Pm. Manning et al., Evaluation of row-spacing, seedbed preparation, and weed control options for dryland soybean, COMM SOIL S, 32(11-12), 2001, pp. 1899-1913
Production systems for dryland full season soybean consist of seedbed prepa
ration, planting operations, weed control activities and harvesting operati
ons. Often production system choices are interdependent across seedbed prep
aration, planting equipment and weed control options. For example, the sele
ction of one system option such as no-till seedbed preparation restricts pl
anting equipment choices. Evaluating production systems requires that a hol
istic approach be employed to account not only for agronomic factors but ec
onomic ones as well. Experiments were conducted in 1992, 1993, and 1994 at
Keiser, AR and in 1992 and 1993 at Marianna, AR on clayey and silt loam soi
ls, respectively. Treatments consisted of various combinations of preplant
tillage (yes or no), row-spacing (narrow or wide), and post-pi ant cultivat
ion (yes or no) for weed control. Grain yield data was collected and analyz
ed using SAS. In addition, economic analysis consisted of generating crop p
roduction budgets that were used to estimate returns to land, labor and man
agement as well as to conduct breakeven and sensitivity analysis. A no-till
system lead to higher grain yield and net returns on clayey soils at Keise
r, AR, while the tilled system lead to more stable returns on silt loam soi
ls at Marianna, AR. Results showed that narrow row spacing was superior reg
ardless of soil type and location. Finally, post-plant cultivation was of l
ittle consequence given the above recommendations.