What is the problem/challenge that is being solved?

Snail farming holds immense potential to tackle the pressing issues of food insecurity and economic empowerment in West Africa. The demand for snail meat is considerably higher than the available supply, resulting in high market prices. Snail meat is highly nutritious, rich in protein, iron, and essential amino acids, making it an excellent food source for improving dietary diversity and nutrition. Furthermore, snail farming is a sustainable agricultural practice. Snails have a low environmental footprint compared to other livestock; they require less land, water, and feed, and they produce minimal waste. These attributes make snail farming an attractive option for promoting sustainable agricultural practices. However, despite these benefits, several challenges hinder the advancement of snail farming. A significant barrier to snail farming  is the lack of technical expertise among prospective snail farmers. These farmer often lack the necessary knowledge and skills to manage snail breeding, feeding, and health effectively. 

Snails are vulnerable to a range of predators, including birds, rodents, and insects. Protecting snails from these predators requires effective measures. Additionally, snails are susceptible to various pests and diseases, which can devastate snail populations if not properly managed. While snail farming generally requires less investment compared to other types of livestock farming, there are initial setup costs for housing and feeding systems. 

What is the solution developed in the LL?

The ADC Snail Farming Initiative focuses on the rearing of edible snails, Achatina fulica and Archachatina marginata. These species are known for their nutritional value and relatively easy rearing requirements, making them ideal for farming.

The complete practice abstract is available in the Knowledge Center of the INCiTiC-FOOD website (https://incitis-food.eu/).

What is the problem/challenge being solved?

Black Soldier Fly (BSF) cultivation offers an affordable alternative sustainable source of proteins that can be used to replace fish meal and oil in animal feed formulation. Thus, the costs for animal feeds are reduced and organic wastes that are a major environmental threat in urban areas utilized.

What is the solution developed in Living Lab?

Egerton LL has invested in rearing of Black Soldier Fly (BSF) and using the BSF Larvae in fish feeds formulations. In addition, the frass, a by-product of BSF rearing can be used as organic fertilizer. This circular food system approach reduces organic waste and thus enhances resource efficiency.

Implementation of Black Soldier Fly rearing

BSF is an insect, the name comes from the color of the adults which are black with metallic reflections. In contrast with the house fly, BSF is not a pest. It does not bite, sting and is not able to transfer diseases. 

Preparation of facilities for rearing of BSF 

Factors to considered in BSF Facility site selection:

The African catfish (Clarias gariepinus Burchell 1822) of the family Clariidae is a highly economic freshwater species found in the tropical and subtropical regions of the world. However, information on its growth pattern, robustnes and survival in aquaponics systems is scanty. 

Consequently, the Living Lab of Njala University studied the growth performance and well-being of the fish using the length-weight relationship (LWR) and condition factor (CF) in an aquaponics setup. The setup consisted of 700 litres water capacity IBC tank stocked with 52 juveniles of Clarias gariepinus (mean weight 15.2 g) and 5.5 m NFT plastic pipes on which 75 stands of Okra (Abelmoschus esculentus) were planted. Fish length and weight as well as water quality parameters (dissolved oxygen, pH, temperature, NO3, NH4, NO2) were monitored in the aquaponics system bi-weekly.

Equation 1 was used to estimate the growth performance: W=a*L^b

W = Observed total weight of the fishes in grams.

L = Observed standard lengths of the fish in centimetres.

a and b are constants.

Equation 1 was transformed using logarithm to obtain a straight-line relationship (Equation 2): log W = log a + log L

The regression coefficient `b` of the unsexed fish that is greater than (> 1) or less than (< 1) demonstrates either positive or negative allometric growth respectively. Positive allometric growth indicates that their weight increases at a faster rate than their length, while negative allometric growth means that their weight increases at a slower rate than their length.

The value of b=3 shows isometric growth (desired growth pattern).

The condition factor is expressed as the Fulton's condition factor (K) using Equation 3: K = 100 *(W/L^3)

K = Condition factor

W = Fish weight in grams

L = Fish length in centimeters 

Condition factor values of 1 or above represent good growth in the given environment, while a score of < 0.5 represents poor health condition. 

What problem is being solved?

In order to obtain a product of high quality, with plants of uniform appearance, the cultivation needs to follow some basic rules. 

Procedure

1. From Seed to Seedling

Substrate selection: The substrate for seedling production can be organic, inorganic, or synthetic. For example, rockwool is a widely used inorganic substrate and very suitable for seedling production, as it has a high-water storage capacity and no added nutrients. 

Preparation: We recommend seeding 1/3 more seedlings than needed in the system adjusting for the germination rate. See our Practice Abstract on “Germination Test”.

Seeding: Depending on the plant variety and seed size, one seed (e.g., lettuce, cabbage) or a few seeds (e.g., basil, parsley, mint) are placed on the substrate. Make sure you use a suitable cube size for the crop you want to produce. 

2. From seedling to adult plants 

As soon as both cotyledons of the seedlings have completely opened, fertilization can be started. You can also start the fertilization from the seed, however, this can results in higher fertilizer costs. For this, a conventional nutrient solution such as Wuxal® Profi fertilizer from Maag, Dielsdorf, CH with an electrical conductivity (EC) slowly increasing from 800 up to 1'600 μS cm-1 should be used. Make sure that in the first two weeks, you do not exceed more than 1000 μS cm-1. Fertilizers, such as Wuxal®, must be used in combination with tap water as they do not supply Ca or Mg to the plants.

When the roots of the seedlings are long enough i.e. 5 cm / 2 inch, normally after 3-5 weeks for lettuce and 2 weeks for spinach, the seedlings can be transplanted to the aquaponic or hydroponic unit. Ensure that the roots have sufficient contact with the system water. It is recommended to do this in the evening so that the plants can slowly get used to the new conditions.

The complete practice abstract is available in the Knowledge Hub on the INCiTiS-FOOD website (https://incitis-food.eu/).

What problem is being solved?

Growing healthy and good quality plants is only possible from good seeds. Germination is the process by which a dormant seed springs to life. Light is an important factor that regulates germination:

The problem to be solved 

Any soilless cultivation method (hydroponics, aquaponics, bioponics) entails a challenge which is picking the right materials for plant support. Such materials, referred to as substrates, are crucial as they hold the plants, keep them moist, and deliver nutrients. Using wrong substrates can compromise plant growth thus  rendering the system inefficient. There is need to find substrates that work well for healthy seed germination and support early plant growth, but are also cost effective and easily available.

Proposed solution: Using sawdust substrate

The Living Lab in Bamenda, Cameroon investigated a series of substrates:  cotton balls, sponges, sawdust, coffee husk, and wheat bran. The suitability of these substrates was screened in the germination test. 

For this, plastic cups with holes for drainage were filled with the tested substrate and seeded with 2 seeds per container. They were placed in trays, watered, and covered with plastic to prevent drying. The seeds were observed daily for germination. 

The seedlings appeared in sawdust within 4 days, but there was no germination in coffee husk and wheat bran. In addition, mold and stability problems were noticed in cups containing coffee husk and wheat bran.

The seedlings were observed for further two weeks and different growth rates and patterns noted. Sawdust promoted quick growth with robust leaves. The seedlings in the coffee husk grew slower albeit steadily. However, they seemed to lack nutrients for sustained growth and transferring them to a greenhouse did not improve their condition.

Hints and tips on implementation

All substrate materials need to be sterilized and all equipment should be cleaned with bleach or commercial disinfectant after every use. 

The cups should be spaced properly in trays

Consistent moisture levels in substrate should be maintained by adding distilled water. 

Substrates showing contamination signs or poor growth despite care, need to be eliminated. 

What problem is being solved?

Before stocking the fish in any recirculating system, such as recirculating aquaculture system or aquaponics, the biofilter should be up and running, otherwise there is high risk of fish being poisoned by ammonia or nitrite accumulation. One should calculate 6 – 8 weeks of time from the start of the biofilter to be ready. Meaning that the population of nitrifying bacteria has established itself on the surfaces in the recirculating system.

1. Stop the water supply to the biofilter.
2. Set the water temperature to , bacteria like it warm!
3. Switch on aeration. As much as necessary, as little as possible. Keep turbulence as low as possible, position the diffusor head on the bottom of the tank.
4. The alkalinity of water should be approx. . It should be maintained by adding sodium bicarbonate (NaHCO₃).
5. Add bacterial culture (if using). The temperature of the culture must be adjusted to the water temperature.
   
   Instead of purchasing bacterial culture, one can use one of the following as a starter:
   
   • sludge or media from another biofilter
   • In the nearby river or lake, scrape the slime from several large stones and mix it gently with water before pouring it over the biofilter. But CAUTION: Make sure the water is not contaminated, especially if you do not know what is happening upriver or if any parasites in the water could harm your fish or the system.
6. Feed bacteria in the biofilter by either adding ammonium nitrate (NH4NO3), any other fertilizer containing NH4 or enough fish feed to reach the concentration of  NH4. 

The complete practice abstract, including the calculation procedure, is available in the Knowledge Center of INCiTiS-FOOD webpage (https://incitis-food.eu/).

Use of Simplified Screw Dripper to prevent clogging in the Hydroponics Systems 

One of frequently occurring problems in the hydroponic and aquaponic systems is clogging of the of the drip type of system. Clogging occurs when particles from the nutrient solution get stuck in the tubes or there is bacteria growth in the tubes. In commercial hydroponic systems that only require small flows of nutrient solution, calibrated pressure-compensating drip systems are often used to supply the plants with a constant amount of nutrient solution between 2-16 litres per hour. These systems mainly include substrate cultures, such as sack cultures or culture troughs, but also some variants of simplified hydroponics. However, commercial drippers are not available everywhere. In addition, despite their comparatively low price, they can still be too expensive, especially in the context of simplified hydroponics. There is therefore a need to find a simple alternative solution to replace the commercial drippers. A possibility has been developed to replace commercial drippers with simplified screw dripper to solve the problem of over watering in the hydroponics system.

Solution to the clogging problems

It is important to state that the use of simplified screw dripper as an alternative to commercial dripper is not the only solution to clogging of the hydroponics system. Clogging of the hydroponics system can be solved through.

1. Regular flushing of the tubes with warm water to prevent clot formation. 
2. Change the growing medium from loose to a heavy medium such as expanded clay.
3. To control algae growth in the system, it is recommended to:

Materials for screw dripper preparation

Tools and Equipment: Below are the important tools and equipment needed for setting up dripper.

1. Screws - 6 mm or 6.5 mm diameter, 30 mm length, 1.5 mm pitch & 6.5 mm diameter, 22 mm length, 2.5 mm pitch.
2. Plastic Hose - 5.8 mm diameter