North Carolinian Mike Howard and his son grow strawberries and an assortment of vegetables for local retail sale. Over the years, they’ve built up a loyal clientele.

About half of their customers go out in the field and pick their own produce; the others place an order and come get it when it’s ready. They count on the Howards for quality, and the Howards count on regional agronomists to help them provide it.

“My family has been farming since 1938,” Howard said. “For decades, tobacco was our family’s mainstay. Today there is a big demand for local produce. Customers want products they can trust, so now that’s our niche. Children, especially, like to go out in the field and pick.”

Howard’s farming has shifted focus over the years. In the 1970s, Howard put up chicken houses. In the 1980s, he began growing strawberries on matted rows. In 1985, as the North Carolina Department of Agriculture expanded its field services program statewide, Howard began turning to his regional agronomist, J. Ben Knox, for crop nutrient management advice. That change was followed closely in the early 1990s by yet another — the innovation of growing crops on plastic.

“Plasticulture was being promoted at the time as a way to produce a cleaner crop with higher yields,” Howard said. “Of course, it also had more annual costs, required more inputs and made it necessary to have buyers lined up ahead of time. I started out with half an acre of plastic and, at first, thought it was easy.”

When Howard expanded his acreage the next year, it was a different story. He found that with chickens, tobacco and both matted-row and plasticulture strawberries, there were too many tasks to do in the spring. So in 1995, Howard decided to limit his operation to chickens and plasticulture crops. The two enterprises have proved to be compatible.

Today the Howards grow many crops, including strawberries, pumpkins, corn, tomatoes, beans and squash. Plasticulture keeps down the weeds, helps conserve soil moisture and makes harvest cleaner. Because each crop has different nutrient needs, the Howards depend on NCDA&CS consulting and agronomic testing services to help them get the fertilization right.

“If we started a crop and didn’t have access to the Agronomic Division, we’d be in trouble,” Howard said. “We use all of the agronomic testing services — soil testing, tissue analysis, nematode assay, waste analysis and solution analysis — and we’ve worked with several regional agronomists. Each one has an area of specialty, but they network and share information so everyone benefits. They help keep us on track.”

When Howard decided to stop growing tobacco and shift completely to plasticulture, several people told him he probably would not need to apply any phosphorus fertilizer. Conventional wisdom said that after decades of fertilizing tobacco, the soil would already be sufficiently rich in this nutrient.

Tests told a different story

Soil test results told a different story. Howard broached the issue with Knox, who pointed out that the soils in Howard’s fields were a patchwork mix of a red clay and a gray, sandier soil. These soil types had different capacities to retain phosphorus. Knox suggested that Howard should consider using the poultry house litter from his own farm for areas needing extra phosphorus.

Howard was hesitant. He knew the litter would be a good source of phosphorus, but he was afraid it would provide too much nitrogen for strawberries. Cautiously, he put out litter in the fall nearly a year before planting strawberries. That winter and spring, he let a neighbor grow barley in the field to deplete some of the nitrogen. The strawberry crop did not incur any problems with excess nitrogen.

Howard is glad he followed up on Knox’s recommendation. His current routine is to apply litter to a ryegrass cover crop in March or April when the layer houses are cleaned out. He still likes the fact that the ryegrass cover crop uses some of the excess nitrogen before strawberries are planted in September. And after strawberries are harvested, he can plant yet another crop — pumpkins — directly into the existing plastic.

The amount of litter the Howards apply depends jointly on the results of the waste analysis and soil test reports. Due to the different soil types, they often spot-apply commercial fertilizer — putting it out only where it is needed based on soil test results. Before planting, they also use a nematode assay to establish whether pre-plant treatment is necessary and solution analysis to check the pH and salt content of their irrigation water source.

“Plasticulture is a hard job and a big expense,” Howard said. “The farmer is dependent on an entire system working. If it doesn’t, he could lose his whole crop. It pays to take precautions. I’m not a gardener. I need to make a living.”

Knox said tissue analysis is one of the best tools available to plasticulture growers.

“Test results are available within a couple of days and give a precise snapshot of the nutrient needs of each crop,” Knox said. “The test can even detect deficiencies before symptoms appear and losses occur. For high-value, intensively managed crops, tissue testing is the best way to optimize fertilizer input costs and obtain desired yields. It is particularly useful for Mike since he grows two successive crops on plastic. By monitoring nutrient use with tissue testing on a bi-weekly basis, he knows exactly how and when to adjust fertigation.”

The Howards are firm believers in the benefits of agronomic testing. But even more than the testing, they appreciate being able to talk to a real person about what their report results mean.

“The good thing about working with regional agronomists is that they know all about sampling procedures, test results and nutrient management,” said Howard’s son Brian, “and . . . they answer their phone after hours.”

The NCDA&CS Agronomic Division has 13 regional agronomists who are striving to lend special assistance to plasticulture growers this year. Thanks to a grant from the North Carolina Tobacco Trust Fund Commission, the Division has been able to hold two plasticulture training workshops, offer growers free vouchers for plant tissue analysis, and offset the travel costs involved in on-site visits by regional agronomists. Growers with an interest in plasticulture are encouraged to contact their regional agronomist for advice. Visit http://www.ncagr.gov/agronomi/rahome.htm for contact information.