Effect of sowing density on grain yield, protein and oil content and plant morphology of soybean (Glycine max L. Merrill)

Abstract

To find out exactly how sowing density and sowing pattern affect soybean grain yield, quality and its components in non-traditional soybean growing regions, such as Germany, two field trials have been conducted at two locations in Bavaria in 2016 and 2017. The experiments were carried out with four sowing densities (30, 50, 70, 90 seeds/m<sup>2</sup>) and four cultivars from different maturity groups (Viola 000, Lissabon 000, ES Mentor 00, Orion 00) as randomized complete block design with four replicates. Almost all evaluated traits varied significantly depending on year × location. There was no interaction between the main factors (cultivar × sowing density). The results revealed that grain yield and height of the first pod increased with increase of sowing density. The number of pods per plant and branching decreased with increasing sowing density. At higher sowing densities at flowering leaf area index was significantly higher than at lower sowing densities. The cv. ES Mentor (00) with 70 seeds/m<sup>2</sup> has proved to be a suitable cultivar in terms of yield and quality in southern Germany (> 3.6 t/ha grain yield and 40% protein).

Seed Yield, Seed Protein, Oil Content, and Agronomic Characteristics of Soybean (Glycine max L. Merrill) Depending on Different Seeding Systems and Cultivars in Germany

“…The higher number of side branches and, consequently, more pods per plant, with precision seeding compared to drill seeding did not lead to an increase in protein or oil content in soybean. However, an increase in crop density tends to lead to higher protein content [51,52] and since the two, i.e., protein and oil content, correlate negatively [53], oil content also increases with decreasing crop density by trend [54]. Our results showed that neither drill nor precision seeding reduced or increased protein content and oil content.…”

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

“…An almost 100% correlation between a decrease in the yield of seeds and protein in soybean in the subsequent years indicates a significant effect of humidity on the value of both traits, however most probably without an essential change in the seed protein content. Popović et al (2012) claim that environment is a dominant element determining protein content in soybean seeds, regardless of the planting density (Sobko et al 2019).…”

“…These differences accounted for 5.40% and 6.60% less plants prior to harvest than after emergence, respectively. According to Sobko et al (2019), the planting density prior to harvest is usually lower than after full plants emergence. Similarly, Schmitz et al (2020) found the average 6.6% plant loss in the stand during growth, irrespective of the row spacing.…”

“…A higher planting density is also accompanied by an increase in the plant height and stand lodging as well as by a decrease in the number of pods per plant and seeds per pod (Ball et al 2001, Kahlon et al 2018. Sobko et al (2019) found that the seed yield and the height of the 1 st pod setting increased with the planting density, while the number of pods per plant decreased; with a higher planting density, the LAI value also increased. However, in the experiment reported by Schutte and Nleya (2019), an increase in the seed yield in soybean due to an increasing planting density was inconsiderable.…”

Response of Soybean [Glycine max L.] Varieties Grown Under Varying Inter Row Spacing in ManaSibu District, Western Oromia, Ethiopia

“…In contrast to this result, Habtamu et al (2018) reported that the main effect of plant population did not show significant variations on harvest index of soybean cultivar. And, Sobko et al (2019) reported that the main effect of inter row spacing on harvest index was stable characteristic within a cultivar and was not affected by planting density of soybean cultivar.…”