September 19, 2011
Soil: The Underground Treasure
Soil is one of the most diverse ecosystems on Earth, haven to not only insects, but also bacteria, fungi, nematodes, amoebas among many other organisms. However, the ecosystem and biodiversity is also understudied, which has resulted in the misuse and erosion of soil due to agriculture and a lack of government involvement to protect this resource in the US. Despite the significance soil has in supporting the majority of ecosystems that exist above it, the influence and financial benefits that agriculture has in the U.S. has led to poor farming practices at the cost of soil biodiversity.
An important aspect of conserving soil biodiversity is to understand the benefits soil biodiversity contributes. Soil biodiversity helps decompose plants such as trees and leaves that have fallen on the ground. Decomposition allows for nitrogen obtained from the decaying plants to be turned into an inorganic form to be used by plants and spreading nutrients, which allows vegetation to grow. Another service is storage and filtration, meaning that the soil biota filters water stored in the soil. The filtered water then flows into streams, providing clean water for many aquatic species to live in.
Yet, the efforts to conserve earth’s ecology have focused primarily on the loss of biodiversity above ground; degradation and loss of biodiversity in soil have gone fairly unnoticed. Land use, nitrogen enrichment and climate change have impacted soil through changes in physiochemical conditions of the nitrogen and carbon content of soil, losing functionally important organisms, and creating long term consequences in the nutrient cycling that makes it possible for plant dynamics and primary producers to exists in many ecosystems (Wall, Bardgett, et al. 2010). Within the United States alone, soil preservation has not been an area of great importance due to the vital role that agriculture plays in US history and future.
“No comprehensive soils protection strategy exists in the United States” (USDA). The US EPA is the federal agency mainly responsible for implementing laws to mitigate polluted air and water, yet no legislative law has been implemented to protect soil biodiversity. The goals for soil conservation within the U.S. as primarily have been interrelated with the greater goals for agriculture and the environment. Agriculture has a deep history within America. Both legislation and general social ideals form the basis of the U.S.’s conservation policy in agriculture.
Agriculture itself provides the food necessary to feed the population. However, this deep seeded role that agriculture plays within American history has led to more than $40 billion annually lost from soil desertification (Ginsburg). The U.S. has a difficult role in controlling erosion due to the large scale intensive agriculture dependency that has made up a profitable part of its economy for over 200 years.
As a result, agriculture has led to numerous farming practices that have led to loss in soil biodiversity: soil erosion, fertilizer and pesticide pollution, deforestation, salinization, desertification, loss of biodiversity of some of the few sources of loss in soil biodiversity.
There are ways to prevent loss of soil biodiversity while maintaining the agricultural dependency our economy relies on. Soil erosion can be reduced by seasonal plowing, crop rotation, multi-crop farming and a plethora of ways to reduce the anthropogenic impact on soil. And, a deeper understanding of the true value of soil—as a basis of almost all primary ecosystems on this planet to create a sentiment of how critical soil is. Yet, like all natural resources provided by this planet it is important to recognize that no matter what measures we take to restore any resource it will never return to its original state of biodiversity.
About the authors: Victoria Chu and Mabel Nevarrez are undergraduate students in the USC Dana and David Dornsife College of Letters, Arts and Sciences.
Soil as we know it is defined differently than dirt, however this isn’t relatively well known in general population. How would you suggest that scientists communicate this fact to both the general public and policy makers, in an effort to stress the importance of soil? You mention government involvement, which is a polarizing issue in any sector, but how is responsibility complicated by the fact that soil is a natural resource (which already presents regulation challenges) and has different owners depending on location. As with any discussion of soil management, you mention biodiversity. In addition to organisms that inhabit the soil and are dependent on it, there is also the issue of nutrient levels, which is especially important to humans as it relates to agriculture. What would the loss of soil biodiversity do to impact the agriculture? As you mentioned, it is estimated that desertification already costs the U.S. economy roughly $40 billion annually. Perhaps framing the importance of protecting soil diversity (and maybe even the soil management field as a whole) in the context of American agriculture and economy would attract more attention.