Exchange Irrigation Scheme developed in two phases. The first phase was when in 1973 56 hectares were developed to supplement to farmers who had been resettled on 2.5 hectare dry land per household. Plot holder then had a "comma" as it is popularly known; thus a 0,1 hectare Phase 2 was when the scheme was rehabited and developed to 165 hectare; that is +109 hectares. The second phase saw allocation of commas to new farmer and addition of commas to existing farmers. In 1997 there were 850 plot holders with an average of 0.2ha plots per farmer.
Objectives
Primary objectives of the irrigation scheme was to equip farmers with a basic source of income materially and cash. Farmers could earn at least a sum equivalent to the government gazetted minimum wage by selling sweet green grocery produced from the irrigated land.
Beneficiaries
About 900 farmers and their families who live near Exchange Irrigation Scheme are the primary beneficiaries of the scheme. Most of the surrounding farmers have dry land rain-fed fields averaging 2.5 hectares. Livestock of these farmer also benefit by foraging at the adjacent bush that is evergreen watered by spillage irrigation water.
Management
The scheme was developed by Agritex, an extensition-work department of the Ministry of Agriculture. It is managed by the scheme management committee elected by participating farmers from among their members. Maintenance is carried out by civil servants at the scheme in unison with the management committee, Agritex officers and plot holders.
Women
Women have 50% representation in the management committee yet the percentage of work by women is only 33. However 80% of workers in the irrigation scheme are women.
Irrigation
Irrigation is water is dam pumped from Exchange Block Dam into a night storage reservoir before being canal distributed into two other resrvoirs further into the scheme for surface flooding of plots. Unlike Ngondoma Irrigation Scheme on the other side of Zhombe, this scheme water is driven by electric pumps. The plots are 0.1ha each and are arranged in blocks of 20ha to 30ha each. There are 6 blocks in total covering all the 165 active arable hectares. The tertiary offtake gates are operated by hand by either the civil servants or members of the management committee. Water is shared evenly at one day per week for each block of the six blocks. The seventh day, Sunday, is reserved for night storage top-ups and for watering nursary beds in any block.
Irrigation Seasons
July–February is maize corn season. March–June is the Beans and Tomato season.
Yields
Normally yields are 7000 kg corn per hectare and more than 1000 kg/ha for beans. At the market prices of $0.43/kg for green maize and $1.50/kg for beans, the two crops have a value of $3000/ha for maize and $1500/ha for beans, giving a combined harvest value of $4500/ha per year. The values quoted above are based on the following; 700 kg per comma. Green maize is usually sold in dozens and a dozen has an average of 7 kg. With this assumption 1 comma would sell for US$300 at US$3 per dozen. 1000 kg/ha to 1200 kg/ha beans. That is 100 kg to 120 kg per comma of beans. Beans usually sell at US$1.50 per kg..
