**3. Results and discussion**

The interactive training and demonstrations delivered to university students, farmers and extension agents have contributed to enhancement of knowledge of using clay pot technology, which has contributed to enhance food productivity in dryland areas of Ethiopia. Cooperation in scientific knowledge sharing and development of partnerships with Brazilian

**Figure 1.** Images showing the demonstration of the project in Africa. Source: Araya and Africa team.

In Brazil, the process was fully automated and the experiments were installed in the community of Lavras, city of Santarém, in a fruit garden using agroforestry. This change in strategy led to substantial gains to the project. The project leadership in Brazil actively worked to automate the low-cost irrigation process. The entire pottery process was documented with video and photographs while the artisans from Icoaraci Center made the clay pots, and equipment for monitoring of parameters such as soil and air temperature and relative air humidity were purchased. The irrigation apparatus, comprising pipes, floats, connectors, hygrometers, gutters, and water tanks were purchased and the whole process in Brazil was automated. A Demonstration Unit (DU) was installed at Embrapa Eastern Amazon, in Belém. During the 39th Agriculture and Livestock Fair in Santarém, a lecture was given to demonstrate the low-

Embrapa scientists has also been enhanced.

cost technology for efficient water use (**Figure 2**).

**2.7. Amazon/Brazil: demonstration area**

82 Soil Moisture

The water seeps out through the micro pores of the clay pots with relatively slow flow and larger surface wetting time—area coverage around the roots of plants. Contrarily, perforated clay pots leak the water much quicker through the macro- and micro-pores and have relatively shorter wetting time—area coverage ratio. On the other hand, the difference between perforated bar and round types is simply the shape of the pots which affects the area coverage along the rows of the Swiss chard plant. Round types were not as suitable as the bar type (of the same capacity) for rows of Swiss chard crops due to their wetting area coverage along the two sides of the bar. Therefore, among the tested clay pot designs, the bar shaped perforated clay pot designs were evaluated as best in term of biomass and economic water use efficiency. The economic and biomass water use efficiency for the perforated bar clay pot design was higher than that of the bucket irrigation system. The other advantages with perforated bar clay pots over the bucket type is that the water source is inside the soil thus evaporation is almost nil and there is also less probability of occurrence of leaf disease due to watering and this ultimately improves the biomass and water use efficiency.

The highest economic performance was obtained in furrow irrigation during the first harvest due to higher investment in clay pots. However, after analyzing return on investment (six consecutive harvests) the bar shaped clay pot irrigation was highly superior in economic performance compared to the furrow irrigation practices. A marginal rate of return indicated that 478.18, 258.82 and 221.47% was obtained in Swiss chard, pepper and tomato, respectively. Sensitivity analysis also indicated that adoption of the findings is feasible and practical.

Comparisons of the irrigation methods using the clay pots showed that there was a significant difference (p < 0.05) for tomatoes irrigated in rows. The authors [13] infer that water availability was adequate and uniform in the clay pots compared to the irregular availability in the soil for the row-irrigated crops. The cumulative yield of the three vegetable crops irrigated using clay pots were significantly superior (p < 0.05) than crops irrigated in rows. There was a 30% increase in yield in the system where water was replaced using clay pots compared to the system wherein green pepper was irrigated in rows. These results show that the technology that irrigates using clay pots can be used even in conditions that use brackish or salty water. Furthermore, the yield of tomato was 32% greater using clay pots than for those irrigated in rows, thus confirming the efficiency of this system. Similarly, the yield of Swiss chard showed an increase in biomass of 51% using clay pots. This increase can be explained by the fact that Swiss chard has a shallow rooting system which facilitates the absorption of water in this system using clay pots as compared to irrigation in rows [4].
