Cover crops are relatively quick to grow and provide an economical solution to replace lost nutrients in the soil in a completely natural way. They are sown in autumn after crops have been harvested and usually in areas that are not going to be used over winter.
Cover crops are reliable, sustainable tools used to manage soil fertility, soil quality, water, weeds and soil/plant diseases. They are often referred to as 'green manures' due to the recycling of organic matter and enhancement of microbial activity in soils.
Popular cover crop varieties are mustard seed and lupin seed. The product benefits are similar – they both add organic matter to the soil; lupin crops fix nitrogen in the soil; mustard has a cleansing effect by reducing soil insects, like wireworm that attacks root crops.
Plant a mix of three parts lupin seed with one part mustard seed.
Cover crops also act as a weed suppressant while the land is bare and are a perfect way to improve soil structure.
Plant cover crops in autumn to grow through the winter season and mulch into the soil before the crops start to flower in late winter/early spring. Rain and wind can cause soil nutrients to be leached and lost over time so cover crops are an ideal way to prepare the soil for spring planting as soil nutrients and health is revitalised.
To get the best out of a green cover crop you need to dig it back into the soil when the stems are still green and soft, but before the cover crop reaches approximately 50cm. It is recommended this is done 4-6 weeks prior to planting your vegetable garden.
After the cover crop has been incorporated in to the soil leave it to breath and absorb nutrients before planting your next crop. In addition to mustard seed and lupin seed use other soil conditioners like Tui Super Sheep Pellets and Tui Blood & Bone to condition and revitalise your soil. Adding Gypsum or Tui Lime will help speed up the decomposition process.