Y: I’m really enjoying this cute farm video game lately, Don. Currently I’m stuck on a difficult puzzle. Using the same field, I plant crop number 1 the first year, crop number 2 the next year, and crop number 3 the third year.
D: So it’s a puzzle about crop rotation. Let me try it, Yaël. [PAUSE] There, it’s solved.
Y: How did you figure it out? There were so many different crops I could choose from, and so many different combinations, that the possibilities seemed endless. How was I supposed to know what three crops to plant?
D: That’s an agricultural problem farmers have always faced. If you plant the same crop year after year, the soil gets drained of nutrients. You also get lots of pests who love that crop.
Y: That explains why the game didn’t like a one-crop system. But if that’s the case, why not plant a different crop every year?
D: A regular pattern creates a natural balance. Certain crops replenish the nutrients, such as nitrogen, that a previous crop took from the soil. That way, no single nutrient gets depleted, and your soil stays healthy. And when you rotate your crops, you stop those bugs from settling down, because you constantly remove their source of food.
Y: That brings us back to the original problem. How do you pick which crops to rotate?
D: Unfortunately, farmers don’t have endless choices of crops to plant, because there are many factors they must consider: soil type, environment and climate, economics, and even what farm equipment is on hand.
