Soil depletion, soil mismanagement lead to decreased farm land

Oct 7, 2022 | Canadian News, News

Earth’s arable land is vanishing. And what is being used to grow crops is at risk of being depleted.

According to a report sent to the United Nations Convention to Combat Desertification (UNCCD), almost one-third of the world’s farmable land has disappeared in the last four decades.

This is a cause of soil depletion, which occurs when soil fertility components are removed without being replaced.

“In recent decades, land resources have been subject to persistent degradation and loss due to global patterns of human domination,” the UNCCD said.

“When we had taken this farm over, they had planted soybeans after soybeans after soybeans. That depletes the soil,” said Dave Birnie, an Oro-Medonte farmer.

Soil depletion is caused by soil pollution, insufficient soil management, nutrient leaching, loss of topsoil by erosion, and continuous cropping.

The UNCCD United Nations Convention to Combat Desertification states soil degradation could result in the loss of $23 trillion in food, ecosystem services, and income worldwide by 2050.

According to National Geographic, soil depletion has caused whole foods to no longer be packed with the same amount of vitamins and nutrients as the they were 70 years ago. But some experts disagree.

“Modern cultivation techniques involve applications of synthetic fertilizers, manures and composts so I doubt very much that fruits and vegetables are less nutritious,” said Paul Voroney, a Guelph University professor and researcher in soil management and cropping patches.

A 2020 book called Agrochemicals Detection, Treatment and Remediation: Pesticides and Chemical Fertilizers, edited by M.N.V Prasad, analyzed the use of synthetic fertilizers and their more natural counterparts. The book supported Voroney’s position that despite the differences, synthetic fertilizers can provide effective growth.

“Most inorganic fertilizers dissolve readily in water and are immediately available to plants for uptake,” the book said. “When used according to recommendations, these types of fertilizers efficiently supply the required nutrients for plant growth and are safe for the environment.”

Despite the position of Voroney, many farmers in the province say soil depletion can be avoided by alternating deep-rooted and shallow-rooted plants with crop rotation to improve soil structure and fertility, a method known as crop rotation.

“We grow corn, peas, winter wheat, oats and red clover. Now we have a proper crop rotation that helps the soil a lot,” Birnie said.

Rotating crops have been used since the Neolithic Revolution, more than 11,000 years ago to control disease and improve plant nutrition. A study in Nature’s The ISME Journal suggests crop rotation can significantly enrich soil with bacteria, fungi, and protozoa.

The use of fertilizers also helps reduce soil depletion by replacing the nutrients that crops remove from the soil.

While fertilizers help replenish soil nutrients, they can also cause significant greenhouse gas emissions when used in crop production processes.

The federal government plans to reduce fertilizer emissions by 30 per cent below 2020 levels by 2030 in order to meet Canada’s emission reduction targets.

Inorganic fertilizers can also cause health risks such as ammonia, and damage the environment with the use of nitrate and other nitrogen compounds that are released into rivers, groundwater, and oceans.

The presence of these toxins in our water reduces oxygen levels, which increases algae growth. Aquatic life may suffer injuries or even die as a result.

President of the Simcoe County Federation of Agriculture Jim Partridge said that despite inorganic fertilizers’ harmful effects on the environment, many are concerned that reducing its use will result in crop loss.

“If you reduce the amount of nitrogen used, you are going to cut your crop yield by at least a third, that means prices in grocery stores will go up about 20 per cent,” he said.