By Gift Briton

Vonice Onkoba, an agronomist, has used chemical fertilizers throughout his farming journey. He changed to organic fertilizer (Zihanga frass) about a year ago after the prices of chemical fertilizers doubled.

“About a year ago, 50kilogram (kg) bag of chemical fertilizer cost approximately $22. Currently, the same quantity is selling at $55 and the price is set to rise further,” he noted.

In one of his strawberry farms, he noticed an unhealthy, shriveled appearance in some of the crops. Additionally, the crops were not flowering despite being mature. At the time, he lacked money to buy the fertilizer to give his strawberries the much needed nutrients they lacked.

In an effort to save his strawberry from dying, Onkoba began a quest for affordable alternatives to cut the cost of buying chemical fertilizers. It is during this quest that he met a friend who advised him to try Zihanga Insect frass (organic fertilizer from black soldier flies). Four weeks after top dressing his crops using the Zihanga insect frass, the strawberries looked very green, healthy and started flowering.

“I prefer the Zihanga insects frass because other than being affordable, it releases nutrients to the plants moderately.  The disadvantage with fast releasing fertilizers like the chemical fertilizers is that they degrade the soil which in most cases may lead to soil acidity,” Onkoba noted.

vonice onkoba at Zihanga production room

Zihanga insect frass is an organic fertilizer produced by Zihanga Limited, a youth based company located in Lower Kabete, Kiambu county. The company produces organic fertilizers  and animal protein using black soldier flies in order to boost food security and offer affordable alternatives to farmers who are currentluy battling with the rise in chemical fertilizer prices.

According to Brian Amenya, Operations Director Zihanga Limited, “BSF is an eco-friendly insect that naturally converts wastes into organic fertilizer within a week.”

After getting a starter pack of black soldier fly maggots through partnership with icipe, Zihanga limited began the mass production of the Zihanga frass fertilizer.

To produce the fertilizer, a farmer should be committed to go the whole route of domesticating the maggots and nurturing them in a special container until larvae stage for seven days.

The black soldier fly larvae is then introduced into chicken waste, human waste, pigs waste or market waste where they feed/convert the waste into an organic fertilizer. The end result from this breakdown is then decomposed in a heap for another one month before the frass is ready for use.

Brian Amenya attending to the BSF

Decomposition is done to make the fertilizer mature or ready for the soil because without it, the fertilizer could easily scorch plants. Also, it is during the decomposition that microbes such as molasses are diluted with water and sprayed on the heap.

Zihanga limited collects waste from nearby slaughter houses, chicken farms and the nearby markets like Wangige and City market in Westlands, Nairobi where they collect some at affordable prices of around shs. 500 (about USD 5) per bag of waste while others like pig wastes are collected without pay.

With Nairobi county alone producing close to 200 tons of waste a day, the company is also positively contributing towards climate change by reducing the greenhouse gas emissions like methane gas which is produced when the waste is rotten.

wastes used to feed the black soldier flies

Amenya notes that even though there are other insects capable of converting wastes into fertilizer, the problem associated with them is that they take too long, nearly six months, to convert the waste.  Also, unlike common houseflies, black soldier flies don’t have mouths and are incapable of transmitting deadly diseases, posing minimal risk to human or animal health, he says.

“After testing the fertilizer at the University of Nairobi(UoN), we confirmed that it had all the required macronutrients like phosphorus, potassium and nitrogen which are necessary for crop growth and productivity,”  Amenya explains.

“Phosphorus is an essential nutrient for root formation, nitrogen accounts for the vegetative aspect of the crop at a tender age and potassium for the flowering.”

Furthermore, the test also showed that the Zihanga frass contains other micro elements including boron and calcium which are equally critical for crop growth.

Amenya says that the Zihanga frass can be applied during planting, approximately 20-30grams per plant/seed depending on the type of crop, it can also be used during top dressing and seed propagation.

Moreover, the fertilizer is widely used in growing horticultural plants like cabbages, strawberries, tomatoes and French beans mainly because it is rich in nitrogen which is responsible the greening of plant leaves thereby enhancing photosynthesis.

The company sell a 50kg bag of the Zihanga frass at $20 and a wholesale price of $12 for 10 bags or more. Over the one and half year period the company has operated, it has served over fifty recurrent customers, most of  whom are referrals. However, they have started online marketing of the product on social media platforms such as Twitter and Facebook, Amenya said.

Zihanga fertilizer

Before he began using the Zihanga frass, Njoroge Kibe, an organic strawberry farmer at Uthiru Cooperation, was recording very low yields which could not satisfactorily serve his customers.

He could receive an order of up to 20 kilograms of strawberry fruit yet the farm only produced five kilograms of the fruit. Months after using the frass, the productivity improved and he could now serve his customers comfortably.

Kibe notes that there are few organic strawberry farmers in the country yet the demand for organic products is so high and the prices are also higher compared to inorganic products, adding that a punnet of inorganic strawberry cost $1 whereas the same punnet for organic strawberry cost $2.5.

According to Kibe, the frass has helped him to reduce post-harvest loss. “The calcium component in Zihanga frass is very important for me because it makes the fruit very attractive and firm making it safe and easier to handle during transportation,” he says.

“I like the Zihanga Frass because apart from its soil conditioning aspect, it can also improve degraded soil and it has high water retention capability that enables it to hold moisture within the root structure of the crop for a long period.”

Additionally, he notes that since he started applying the organic frass, the soil has had increased worms, a sign that the soil is rich.

“The first risk a farmer is likely to face after applying the inorganic fertilizers is leaching. Leaching is the case where the nutrients of the fertilizer are washed away by rain moments after applying the fertilizer and by using the organic fertilizer, the leaching risk is minimized,” Kibe added.

Mr. Kibe attending to his strawberry fruits

Though Amenya says the organic fertilizer can regulate the soil pH that is, acidity or alkalinity, when used in excess, the fertilizer can scorch up the crop. To avoid the scorching risk while also increasing its absorption, the fertilizer should be mixed with the soil and applied at least 2 inches away from the crop especially during top dressing, he adds.

Weather is one of the main challenges facing the production of the organic frass, Amenya says, noting that the production speed tends to be very low during cold weather. This is due to the fact that a specific temperature of not lower than 28 degrees Celsius must be maintained for the black soldier fly to convert wastes faster.

Moreover, with the production of the Zihanga frass involving interacting with wastes, Amenya notes that finding willing personnel to work in the farm is a challenge to the company, saying that “many young people are coy about activities that deals with waste.”

Recent the International Centre of Insect Physiology and Ecology (icipe) studies on black soldier fly have demonstrated the potential of black soldier fly frass fertilizer-a byproduct of Black Soldier Fly larvae that contains their waste, exoskeletons and leftover food- as an environmentally safe (organic fertilizer), more affordable and sustainable option for increased maize production.

With about 800 million people in the world hungry and another two billion suffering from life-threatening diseases related to under-nutrition and contamination from pesticides, Food and Agriculture Organization (FAO) notes that organic agricultural systems such as this can make a significant contribution to the reduction of food insecurity and poverty.

Apart from Zihanga limited, other organizations such as insectipro, an insect farm located in Limuru, is also using the black soldier fly to convert wastes into organic fertilizers and insect protein.

Read Also: Black Soldier Fly, a Solution to Organic Waste