we are having a late spring. I suppose that depends on your definition or basis for the comment. I believe some people are still trying to use 2012 as a comparison. In 2012, we certainly did have an abnormally early spring, so comparing any other year to it, even an average year, will seem later than “normal.” I think our “normal” is out of whack.
Probably the most common way of assessing where we are in plant growth compared to other years is comparing Growing Degree Days (GDD). Growing Degree Days are calculated by taking the average between the daily maximum temperature and daily minimum temperature and subtracting the base comparable temperature for each day. Days are then added together to compare periods. There is a fair amount of research tied to GDD’s and so it is quite often used to predict planting dates, maturity dates and everything in between on row crops. In 2012, April was really not that much different than the average, but March was a different story; it even surpassed April in GDD’s.
Plant growth is highly influenced by the ambient temperatures but also very dependent on adequate moisture and photosynthesis. Heat units without adequate moisture or sunshine are just not the same. Moisture is easy enough to understand, but getting enough sunlight for photosynthesis is important for energy. Photosynthesis probably has less impact on yield as compared to its impact on energy for the plant and for what consumes it. Those soluble carbohydrates in the forages are highest after good sunny days. This variability can even be tracked in a normal day with values peaking in the afternoon and lowest being in the early morning. Numerous days with little or no sunshine can therefore impact forage quality, mainly energy. On the other hand, it is a nice reminder that when you are cutting forages for hay or balage, those forages will have the highest energy when cut on a sunny afternoon.
Where am I going with all of this? I guess to say we are just a little behind the average this year in forage growth. Comparative clippings I’ve taken over the past few years puts us realistically only about 300-400 pounds of dry matter per acre behind the norm for the southern part of Indiana. Bring on the sun!"
When the sun comes out, do you have enough nutrient? You have too much water in the east and not enough in the west but do you have enough nutrient? Pasture and grasslands are some of the poorest soil and tissue sampling results I take.
Could your grass use more sun, less water and some food?