A cooler than average start to the growing season has added some uncertainty to post-plant nitrogen fertilization strategies for Ontario corn producers. Soil supply of nitrogen to the corn crop is likely lower than normal due to reduced N mineralization from both soil organic matter and manure, and the Maximum Economic Rate of Nitrogen (MERN) […]
Summary Background Throughout the growing season, microbes within the soil break down organic nitrogen contained in soil organic matter and release it as plant-available ammonium. This process is known as nitrogen mineralization. Nitrogen mineralization is favoured by warm soil temperatures with adequate soil moisture and aeration. Excess moisture can slow mineralization or increase the potential […]
Purpose: Pre-sidedress soil nitrate test (PSNT) provide a means of estimating soil nitrogen supply, and can aid producers in fine-tuning their nitrogen application rates for corn. One drawback of current soil nitrate tests is that they are only calibrated for situations where all of the nitrogen being measured has come from soil mineralization, that is […]
Co-Authored by Ian McDonald Background: In 2013 a range of corn fields were sampled to determine what impact the weather has had on the level of residual soil nitrate. This year April was cool and relatively wet while the first half of May came in warm and dry followed by conditions since mid-May that have been […]
Coordinated by: Ian McDonald and Greg Stewart, OMAFRA Background Annually the OMAFRA field crops team surveys a range of corn fields to determine what impact the weather has on the level of residual soil nitrate. In 2012 weather conditions have been almost polar opposite to last year when April was cool and May was wet. […]