Table 1.
12 and 26-year-old trees (1997 and 2012, respectively) intercropped with soybean at the same study site.
Fig 1.
Sampling locations from the tree row into the cropping alley.
The crop like symbol refer to sample plot.
Fig 2.
Diurnal PAR for soybean in control plots and within 2 m, 4 m and 6 m of poplar, maple and walnut.
Values presented are means (N = 4), error bars indicate the standard error of the mean.
Table 2.
Differences in measured parameters associated with soybean plants in three intercropping treatments and monoculture control 12 (1997) and 26 (2012) years after establishing poplar, maple and walnut intercropping systems.
Table 3.
Within plot microclimate and soybean responses 2, 4, and 6 m from tree row to three 26-year-old hardwood intercropping systems and monocropped soybeans.
Fig 3.
Diurnal NA for soybean in control plots and within 2 m, 4 m and 6 m of poplar, maple and walnut.
Values presented are means (N = 4), error bars indicate the standard error of the mean.
Table 4.
Differences in a variety of environmental parameters measured (2012) in three intercropping treatments and monoculture control 26 (2012) years after establishing poplar, maple and walnut intercropping systems.
Table 5.
Multiple regression analysis of environmental factors and photosynthetic rates of soybean in different treatments in 2012.