In attempts to incorporate varying media within the website, here is my first go at using Google Hangouts to LiveCast a presentation. The recorded presentation below provides nitrogen fertilization considerations for newly planted and developing orchards. Total length is around 15 minutes.
A quick overview of the presentation:
- Nitrogen is nitrogen. Several studies within CA have indicated that there is no benefit in using different types of nitrogen for fertilizing young almond trees. Some fertilizers, however, may influence soil pH as well as be more prone to leaching;
- Studies within Merced and Colusa COunty have indicated that newly planted trees will maximally grow with actual nitrogen applications between 3-4 ounces. This has to be adjusted for tree density and application efficiency;
- Developing trees have developing rootzones which leads to inefficient applications. If fertigating, the best irrigation system would deliver nitrogen directly to the rootzone of the tree (e.g. single line drip with punched emitters). If not possible, controlled release fertilizer has been shown to grow as well as conventional fertilizer and have a lower labor cost (one application and done for the season). The 120 day controlled release blend in this trial was supplied by Agrium Technologies;
- Do not apply more than one ounce of actual nitrogen per application per year of growth. This helps reduce lanky growth and nitrate uptake toxicity;
- Take into account residual soil nitrogen and nitrogen within the irrigation water if using a well. In some cases, these may provide sufficient nitrogen;
- Finally, don’t start too early. Give the trees time to grow and draw down some of the moisture within the rootzone. Around 6″ of growth should be visible prior to the first fertilization.