nitrogen and produce nitrogen. Cropping history, manure applications, soil health practices, soil type, fertilizer delivery options, labor, and logistics all play a role in determining the right rate.

Over the next week+, we'll share several tools and approaches we use to help clients make nitrogen decisions, including:
• Nutrient Management Planning
• Penn State's Nitrogen Support Tool
• Adapt-N
• Pre-Sidedress Nitrate Testing (PSNT)
• Zone Management
• DIFM Nitrogen Response Trials

Each example comes from a real Pennsylvania corn field in 2026. The data is as current as we can make it.

Because getting nitrogen right isn't about finding one answer. It's about using multiple sources of information to make better decisions.

06/01/2026

Replant or keep it?

Join Rosetree Agronomist Eric Rosenbaum as he evaluates this soybean field the same way we recommend every grower does: by taking the time to gather 10–12 population counts across the field, assess the median stand, evaluate the range in populations, and determine how uniform the stand really is.

A field's average population is only part of the story. Uniformity, gaps, plant health, planting date, and yield potential all play a role in determining whether a replant makes agronomic and economic sense.

Watch as Eric walks through the process and explains why sound replant recommendations require evaluating the whole field - not just the worst areas.

What are replant decisions looking like in your fields this year?

05/29/2026

BUG OF THE WEEK ANSWER

This week's mystery insect is... Bean Leaf Beetle!

Bean leaf beetles typically have two generations per year and are a common soybean pest across the region.

Before considering treatment, remember the thresholds:

• VE-R1 soybean stage: Approximately 30% defoliation

• R1 through maturity: Approximately 15-20% defoliation

One of the most interesting aspects of bean leaf beetle management is the economic component. As soybean prices increase, the amount of yield worth protecting also increases, which can lower the economic threshold for treatment. (Take a look at the economic threshold chart included with this post)

The key takeaway: Scout fields, estimate defoliation accurately, and compare what you're seeing to established thresholds before making a treatment decision ... not every beetle requires a spray pass.

05/29/2026

WRAPPING UP MAY WITH ONE FINAL "BUG OF THE WEEK"

This insect produces two generations each year and is a common visitor in soybean fields throughout the growing season. Early-season feeding can create small, round holes in soybean leaves.

Think you know what it is?

Drop your guess in the comments, and we'll reveal the answer later today along with management considerations.

05/29/2026

As we mentioned yesterday, more nitrogen decisions are moving beyond “what we’ve always done” and toward using field-specific data and actual growing conditions to fine-tune recommendations.

That’s especially true in a year with variable weather, high nitrogen costs, and uneven field conditions heading into sidedress season.

Penn State Extension recently shared a strong article outlining several diagnostic tools and approaches being used to help evaluate nitrogen needs in-season, including:
• PSNT soil testing
• Tissue testing
• Crop canopy sensing
• Nitrogen modeling tools (like Adapt-N)
• Field-by-field evaluation methods

Good educational read as sidedress season approaches!!

Several tools are available to help determine an appropriate sidedress nitrogen rate for corn.

05/28/2026

Sidedress decisions are coming fast — and nitrogen investments feel a lot different this year.

Nitrogen prices are high, weather has been all over the place, and every field seems to be carrying a different story heading into sidedress season.

A lot of nitrogen programs are built around “what we’ve always done,” but nitrogen availability changes year to year — and even field to field.

Rainfall affects nitrogen loss.
Temperature impacts mineralization and crop uptake.
Soil type changes holding capacity.
Hybrid selection and yield goals influence demand.

That’s why we’re running more fields through scientific decision-making tools this season (like adapt N) that utilize field-specific data to help fine-tune sidedress recommendations based on actual growing conditions, management history, and yield potential.

The goal isn’t simply cutting rates. It’s making sure every pound of nitrogen is working toward return on investment while still protecting yield potential.

What is your operation operation doing differently when it comes to sidedress nitrogen decisions this year?

05/23/2026

Is this field a "replant" ????

Uneven emergence can be caused by a number of things:

• Poor planter maintenance and setup
• Bad soil conditions like compaction or planting too wet
• Shallow planting depth
• Disease or insect pressure
• Soil temperatures and variety response

Sometimes the best diagnosis comes from eliminating the obvious.

In this field, the planter performed well. Soil conditions were excellent. There were no noticeable insect or disease issues.

What was left?

A variety that germinated in cold soils with cold water uptake, resulting in a 10 to 15% reduction in emergence uniformity.

This field is not replant worthy, but it is important to recognize this variability now so there is a better understanding of yield performance at harvest.

Not every uneven stand means replant. Finding the true cause helps make the right management decision.

05/22/2026

Fun Friday ANSWER - how did our team rate the slug impacts to this field?

Rosetree Agronomists rated this field a 2.

Why? The soybeans are already at the 1st trifoliate growth stage, meaning plant growth is currently outpacing slug feeding. Growth remains uniform across the field, and plants are not showing signs of stagnation.

Even better — several management decisions stacked the odds in this field’s favor:
• Planted ahead of the main slug hatch
• 30” rows
• Green planting situation
• Starter fertilizer program

Individually, each choice may seem small. Together, they significantly reduced the likelihood of needing rescue treatment or replant.

Now, if these beans were still at the cotyledon or unifoliate stage… our mitigation plan might look very different.