Cu phytoextraction and biomass utilization as essential trace element feed supplements for livestock

Area of Science:

• Agricultural Science
• Environmental Science
• Plant Science

Background:

• Copper (Cu) is vital for animal growth and health, often supplemented in feed.
• Copper contamination in agricultural soils poses environmental concerns.
• Alfalfa (Medicago sativa L.) is explored for its potential in copper phytoextraction and biofortification.

Purpose of the Study:

• To assess alfalfa's potential for copper biofortification as a livestock feed supplement.
• To investigate the effect of Ethylenediamine-N,N extsuperscript{ extprime}-disuccinic acid (EDDS) on copper uptake in alfalfa grown in soils with varying copper levels.
• To evaluate the feasibility of using biofortified alfalfa to alleviate soil copper contamination.

Main Methods:

• Alfalfa was cultivated in soils with low (11 mg kg^-1), moderate (439 mg kg^-1), and high (779 mg kg^-1) copper concentrations.
• Ethylenediamine-N,N extsuperscript{ extprime}-disuccinic acid (EDDS) was applied at rates of 0, 0.5, 2, and 5 mmol kg^-1 to enhance copper bioavailability.
• Biomass yield and copper concentrations in alfalfa shoots were measured after the first cutting.

Main Results:

• Alfalfa growth was inhibited in highly copper-contaminated soil, especially with 5 mmol kg^-1 EDDS, reducing biomass by 45%.
• Copper concentrations in alfalfa shoots significantly increased with higher soil copper levels and EDDS application, reaching up to 6700% above control levels.
• Alfalfa shoots exhibited higher copper concentrations compared to some fodder plants, with notable increases in moderately contaminated soils (up to 450 mg Cu kg^-1) when treated with appropriate EDDS dosages.

Conclusions:

• Alfalfa grown in clean or moderately copper-contaminated soils (up to 450 mg kg^-1) can be biofortified with copper using optimized EDDS application.
• Biofortified alfalfa shows promise as a partial copper supplement for livestock, contributing to soil remediation.
• This study supports the integration of copper phytoextraction and biofortification for sustainable livestock production and environmental management.