Blog Understanding Soil Biodiversity
Q&A with Dr. Manoj Kaushal: Soil Scientist at the Alliance of Bioversity International and CIAT
By: Rachel Kibui, Manoj Kaushal
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Dr. Manoj Kaushal during the interview in Nairobi.
Healthy soils are key towards enhancing productivity and nutritional wealth for crops and food products. Soil biodiversity is important for enhancing healthy soils, making it important to understand soil biodiversity. Here, Dr. Manoj Kaushal shares his insights.
Manoj Kaushal
Scientist IWhat is soil biodiversity?
Soil biodiversity is the variety of life forms found in the soil. This includes organisms such as bacteria, fungi, insects, earthworms, mites, nematodes, and plant roots. These organisms interact with each other and their environment to form a complex ecosystem that is crucial for soil health and plant productivity.
What are the different aspects of soil biodiversity?
Some of the key areas of soil biodiversity include the microorganisms which are the bacteria, fungi and actinomycetes. These are the most abundant microorganisms in soil and are crucial for various functions such as the decomposition of organic matter, the recycling of nutrients and the formation of symbiotic relationships with plants.
The mesofauna and macrofauna are the larger organisms found in soil such as ants, beetles and earthworms. These help in soil aeration, breaking down organic material and recycling nutrients.
Plant roots are also important as they influence soil structure and nutrient availability, and provide food and habitat for numerous soil organisms.
Why is soil biodiversity so important?
Soil biodiversity contributes to ecosystem services such as nutrient cycling, water regulation, carbon sequestration, and the control of pests and diseases.
Additionally, diversity in soils is crucial in maintaining soil structure, fertility, and building resilience against environmental-related stresses such as drought.
Soil health directly impacts food production, as it is the basis of healthy crop productivity. More biodiversity in soil means more fertile soil, better crop production and, therefore, greater economic empowerment among farmers and subsequent food and nutrition security.
How would you define healthy soil?
We talk of a healthy human being when the person is ‘fully functional’. This is the same case with soil. Healthy soil has the ability to optimally function and perform for crop growth and production; it is when the soil is able to give back nutrients to the crop.
Healthy soil is characterized by better organic matter, better water retention and is less susceptible to pests and diseases, leading to greater farm productivity.
Dr. Manoj Kaushal leads a team in collecting soil samples in Kisumu County.
Over the years, soil biodiversity has significantly reduced. What are the reasons for this?
One of the issues that have affected soil biodiversity is over-use of synthetic fertilizers. While there has been a push on use of these fertilizers to boost crop production, its inevitable effect on soil biodiversity has barely been considered.
Another reason is the excessive tillage and use of heavy farm machineries which cause disturbance to the soil, affecting its structure.
Monocropping has also affected soil biodiversity. Monocropping causes soil nutrient mining and reduces yield because the same of amount of nutrients is pulled away by the same crop every season. This reduces soil biodiversity while increasing incidences of pests and diseases.
Climate change has also adversely affected soil biodiversity. During drought, temperatures are often too high, while floods wash away topsoil, which hosts a lot of biodiversity.
Lastly, deforestation and pollution have also negatively affected soil biodiversity, leading to soil degradation and loss of ecosystem functions.
There has been a misconception that there is not much need to take care of soil, as it has the ability to independently ‘take care of itself'. What are your thoughts on this?
The truth is that we need to take care of our soils. If we do not take care of our soil, it will not take care of us. Production will be compromised and so will food and nutrition security.
One of the key solutions towards enhancing soil biodiversity is embracing agroecology and sustainable farming approaches. Conservational methods such as mulching are key not only for maintaining soil moisture, but also for fertility and creating good habitat for mesofauna.
There is also a need to ensure minimum tillage, as this will lead to minimal disturbance on soil and effects on its structure.
Farmers need to use organic manure as opposed to synthetic fertilizers which cause highly acidic soils, thus affecting biodiversity.
So, whose duty is it to ensure soil biodiversity?
Soil biodiversity is a collective duty. Farmers need to employ practices that are biodiversity-friendly, such as agroecology. Policymakers need to come up with policies that promote this. Researchers need to do propose interventions for soil in different regions. Extension officers need to train farmers on the need for biodiversity conservation. Each of these stakeholders has a role.
How can the agenda of behavior change and adoption of sustainable farming practices be driven?
Driving this agenda is easy if the willingness and resources are available. This is especially because farmers themselves have witnessed the reduction of soil fertility in their own farms.
In Kisumu county, the CGIAR Initiative on Nature-Positive Solutions (Nature +) has already established two aggregated farms and a model farm in Vihiga county with permaculture activities. One key component of this initiative is soil health and soil testing is already ongoing. When soil health in these farms is restored, the 200 farmers under this initiative will do the same in their own farms, and train their neighbors, friends and relatives, thus amplifying the reach.
Anything else you would like to add?
Beyond sustainable farm productivity, soil biodiversity also influences long-term crop properties such as nutrient and antioxidant profiles which improve the crops’ quality. While providing training and knowledge on soil biodiversity to farmers, it is essential to include these aspects so that farmers can have complete understanding.
