Del Voight –Penn State Extension
Each season there is much to be learned about crop production regardless of your experience. This season proved to be another interesting season. In checking soybean research plot fields located at the Southeast Research Farm in Landisville on Farmlogs, since planting, in my soybean plot received 46 inches of rain (60% higher than normal) and 3600 heat units (9% higher than normal). The rain really caused some unusual challenges. Here are some lessons I learned this season.
Last fall and mid summer weed issues
We were not able to get cover crops established last fall so we opted to put down a fall applied treatment ahead of soybeans in November. Then this spring we planted directly without having to burn down in the spring using no till equipment. Fields were clean going into planting. I expected the fall residual to hold until a second in crop spray could clean it up. Well with all the rains we had to treat much earlier than normal. I chose not to use a residual since the crop was beginning to canopy, however a lesson was to be learned more rains continued and additional flushes of new weeds emerged and again I had to run the soybean over to clean up the fields. If I had to do this season over I would definitely chose a residual herbicide to manage future weed flushes.
Old but new insects
Another lesson was a new insect I have not seen in quite some time. Soybean thrips showed up in Mid June. I was at a meeting in Montgomery county and a grower asked if I could check a field near his farm. I could not put a finger on the issue, so I collected samples and took them to the Southeast Research station. Dr Collins noted the thrips crawling out of the bag in large numbers. Once my eyes were trained onto the tiny pest I inspected numerous fields in my base county and found them all over in each field. At the time Dr Collins related the risk of transmission of soybean vein necrosis, a virus that would come later in the season. Sure enough I received calls on the vein necrosis in late august. The lesson was always keep your mind open to potential other pests that might not be in the normal realm of pests that w
e typically scout for in season.
Another lesson cam
e late in the season. Our crop tour in August illustrated the great potential for this year. Ample rain and adequate heat were in place. We estimated some large crop potential. Then the rains kept coming and more and more diseases began to invade the soon to harvest crop. Soybean began to swell in the seed pod, corn began to grow diplodia and other diseases in the ear. It was difficult to place real estimate on the acres affected by the fall harvest rains. Sitting at a local mill that was receiving grains in it was easy to tell most loads were lower in test weight and I learned a lot about the USDA grain quality guidelines. I would say the majority of grains I witnessed were just barely passing the USDA standards. https://sites.psu.edu/38cmeg/2018/10/01/usda-quality-standards/
I have not seen such high yields turn into a mixture of various anomalies. This picture is some of the soybeans and one can see the purpling and whitish color. At least none of these turn into mycotoxins like can occur in corn. The soybean quality continued to decline along with yields right through the fall season.
This year nutrient management provided some lessons as well. With the high price of fertilizer many growers hauled manure in place of commercial fertilizer. I observed many fields that the producer had applied adequate manure to provide corn with its needs. However, with the early season rains, much of the N was lost for a host of reasons. I found the Chlorophyll meter to be a valuable tool this season to assist in making N side dress decisions. Many growers ended up putting a large amount of N on the corn even though the grower calculated they would have enough. Further potassium (a non mobile nutrient) showed its effects this year with that tell tale sign of deficiency of yellowing from the outside of the leaf toward the midrib. The lesson was that now more than ever a fertility plan needs to be in place. This includes a current soil test, and the knowledge that commercial fertilizer, while it is high in price, cannot be left out of the management plan in many cases. With respect to N, be sure there is enough there for the crop and let the plant tell you if more is required by using the meter and then following the recommendations.
My final lesson came recently during harvest. On my way to certify the first harvest for the National Corn Growers Association this fall, I remember thinking that this might not be a bumper crop season. I was surprised to certify a yield of 251 bu/acre and mile down the road on a second harvest certified a 292 bu/acre yield. The farmer related that he had not had sunshine over the last three weeks! After contemplating how this could be, I concluded it comes down to population and the ability of new hybrids to resist the impact of water stress. Yield is determined by the number of harvestable ears and the number of kernels per ear. /For these tremendous yields to occur, growers are achieving a 32,000 final stand with modest ears but whole lot of them. There was a lot of variability in the ear size as this picture illustrates.
The lesson was that top corn hybrids are better able now to yield under extreme fluctuations in temperature and moisture. This years rains are not completed and the soil factors are not completely apparent. I expect to learn more lessons about soil physical processes and microbial populations as these certainly will also be affected by compaction and lack of oxygen in the soil. The fall harvest continues between the rain drops I am sure this season will go down as one of the more challenging seasons. Hopefully you too learned some lessons like this from observing your crops this year. Now our challenge is to put these lessons to work as we plan for another successful year in 2019.