For sandy soils, especially under sprinkler irrigation, applying nitrogen in split doses, starting with a small amount and delivering the bulk via sidedressing or through the irrigation system, is highly effective.
Optimizing Nitrogen for Sandy Soils
Sandy soils present unique challenges for nutrient management, particularly with highly mobile nutrients like nitrogen. Their coarse texture means water moves through quickly, leading to rapid leaching of nitrogen below the plant's root zone. Low organic matter content also contributes to poor nutrient retention. Therefore, the timing and method of nitrogen application are critical to improve nitrogen use efficiency and minimize environmental impact.
Recommended Approach Under Sprinkler Irrigation
Effective strategies for sandy soils often involve applying nitrogen in multiple smaller doses rather than one large application. This approach helps ensure that nitrogen is available to the plant during critical growth stages and reduces the amount lost to leaching.
Based on successful practices, under sprinkler irrigation on sandy soil, one of the best choices for nitrogen fertilizer timing is to use a small amount of nitrogen as a starter application. This initial dose provides essential nutrients for early plant establishment and growth.
Applying the Bulk Nitrogen
After the initial starter, the majority of the nitrogen needed by the crop should be applied later in the growing season as the plant's demand increases. The reference highlights two excellent methods for this bulk application:
- Sidedressing: Applying the fertilizer in bands along the sides of the crop rows. This method places the nitrogen close to the root zone, allowing for efficient uptake.
- Through the Sprinkler Irrigation System (Fertigation): This involves dissolving water-soluble nitrogen fertilizers in the irrigation water. Fertigation allows for frequent, small applications of nitrogen, precisely matching the plant's uptake rate and minimizing leaching.
Applying the bulk of the nitrogen either as sidedress, or through the sprinkler irrigation system, helps to spoon-feed the crop, providing nutrients as they are needed and significantly reducing the risk of nitrogen loss compared to a single, large pre-plant application.
By splitting the application and using methods like sidedressing or fertigation under sprinkler irrigation, growers can dramatically improve nitrogen availability to the crop in sandy soils, leading to better yield and reduced environmental concerns.
