The term best management practices (BMPs) can be applied to practices that maximize yield or practices that promote sustainability. These practices do not always share the same exact goals, however there is growing momentum and science that says you can be successful with both. Regardless, as growers are planning their crop decisions for spring planting season, most know what the best BMPs are and often spend time trying to update them to improve efficiency and profitability.
As we move quickly into spring and with temperatures warming up, growers will begin to start farming. Spring activities include soil preparation, applying fertilizer and winter annual weed control and each of these will have BMPs attached.
Good soil management is the road to good soil health and stewardship. A farmer’s goal should be to maintain or improve soil quality and build soil health. As a farmer myself, I know weather doesn’t always cooperate and there’s always a need to maximize profits, however I believe that most farmers are good stewards of the land and try to do the right things. For our BPM discussion, let’s start with the soil.
Our goal is to conserve top soil, improve soil quality and enhance soil health. One of the most effective ways to enhance soil health is to reduce tillage. Tillage destroys soil structure and causes organic matter to burn off faster. Organic matter is important to structure and health. Also, it’s important not to traffic the soil when it’s wet. Trafficking compacts soil and reduces aeration and infiltration. Lastly, to have good quality you have to have abundant microorganisms, including worms and arthropods that are active. An optimum soil for active microorganisms has a neutral pH (6.7 to 7.5), electroconductivity needs to be less that 1 deciSiemens per meter, and the soil needs to be porous with good aeration, infiltration and drainage.
Another area to apply BPM is fertilizer application. Farmers apply fertilizer either in the fall, spring or during the growing season. Fertilizer is important to plant growth and soil health, but it can be inefficient and have detrimental side effects if applied at the wrong time or at an excessive rate. When it comes to fertilizer and BMPs, we are talking mainly about nitrogen. Nutrients like phosphorus and potassium are not mobile in the soil and tend to stay in place. However they can move with soil and water and get into surface waters.
When nitrogen and phosphorus get into surface waters, they can stimulate algal growth causing hypoxia or loss of oxygen, which leads to death of marine life. Keeping nitrogen and phosphate out of surface waters is the goal. Conserving and protecting the soil and minimizing runoff keeps phosphorus and some of the nitrogen out of surface waters.
Nitrogen is very dynamic and changes states. It is in the ammonia form, it is very stable in the soil. Unfortunately ammonia easily converts to nitrate when soil temperatures get above 50 degrees (F). Ammonia is very mobile and easily gets into ground and surface waters. And if the soil becomes saturated, nitrate will denitrify to nitrous oxide, which is a greenhouse gas. To prevent nitrogen losses from leaching, since you can’t do anything about rain, apply nitrogen in stages with most of the nitrogen going on right before a plant’s rapid uptake stage. Improving soil structure is a highly effective way to prevent saturation and denitrification. Also, farmers that practice tillage can reduce its negative impacts by using a shallow, non-destructive process.
And last is weed control. There is a class of weeds referred to as winter annuals that germinate in the fall or very early spring. Again, soil health plays the biggest part in proactive weed management. Incorporating a proactive approach to weeds has shown to significantly reduce weed proliferation. Additional control methods include tillage or the use of herbicides. Again you can use shallow, non-destructive tillage to remove a flush of weeds or an herbicide combination that effectively terminates the growth of weeds. Just remember that BMP means using the right product at the right rate and at the right time. Do not wait for the weeds to bolt (elongate) or weed control will be difficult and herbicides less effective. Also, when it comes to herbicide use avoid spraying near waterways and stay away from well heads.