July 30, 2015

Healthy Soils are the Basis for Healthy Food Production


2015 International Year of Soils

The most widely recognized function of soil is its support for food production. It is the foundation for agriculture and the medium in which nearly all food-producing plants grow. In fact, it is estimated that 95% of our food is directly or indirectly produced on our soils. Healthy soils supply the essential nutrients, water, oxygen and root support that our food-producing plants need to grow and flourish. Soils also serve as a buffer to protect delicate plant roots from drastic fluctuations in temperature. 

Soil health has been defined as the capacity of soil to function as a living system. Healthy soils maintain a diverse community of soil organisms that help to control plant disease, insect and weed pests, form beneficial symbiotic associations with plant roots, recycle essential plant nutrients, improve soil structure with positive effects for soil water and nutrient holding capacity, and ultimately improve crop production. A healthy soil also contributes to mitigating climate change by maintaining or increasing its carbon content.

Key Soil Facts:
  • 95% of our food is directly or indirectly produced on our soils.
  • A shortage of any one of the 15 nutrients required for plant growth can limit crop yield.
  • By 2050, agricultural production must increase by 60% globally--and by almost 100% in developing countries--in order to meet food demand alone.
  • It can take up to 1,000 years to form one centimeter of soil.
  • Sustainable soil management could produce up to 58% more food.

Food availability relies on soils: nutritious and good quality food and animal fodder can only be produced if our soils are healthy. A healthy living soil is therefore a crucial ally to food security and nutrition. In the past 50 years, advances in agricultural technology led to a quantum leap in food production and bolstered world food security. However, in many countries this intensive crop production has depleted the soil, jeopardizing our ability to maintain production in these areas in the future. With a global population that is projected to exceed 9 billion by 2050, compounded by competition for land and water resources and the impact of climate change, our current and future food security hinges on our ability to increase yields and food quality using the soils that are already under production today. Numerous and diverse farming approaches promote the sustainable management of soils with the goal of improving productivity, for instance: organic farmingconservation agriculture, and zero tillage farming.

Organic farming is agricultural production without the use of synthetic chemicals or genetically modified organisms, growth regulators, and livestock feed additives. It also emphasizes a holistic farm management approach, where rotations and animals play an integral role to the system. Soil fertility is the cornerstone of organic management. Because organic farmers do not use synthetic nutrients to restore degraded soil, they must concentrate on building and maintaining soil fertility primarily through their basic farming practices.

Conservation agriculture practices have significantly improved soil conditions, reduced land degradation and boosted yields in many parts of the world by following three principles: minimal soil disturbance, permanent soil cover and crop rotations. To be sustainable in the long term, the loss of organic matter in any agricultural system must never exceed the rate of soil formation. In most agro-ecosystems, that is not possible if the soil is mechanically disturbed. Therefore, one of the tenets of conservation agriculture is limiting the use of mechanical soil disturbance, or tilling, in the farming process.

Zero tillage is one of a set of techniques used in conservation agriculture Essentially, it maintains a permanent or semi-permanent organic soil cover (e.g. a growing crop or dead mulch) that protects the soil from sun, rain and wind and allows soil micro- organisms and fauna to take on the task of “tilling” and soil nutrient balancing - natural processes that are disturbed by mechanical tillage. 

No comments:

Post a Comment