An advertisement agit-prop for using superphosphate and nitrogen-based lime fertilizer in agriculture. Father Brázda has sown and his friends - the artificial fertilizers - help him reap a rich harvest. We can illustratively watch how they take care of the sown plants, provide them with nutrition and fight the weeds to make the grain strong and increase its yield. Another farmer, experiencing a low harvest in an agricultural cooperative, wonders how Brázda could achieve such great farming results.