Project Details:

Enhance nutrient uptake in soybean production systems - year 2

Parent Project: Enhancing nutrient uptake in soybean production systems
Checkoff Organization:Michigan Soybean Promotion Committee
Categories:Soybean utilization
Organization Project Code:2007
Project Year:2020
Lead Principal Investigator:Kurt Steinke (Michigan State University)
Co-Principal Investigators:

Contributing Organizations

Funding Institutions

Information and Results

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Project Summary

Increased biomass production is the major driving force leading to greater nutrient accumulation within the plant. Dr. Steinke has documented similar biomass production (lb/A) from seeding rates as low as 50,000 seeds per acre up through 170,000 seeds per acre. Additional recent research from Illinois and Wisconsin has highlighted the importance of season-long nutrient accumulation as grain tissues remobilized a majority percentage of N, P, Cu, and S to developing seed during grain fill. Much of the late-season nutrient uptake and partitioning to grain comes from the soil, emphasizing the importance of sufficient soil nutrient resources in the later reproductive growth stages to prevent yield limitations.
A primary issue with the lower plant populations, however, has been providing sufficient water resources to support the additional grain development especially lower in the plant canopy. Lack of soil moisture due to 4-8 week late-summer periods without rainfall have hindered any potential yield gains at reduced seeding rates due to pod and grain abortion. Comparing nutrient uptake and partitioning within both irrigated and non-irrigated systems at multiple seeding rates and multiple nutrient application methods will provide vital management information for Michigan soybean growers moving forward.
Application technologies have changed in such a way that growers can now apply nutrients at just about any point of the season and as a liquid, soil applied, foliar, granular, broadcast, in-row, Y-drop, etc. Questions that continue to arise are which method to use, where may a greater yield response be expected, and does soil test concentration impact performance? Our goal is to identify opportunities where soybean growers may be able to proactively modify nutrient applications and increase the potential for yield response. Current research has shown how nutrients and biomass are partitioned throughout plants in varying yield environments but fail to address nutrient application timings especially at near-critical soil test concentrations.

Project Objectives

Objective 1. Determine the impact of 2x2 starter, vegetative K, reproductive P, and combination of all three components on soybean biomass accumulation, mineral nutrition content, and partitioning of nutrients. Our working hypothesis is that application of these nutrients closer to peak periods of uptake may ensure soil nutrient sufficiency throughout the growing season to support greater yield potentials, but results will depend on soil test concentrations and in-season nutrient availabilities.

Objective 2. Determine the effect of multiple nutrient application methods on soybean plant populations at different soil moisture levels. Our working hypothesis is that more timely nutrient applications at lower plant populations under irrigation will provide the necessary nutrient sufficiency to support the greater per plant biomass and grain yield observed.

Objective 3. Determine the impact of fertilizer (or biological product) application timings on soybean grain yield, biomass production, and tissue concentrations. Our working hypothesis is that in-season nutrient applications close to peak uptake periods may provide greater nutrient availability at near-critical soil nutrient concentrations.

Project Deliverables

Measureables will vary by individual study but may include 1) plant height and SPAD readings at V3-4 and R5, 2) tissue sampling at R1, 3) canopy coverage and biomass accumulation, and 4) grain yield and moisture. In-season or end-of-season videos providing field updates may also occur. To quantify differences in nutrient uptake and partitioning by seeding rate, three whole plant samplings will occur for project #1 and #2 above. All studies will be highlighted for summer research tours, discussed at appropriate extension meetings, and results posted at

Progress of Work

Updated September 23, 2020:
In 2019 both soybean trials were planted on 28 May as opposed to the 2020 planting date of 07 May. The difference in time between the two dates within the month of May is three weeks. This change or difference in planting date may result in increased biomass production and greater yield potential at both irrigated and non-irrigated locations. Early planted soybeans may increase the amount of time between each reproductive stage, which can lead to additional nodes, pods, and seeds per plant as compared to soybeans planted at a later date. Observations in the field suggest biomass accumulation is greater in 2020 compared to 2019 and as a result could increase nutrient uptake, remobilization, and potentially grain yield beyond 75 bu/A. Previous research suggests grain yield above 75 bu/A may increase the uptake of nutrients from the soil directly to the grain after growth stage R5.5 and could potentially generate a greater nutrient response to surface and subsurface applied fertilizers. However, white mold is present within all seeding rates at the irrigated location. White mold incidence may be due to greater biomass, cool nightly temperatures, and prolonged morning dews at the beginning of August. It is undetermined at this time whether seeding rate and fertilizer influenced white mold incidence. Disease ratings for white mold will occur at R8. Moreover, the non-irrigated location suffered poor emergence due to wet conditions and soil crusting shortly after planting. Reductions in plant stand may influence nutrient uptake and biomass accumulation patterns when compared to the desired plant stand of the non-irrigated location in 2019.

Final Project Results

Benefit to Soybean Farmers

The long-term goal of this research is to enhance the efficiency of soybean producers’ nutrient applications to the crop and simultaneously improve both the production and profitability of Michigan agriculture. These projects will also serve as a tool for soybean producers to utilize when making nutrient investment decisions.

Performance Metrics

Project Years