Project Details:

Improving Soybean Yields by Enhancing Seed Filling

Parent Project: This is the first year of this project.
Checkoff Organization:Kansas Soybean Commission
Categories:Crop management systems, Soil fertility, Environmental stress
Organization Project Code:1976
Project Year:2019
Lead Principal Investigator:Ignacio Ciampitti (Kansas State University)
Co-Principal Investigators:
Keywords: management, seed filling, Yield

Contributing Organizations

Funding Institutions

Information and Results

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Project Summary

Past research looking at intensifying soybean yields was specifically focused on a few treatments applied at early reproductive stage (R1-R3), but based on recent preliminary research, more attention needs to be invested into “late-season” (R4-R6 stages) management factors. Soybeans accumulate between 30-50% of the final yield during the seed filling period (R5-R7 stages) and thus more emphasis on potential factors enhancing seed filling via “late-season” management practices should be evaluated to capture further yield improvements on this crop at the field scale. Relative to the final total yield (biomass) at harvest, soybeans only accumulate 60% until R5 stage, with the other 40% accumulated during the seed filling (R5-R7), lasting 30-40 days.
Still, the main question is “What can be the potential impact of improving yields by enhancing seed filling”. To answer that question we are presenting an example with data collected from Rossville during the 2017 growing season (Figure 2). The information shows the rate of dry matter accumulation on soybean seeds from the R5 to R7 stages, portraying the total number of days (37 days) for an overall soybean yield of 61 bu/acre. In this example, improving “green leaf area” duration and extending the seed filling period by only 7 days provided a yield benefit of more than 10 bu/acre. Yield level was approximately 50 bu/acre with a 30-days seed filling duration to more than 60 bu/acre when the duration was prolonged to a total of 37 days of R5-R7 (increasing nearly 1.5 bu for each additional day in seed filling). Therefore, management practices that can contribute to extend the seed-filling period (at least for a few days) impacting soybean yields across different production environments should be further investigated.

Project Objectives

Identify “late-season” management practices that improve final seed number and weight, overall seed yield for soybeans. “Enhancing seed filling”, is critical for improving soybean yields under varying production environments and changing climate-economic scenarios. By definition “late-season” will be considered as production practices implemented from full-pod (R4 stage) through seed filling (R5-R7 stages).

Project Deliverables

The project will provide outcomes to help identify on-farm production practices that are blocking yield potential and provide data for possible management practices to increase yields. All project outcomes will be disseminated in diverse research and extension communication outlets to help Kansas soybean producers for maximizing financial returns and preserve the land and water resources under their control.

Progress of Work

Updated July 2, 2019:
Plots were planted at the end of May and then replanted in late-June due to poor stands. Plants are slowly progressing and treatments will be implemented in the next coming months, late-season management.

View uploaded report PDF file

Updated September 13, 2019:
Plots were planted at the end of May and then replanted in late-June due to poor stands. Plants are progressing much faster due to adequate growing conditions.
Treatments were implemented in the last week and the following measurements will be determined in all treatments:
- Grain yield components – pod number, seed number per pod, and seed weight.
- Plant biomass and dry mass will be calculated and samples will be prepared for nutrient testing (complete nutrient analysis).
- Seed filling weight changes during the late-season, and changes in seed water content to predict 13% harvest time for each treatment based on weather conditions.

View uploaded report PDF file

Updated December 14, 2019:
Plots were harvested by the end of October (Figure 2). The control treatment together with the Insecticide and Intensified management presented the lowest yields, roughly 40 bushels per acre. The plant nutrition with standard and complete management presented mid- yields close to 44 bushels per acre; while the fungicide application alone resulted in the highest yield, more than 48 bushels per acre.
Next steps, biomass and seed samples are currently analyzed and prepared for nutrient evaluation. In addition, seed filling data is evaluated to dissect the effect of treatments.

View uploaded report PDF file

Final Project Results

Updated April 10, 2020:
The objective of this study was to identify “late-season” management practices contributing to increase final seed weight and seed yield in soybeans. Rate and duration of seed filling were not affected by any of the evaluated treatments (Figs. 2, 3 - see attached report). Thus, variation observed in all the investigated variables can be mainly attributed to the spatial variability of the experimental conditions.

View uploaded report Word file

Seed yield ranged between 34.2 and 52.3 bu ac-1 and seed weight ranged from 132 to 166 mg seed-1, respectively. However, statistical differences among treatments were not detected for neither yield nor seed weight. Treatments applied neither affect final seed weight nor seed yield. Furthermore, across all treatments similar trends were observed for the seed growth rate and seed filling duration. Future research should consider evaluating the effect of the treatments here tested at different crop growth stages.

Benefit to Soybean Farmers

The project will provide outcomes to help identify on-farm production practices that are blocking yield potential and provide data for possible management practices to increase yields.

Performance Metrics

Project Years