Location: National Soil Erosion Research Laboratory
Project Number: 5020-12130-004-026-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Apr 1, 2025
End Date: Jul 31, 2028
Objective:
Assess the potential impact of soil anaerobic conditions on phosphorus (P) solubility and develop a mechanistic crop nutrient uptake model for making more precise P application recommendations.
Approach:
Soil water dynamics may influence the amount of phosphorus (P) desorbed/released from the soil depending on the soil redox status. Few studies have examined the effect of reducing conditions on P solubility in soils; thus, we plan to conduct laboratory experiments in combination with field measurements to quantify these soil P dynamics.
Current P fertility recommendations are highly empirical in nature, and do not consider the impact of soil physiochemical characteristics (e.g., texture, pH) or management (e.g., tillage). Instead, recommendations based solely on agronomic soil test P values (e.g. Bray-1, Mehlich-3) represent a yield response to average conditions, rendering field grid sampling and any precision fertilizer application techniques less useful. Overall, the current approach makes nutrient recommendations imprecise, resulting in over-application or under-application. Such imprecision impacts production economics and agronomic efficiency. Development of a mechanistic nutrient uptake model will permit for making soil and management-specific P recommendations. This model will be able to predict variation in P use and efficiency from an array of soils and crops.
