Mj. Shaffer et al., LONG-TERM EFFECTS OF EROSION AND CLIMATE INTERACTIONS ON CORN YIELD, Journal of soil and water conservation, 49(3), 1994, pp. 272-275
Citations number
14
Categorie Soggetti
Water Resources",Ecology,"Agriculture Soil Science
An accurate assessment of the impacts of soil erosion on corn producti
on ss needed for conservation and management programs. Climatic variab
ility produces a range of crop yield responses on eroded and non-erode
d soil profiles and often masks the long-term trends and differences.
Short-term corn yield data from representative soils across the North
Central region were supplemented with calculated yields from the NTRM
model to develop long-term yield responses for the historical climate
records at each of seven highly-managed rainfed sites across the regio
n. Results showed that long-term average regional corn yields were red
uced by 10% for severely eroded versus control plots. Till-derived soi
ls showed yield reductions averaging 12%, while loess soils lost an av
erage of 7%. Sensitivity runs with the NTRM model made after field val
idation with 119 plot-years of data suggested that changes in soil phy
sical properties, especially plant-available water bolding capacities,
probably accounted for most of the yield differences. Mean growing se
ason (May-September) precipitation across all sites for the short-term
field study was 35.3 cm, compared with 36.3 cm for the long-term hist
orical record. This resulted in a mean short-term corn yield reduction
of 9% for severely eroded soils versus a reduction of 10% for the sam
e soils based on long-term climate projections. However, the close agr
eement between the short- and long-term studies with regard to mean gr
owing season precipitation and corresponding corn yields should not be
used to make the general conclusion that 3 to 6 years is an adequate
time period for research on long-term crop response to eroded soil con
ditions.