Agrotips

Prepare for a fall vegetable garden by soil testing.

If you are thinking about planting a fall vegetable garden in July or August, then you need to take the first step in June - Soil test. The test is free, and sampling instructions are available online at www.ncagr.com/agronomi/pdffiles/samhome.pdf. Sample boxes and information sheets are available at all county Cooperative Extension offices. Within two weeks, you should have the information you need to apply lime and fertilizer for a productive garden.

Test source water for irrigation systems.

Before you turn on that drip or overhead irrigation system, it is a good idea to collect samples of your source water and have it tested by the NCDA&CS Agronomic Division. Chemical problems with source water can affect plant growth and quality. By testing water now, you can correct any problems before you start irrigating your crops.

Solution analysis is a service that measures the chemical properties of water that affect plants. In Eastern North Carolina, high alkalinity is a potential water problem. Irrigating with highly alkaline water can lead to an increase in soil pH that can limit availability of some essential plant nutrients, especially micronutrients.

The solution analysis report indicates whether alkalinity is a potential problem and, if so, provides helpful advice to correct it. Some other potential source water problems include high soluble salts, iron, boron, sodium or chloride. Once identified, these problems can either be corrected or effectively managed to prevent plant growth problems.

If crop plants are stunted or discolored, check for nematodes.

The best way to find out if nematodes are responsible for an area of poor crop growth is to collect and submit two sets of soil samples: one for nematode assay and one for fertility analysis. An accurate diagnosis during the growing season provides a sound basis for effective management in the future.

For nematode assay, collect samples at the margins of affected areas where symptoms are moderate to severe. Avoid areas where plants are already dead or dying. For each nematode sample, collect at least 20 cores from the top 8 to 12 inches of soil, mix them together, and then fill a one-quart plastic bag about three quarters full. Be sure the sample includes at least a small handful of roots from the affected plants. Send a completed Nematode-Problem Diagnosis Information sheet along with the samples as well as the appropriate fee ($3 per sample). For fertility analysis, use excess soil to fill a standard soil test box. Fill out the orange information sheet designated for problem soil samples.

Package and address soil test and nematode assay samples separately so they will arrive at the correct laboratory. Use the Mail Service Center address when sending samples through the U.S. Postal Service.

Fertilize centipedegrass lawns in June.

The nitrogen fertilization rate and schedule for centipedegrass are different from those of other warm-season grasses. Centipede requires only 0.5 pound of nitrogen per 1,000 square feet per year, and all of this amount should be applied in June. The majority of fertility related centipede growth problems result from applying too much lime and phosphorus or inadequately maintaining soil potassium levels. These problems can be prevented by soil sampling and following recommendations. If you have not taken a soil sample in the last two or three years, you may want to do so to find out your lawn’s fertility needs. When filling out the soil information sheet for your sample(s), remember that centipedegrass has its own crop code (022).

Important Reminder: Do not fertilize cool-season lawn grasses—fescue, ryegrass and bluegrass—during the summer. Wait until September.