Role of Soil Health in Climate Change Mitigation

Soil health is a critical aspect of sustainable agriculture, yet it is often overlooked as a vital climate mitigation strategy.

In Zimbabwe, where agriculture is a cornerstone of the economy, improving soil health is an essential step toward mitigating the impacts of climate change. Farmers can increase crop yields, improve food security, and reduce greenhouse gas emissions by implementing practices that promote healthy soils.

In recent years, Zimbabwe has experienced a shift in weather patterns, with prolonged droughts and irregular rainfall. These events have devastated the country's agriculture sector – contributing to more than 16% of the country's GDP. In response, Zimbabwe has implemented various climate-smart agriculture practices to increase resilience and adapt to a rapidly changing climate. However, more must be done to address soil health as an integral part of climate-smart agriculture.

One of the key methods to promote soil health is using conservation agriculture (CA) practices. Conservation agriculture encompasses a range of techniques, such as crop rotations, reduced tillage, and mulching. By reducing soil disturbance, these practices maintain or increase soil organic matter, improve soil structure and water infiltration, and protect against water and wind erosion. Moreover, CA practices help to retain moisture in the soil, limiting the need for irrigation and reducing the potential for water runoff and soil degradation.

Promoting agroforestry, which involves growing trees and crops on the same land, can also improve soil health. Trees help to fix nutrients and store carbon in their trunks and roots, preventing carbon from being released into the atmosphere. As a result, incorporating trees into agricultural land can increase carbon sequestration in the soil, which can help to mitigate climate change.

Using cover crops as a sustainable soil management practice is also an effective strategy. Cover crops protect soil from erosion, improve soil quality, and contribute to soil carbon sequestration, which involves the capture and long-term storage of atmospheric carbon in soils. More organic matter in the soil leads to improved soil health and productivity and fewer greenhouse gas emissions from agriculture. Legumes, like beans, peas, and groundnuts, can also be used as cover crops since they fix nitrogen in the soil, reducing the need for synthetic fertilizers and their associated environmental impacts.

At the same time, extension workers are vital stakeholders in improving soil health in the country. Their main responsibility is to educate and support farmers in implementing sustainable agricultural practices that promote soil health. Extension workers typically work closely with farmers to achieve this goal. They provide information on managing soil fertility, controlling erosion, maintaining soil moisture, and preventing soil degradation. This information is usually delivered through training events, workshops, and demonstration farms.

Through its extension workers, the Agricultural Research and Extension (AGRITEX) also help farmers design and implement soil conservation plans tailored to their needs. These plans may involve strategies such as crop rotation, cover cropping, minimum tillage, and agroforestry. By implementing these practices, farmers can improve soil quality and productivity while reducing the need for chemical inputs.

Extension officers are instrumental in the dissemination of information on agricultural policies. For example, Pfumvudza is a new climate-smart agriculture approach recently introduced in Zimbabwe to help smallholder farmers combat climate change effects, improve soil health, and increase crop yields. This approach aims to ensure food security and nutrition for rural households.

The Pfumvudza approach involves farmers using small plots of land to grow multiple crops to reduce soil disturbance, improve water retention and increase yields. By planting maize and other crops in more organized patterns and using less water, farmers can optimize yield while conserving the soil. It also aims to increase soil fertility through organic matter and crop residue, contributing to enhanced soil health, higher crop yields, and increased carbon sequestration. Moreover, this approach can reduce greenhouse gas emissions since the emphasis is on reducing tillage to minimize soil disturbance.

In support of the initiative, the Zimbabwean government has pledged to support farmers through various means, including training and inputs such as seeds, fertilizers, and implements. This initiative aims to ensure that smallholder farmers adopt climate-smart agriculture practices and to help them build resilience to climate change impacts.

However, as noble as it seems, extension workers in Zimbabwe face challenges from the ruling party-aligned political leaders seeking to use Pfumvudza as a political tool to gain support from the farming community. This interference impacts the efficiency of the extension workers in reaching and educating farmers.

Equally notable, the Pfumvudza approach is a new policy initiative still being rolled out in different parts of the country. Extension workers face challenges in implementing the approach due to policy inconsistencies and lack of clarity on key issues such as inputs, funding, and monitoring and evaluation.

Since the turn of the millennium, Zimbabwe's land reform policies have resulted in land redistribution from large commercial farms to small-scale farmers. While this has helped increase access to land for many people, it has also led to unsustainable farming practices and soil degradation due to a lack of infrastructure, inputs, and technology investment.

Politicians may prioritize short-term gains over long-term sustainability, leading to the over-exploitation of natural resources and soil degradation. For example, excessive tobacco farming, the country's main cash crop for many years, has negatively affected soil health due to unsustainable farming practices such as mono-cropping deforestation and excessive use of inputs.

Soil health must be prioritized as a crucial climate mitigation and adaptation component. Conservation agriculture practices cover crops, and agroforestry improves soil health, enhances crop yields, and mitigates climate change. The government must support farmers in adopting these practices, contributing to a more sustainable and resilient agriculture sector in the long term.