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Research Conducted
A Roundup Ready 2 Yield (RR2Y) soybean variety with a maturity group of 0.3 was planted at the Williston Research Extension Center on 05-30-2018 to determine a suitable planting geometry for no-till dryland condition of western North Dakota. Row spacings of 7½, 15, 22½, and 30 inches were maintained as main plots and plant populations (seeding rates) of 90, 120, 150, and 180 thousand per acre were considered as sub-plots.

Why the research is important to ND soybean farmers
Soybean acreage has been steadily increasing in ND, including the western part of the state, which has exceptionally drier climate than the eastern part. There is a lack of information on suitable planting geometry for this part of the state. Determination of suitable plant population and row spacing is crucial to have a sustainable higher soybean yield and the farm income under no-till dryland condition.

Final findings of the research
There was no effect of plant population and row spacing on normalized difference vegetation index, canopy temperature, available soil moisture, plant height, test weight, grain protein, grain oil, and 1000 grain weight. When averaged across the row spacing, there was no effect of plant population on above ground biomass (ABM) and grain yield; however, when averaged across the plant population, a row spacing of 7½” produced 525 to 1250 more lb/a of biomass and 4 to 5 more bu/a of grain (Fig. 1C) than the wider row spacings. There was an evidence of the interaction effect of plant population × row spacing on grain yield; but, as 90 thousand plant population produced higher or equal bushels of grain at different row spacings, and 7½” row spacing produced higher or equal bushels of grain at different plant population, the interaction effect was not further elaborated.

Benefits/Recommendations to North Dakota soybean farmers and industry
This experiment confirmed our findings in 2016 and 2017 that a row spacing of 7½” and 90 thousand plant population per acre (seeding rate) is a suitable planting geometry for no-till dryland soybean production in western ND. The study recommends planting soybean at a lower seeding rate and narrow rows, which reduces expensive seed cost, enhances yield, and increases the farm income of ND soybean producers.