Effect of planting density and row spacing on the yielding of soybean (Glycine max L. Merrill)

Abstract

The paper presents the effect of planting density and row spacing on the growth, development and yield of soybean, cv. Merlin, under very diversified thermal and humidity conditions in the north-central part of Poland. The field experiment was performed in 2016–2019. Three planting densities were applied (70, 90 and 110 seeds per 1 m²) with two row spacing (16 and 32 cm), in 4 replications. Under good humidity and thermal conditions in 2016 and 2017, the yield of seeds and protein in soybean was 3.3 times higher than if exposed to extreme drought and accompanying high air temperatures in 2018 and 2019. The highly diversified thermal and humidity conditions also contributed to a significant decrease in the effect of the factors applied on the structural yield components, leaf area index and dry matter of nodules. As a result, no need of increasing soybean density was observed; along with row spacing, it should be chosen according to the region.