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Green Manure and Natural Soil Fumigation

Posted in Garden Advice on April 19, 2021

Soil remediation and nitrogen fixation - Green Manure crops can add a natural nitrogen fertiliser to soil and help control some pests and diseases.

Green Crop Lupins

Growing Burnet’s Green Feed Lupins is a natural way to add nitrogen fertiliser to your soil. Lupins are a member of the pea family (Fabaceae). This family of plants have a mutualistic (symbiotic) association with bacteria such as Rhizobium in their roots. The bacteria can fix atmospheric nitrogen as ammonia, nitrites, and nitrates which can be used by the plants, reducing the need for adding other nitrogen fertiliser.

Green Crop Mustard

Mustard can be grown in your vegetable patch as a summer/autumn cover crop to help suppress weeds and control soil pests and diseases.

Scatter the Burnet's Green Crop Mustard seeds over the cleared vegetable bed and firm them into the soil with your hand or the back of a rake. The crop will cover the area within a couple of weeks and leaves can be harvested for use in stir fries. The plants can handle light frosts, but it is best to chop the plant’s roots and leaves into the soil before heavier frost damage them. The dug in roots and leaves will suppress nematodes and common soil diseases such as Phytophthora root rot. It acts as a biofumigant; mustard plants produce glucosinolates, which breakdown as the plant decomposes into allyl-isothiocyanate, which acts like methyl isothiocyanate, the active ingredient in the chemical fumigant metam sodium. 

Green Crop Manure Seed Mix – Lupins, Mustard and Garden Oats

This mixture provides the benefits of the lupins and mustard mentioned above, with the protein and organic matter of oats.

Apply your Burnet's Green Crop Manure Seed Mix to revitalise the soil, it adds lots of natural nitrogen fertiliser, it controls pests and disease, and it helps suppress weeds.

Green crop, made up of mustard seed, lupin seed and garden oats, is easily sown into your unused vegetable patch. Just sprinkle the mix, then lightly rake the seeds in so they are covered with soil, water and wait for them to come up, which will happen within days. Then, just let them grow and do their thing. Lupin fixes large amounts of nitrogen from the air, improving the nutrient properties of the soil. Mustard seed acts as a pesticide and fungicide, helpful in control of nematodes, wireworm, and other problems with root crops. Garden oats add protein and organic matter to your soil.

Dig the mixed crop at least 30 cm into your soil in winter or early spring before they come into flower. This will also encourage earthworms which are beneficial in your soil; helping breakdown the dug in crop, aerating the soil, and distributing the nutrients.

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