Selenium is important for plants and humans, but it's often lacking in soil and therefore in our diets. This study looked at adding different amounts of selenium to cowpea plants to see how it affected the selenium levels in the seeds. They found that adding selenate was better than selenite at increasing selenium in the plants. By adding 10 grams of selenate per hectare, the cowpea seeds could provide enough selenium to boost human intake by 13-14 micrograms per day. Phytic acid in the seeds didn't change much with the selenium additions.