Wheat Harvest June 6, 2017
We managed to get the wheat harvested on the above date with a small Gleaner GL2 plot combine. To recap, we have 40 plots with 4 treatments - this means that each treatment is replicated 10 times. In essence we have two levels of nitrogen application (roughly 33%, 66% and 100% of Rx) and two levels of potassium namely 0 and 100% of Rx.
Table 1 shows the overall result which in essence says two things namely (1) there was a significant yield response to nitrogen fertilization and (2) there was no significant yield response to the recommended potassium (K2O) fertilizer.
While the treatments to our first trial (Table 2) were slightly different, the conclusions (i.e., the crop responded to N, but not to K) are the same.
In terms of wheat yield response to N, Figure 1 shows that between the 60-0-0 and the 90-0-0 there is a lot of overlap between the data points and its a nice graphic display of why Table 1 suggests there is no statistically significant yield difference between the 60 and 90 units of N applied.
If we look at crop yield response to potassium (Figure 2), the same amount there is a good deal of overlap between the points. When comparing the 90-0-90 to the 90-0-0 treatments by replicate, 6 out of 10 reps showed the yield in the 90-0-90 treatment was higher, while 4 out of 10 reps showed the 90-0-0 treatment was higher.
We were disappointed by the yields this year - some of it had to do with the damage done by a particularly cold snap in March, but some is on me (Buz). I encouraged Carl to make as few trips across the field as possible, and one trip he saved was the post-emerge herbicide trip. Only other herbicide Carl applied was burn down of the warm season cover crop. From the vantage point of the combine, I could see that while our soils are getting healthy, we are still going to have to rely on herbicides for a while, as it was pretty visible to me how weed pressure affected yield. We live and learn.
I thought I'd include a few shots from the harvest itself. We are most grateful to our friends that rented the plot combine to Carl at a very reasonable rate - a big time saver over the regular combine a weigh wagon.