The drought monitor report as of Tuesday, July 28, is basically unchanged from last week. Hard to believe in our area with the heat of the last week, but the humidity and relatively calm winds slowed evaporation a bit. The state is continuing to trend drier and this upcoming week’s weather won’t help. The six-to-10-day forecast (Aug. 4-8) indicates a 60 to 70% chance of above normal for temperatures and near normal for precipitation. The eight-to-14-day forecast (Aug. 6 to 12) indicates a continued 60 to 70% chance of above normal for temperatures and a 33 to 40% chance of below normal for precipitation. Not great for our summer row crops, especially soybeans and a sorghum crop just starting to head out.

Everyone from homeowners and backyard gardeners to agriculture spends a great deal of time and money on weed control. Billions of dollars are spent every year on lawns, gardens, pastures and crop fields. Even organic farming practices spend a great deal of time, labor, and money on weed control. Today, why are weeds so successful and do so well in our managed ground?

First, a weed is simply a plant where you don’t want it. Period. For this column, we’ll focus on non-crop weeds and ignore things like volunteer wheat or that flower or vegetable that came up from last year’s plants. To understand why weeds do so well, we need to understand the system we have created.

• Whether a yard or a crop field, we are creating a managed, artificial ecosystem, dramatically different from a natural one. It works well and suits the purpose and allows for optimal production under controlled conditions, but it requires constant management and inputs. And our plants are developed for optimal production under those conditions (regular spacing, rows, minimal intraspecific competition). Our goal is to provide them with adequate fertility and conditions to optimize production. However, it is an immature ecosystem.
• Contrast our managed, orderly ecosystem with an undisturbed prairie or forest — a mature ecosystem. It’s stable. Every niche is filled. It’s disorderly but it’s in equilibrium and not designed for optimal production but to hum along and survive. We want all of our plants to be synchronized from germination to harvest. Compare that to a natural system and not all seeds for a plant species germinate all at once or even in the same year. There are many different plant species present, even in native prairie. It’s a more resilient system as native plants are better adapted to the stresses and seasonal cycles. We produce primarily annual crops; many weeds are annuals but many are biennials and perennials. The perennials can spread by more than just seed. And in the natural, undisturbed system you won’t see many of our problem weeds, such as pigweed species, as it’s hard for them to become established. One last thing is that native plants are just that, native to the area, while many of our crop plants come from other continents.

Next week, why weeds love our managed ecosystems and what we can do in addition to tillage and chemical control.

Dr. Victor L. Martin is the agriculture instructor/coordinator for Barton Community College. He can be reached at 620-792-9207, ext. 207, or martinv@bartonccc.edu.