Archived
This content is available here strictly for research, reference, and/or recordkeeping and as such it may not be fully accessible. If you work or study at University of Kentucky and would like to request an accessible version, please use the SensusAccess Document Converter.
Publication Date
1981
Description
The process of phosphorus (P) fixation by soil was long thought to result in large losses of P, an idea that led to a common belief that plants can recover only about 10 % to 25 % of applied P. Because such small recoveries were considered unrealistic and contrary to common farming experience, the efficiency of P utilization in agricultural ecosystems has been investigated. This was done by using (1) a balance sheet approach in long-term P maintenance trials that had reached a steady state, and (2) published data fitted to a common nutrient cycle for nonsteady-state conditions. The efficiency of P utilization in steadystate ecosystems was defined as the amount of P taken up by the plants as a percentage of the total amount of P required to maintain the available soil P pool at equilibrium. The efficiency of P utilization in nonsteady-state ecosystems was defined as plant P uptake, plus gains or losses in the available soil pool, as a percentage of the total P inputs to the soil. New Zealand evidence shows that P utilization in grassland ecosystems ranges from 70 % to 90 % of the added and recycled P, the remaining 10% to 30% being lost in and from the soil. These findings have been incorporated into fertilizer recommendation schemes that are currently undergoing field testing in New Zealand.
flict with traditional and still-maintained theories of large-scale P fixation by soil. The concept of nutrient efficiency defined in this paper is of practical importance since it can be used to calculate nutrient inputs required to maintain steady production in any agro-ecosystem.
Citation
Karlovsky, J, "Phosphorus Utilization in Grassland Ecosystems" (1981). IGC Proceedings (1981-2023). 1.
(URL: https://uknowledge.uky.edu/igc/1981/section3/1)
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Phosphorus Utilization in Grassland Ecosystems
The process of phosphorus (P) fixation by soil was long thought to result in large losses of P, an idea that led to a common belief that plants can recover only about 10 % to 25 % of applied P. Because such small recoveries were considered unrealistic and contrary to common farming experience, the efficiency of P utilization in agricultural ecosystems has been investigated. This was done by using (1) a balance sheet approach in long-term P maintenance trials that had reached a steady state, and (2) published data fitted to a common nutrient cycle for nonsteady-state conditions. The efficiency of P utilization in steadystate ecosystems was defined as the amount of P taken up by the plants as a percentage of the total amount of P required to maintain the available soil P pool at equilibrium. The efficiency of P utilization in nonsteady-state ecosystems was defined as plant P uptake, plus gains or losses in the available soil pool, as a percentage of the total P inputs to the soil. New Zealand evidence shows that P utilization in grassland ecosystems ranges from 70 % to 90 % of the added and recycled P, the remaining 10% to 30% being lost in and from the soil. These findings have been incorporated into fertilizer recommendation schemes that are currently undergoing field testing in New Zealand.
flict with traditional and still-maintained theories of large-scale P fixation by soil. The concept of nutrient efficiency defined in this paper is of practical importance since it can be used to calculate nutrient inputs required to maintain steady production in any agro-ecosystem.
