Archives: Courses

Josh McGrath – Modifying Starter Fertilizer Placement to Increase Effectiveness


  1. Compare continuous seed-row, pulsed seed-row, and continuous offset placement.
  2. Evaluate the rate, source and placement interaction effect on nutrient response.
  3. Evaluate the rate, source, and placement interaction effect on crop performance

Professional Profile

Assistant Professor, Extension Specialist – Agricultural Soil Management. Applied research and extension in agronomic soil fertility and nutrient management to maximize profitability, efficiency, and protect natural resources. Specializing in site-specific nutrient management, manure management, and water quality protection

Raj Khosla – Precision N Management

Precision Nitrogen Management Strategies to Increase Profitability and Sustainability of irrigated cropping systems

Raj Khosla presents his 2020 data from the project “Precision Nitrogen Management Strategies to Increase Profitability and Sustainability of Irrigated Cropping Systems” In traditional farming systems farmers choose to manage nitrogen (N) fertilizer at a uniform rate across a field based on an average yield goal. Dr. Steve Stokes, the opening Keynote speaker at a recent Info-Ag conference made a profound statement: “When you manage the “average” you miss your target 100% percent of the time”. Management decisions based on the field average results in significant over and under-application of N in a majority of the field. There is strong evidence that spatial and temporal variability exists in crop yield and hence N distribution and availability to plants (i.e., variability across the field within a given growing season and variably over time for a given field location). While this poses a challenge it also provides an opportunity to quantify, record, and manage N fertilizer both spatially and temporally. Fluid fertilizers are easy to apply for farmers and give versatility for optimal spatial and temporal management.

The overall objective of this research project is to increase the productivity, profitability, and sustainability of irrigated cropping systems in the western US.

Raj Khosla is the head of Agronomy department at Kansas State University. He recdently came from Colorado State University where he was involved with quantifying and managing spatial variability of soils by precise crop input management in an environmentally sensible manner. Dr. Khosla was evaluating different techniques of delineating and managing “production level management zones”. In addition, he was evaluating remote sensing techniques to quantify crop stress conditions for nitrogen in irrigated corn, and detecting weeds in dryland no-till fields. Many of the research concepts will be carried into Kansas State University projects or collaborations with Colorado State.