Sustainability and Plant Minerals

Importance of Minerals to Plants

• All plants require functional minerals for growth and normal development.
• These minerals include primary nutrients such as nitrogen, phosphorus, and potassium, and secondary nutrients like calcium, magnesium, and sulphur.
• Micro-nutrients, despite being needed in smaller amounts, are also essential. These include elements such as iron, manganese, zinc, copper, molybdenum, and boron.

Mineral Acquisition

• Plants take up minerals from the soil through their roots. These nutrients are usually dissolved in water and absorbed through active transport.
• Many plants have evolved relationships with root-symbiotic microbes, such as mycorrhizal fungi and bacteria, that help in the uptake of less accessible nutrients or those present in non-bioavailable chemical forms.

Sustainability in Plant Mineral Use

• To maintain soil fertility, it's important to replace the minerals that are removed when plants are harvested.
• Crop rotation and intercropping are traditional methods that encourage nutrient cycling. Different plants have different nutrient requirements and can draw from different soil depths.
• Usage of green manure crops or crop residues can recycle nutrients back into the soil, reducing the need for synthetic fertilisers.
• Favouring natural predators over chemical pesticides helps conserve beneficial soil organisms that aid in mineral recycling.

Environmental Impact of Fertilizers

• Overuse of synthetic fertilisers can lead to eutrophication of nearby water bodies, causing algal blooms that result in a loss of aquatic biodiversity.
• High levels of nutrients, especially nitrogen compounds, in drinking water can have direct negative effects on human health.
• The production and distribution of synthetic fertilisers involve significant energy use and carbon emissions, contributing to climate change.
• To minimise these impacts, it is necessary to improve fertiliser efficiency, use organic alternatives, and employ precision agriculture techniques to optimise usage.

Role of Plants in Sustainable Agriculture

• Choosing plant species or varieties that have good nutrient use efficiency can reduce the need for fertilisers.
• Certain plants, such as legumes, enable soil nitrogen fixation due to their symbiosis with nitrogen-fixing bacteria, reducing the need for nitrogen fertilisers.
• Breeding or genetically modifying plants to improve nutrient uptake efficiency or to enhance their association with beneficial soil microbes are promising areas of research for sustainable agriculture.