Minimizing phosphorus (P) losses with the 4Rs and cover crops in Kansas, USA

The Kansas Agricultural Shed Field Laboratory was established in 2014 by IPNI, with support from the 4R Research Fund. The project, led by Prof. Nathan O. Nelson (PI) of Kansas State University, aims to protect water quality and maximize nutrient use efficiency while simultaneously providing producers with flexible management options for phosphorus (P) fertilizers.

This goal will be achieved through the integration of the 4R nutrient stewardship with cover crop use in corn‐soybean production systems. The overall objective of this research is to determine how interactions between cover crops and P fertilizer management impact P loss, P use efficiency, crop yield, and net return.

The Kansas Agricultural Watershed (KAW) Field Laboratory is composed of 18 watersheds, ranging from 1.1 to 2 acres in size where effects of agricultural management on water quality and quantity are studied. Each plot is equipped with an H‐flume which measures runoff from natural rainfall. Prof. Nelson explains the use of these samples: “An important part of this project is estimating the total amount of phosphorus that is lost from each plot, or each treatment. In order to do that, we need to know two things: how much water has left the plot, or the total volume of runoff, and the second thing we need to know is the concentration of phosphorus in the water that left”.

The project will run until September 2019, and is expected to enhance our knowledge on how cover crop use impacts the 4R stewardship recommendations for P fertilizer; as well as helping producers understand the impact of cover crops and fertilizer management on their crop yield, water quality, and net return.

Read more about this project here and watch IPNI’s video.