Managing Your Soils

The first field day of the season turned out to be a warm, beautiful spring day. Fruit and Vegetable Specialty Mentor, Debra Brubaker, welcomed our group to Village Acres Farm and introduced us to Penn State Extension Educator Tianna Dupont. The day began with a conversation about the farm and the Brubaker's soil management practices. Debra's father, who is in the process of handing the farm business over to her, spoke about the influence of his own father's views on his soil management views and organic practices. He and Debra discussed the challenges of managing Village Acres Farm, where the fields are low, composed of much clay, and tend to be wet. Such field characteristics have led them to experiment with different machinery and cover crops; falling out of favor with a crimper-roller, and utilizing various combinations of rye, hairy vetch, clover, alfalfa, peas and mixed grasses on his fields, depending upon the time of year.

Next, our group headed out to the field to learn how to monitor soil quality. The first test that Tianna had the group practice was a quick and easy way to measure soil infiltration rates. A good infiltration rate is important because it is an indicator of how easily your soil might erode during periods of rain. To measure soil infiltration, make a small hole in the field with a circle of tubing, and then quickly pour water into the hole, one inch deep. Have a pocket watch handy, and measure how long it takes for the water to fully absorb. The infiltration rate can be calculated by (1" water x 60)/(Time).

A good quality soil will also consist of approximately 50% air and moisture. This quality provides space for soil organisms to thrive. In order to measure water-holding capacity, Tianna had the group take a small ring of PVC piping with some mesh placed across one opening, and place a small sample of field soil upon the mess. This piping was then submerged in water for 5 minutes, and the soil that remained was examined. Healthy soil will not dissolve entirely, but rather will maintain its clumps to a certain degree.

Next, we discussed soil nutrient testing. Tianna's advice is to pick a lab and stay with them. Different labs perform their tests in various manners, and produce their reports in different ways. In order to monitor your land overtime, it is helpful to stick with the same lab, and to ask them as many questions as need about what their scales are and what their recommendations mean. In order to collect a sample to send out, follow these basic steps:

• Decide on the number of samples that you will send out, depending upon how many fields that you manage differently
• For each field that you want to test, take at least 15 samples from that field, zigzagging your way across it
• Use a tube or shovel that will allow you to take samples that are about the same diameter and depth
• Mix these 15 samples together well, and draw one cup of soil from this mix to send to the lab. Do not worry if the soil is a little wet.

After lunch, our group sat down with Deb and Tianna to review soil test results and learn how to interpret them. Terminology differs by lab, so make sure to ask the lab if you aren't sure about the information they are giving you. Also, beware of conversion rates when heading the lab's recommendations. The soil tests often do not report on Nitrogen content of the soil, but you can estimate the amount of Nitrogen that you have, yourself. Legumes add new Nitrogen to the soil, and grasses recycle the Nitrogen that currently exists. To estimate the amount of Nitrogen in the soil, Tianna recommends using a cheat-sheet of legume Nitrogen levels. Measure the height of your legumes, multiply it by the area of cover and then by the amount of Nitrogen that the legume you have planted tends to provide.

Finally, the group wandered over to the high tunnels. The biggest problem for high tunnels tends to be salt content. This is because water, and particularly municipal water, tends to have a high salt content. Rain washes the salt out of the soil easily, but high tunnels prevent this salt-flushing from occurring. The best way to resolve this issue is simply to remove the cover every once in a while to allow rainfall to flush the high tunnel soils. An EC meter may be a worthwhile purchase if you are concerned about the salt content in your high tunnels.