Sally A. Flis, Ph.D. – Feed and Crop Support Specialist, Dairy One

As I was driving around New York and looking at crops recently , variability is a word that came to mind. Variation in corn can be seen among and within fields. Given the variability of crops this year, here are a couple of questions that you should start thinking about:

    1. Will the crops outgrow any of this variation, especially in field variation?
    2. What can be done to manage variation during harvest?

1. The answer to whether or not crops will outgrow variation is that the results are dependent on a variety of factors. In a corn field, there is potential to get out on the field and apply nitrogen (N) to at least green up the yellowing parts of the field. However, this is dependent on factors such as the height of the corn – can you still get in with equipment to apply N? And do you have access to some variable rate equipment? If you apply N to the whole field at the rate for the corn that has the most yellow, you will be over applying to the other areas of the field and just changing your variability rather than make a more uniform field.

Corn Field Variabilty 070815

Cornell Cooperative Extension, NWNY Dairy, Livestock and Field Crops Team,

2. Variability across fields will be more manageable at harvest. But there are some challenges to this – how much storage area do you have? How many different piles of feed or storage areas can you manage? What is your feeding rate? Is there a need for different types of forage on the farm? Variability across fields can be managed by staggering harvest or by separating harvested feed based on quality. Now is the time to start looking at fields with your agronomist and your nutrition consultant to determine how to manage variability at harvest. A few things to remember for forage quality and weather are that wet weather will increase neutral detergent fiber (NDF), yellowing of corn will tend to decrease crude protein (CP), and all weather and nutrient stresses on corn can decrease ear size and fill, which will decrease starch concentration.

Weather and soil type are the two biggest contributors to variability of crops, both of which we have little control over. So, the next best step is to monitor crops and fields as they are growing and determine harvest management plans to deal with crop variability.