Important Plant Minerals D. Crowley, 2008

Important Plant Minerals To know what minerals are required by plants and how fertilisers can help promote healthy growth

Minerals How do plants absorb the minerals they need? Roots are adapted to absorb the minerals needed to remain healthy (although some plants have adapted some special ways to get more minerals, e.g. a Venus fly trap) Venus fly traps often live in areas where minerals are scarce – to compensate they can trap and digest insects, getting valuable minerals from them

Minerals There are 3 essential minerals: - Nitrates – needed for protein manufacture Phosphates – needed for respiration and photosynthesis Potassium – needed for enzymes involved in respiration and photosynthesis Iron and magnesium are also needed in trace amounts for chlorophyll production

Sick Plant If minerals are lacking, plants can become sick: - Lack of nitrates – stunted growth & yellowing of older leaves Lack of phosphates – poor root growth & purpling of young leaves Lack of potassium – yellowing of leaves with dead spots on them

Plant Biomass Complete the plant biomass worksheet

Plant Biomass Biomass – the mass of all materials in an organism (except water) Water is not made by plants (plants absorb different quantities of water so it would not be fair to compare as they may have absorbed different quantities of water) Nitrogen Ammonium nitrate Phosphorus Nucleus Plants would not be able to photosynthesise and would die (leaves would not be green as chlorophyll is not being made) Major elements - nitrogen, phosphorous, potassium; minor elements - copper, iron, magnesium, zinc and sulphur (due to % presence within the fertiliser) Hydrogen; oxygen; carbon; nitrogen; phosphorus; copper; potassium; iron; magnesium; manganese; zinc; sulphur

Food The world population is constantly growing (>6 billion people) All these people require food, however crops cannot be grown in areas where there are insufficient minerals Intensive farming is a practice which allows for huge amounts of food to be produced using a variety of techniques, however there are some associated problems with this practice…

Intensive Farming Intensive farming results in: - Hedges removed to make large fields (this destroys the natural habitat and reduces biodiversity) Fertiliser misuse can pollute rivers and lakes Pesticides disturb food chains (many harmless insects are destroyed)

Fertilisers Fertilisers are essential to modern farming, as they allow crops to grow well, increasing their biomass (producing lots of food for us) Fertilisers are needed because plants remove minerals from the soil which need to be replaced

Fertiliser Problems Fertiliser problems arise when the fertiliser finds its way out of the soil and into rivers and streams This can happen easily if too much fertiliser is applied or it rains immediately after it has been applied The result is called eutrophication Caspian Sea (rapid algae growth can be seen in the northern part increasing the water’s turbidity (cloudiness))

Eutrophication Eutrophication occurs when excess nitrates make their way into rivers and lakes causing rapid growth of some plants and algae Some plants then start dying due increased competition for light which results in micro-organisms feeding on the dead plant (they respire using up lots of oxygen) This increased level of decomposition results in high levels of oxygen being taken from the water, making it very difficult for larger organisms such as fish to survive - a real danger

Eutrophication Excess nitrates make their way into rivers and lakes causing rapid growth of some plants and algae Some plants and algae then start dying due increased competition for light Micro-organisms feed on the dead plant (which respire using up lots of oxygen) A lack of oxygen in the water can be very bad news for larger organisms such as fish