Resources

Phosphorus Fertilizer Placement and Tillage Interaction for Corn and Soybean in the U.S.

Crops: Corn for grain Corn for silage Soybeans
4R Practices: Metadata Project

Meta-analysis of Phosphorus Fertilizer Placement and Tillage Interaction for Corn and Soybean in the U.S.

Lead Researcher:

Dr. Dorivar Ruiz Diaz

Professor

Kansas State University

Start Date: 2014

End Date: 2015

Collaborating scientists and universities

  • Dr. David Mengel, Kansas State University
  • Dr. Cristie Preston, Senior Agronomist, Nutrien

Matching Funds

  • Kansas Soybean Commission
  • Kansas Corn Commission
  • USDA-NRCS
  • Kansas Agricultural Experiment Station
  • Kansas State University Department of Agronomy

Project Summary

Phosphorus placement and interactions with tillage has been evaluated extensively for corn and soybean in the US. Results suggest that placement of P fertilizer can play an important role in early P plant uptake and yield as well as potential P loses to surface water for some soils and tillage conditions. The rate of P uptake per unit of root in corn decreases throughout the vegetative growth phase; and therefore early season P fertilizer applications and placement can be particularly important for optimum plant growth. Broadcast application can result in a more uniform distribution and likely affecting more soil volume. Crops have shown a response for various levels of soil test, including low soil test P (STP) conditions and medium to high STP. However, accumulation of P near the soil surface may result in higher lost potential with runoff; and possible decreased P availability due to increased soil-fertilizer interaction in soils with high P sorption capacity. Broadcast application may be more practical for some producers and suitable for some soils and tillage conditions. However, soils and tillage conditions and the interaction with P application methods should be evaluated with larger datasets and across different soils and environments. Potential P loses with water runoff can be affected significantly by phosphorus placement and tillage. Many studies in the US evaluated water runoff and P loses as affected by tillage and fertilizer. However studies often show different results, which may be due to differences in soils, rainfall amounts and intensities, slope, moisture content, and infiltration rate. Evaluation and summary of the existing literature can help to identify factors contributing to potential P loses in addition to tillage and fertilizer placement. Crop response and P loss potential can be affected by the interaction between soil and tillage factors with P fertilizer placement. Accurate evaluation of these interactions would require large dataset that comprise a variety of soils, tillage and placement combinations.

Project Goals:

  • Analyze and summarize published and unpublished field-based data on corn and soybean response to P placement and the interaction with tillage.
  • Complete a data review on yield response and phosphorus loses with surface runoff as affected by P placement and tillage interaction.
  • Include data review of estimated P use efficiency with placement and tillage interactions; and estimate the economic return associated with different systems.

Project Results:

  • Very limited amount of work is available on the long-term effect of specific management systems used by producers for tillage and/or placement on potential P loses to surface water.
  • Some states in the US have limited amount of published data on the overall topic of tillage by P placement interaction for both agronomic and environmental implications.
  • Results of all evidence analysis show higher corn yield means with broadcast applications in soils with soil-test P below <20 ppm phosphorus.
  • Higher corn yields were also observed with conventional tillage in soils with high STP.
  • Analysis of direct evidence shows generally lower corn yields in no-till systems with little difference between placements.
  • Band P fertilizer applications yielded highest in high STP and may provide a yield increase only if the rates are limiting (< 19 lb P ac-1).

Annual Reports

2015

2016

A ‘Manage’ ed approach for 4R nutrient stewardship on drained land

Crops: Canola Corn for grain Corn for silage Cotton Hay Potato Rice Ryegrass Sorghum Soybeans Sugar beets Sugarcane Winter wheat Wheat
4R Practices: Metadata Project

A “MANAGE”ed Approach to 4R Nutrient Stewardship on Drained Land

Lead Researcher:

Dr. Laura Christianson

Assistant Professor

University of Illinois

Collaborating scientists and universities

  • Dr. R. Daren Harmel, USDA-ARS

Start Date: 2014

End Date: 2015

Matching Funds

  • Texas State Soil and Water Conservation Resource Board

Project Summary

As agriculture in the 21st century is faced with increasing pressure to reduce negative environmental impacts while continuing to efficiently produce food, fiber, and fuel, it becomes ever more important to reflect upon more than half a century of drainage water quality research to identify future paths towards increased sustainability. This work provided a quantitative review of the water quality and crop yield impacts of artificially drained agronomic systems across North America by compiling data from drainage nutrient studies into the “Measured Annual Nutrient loads from Agricultural Environments” (MANAGE) database. Of the nearly 400 studies reviewed, 91 individual journal publications and 1279 site-years were included in the new MANAGE Drain Load table with data from 1961 to 2012.

Project Goals:

  • The MANAGE Drain Load database: Review and compilation of more than fifty years of drainage nutrient studies.
  • 4Rs water quality impacts: A review and synthesis of forty years of drainage nitrogen losses.
  • A quantitative review and synthesis of fifty years of drainage phosphorus losses.

Project Results:

  • Increasing nitrogen application rates both improved crop yields and increased dissolved nitrogen loads in drainage. “Fine-tuning” these rates is clearly important from economic and environmental standpoints, but it would be short-sighted and unrealistic to focus solely on this practice.
  • The order of magnitude difference between agronomic phosphorus application rates and phosphorus loadings that can cause ecological damage presents a serious environmental challenge, especially compared to nitrogen. Across the literature, generally less than 2% of applied phosphorus was lost in drainage in a given site year.
  • Practices such as applying at planting or side-dressing had lowest median nitrogen losses (not significant).
  • Adherence to 4Rs strategies is vital regardless of the nutrient source, and accurate implementation of the 4Rs approach will require site-specific knowledge.

Annual Reports

2015

Publications

Enhanced Efficiency Fertilizer in Corn Systems in the Midwest

Crops: Corn for grain Corn for silage
4R Practices: Metadata Project

Meta-analysis of Enhanced Efficiency Fertilizers in Corn Systems in the Midwest

Lead Researcher:

Dr. Rachel Cook

Assistant Professor

North Carolina State University

Start Date: 2014

End Date: 2015

Matching Funds

  • Dow AgroSciences

Project Summary

The 4R approach to nutrient stewardship has helped develop a better context for driving best management practices in production agriculture. As the agricultural community becomes more involved in exploring the three aspects of sustainability, including the economic, social, and environmental triple bottom line, the 4Rs (right source, right rate, right time, and right place) provide a framework for better management of fertilizer applications.

The exceedingly large number of possible combinations of source, rate, time, and place, even within one cropping system, can make it difficult to compare results from studies located in different regions, with different climate, soils, and accepted management practices. To prevent needless duplication of study parameters and suggest future study directions, the soil fertility and fertilizer community needs to systematically compile what we know in order to move forward in the most efficient manner possible.

Project Goals:

  • Compile a database that will characterize environmental variables (latitude and longitude, precipitation, soil texture, soil organic matter, and plot size).
  • Meta-analysis will re-evaluate the current literature on nitrapyrin, and expand the analysis to include other nitrification inhibitors, urease inhibitors, and controlled release fertilizers will create a more useful and broader-scoped analysis of the environmental and agronomic benefits of these management practices in Midwestern corn production.

Project Results:

  • Application timing and nitrogen rate had a greater effect than nitrogen source with enhanced efficiency properties for management and environmental factors for this specific meta-analysis.
  • A need for an additional assessment that coverages greater regions and specific systems that are susceptible to losses is clear.
  • Nitrate leaching and water-quality information reported with measures of variability are the biggest information gap at this time for both tile-drained and non-tile-drained systems.

Annual Reports

2014

2015