For many years, Mishick Mwanza was a guitarist with a popular band in the city of Lusaka, the capital of Zambia. He migrated there as a teenager, after growing up helping his uncle grow vegetables on a wet piece of land along Makungwa stream.
When his uncle died in 2012, Mr. Mwanza stopped his music career. He explains, “I decided to go back to the village to reclaim my uncle’s garden and resume vegetable production.”
Mr. Mwanza comes from Lufu Village in Chipata District, in Zambia’s Eastern Province. He now grows many crops, including vegetables such as tomatoes and okra. Poor rains have become a big challenge for Mr. Mwanza. Most of the wetlands in his area fail to hold moisture for a long period after the rainy season, making vegetable farming difficult. But Mr. Mwanza has found a solution to meet this challenge: irrigating his crops with plastic water bottles.
According to Mr. Mwanza, climate change has shortened the season for vegetable production, and many small-scale farmers in his area have abandoned dry season vegetable farming.
He adds, “If we had enough water for our crops during the dry season from April to November, we would be able to produce enough food for ourselves and even have surplus for sale.”
Mr. Mwanza says he learned the water bottle irrigation technique from a workshop on simple irrigation methods for small-scale farmers. He explains: “The workshop was based on a technique of using clay pots placed near every plant station in the garden. Unfortunately, when I went back home, I was unable to get anybody to mould clay pots for me. However, I observed that many people threw away plastic bottles, so I decided to try using them in place of the clay pots.”
He adds, “Every time I go to town, I collect plastic bottles like a mad person.”
Mr. Mwanza uses a pin to make a small hole in the bottom of the bottle, and then fills it with water. He places a bottle near every tomato plant.
At first, the technique proved difficult to master. If the lid was on, the water would not drain out of the bottle. But if the lid was off, it drained too quickly. He tried several methods, then discovered that if he made a hole in the bottom of the bottle and another in the side, the water would drip more slowly. With more experimentation, he learned that it takes three or four days for a 390-millilitre bottle to completely empty.
Mr. Mwanza explains that the advantage of using plastic bottles to irrigate tomatoes is that the water goes straight to the roots and very little is lost. He says he used to water his tomatoes in the morning and afternoon, but this was labour-intensive. Now, he only has to worry about watering every four or five days, when he needs to refill the bottles. He adds, “This method is also very efficient. Using watering cans, I had to flood the whole bed with water. Some of the water sank into the ground, but a good amount just evaporated.”
Edward Phiri farms in the nearby village of Kaduku, and also uses plastic bottles to water his crops. He says: “Irrigation of crops using plastic bottles is very easy . . . . I have just planted young Gliricidia trees in my field and very soon the rains will go, but I plan to supply water to my trees using plastic bottles until they are strong enough.”
Using plastic bottles has worked well for Mr. Mwanza, although he says it is only practical during the dry season. Another challenge is that, during this time, the sun is hot and the bottles can become brittle. Some break if they are handled roughly.
It is not necessary to use clean drinking water to irrigate the plants. Mr. Mwanza uses water from a shallow open well, which means that there are sometimes particles in the water which can block the irrigation hole in the bottle.
Masautoso Sakala is the local extension officer for the area. He advises farmers to use a drum filled with river sand to filter particles of dirt from the water. When water is poured into the drum, it seeps through the sand and then through a drainage pipe into the watering can. In this way, dirt particles are left in the sand and don’t block the small holes in the water bottle.
Mr. Mwanza uses this simple system to irrigate his vegetables. He says: “This method of watering has worked very well with tomatoes and okra. Now I want to try it on leafy vegetables. If it works equally well, I expect to make a lot of money because lodges offer a very good price for leafy vegetables like spinach and cauliflower, which are rare during the dry season.”