Gross margin analysis: spring planted soybean variety Gwydir[PBR], Nunderi 2021–22

Abstract

Key findings • The Gwydir[PBR] soybean crop was planted on 6 September 2021 and yielded 4.91 t/ha with a grain protein (GP) concentration of 44% dry matter (DM) basis. • The crop gross margin (GM) was $2026/ha. • Significant weathering damage occurred due to above average rainfall and higher average temperatures in February, resulting in a lower grain price. • Compared with traditional December planting dates, this spring planted Gwydir[PBR] crop had a longer vegetative growth phase, however, this did not result in excessive plant biomass, plant height or lodging. • A second crop of soybean (variety Hayman[PBR]) was planted on 11 February 2022, immediately after the crop of Gwydir[PBR] was harvested, however, it was lost due to flooding on 28 February. • The risk factors for soybean crops planted 4–8 weeks before the start of the traditional coastal planting window include: º inadequate soil moisture to establish dryland crops º slower germination and emergence due to cold soil temperatures º early incursions of insect pests particularly pod sucking bugs º the potential for leaf diseases such as powdery mildew or soybean leaf rust to develop during cooler spring conditions. • This experiment tested the potential to plant 2 soybean crops in the spring and summer sugarcane fallow period, boosting income and grain production and providing benefits to the cane farming system including nitrogen fixation and weed control.