Mennonite Central Committee (MCC) is increasingly using Conservation Agriculture (CA) techniques in its work with dozens of partner organizations. Most of this work is in Africa, and many of the projects are funded through MCC’s account at the Canadian Foodgrains Bank.
To learn more about conservation agriculture, how it really works and the difference it makes, we spoke to Dan Wiens, a food security and livelihoods coordinator with MCC. He works with farmers on integrating CA methods into their agricultural practices.
MCC photo/Alison Ralph
What is conservation agriculture?
It’s a style of farming that has three principles. The first is minimum soil disturbance; some people call it minimum or zero tillage. The second involves a ground cover, often mulch. The last principle is some form of crop rotation or even an association between different types of crops planted side by side.
Let’s start with minimum or zero soil tillage. Why is this important?
There are billions of microbes in every handful of soil, and they give plants the nutrients they need to grow. Tilling, or turning over the soil and breaking it up, destroys a lot of those microbes. Generally, the more you till, the more microbes you kill. If you don’t till, you are maintaining the flora and fauna that give life to the soil.
MCC photo/Nina Linton
Low or no tillage also helps retain water. There will be less evaporation from a larger clump of soil than from a flat surface that’s been loosened by tilling. And tilled soil is more likely to be eroded by wind and rain. So reducing tillage reduces erosion.
MCC photo/Matthew Sawatzky
Why is ground cover important in CA?
Ground cover is any biological material that’s protecting the soil from the sun and hard rain. The benefits are similar to reduced tillage; the major one is that some sort of ground cover or mulch really helps to retain water in the soil. Mulch, such as sesame stalks or wild grass, can be used between plants that are growing. Farmers can also leave their crop residue, or stubble, on the fields after the harvest is over.
MCC photo/Matthew Sawatzky
What is crop rotation and why is it important?
Farmers are realizing that heavy dependence on synthetic fertilizers is killing our soil. It’s making the soil more acidic, along with other problems. The production of synthetic fertilizers relies on using fossil fuels, and we are running out of those resources. The price of oil for example will rise, and farmers cannot afford the higher prices.
This is where crop rotation and intercropping comes in. Crops can be used to manage and improve the fertility of soil.
Crop rotation means planting one thing during a growing season and another thing the next. For example, you can have wheat one year and beans the next.
Intercropping means you have a number of plants in the same field at the same time. So you might plant corn and beans. The vines from the beans spread out on the ground, acting as a ground cover or mulch. And the beans climb up the corn stalks. This improves soil fertility, and it can also provide additional food and income for farmers.
MCC photo/James Souder
Many of the farmers we work with have traditionally used intercropping, but in the early years of CA we didn’t encourage it. That was a mistake. We are now saying to those farmers, "You know the way you used to do it with intercropping? It’s a good idea." We have seen situations where there’s a drought one year and the corn didn’t grow at all. But if they intercropped,with cowpeas, for example, which are somewhat drought resistant, they got a crop.
For most farmers, controlling weeds is a huge problem. How does CA deal with that?
The practice of tilling actually began as a way to control weeds. And this is still very much an issue for farmers. Mulching helps to some extent, but it depends on the type of weeds you are trying to eliminate and soil conditions. Some weeds are eliminated, but others continue to be an issue.
Even here in Canada, where farmers are using CA techniques, many still use herbicides to kill weeds because ground cover does not control all weeds. The judicious use of herbicides is generally considered okay, as long as it doesn’t end up in the water system.
Is it difficult to sell farmers on the principles of CA?
Initially, yes. Many farmers have been using cultivation methods like the plow for generations. Changing that doesn’t happen quickly. The biggest obstacle is the amount of labor that may be involved, especially in the beginning. When you cut back on tilling you have to do more weeding. Some farmers are using animals to till the soil, plows behind cows for example. Going back to using the hoe is seen as a step backward.
That’s why there’s work being done on using animal power for minimum tillage. There’s something called a ripper—a single metal rod that digs deeper into the soil. You can use it behind a cow but it disturbs the soil less than conventional tilling and can be used in a field with mulch.
MCC photo/Conrad Kasongola
The other thing is that many farmers don’t have immediate access to mulch, so they have to cut and carry from other locations. And if they are using residue from the harvest as mulch, they can run into problems after a drought because they haven’t produced a crop.
But generally speaking, after the first few years, most farmers find that the workload declines and their production increases as the land improves. That’s an incentive for their neighbors, who may have been reluctant to introduce CA on their own land.
However, we do notice a split along gender lines when we talk about the benefits of CA. Traditionally in many of the places that we work, men do the plowing and women do the weeding. So, if you don’t use the plow anymore and there are more weeds in those early years, that burden falls to the women. This is something that needs to be considered when CA is introduced to a community. The traditional roles need to be discussed and the workload has to be redistributed. If that doesn’t happen, women will suffer from burn out.
MCC photo/James Souder
What’s ahead for CA and the farmers that MCC works with?
We are seeing some good results in our CA projects and I am encouraged. We are making progress. In some places where CA is helping farmers retain water in their soil, we have seen a 100 percent increase in yields.
In the early days of introducing CA, it was pretty formulaic and that was a mistake. We told farmers what to do and didn’t encourage a lot of experimentation. Now we are encouraging farmers to try different things, learn from their neighbors, other farmers and the farmer schools being set up. Farmers in one place will come up with one approach and in another place it will be something else. We can all learn from each other.
Necessity is the mother of invention they say, and we need to learn how to do things differently. People have been hungry for a long time, but we are reaching a critical point. Climate change means more unpredictable weather; farmers today experience drought more often now than 30 years ago. We are living on borrowed time and we need to adjust to that reality.