Caring for Our Common Home with Biogas and Napier Grass
Climate change has both positive and negative effects on agriculture in the sense that it can increase crop yields in some places while decimating others, but the negative impacts have outweighed positive impacts to date. Already, the CGIAR Research Group on Climate Change, Agriculture and Food Security estimates that climate change has reduced global yields of wheat by 5.5% and of maize by 3.8%. By 2090, CCAFS projects that climate change will result in an 8% to 24% loss of total global caloric production from maize, soy, wheat, rice. Where these declines in productivity occur will vary. For example, sub-Saharan Africa will be hit particularly hard; it is estimated that across Africa maize yields will drop by 5% and wheat yields by 17% before 2050.
Modern commercial agriculture systems are not without fault, however, as agriculture is a major contributor to climate change, currently generating 19% to 20% of total greenhouse gas (GHG) emissions, according to CCAFS. With a view toward integrating agricultural development, climate-responsiveness, and overall care for our common home, Catholic Church-run farms in Africa are deploying the Climate-Smart Agriculture (CSA) principles defined by the Food and Agriculture Organization of the United Nations. CSA provides an integrated approach to managing natural landscapes aimed at sustainably maintaining and increasing food productivity, adapting agriculture to climate change, and reducing emissions. Missio Invest promotes the sustainable use of land resources and invests in Church-owned and run farms that apply climate-smart farming practices and act as demonstration sites to spread such technologies.
St. Matthias Mulumba Senior Seminary, a national theologate in western Kenya with 30 acres of arable land, obtained a $38,000 loan from Missio Invest in 2015 to improve its farming operations. Currently, the seminary is practicing integrated farming with 15 acres of maize, eight acres of tea, and seven acres of trees and grassland, as well as a dairy and piggery unit. The farm recycles animal waste to improve soil fertility, with the pasture and grassland producing key feedstuff to the livestock. Maize productivity has doubled from 10 bags to 20 bags per acre thanks to improved fertilization and nutrient cycling.
The livestock waste is also put to work to generate biogas, which is used as a substitute for firewood in cooking at the seminary. Biogas takes a problematic methane gas present in decomposing waste and converts it into carbon dioxide, a much safer gas. Methane gas has approximately 20 to 30 times the heat-trapping capabilities of carbon dioxide. The nutrient-rich bio sludge from the biogas digestor is used to fertilize and irrigate Napier grass, a perennial tropical grass with low water and nutrient requirements. The Napier grass feeds the dairy cows and is used to control soil erosion. It is also valuable in pest management, as it draws insects like stemborer moths from maize, thereby reducing the need for insecticides. The milk production at St. Matthias Mulumba has increased from 40 liters to 100 liters in a day. The seminary has also installed a solar water heating system and planted seven acres of trees.
Another example is is a garden pea farm operated by the Little Sisters of Saint Francis, also in Kenya. The sisters obtained a $100,000 loan from Missio Invest in 2018 and installed a five-acre solar-powered drip irrigation system. The system has helped the farm more efficiently utilize and conserve water. Because it limits the growth of weeds, it has made it possible to reduce the use of herbicides, which can be toxic to organisms living in the soil and carry pollutants to nearby rivers. The Sisters have planted 2,700 trees on their way to creating a biodynamic farm.
Church-operated farms such as these aim to take good care of the earth and its creatures while bringing resilient agricultural practices to the communities they serve.