Last week’s article discussed the importance of considering climate when deciding what crops may fit into a no-till rotation in this part of the world. There are numerous other factors that also need consideration and this week will continue this exploration.
We will only touch on many of these briefly but it should provide an idea of what criteria go into making a suitable rotational crop with corn, grain sorghum and wheat.
· Soil type – certain crops are much better adapted to certain soil textures. Some crops such as winter canola are poorly adapted to sandy soils but well-adapted to medium textured soils.
· Drainage – many potential rotational crops require good soil drainage and aeration. This often goes hand-in-hand with soil texture as the heavier (more clayey) the soil the more likely poor drainage and low oxygen levels will occur.
· Soil pH – after decades of nitrogen fertilizer additions, soils in much of Kansas, especially in our area and under the lighter soils found south of the Ark River, have soil acidity levels of pH 5.5 or lower. For a variety of factors, especially cost, producers work with these conditions instead of correcting them. Potential crops, particularly those fixing nitrogen, nodulate poorly in acid soils. It helps if you remember that the difference between pH 7 (neutral) and pH 5 (acid) is not 2 but 100 times since pH is a log scale. As soil moves farther from neutral in either direction, nutrient availability and toxicity can become problems.
· Herbicide history – using persistent sulfonyl urea herbicides such as Finesse, Amber, and Ally can prevent certain rotational choices for several growing seasons. Another herbicide class, triazines such as atrazine, can also prevent the planting of certain crops for a season. These problems are made worse under high pH conditions.
· Surrounding crop herbicide use – certain broadleaf crops, like cotton and sunflower, are extremely sensitive to growth regulators such as 2, 4-D. Even when using low volatility formulations damage can occur from drift from several miles away.
· Residue levels – this is especially important when growing crops such as wheat and corn that can generate large volume of residue. Many alternative crops are small seeded and even when using the best no-till planters heavy surface residues can lead to serious stand establishment and winter survival issues. The no-till rotation established should alternate between high and low crop residue level crops to make residue levels manageable. Or you must find a way to remove an adequate amount of residue to facilitate planting
· Fit – will the new crop fit with your crops or present challenges. Sesame is a good potential crop for the southern half of Kansas but won’t normally be harvested until late October and that makes planting wheat a challenge. Winter canola needs to be planted here by mid-September and that limits your summer crop choices.
· Equipment – what equipment is necessary to produce the crop? Does the crop require equipment you don’t own or attachments you will need to purchase?  Does it require specialized equipment?
·  Markets – is the market for the crop close enough to make sense economically? There is a strong market for white, food grade corn but the market is hundreds of miles away. Also included here is the proximity of drop off locations. If you have to haul the crop beyond a certain distance, do the benefits and price of the crop offset the time, labor, and money involved in the added distance?
· Crop insurance – can you obtain crop insurance for the crop in your area easily. What will it cost for a reasonable level of coverage?
· Knowledge – how steep is the learning curve to consistently and successfully produce the crop? What resources are available for obtaining information?
Now that we have a general idea of what we need to consider when choosing potential crops, we can start examine what’s out there next week.