Soybean – (Year 3 of a 6-Year Crop Rotation)
Parkland Crop Diversification Foundation
To assess the economic and agronomic impact of a 6-year rotation, using integrated management practices.
The average spring wheat yield for each treatment (Table 2) indicates a responsiveness to added
nitrogen over the amount provided by the green manure in 2018. Table 2 appears to indicate a
decrease in yield for treatment 4; however, the reduced yield for that treatment can be attributed to
poorer plant establishment in some plots.
Table 5 shows a summary of statistical information for spring wheat and soybean. Average yield and
test weight do not differ significantly between treatments for either spring wheat or soybean.
In 2021, a green manure will be planted on the site.
The use of green manures for fertility has the potential to reduce fertilizer inputs during the following
cropping year. In 2018, a green manure was planted and terminated in late July, with some regrowth.
The green manure yielded 6100 lb/ac (dry), resulting in an estimated 152 lb/ac of available N. However,
some of this N was only slowly available as the plant material decomposed. Further, a relatively low
legume-to-cereal ratio (35-65) may have tied up some available N during the decomposition phase. A
spring 2019 soil test showed 115 lb/ac available. AC Goodeve wheat was planted on the site on May 14,
with N fertilizer added according to the treatments and costs shown in Table 1. Figure 1 shows the full
six-year rotation for the trial. Soybean was seeded in 2020.