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Data Collection

A picture of myself taking soil samples in a strip.

Just before the side-dress nitrogen fertilizer is applied to the corn fields, it is time to do a lot of field work. To begin, the PSNT (pre-side dress nitrogen test) is taken. They are soil samples taken in relation to the GPS points in the field. It requires 8 cores of soil from 12 inches deep. Along with that is sample of 8 cores at 8 inches deep to measure the concentration of other macro nutrients like potassium and phosphorous. Each field has a L, R, and an N strip. The N strip is where the extra fertilizer is added to. Depending n the size of the field, the number of points vary. In some fields there may be up to 19. That is 114 soil samples for one field!

Another job is to walk the greenseeker. The greenseeker is a device that measures Normal Digital Vegetative Index (NDVI). It is used to quantify vegetation by measuring the difference between near-infrared (which vegetation strongly reflects) and red light (which vegetation absorbs). This is one way to estimate the potential yield.

ndvi formula

The formula for NDVI. NIR stands for the near-infrared light reflected and Red is the amount red light absorbed.

Covering each strip does take a long time since there is only one greenseeker. It’s especially grueling during the heat and humidity of summer while keeping at a constant speed at 3 feet above the canopy.

A picture of myself walking the greenseeker at Aurora.

Drones flying can be very challenging.  Weather and surrounding objects play a large role in the success of a drone flight for a particular field.  The drone is responsible for taking multi spectral satellite images that measures the amount of reflected light by the plants from the sun.

A close view of the drone used to take light images.


It has been an insane period of time traveling across the New York from Peru, to Hudson Falls, and to Perry. In total 30 fields and 5 research plots were soil sampled, had greenseeker data, and drone images taken. A total of 3147 soil samples! The next part of the project is processing the data in order to make sense of it all.


Hello everyone my name is Travis Mattison and I and currently a junior in the Agricultural Sciences Major. I am doing my internship this summer with a precision agronomy company out of Rochester, NY called Agrinetix.  Agrinetix has its hands in all aspects of agriculture from selling GPS guidance systems and autosteer to fertility management plans, water management,  spray and fertilizer application control systems as well as a GIS department that does EC/field mapping, NDVI imagery and yield and planter mapping. This summer my main focus is working as a technology integrator installing and maintaining Trimble Guidance systems, 360 Yield center products, Precision planting products and Raven control systems.

The First two weeks were an extremely busy planting season. I was on the road almost everyday traveling to different farms across New York state mostly servicing Trimble GPS systems controlling auto-steer in the tractor as well as planter controls. After the hectic first couple weeks myself and the other tech integrator Chris went out to Ohio State University Agriculture Research and Development Center for a two day training conference put on by Trimble on a new product they released. The release was for the GFX750 display and NAV 900 controller as well as the Muller ISO ecu. This was a great experience receiving training on the product as well as networking with others in the precision agriculture industry from all over the United States and Canada.

Males, Mites, and Aphids

The workload for these last two weeks has steadily increased. The pests have gradually been increasing in the fields and I have begun to see more aphids and a few two-spotted spider mites. However, since the temperature hasn’t been as high as it usually is by this time of year, there are still not too many problems with pests. We are expecting temperatures to increase in July and two-spotted spider mites to become more of an issue then.

Look Closely to See a Two-Spotted Spider Mite!

During week three, I found an abundance of aphids in one section of a field. Ultor, an aphicide, was sprayed on just those twelve rows which terminated the aphid population.


The newest addition to our daily schedule is roguing. Roguing is scouting for male plants. The fields we are roguing had high seed percentages per barrel this past fall. Therefore, it is our job to find them, mark them, and cut them down. Later in the season, other workers will come in and remove the hills that we’ve marked to ensure that the males do not grow back next year. It is usually very obvious to spot the male plants because they have visibly large pollen sacs attached to the bines, as pictured below. However, if the plant hasn’t fully expressed itself yet, it can be very difficult to spot male plants which means very thorough checks must be made to ensure none are missed. My colleague and I scout every other row of a field to check for males. If a field is abundant in males, it can take us around six hours to complete a ninety row field. Therefore, we break up the time spent scouting over a few days. There are some bines that can also be hermaphroditic, due to an environmental stress that the bine may be under. We have to severe these bines as well to ensure that pollination does not occur.

Male Bines 

Hermaphroditic Bine

Another task which I have been assigned with is taking soil measurement readings in two fields. My supervisor manages the irrigation in these fields. The water conductivity of the soil is highly variable in these two fields, which means that soil moisture must be closely tracked to ensure that the bines aren’t receiving too much water to cause leaching, and so that they don’t dry out. My job is to take three readings in each of the eight zones so that I can develop a graph that shows the soil moisture for each zone in the field. My supervisor then makes decisions on the length of time the irrigation will run and how many times a day these fields will be irrigated.

To finalize this post, there are hops growing now! Below you can see baby cones developing on Simcoe and larger cones that have started growing on Palisade. If you can’t tell by the picture below, I am absolutely loving working with the hops!

Baby Simcoe cones

Palisade Cones

Nrich Strips

Corn is an extremely important crop to agriculture in New York State and nitrogen is the most limiting nutrient. The work being done my supervisor in the Nutrient Management Spear Program is to study how added nitrogen affects corn yields. The studies are called Nrich strip trials.

In order to begin the study, fields with at least three years of yield data are selected, preferably large ones since they typically have more variability. The yield data is arranged to represent 4 different quadrants in the field.

Quadrant 1- High yielding, low variability

Quadrant 2- high yielding, high variability

Quadrant 3- Low yielding, high variability

Quadrant 4- Low yielding, low variability

A week after planting, a strip spanning the length of the field is laid out. It is where the extra nitrogen fertilizer is applied at side dress time, usually 75 lbs. more per acre. The strips are about two chopper or combine passes wide in order to draw accurate conclusions.


A quadrant map of two fields selected for this project. The gray marks indicate the area for extra nitrogen fertilizer.


Once the trial is set up, GPS points are taken in the field. The points are the locations from where the pre-side dress nitrogen test (PSNT) will be taken. A PSNT measures the amount of nitrate (NO3-) in the soil. Nitrate is an inorganic form of nitrogen that plants most readily take up. Along with the PSNT, drone images, and green seeker data is taken when there are six collard leaves on the plants, otherwise known as V6 stage. That is where I will begin my next post.


A hand-held GPS.

GPS points taken from the field are downloaded into Arc Map to create a map like this. The white rectangle represents the Nrich strip.




















This is a diagram explaining what collard leaves on a corn plant look like.

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