In a world that is transitioning from conventional farming to sustainable farming, a good source of organic fertilisers is of vital importance when it comes to maximising land productivity. Organic fertilisers are expensive and majorities of communal or small scale farmers can barely afford even a small quantity, fertilising a 2 ha piece of land is almost impossible. Researchers are looking for ways in which soil productivity can be improved, without compromising the lives of soil organisms. Neem seed cake might just be the answer you’re looking for.
The neem tree
Azardirachta indica, commonly known as neem is native to Asia. In India, it is called as the “village pharmacy” (1), due to it’s ability to heal different ailments. The tree has gained importance resulting in it being grown all over the world. It is very easy to grow and care for.
Namibia is not an exemption, neem trees have found their way throughout the diverse range of the Namibian ecosystems. Namibia is considered a dry country with central parts being mountainous, but they have become widely distributed due to it’s ability to thrive well even in areas with very little rainfall per annumvery tolerant to high temperatures (2). This makes it possible for it grow and perform well in dry areas like Namibia. In Namibia neem trees begin to flower from mid September with fruits ripening in the months of December to March depending on the location.
Majority of the Namibian people plant neem trees due to their ability to grow fast (2) and provide shade for both humans and livestock. The fruits can be eaten by livestock, especially small stock. They have been reported to be effective in killing internal parasites. The fruits can also be collected when dry or while fresh and sundried to be stored for further processing.
What is Neem seed cake (NSC) ?
During the process of neem oil extraction, when the matured, dried neem seeds are passed through an oil press, two products are produced, a) the oil, which is the product of interest in most cases and; b) the by-product which is now called the neem seed cake.
Neem seed cake (NSC) as fertiliser
Various field experiments involving NSC have been undertaken and researchers have reported NSC to be a good source of nitrogen, potassium and phosphorus. This elements are the macro molecules which are vital for proper growth and development of plants. The seed cake has been reported to improve soil nitrogen by 50%, phosphorus by 30 as well.
Apart from NSC being incorporated in soils to fertilise, it is also a good soil conditioner and improves soil texture, structure and water holding capacity. Several researchers have reported an increase in the quantity and quality of crop harvests as a result of neem seed cake incorporation.