While gardening is generally seen as a green activity, many of the fertilizers that you’re using may be both inefficient and harmful to the environment. Scientists know this, and many researchers are currently working to create greener, less harmful fertilizers that are also better at giving plants the micronutrients they need.

At the University of Adelaide, scientists have now turned to high-tech materials in their quest to developer friendlier fertilizers. Specifically, they are looking at graphene as a possible environment-friendly fertilizer carrier.

Using graphene oxide for a more targetted delivery of micronutrients

Crops require micronutrients for their growth and development. These micronutrients, however, are usually fed to the plants using fertilizers made with water-soluble salts. In acidic sandy soils or high rainfall environments, these salts can be lost through leaching and run-off.

This usually means that you need to use a lot of fertilizer to compensate for the run-off, which is both expensive and has a severe environmental impact.

The researchers, led by University of Adelaide graduate student Shervin Kabiri, have addressed this problem by using graphene oxide as a carrier for micronutrients. Graphene oxide can be manufactured at a low cost and is water-dispersible. In addition, metal ions bind easily to the surface of graphene oxide, making it easy for micronutrients such as zinc and copper to be loaded into it.

More importantly, the team found that graphene oxide exhibited a two-phase behavior when releasing the micronutrients. It first released a fast burst of micronutrients, followed by a longer, slower, more controlled release. The latter is great for crops, as seedlings need an initial burst of nutrients followed by a slower, more sustained release.

“Fertilisers that show slower, more controlled release and greater efficiency will have reduced impact on the environment and lower costs for farmers over conventional fertilizers, bringing significant potential benefit for both agriculture and the environment,” explained Professor Mike McLaughlin, head of the University of Adelaide’s Fertilizer Technology Research Centre at the Waite campus.

“Our research found that loading copper and zinc micronutrients onto graphene oxide sheets was an effective way to supply micronutrients to plants,” he added. “It also increased the strength of the fertilizer granules for better transport and spreading ability.”

In testing with the graphene-based fertilizer, Kabiri and his team found that the graphene help plants absorb more zinc and copper. Work is continuing with getting the graphene to work with macronutrients such as nitrogen and phosphate.

Other environment-friendly fertilization methods already exist

While it may take a while before more efficient and environmentally friendly fertilizers based on graphene become available to gardeners and farmers, that doesn’t mean that you can use environmentally friendly methods to fertilize your garden now.

The simplest way to reduce the environmental impact of using fertilizer is to utilize an organic fertilizer made of dry plant and animal matter. Unlike wet fertilizers, dry fertilizers stay on top of the soil for a longer period of time, requiring fewer applications. These also tend to release their nutrients slowly, somewhat similar to the graphene-based fertilizers.

Here are a few organic fertilizers you can try.

Bone meal

A byproduct of the meat processing industry, bone meal is an excellent source of phosphorus and calcium and is ideal for fertilizing bulbs, trees and shrubs. Take note that phosphorus tends to move slowly in soil, so bone meal is best applied to the bottom of planting holes, near the plant’s roots.

Cottonseed meal

The nutrients in cottonseed meal are readily available in plants in warm soils and don’t have the risk of nitrogen burn commonly associated with chemical fertilizers. Take note that cottonseed meal is slightly acidic, making it ideal for certain acid-loving plants, but less so for others.

Alfalfa pellets

Alfalfa pellets are usually used by livestock farmers as a nutrient-rich feed. It can, however, also be used as a great organic fertilizer. Alfalfa pellets add nitrogen and trace minerals to your soil.

When fertilizing with alfalfa pellets, just be sure to check if they’re weed-free. Some lower-quality alfalfa meal may have weed seeds mixed in them.

Bat guano

Bat guano – the feces of bats – can be found in most garden centers as a powdered natural fertilizer. Bat guano is rich in nitrogen, phosphorus and potassium. In addition, bat guano also helps improve the texture of the soil, helping hold together loose soils while making dense soil lighter.

Fish emulsions

Some gardeners may be turned off from fish emulsion as it can often have an unpleasant smell. Don’t let that turn you off; however, as fish emulsion helps enhance soil health. This is because fish emulsion encourages the growth of beneficial organisms such as earthworms, bacteria and fungi. These organisms help break down nutrients in the soil, making them more readily available for plants to absorb.

Compost

The great thing about composting is that it also helps you get rid of any organic waste produced by your household. This means that composting can be a sustainable way for you to both fertilize your garden, as well as dispose of your household organic waste. This also means that you don’t have to spend as much if you’re composting compared to constantly buying fertilizer.

Even without high-tech developments, it’s still quite possible to fertilize your garden without harming the environment. New developments in environmentally friendly fertilizers, such as the new graphene-based fertilizer, are great; however, that doesn’t mean that you have to wait for these to start gardening in a more environmentally friendly manner.

Sources:

Newswise.com

HomeGuides.SFGate.com 1

EpicGardening.com

HomeGuides.SFGate.com 2

GardeningKnowHow.com