According to the FAO (United Nations Food and Agriculture Organisation), one third of the planet’s soils are degraded. Production potential is jeopardised due to soil depletion. The main challenge with conservation agriculture (CA) for farmers is regenerating and conserving the quality of soils that have been subjected to excessive human and/or meteorological strain. Details and other major challenges for conservation agriculture.
Agricultural practices and carbon sequestration
The planet’s rate of CO2 has increased by 31% since 1750. It is one of the main causes of global warming, through greenhouse gas emissions. It is due to the combustion of fossil fuels in 2/3 of cases. Another third comes from changes in land use and the cultivation of land. Yet there are solutions for sequestering carbon through agriculture, and soil conservation in particular. CA increases the stock of carbon in soil by 0.5 tonnes per hectare per year compared to conventional farming. Carbon is stored through the soil-plant system. In practical terms, atmospheric CO2 is captured by crops or cover crops for photosynthesis. It is then transformed into plant matter and buried in the soil, which regulates the climate as well as providing many other agronomic advantages such as reducing erosion and increasing biodiversity and nutrient reserves.
Economic challenges: Labour and cost savings
Conservation agriculture advocates minimum or no tillage. It drastically reduces labour and energy requirements (diesel). Savings are estimated at 30 to 40% in terms of time and labour, compared to conventional cropping. Machine investment and maintenance costs are also reduced in the long term.
Healthier soils, equivalent yields
By applying the principles of conservation agriculture, soil health is improved. Over time, water infiltration capacity increases, reducing surface runoff and erosion. The soil’s natural biological resources are also preserved: fauna, microfauna, and flora, etc. Biodiversity increases. According to the APAD (French association for the promotion of sustainable agriculture), microbial activity is twice as high, and there are 15 times more earthworms than with a conventional system. Organic matter increases at the same rate as soil fertility, which, according to some sources, has gone up by 1% in 10 years. As well as being beneficial to the ecosystem, yields are comparable with conventional cropping. They also tend to increase over time and become more stable. The soil becomes more resilient to climatic difficulties.
Constraints for conservation agriculture
Weed management is one of the biggest constraints in CA. Systemic weed control products, such as glyphosate, are often applied to control weeds. In some cases, light surface tillage may be needed. In all cases, basic training in agronomy is recommended in order to know the soil and to feel confident in experimenting before applying CA methods. It can be beneficial to join specialist farming groups. Organic farming, for example, is subject to major constraints due to chemical products being prohibited. However, positive results have been found using various techniques: dynamic rotational grazing, shallow tillage, strip-till, etc.
Sources:
https://www.fao.org/conservation-agriculture/overview/why-we-do-it/en/