Conservation Agriculture: A strategic approach to address climate change and food security.

The 5^th of December each year, is observed and celebrated as the World Soil Day to highlight the importance of healthy soils and to advocate for the sustainable management of soil resources. 

The theme for 2019 is Soil Erosion, Save Our Future!  

We are living in the age of Sustainable Development and each and every one of us has a role to play – to preserve our beautiful planet and combat climate change for the sake of future generations.

Concerning the future, we must take into account the potential effects of climate change on soils and agriculture at large. On the other hand, we must also consider the impact that agriculture and soils have on climate change and global warming.

The current estimates indicate that 10-12% of global anthropogenic greenhouse gas emissions are attributed to agriculture, tillage being the major culprit. In addition, approximately 70% to land use change emissions are attributed mainly through deforestation, which agriculture has a hand.

Food and Agricultural Organization (FAO) of the United Nations estimates that by 2050, the demands of new croplands due to population pressure (of about 9.5 billion people), diet change and demand for biofuels is expected to reach approximately 3.2 billion ha, mostly at the expense of grasslands, forests and rangeland ecosystems.

The components of modern agriculture such as land use change, conventional tillage and the excessive application of Agro-chemicals (fertilizers, pesticides and herbicides) induce soil degradation and impact the environment negatively.

Conventional Tillage it is one of the major causes of soil loss through erosion (both wind and water erosion). It destroys the soil structure and expose the precious organic matter for decomposition, and eventually lead to reduction in soil fertility status and the overall quality of the soil.

Generally speaking, conventional tillage destroys the physical, chemical and biological properties of the soil but people to this day, till their land mostly to facilitate planting, water infiltration and to control weeds. In addition to tilling, the unscrupulous use of Agro-chemicals is exacerbating the challenge of soil degradation and it contributes to air and water pollution. 

The current global estimates indicate that about 80% of agricultural land suffers moderate to severe erosion (FAO, 2018). Moreover, approximately 30% of the world’s cropland has become unproductive and abandoned due to soil erosion leading to one in every 9 persons in the world being food-insecure and about 66% of the global population being malnourished (FAO, 2018)

Sustainable land management strategies such as conservation agriculture (CA) have been identified and adopted in other parts of the world to prevent soil erosion, improve soil quality, conserve soil moisture and preserve the environment but most importantly, to match food production with the increasing world population

A management system is considered to be CA if it consists of the following three principles; i) Permanent soil cover through crop residues or mulch ii) Minimum soil disturbance or no-tillage, and iii) Crop diversification through crop rotation and/or cover crops

The mandate of CA is to preserve and improve soil organic matter (SOM) content. Since the soil is a living entity, organic matter (OM) is to the soil, what a heart to the body. Without OM, a soil is DEAD!

The benefits of CA include increased soil organic matter content for better soil health and overall quality of the soil, increased crop productivity and farm income through maximum use of available resources with minimal effects on the environment. It also purports to address the intensive labor requirements in smallholder agriculture.

Despite all these benefits, CA adoption is still very low, more especially in Africa. Here in South Africa (SA) a literature review study by Dr. Corrie Swanepoel of ARC and her colleagues of ARC indicated that SA soils are naturally very low in soil organic matter. About 60% of our soils have less than 0.5% of organic matter.

Moreover, during the 2008/2009 season, only 7% of the cultivated area in SA was under no till, possibly the area under CA was even way lesser than that. This is one of the reasons why we have poor soils in the country with less OM content.

The concentration of organic matter content for most upland soils ranges from 1% to 6% for the total mass. Soil with less than 1% organic matter content are mostly limited to desserts, while soils in low lying and wet areas can have as much as 90% of organic matter.

It is therefore, of utmost importance to start adopting sustainable practices such as CA in order to meet global food demands of the growing population while preserving the environment for the sake of future generations.