Development of Narrow Row Soybean Production for Irrigated Soybean in Mississippi.

The majority of irrigated soybean in Mississippi are planted on raised beds spaced 100 cm apart, in either single or twin row arrangements.  Recently, there has been interest from soybean producers in producing soybean in narrow rows (50 cm) on wide beds.  Previous research indicates that narrower row spacing can provide advantages over wider row spacings, including improved weed management, increased light interception, and potentially higher seed yield.  Concurrent with the interest in narrow rows, there has also been substantial producer interests in increasing soybean seeding rates.  The purpose of this research was to compare soybean growth and seed yield for multiple row-spacings and seeding rates for irrigated soybean production in Mississippi.  Field scale studies were established at three locations in the Mississippi Delta. At each location, soybean were planted in 100 cm single rows, 100 cm twin rows and 50 cm rows on wide (200cm) beds.  With each row spacing, soybeans were planted at 247,000, 345,800 and 444,600 seeds per hectare[JO1] .  Stand counts were determined at V2 and again at R8.  Light interception measurements were taken throughout the growing season and seed yield was determined at harvest.  Soybeans planted in 50 cm rows resulted in faster canopy closure than soybean planted in both single and twin rows.  This research will be repeated for multiple growing seasons to access row spacing × seeding rate interactions under multiple environmental conditions. 

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