Landscape Management of Agronomic Processes for Site-specific Farming
The objective of this project is to measure and model landscape dynamics for a hummocky topography in the Black Soil Zone of east central Alberta. Then evaluate the potential benefit of variable rate application.
IPNI-1999-CAN-AB19
01 Mar 2000
1999 Annual Interpretive Summary
Landscape Management of Agronomic Processes for Site-Specific Farming, 1999
This newly initiated three-year project is focusing on how landscape-scale variability influences soil properties and processes that are related to release of N, P, K, and S, and crop responses to both soil and fertilizer N, P, K, and S. The long-term objective of the project is to develop agronomic models which will assist farmers in making fertilizer management decisions based on landscape units.
The field test site chosen for this trial has rolling topography in the Black soil zone of eastcentral Alberta. The cooperating farmer has been using a combine yield monitor and GPS to measure yield variability on his farm, as well as variable rate fertilizer application to compensate for in-field differences in soil residual nutrients. Soil and crop measurements were conducted in 1999 using both grid and landscape transect sampling to assess crop establishment, growth and development, and soil nutrient supply. Crop biomass production increased from the upland shoulder to backslope to depressional footslope landscape positions. The higher productivity of footslope positions resulted in higher nutrient demands and was reflected in increased uptake of N, P, K, and S. Ion exchange membrane probes were used to measure soil nutrient supply rates throughout the growing season and revealed that the moisture and temperature conditions characteristic of the landscape controlled nutrient release. These landscape-based nutrient dynamics will be used to test mechanistic simulation models for their ability to predict soil nutrient supply and aid in refining fertilizer recommendations. AB-19