If you haven't already, performing a laboratory soil test is a valuable tool when growing vegetables in the ground. The test will evaluate nutrient levels and acidity (pH) level, which impacts how much nutrition the plant roots can access in the soil, plus which nutrients (if any, aside from nitrogen) might benefit from being supplemented. That way, you avoid over-applying nutrients the plants don't need. If the nutrients are already plentiful (which soil testing labs sometimes categorize as "excessive"), then making sure the pH is where it needs to be assures that the roots can access those nutrients. pH adjustments are fairly easy to make, but it helps to know what the starting level is so you know how much lime or sulfur might need to be added. (It's also possible the pH is already at a sufficient label, but testing is the only way to be certain.) Lab testing can also screen for lead level, in case the soil is heavily contaminated.

Nitrogen is the nutrient needed in the greatest quantity by plants, including vegetables. Soil tests don't measure it since levels naturally fluctuate so readily, but there are guidelines as to how much plants will tend to need, which you can learn about on our Fertilizing Vegetables page, plus any notes about fertilization on the pages for individual crops. Some nutrients will gradually be made available to roots from the composts you applied as well.

The pictured seedlings look fine so far, but they are so young that we would not really see indications of a nutrient deficiency at that stage. If concerning symptoms appear later this season, feel free to send photos for assessment, ideally while the symptoms are still fairly new and not extensive. There are a number of potential ailments each crop is vulnerable to, but following the cultivation tips in the pages linked above will help to minimize risk (giving plants good spacing, not wetting leaves when irrigating, growing disease-resistant cultivars, and so on), and some plant disease spread and severity is highly dependent on weather as well, so won't necessarily repeat itself from one year to the next.

Miri