A healthy food diet is important when it come to improving your sperm quality. BBC have som very interesting points, so I would recommend that you read their article to gain more insight on how to improve your sperm quality.
"A number of studies have shown that a good dietary intake of antioxidants and micronutrients is critically important for normal semen quality and reproductive function. Healthy men with a higher antioxidant intake from both diet and supplements are likely to have more sperm and their sperm will be more motile"
Click on the picture to read the article from BBC.