NDSU has been researching intensive soybean management since 2008 and has come up with some ideas which planting rates, row spacing and inputs will maximize soybean profits.
Study results indicate the combination of planting 150,000 pure live seed per acre in 14-inch rows, followed by the combination of special foliar inputs, provides the highest return on investment among the options explored.
"Planting rates of 150,000 and 200,000 pure live seeds (PLS) per acre have been compared with an average early season established stand of 138,000 and 175,000 plants per acre, respectively," says Greg Endres, NDSU Extension agronomist, Carrington. "NDSU currently recommends an established soybean stand of 150,000 plants per acre, with a variance of 10 percent, to maximize yield potential. Current results from the study indicate a yield advantage of just less than 1 bushel per acre, or 1.5 percent, averaged across site-years for the high planting rate. However, when costs and benefits are calculated, the lower planting rate is more economical."
Fourteen-inch row spacing has averaged 1.1 bushels per acre or about a 2% greater yield than using 28-inch rows.
"This confirms other university data indicating a higher yield potential with intermediate rows versus wide rows," says Hans Kandel, NDSU extension agronomist, Fargo. "Also, in the NDSU study, canopy closure occurred an average of a month earlier with the 14-inch rows, compared with wide rows. Quicker canopy closure provides advantages, including greater weed competition, soil moisture conservation and increased capture of sunlight, all potentially resulting in higher yields using the narrower rows."
Special foliar inputs, including a nutrient combination, plus a growth promoter at early vegetative stages, were applied sequentially. This was followed by a fungicide treatment during the flowering to early-pod formation stages. Across site-years, the special inputs increased soybean yield 2.2 bushels per acre, or about 4%, compared with the untreated check. However, there only was a modest return on investment.
"In another ongoing study conducted at Carrington to examine special inputs for soybeans, numerous individual products or combinations applied at various plant stages have not consistently provided yield gain or economic returns," Endres says. Farmers should use caution when considering additional inputs beyond recommended management practices that are based on university research."
The intensive management study will be continued this crop season at Carrington and Fargo.
"This year, an addition to the research is comparing soybean performance under tiled versus undrained soil environments at Fargo," Kandel says. "In addition, other soybean production management studies are planned in 2011 to continue investigating soybean response to other factors, including tillage systems, planting dates, fertilizer placement, seed inoculation and special inputs."
The research is being supported by the North Dakota Soybean Council.
Source: NDSU Extension Communications