Data from: Soybean yield is positively linked to organic matter, but planting date remains more influential

Establishing connections between soil health indicators and crop
performance will help ensure that tests recommended to farmers relate to
outcomes of interest. This study assessed the relationship of soybean
[Glycine max (L.) Merr] yield with three common soil health indicators:
soil organic matter (SOM), permanganate oxidizable carbon (POXC), and
autoclaved citrate extractable nitrogen (ACE‐N). These tests were assessed
alongside other factors (soil test phosphorus, soil test potassium [STK],
mapped clay, planting date, summer precipitation, and location). Soil
samples were collected from 457 producer‐managed fields between 2019 and
2021 in Arkansas, Michigan, North Carolina, and Wisconsin. Planting date
and yield were reported by producers, while mapped clay and rainfall were
determined using publicly available data. Simple linear regression was
used to assess the relationship between soil health indicators and yield:
the natural log of SOM and POXC were positively associated with soybean
yield (R2 = 0.07, p < 0.001; R2 = 0.03, p < 0.001), while
ACE‐N was not (p = 0.872). Multiple linear regression was used to further
test the relationship of SOM and POXC with yield, while accounting for
other factors that contribute to soybean yield. Models explained 27% of
variation in yield, with significant factors including SOM or POXC,
soybean planting date, STK, and mapped clay. Based on standardized
coefficients, planting date was the most influential factor associated
with yield. Broadly, our results indicate that improvements in yield are
linked to higher SOM, but management decisions like planting early are
critical for achieving high yields.