Loss of trace elements from agricultural soil.

Area of Science:

• Environmental Science
• Soil Science
• Agricultural Science

Background:

• Soil erosion is a global challenge exacerbated by land management and climate change.
• Understanding trace element loss (essential and toxic) from agricultural systems is crucial but poorly understood.
• Previous research primarily focused on soil loss rates, neglecting element mobility.

Purpose of the Study:

• To quantify the loads and forms of key trace elements (copper, cadmium, manganese, nickel, selenium, zinc) lost from different agricultural systems.
• To compare trace element losses between arable and pasture land during storm events.
• To investigate the influence of land management practices on trace element mobility in runoff.

Main Methods:

• Monitoring trace element concentrations and loads in runoff from three agricultural systems over five storm events.
• Analyzing soil properties, annual fertilizer additions, and rainfall intensity.
• Differentiating between dissolved and particulate-bound fractions of trace elements in runoff.

Main Results:

• Arable fields exhibited soil losses an order of magnitude higher than pastures.
• Particulate-bound trace element losses were significantly higher in arable systems compared to pastures.
• Nickel showed the greatest average loss (27%), while zinc had the lowest (2%). Cadmium, selenium, and nickel were predominantly lost in dissolved forms.
• Dissolved losses of manganese and zinc were lower than particulate losses.

Conclusions:

• Overall trace element loss and its form (dissolved vs. particulate) significantly differ between arable and pastoral systems.
• The physico-chemical properties of individual elements influence their mobility and loss pathways.
• Arable land management practices lead to greater losses of essential trace elements compared to pastures.