Healthy Soils, Healthy Rice

Soil is the most important natural resource after water and oxygen for life on Earth. Soil is the foundation of our food system. Our planet’s as well as each our own survival depends on soil as over 95 percent of our food originates from it. However, in the face of climate change and human activities, soils around the globe are being degraded through excessive agricultural practices that negatively impact its health.

To paint a picture of the extent of soil consumed by human activity: 1.6 billion hectares were dedicated to cropland worldwide in 2022. This is roughly equivalent to the land area to cover Russia (1.7 billion hectare) or South America (1.8 billion hectare). All agricultural lands, including farms and pasturelands, arrive at 4.8 billion hectare—2.7 to 2.8 times the size of Russia or South America, respectively. In other words, the amount of soil required to feed the world—an effort we are still falling short of—is enormous.

What is soil?

Soil is composed of roughly half water and air, while the other half is mostly inorganic materials, along with a smaller proportion of organic matter. The inorganic components stem from rocks that have broken down into ever so smaller particles. Meanwhile, the organic matter—both living and dead—is what makes soil fertile. It is this composition that forms the proverbial ground for storing and supplying nutrients to plants.

Soil organic matter consists of living and dead biomass, such as microorganisms (fungi, protozoa, algae, and more), plant matter, animals and insects. The range of organisms in soil is estimated to represent about 25% of the world’s biodiversity alone. Living microorganisms and insects feed on and recycle organic residues in soil, and in the process mix organic matter with the mineral components of the soil. The process also helps improve water infiltration and aeration which in turn stabilizes the soil composition.

In that decomposition process, encompassing plant and animal residues, humus is formed. Humus is the dark material that remains after most of the organic matter has broken down. When organic materials are either fully or partially disintegrated, the resulting humus stores essential nutrients, releasing them over time for plant uptake. It is important for land conservation as it reduces rain runoff or irrigation water outflow, for example, in sandy soil, as well as soil compaction problems that occur, such as in clay soil. As soil rich in humus acts like a porous sponge, it can reduce, if not prevent, the spread of chemical substances added to the ground.