| Rezvan Karimi Dehkordi
Ph.D. Student
Movement of nitrate and phosphorus from swine manures in annual and perennial cropping systems
Excess application of livestock manure for crop production to land can result in loss of phosphorus (P) and nitrate-N (NO 3-N) from agricultural areas and consequently water quality degradation of streams and lakes.
Nitrate Nitrogen Leaching
Nitrate-N (NO 3–N) is one of the primary sources of N to most crops. The chemical characteristics of NO 3–N make it susceptible to leaching through the soil into ground water bodies. Nitrate N concentrations in excess of 10 mg L -1 in drinking water can cause significant risk to human health.
Phosphorus Leaching
Phosphorus is considered as a pollutant due to its effects of promoting algal growth and eutrophication of surface waters. At very low P concentrations, biological growth can be stimulated when dissolved reactive P concentration exceeds 0.01 mg L -1. Traditionally, most data on P movement in soil were obtained from soil analysis of extractable P as a function of depth, which has led to the general assumption that no substantial vertical P movement or leaching loss occurs because of high P-fixation capacity in many mineral soils. Nevertheless phosphorus can be lost from the soil if the amount applied exceeds the sorption capacity of the soil and the rate of uptake by plant roots.
Modeling Nutrients Moving
Water quality computer models are useful tools to predict the risk of nitrate nitrogen and phosphorus contamination to surface and ground waters. Calibration and validation of these models are necessary for the conditions under which they will be used. A properly validated model provides a more rapid and cost effective mean of estimating NO 3–N leaching under different agricultural management practices. Therefore, farmers can more accurately determine the amount of fertilizer to manage yield and avoid overfertilization. Political decision makers can identify agricultural best practices. LEACHMN and Versatile Soil Moisture Budget (VSMB) model were selected for this study to determine which model is better to predict the amount of nutrient loss from different cropping system and location within Manitoba on an annual basis.
Research Objectives
To determine the influence of:
Swine manures (solid versus liquid), cropping systems (perennial vs annual) and nutrient management systems (Nitrogen-based vs P-based) on the loss of water and nitrate below the root zone.
To compare the use of field core lysimeters with traditional soil profile sampling in measuring nutrient loss from the soil.
To use computer model to summarise and extrapolate field results to other Manitoba soils.
Supervisor:
Dr. O. O. Akinremi, Professor in Soil Science
Expected Date of Completion:
Previous Degrees:
B.Sc., Soil Science Department, Isfahan University of Technology, Iran (2004).
M.Sc. Soil Science Department, Isfahan University of Technology, Iran (2007).
Email:
umkarimr@cc.umanitoba.ca
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