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Soil Erosion Problems and Solutions

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Soil analysis

If you’re a farmer with the goals of maximizing your crop production while protecting the environment from runoff, then analyze your soil. This simple test will protect your fields and adjacent waterways and save money. Before you drop a single seed this year, have a soil analysis done. You’ll conserve energy with a plan for fertilizing your fields, particularly if you’re a grower who mixes their own media.

Why Is Soil Testing Important?

There are several reasons why you want to test your field’s soil. Scientists conduct these tests for engineering, geochemical, and ecological investigations in addition to agricultural studies. This set of chemical processes determines the available nutrients in the ground and the various properties that are essential for prime soil health. Here are three top reasons to test your soil:

Crop Nutrition

One of the most commonly used tests in today’s agricultural industry is to determine the available combination of nutrients, composition, and the soil’s pH level. When armed with a recent soil analysis, farmers can accurately calculate the amount and type of fertilizer needed for maximum production.

A soil test will ascertain a field’s fertility, potential toxicities, and expected growth potential of the land as modeled by the Law of the Maximum. According to this universal law, it only takes one deficient nutrient to reduce a crop’s potential yield significantly.

Changes Over Time

A soil’s chemistry changes over time as natural and chemical processes break down its compounds. This theory is especially true for transplanted land that finds itself in a foreign ecosystem, with new flora and climate conditions. An accurate soil analysis will give you the tools to significantly improve the ground, particularly when analyzed within 24 hours after its extraction.

Soil Contaminants

Soil is often contaminated by a variety of elements such as arsenic, barium, cadmium, copper, mercury, zinc, and lead. Lead is particularly dangerous, and you can take several steps in your garden to reduce the risk of this unwanted mineral in your food. Place gardens far from heavily traveled roads and consider liming the ground as recommended by a soil test. A pH level of 6.5 minimizes lead availability.

What Are the Goals of Soil Analysis?

The overall goals of soil analysis are varied, from determining the level of available plant nutrients to predicting an increase in yields and profitability. Farmers can also use this test to calculate the necessary amount of fertilizer needed for each individual crop.

Laboratory Soil Tests

One option for land analysis is to hire a commercial lab. Choose a local facility when possible, as they are likely most familiar with the local soil’s chemistry. The advantage of this knowledge is the technicians know exactly which tests to perform that will reveal the most valuable information.

A laboratory soil analysis checks for all 13 mineral plant nutrients in three categories:

  • Major nutrients including potassium, nitrogen, and phosphorus.
  • Secondary nutrients including magnesium, sulfur, and calcium.
  • Minor nutrients that include manganese, zinc, boron, copper, molybdenum, chlorine, and iron.

In addition, your lab results will consist of a professional’s interpretation of the findings, along with expert recommendations. Your lab report will outline any anomalies, exceptions, and shortcomings in the soil samples.

Soil Sample Analysis

The technicians at Colorado State University recommend that farmers collect between 10 and 20 test samples for every 40 acres of land. By testing this wide assortment of specimens, you’ll have a good understanding of precisely what your soil needs in order to perform its best.

When you know your land’s nutrient content by the process of chemical analysis, it’s easy to determine the precise amount of additives needed to achieve the highest quality yields. Plants can tolerate soil with up to 80 percent nitrogen, 40 percent phosphorus, 60 percent potassium, and 40 percent magnesium.

When Should Soil Be Tested

Take your first soil samples annually in the fall, after you harvest and before adding any fertilizer. It’s best to collect your test subjects when the soil is at its optimum moisture level. In the case of permanent crops such as orchards and vineyards, conduct a soil sample analysis every four or five years.

How to Collect Soil Samples

Take your soil testing samples either by probe or with an old-fashioned shovel. If you decide to use a shovel, dig a pit, and cut the edges vertically along the wall, being careful not to let any dirt fall into the hole. Crop and remove the exposed dirt to the left and right of the soil you intend to collect for your samples.

If you plan to use a probe, take your sample at a depth of normal tillage. For field crops, that’s up to 30 cm or for permanent crops, take your sample between 30 to 60 cm. Collect enough dirt to complete a series of tests, with one kilogram of each soil sample being plenty to analyze. Then, separate each bit of dirt in a plastic bag and label it with the following information:

  1. The farmer or land owner’s name.
  2. Address.
  3. Designation of the plot.
  4. Depth of sampling.
  5. Any previous fertilization.
  6. Type of crop you plan to sow.
  7. Date of sample.

DIY Soil Test Kit

Do-it-yourself soil test kits are helpful. However, they usually only test for the three major nutrients as well as acidity. These electric meters are available at most gardening stores and measure pH, water content, and basic health of the soil.

It’s a well-known fact that laboratory tests are more accurate than the do-it-yourself kind. To make things easier, some labs offer a prepaid mail-in kit for field management and water testing. This process helps facilitate the packaging and delivery of samples for more extensive testing than the over-the-counter options, such as precise flow injection technology or near-infrared scanning.

Soil sample analysis is an essential part of the pre-growing season. The results are an indispensable tool for managing crop nutrition, and to wield this tool effectively, you must know how and when to take testing samples. Equipped with this helpful article, you’re well on your way to a healthy harvest this season.

Soil texture

Dig your hands down into the earth. What do you feel? Every handful of soil has its own individual texture, and those characteristics offer a significant contribution to crops. What determines the unique textures of soil? Why is it important, and which type of soil has more erosion resistance? Find the answers to these questions and more with this informative article.

What Is Soil Texture?

When a pedologist mentions ‘soil texture,’ they’re referring to the amount of various sized sand, clay, and silt particles in a sample of dirt. The composition of these grains makes up the inorganic parts of soil and are the bits and pieces that bind with organic matter to form topsoil.

The size of soil’s particles and their spacing also determines how much water will flow through it. Soil with a higher concentration of large grains of sand will have a greater infiltration rate, while dirt that is primarily clay will pool water on its surface as opposed to absorbing it.

Soil Textural Classes

A soil’s textural classification refers to the combination of sand, silt, and clay that make up the soil. It can be determined using exploratory research methods such as feel. A coarse-textured soil is probably composed primarily of sand, while a fine-textured soil is most commonly dominated by clay.

Farmers can also take a quantitative approach with a hydrometer. With this lab-based method, the soil is mixed with a sodium hexametaphosphate solution to separate the earth’s aggregates into identifiable parts. The U.S. Department of Agriculture outlines 12 primary soil texture classifications including the four most common types: sand, loam, silt, and clay.

Sand

Sand is the largest sized dirt particle. Each grain ranges in size from 2.0 mm down to 0.05 mm. It feels gritty to the touch. Since sand is just a bit of gravel, it drains well but doesn’t do an adequate job of retaining essential water and nutrients. Gravel particles that are larger than 2.0 mm are not considered when determining texture.

Loam

The soil that’s referred to as loam offers a proportion of 40% sand, 40% silt, and 20% clay in a single sample. It’s often the dirt of choice for making bricks and provides plenty of organic material for growing crops.

Silt

Silt particles are considered moderate in size. However, with sizes ranging from 0.05 mm down to 0.002 mm, individual particles are too small to see with the naked eye. It has a similar shape as sand particles, just worn down to a smooth texture.

While it’s not as strong as sand, silt is better at holding both water and nutrients. Because it’s prone to losing small amounts of minerals from each particle, silty soil generally makes more minerals available to your plants.

Clay

The smallest sized dirt particle, clay is less than 0.002 mm in diameter. To put that in perspective, you’ll need to line up 12,000 clay particles side by side to measure one inch. Clay feels sticky in your hands and is an excellent building medium.

What Determines the Texture of the Soil?

The percentage of materials determines a soil’s textural class, including the common particles we’ve already met: sand, silt, loam, and clay. Its texture is an important characteristic that influences a diverse number of properties, including water infiltration rates, aeration, susceptibility to erosion, and pH buffering capacity.

The Importance of Soil Texture

The texture of your field’s soil is essential to a successful harvest on a variety of levels. From saturation to water-holding capacity, let’s discuss each component of soil texture’s importance.

Infiltration

The amount of clay, sand, or silt in the dirt defines the rate at which water is able to drain through it. Once saturated, water moves more quickly through sandy soils than it does through soil that’s heavy in clay.

Availability

Soil texture influences how much water is available to your plants. Once your field’s saturation level reaches capacity, your clay soil will hold more water than its sandy counterpart.

Drainage

Well-drained fields are usually a sign of proper soil aeration. This texture of dirt is rich with air, which promotes a healthy root system and leads to a bumper crop.

Erosion

Different textured soils also respond differently to erosion. Some are more susceptible to loss based on their percentage of silt and clay particles. Those soils have a higher erodibility level than a sandy soil under the same weather and tilling conditions.

Organic Matter

Various soil textures also offer different levels of organic matter. This material breaks down faster in sandy soils than in silt and clay, likely due to the higher availability of oxygen for decomposition.

How Soil Texture Affects Erosion

Now we understand that a soil’s texture is directly related to the amount of clay, silt, and sand particles it contains. But what does this have to do with soil erosion? Soil texture has two main effects on erosion.

First, it influences the rate of infiltration and water’s ability to enter the soil. When it rains, does the water run off rapidly? If so, then you probably have sandy soil. This type of dirt has large pores that act like pipes, channeling water right into the ground.

Does the water collect on the surface or in low lying areas? If it does, then you probably have clay soils that are not known for providing good drainage.

Second, some types of dirt particles don’t detach as easily as others. Silt particles wash away easily because they’re tiny and don’t readily combine with other soil aggregates.

Which Type of Soil Is More Erosion Resistant?

One study suggests that an estimated 30 tons of agricultural soil are lost in the United States to erosion each year. This loss outpaces the rate of formation by an astonishing eight times.

So, which type of soil offers the most erosion resistance? The answer is clay. Clay is better at resisting erosion because it’s small particles hold water, making it a stickier compound than sand.

A soil’s texture affects many aspects of your garden, including erosion. Use this handy guide to help determine your dirt’s composition and how you can use that information to help you conserve topsoil.

An Introduction to U.S. Soil Conservation Programs

Soil. It’s underfoot, where food is grown, and the foundation on which homes, roads, and important infrastructure are built. Wind and water soil erosion poses serious consequences to land, crops, vegetation, and human health. During erosion and runoff, sediment might be carried into the air or deposited downstream or on roadways. Infrastructure is compromised and pollutants are distributed. 

The effects of the growing agriculture industry on United States land prompted the U.S. government to implement programs and acts that work to conserve and preserve soil from erosion and degradation. Since the 1930s, the United States has expanded its various conservation programs in order to utilize the land to its full potential while reducing the harm caused by human activities such as agriculture. 

Today, several federal soil conservation programs operate under the United States Department of Agriculture and a USDA conservation service, the National Resources Conservation Service (NRCS). This program oversees the programs designed by the USDA, and with contribution from the U.S. Forest Service, to reduce the impact of soil erosion while making preservation efforts in the Great Plains and on U.S. wetlands.

History of Conservation Programs

The U.S. government has implemented programs to combat soil erosion caused by humans. Many of these acts focus on sustainable farming and agriculture.

1935 Soil Conservation Act: Congress enacted this program in order to “…provide for the protection of land resources against soil erosion, and for other purposes.” This act authorized the Conservation Options Program and the voluntary Soil Conservation Service, the predecessor to NRCS. These offshoots provided technical assistance to those looking to implement soil management programs and reduce the harmful effects of agriculture.

1936 Soil Conservation and Domestic Allotment Act: U.S. federal policy amended the Soil Conservation Act to encourage participation in agricultural conservation programs. This gave rise to the Agricultural Conservation Program, a voluntary program that provides producers the financial assistance they might require to put into use approved conservation practices

1956 Great Plains Conservation Program (GPCP): This voluntary long-term program sought to address the issues of soil erosion from wind and water, specifically on the Great Plains — an area of prime agriculture real estate. Producers were encouraged to adopt conservation practices to reduce erosion and employ best practices for the use of water and soil resources. Functions of this program included “anti-pollution practices, measures to enhance fish, wildlife, and recreation resources, and practices to promote economic land use.”

1956-today: The NRCS has greatly expanded in the years following, and today there are approximately two dozen programs designed to assist producers by providing education, and technical and financial assistance to implement conservation practices.

At the heart of these programs lie common goals:

  • Address natural resource and environmental concerns associated with agriculture.
  • Reduce soil erosion.
  • Enhance water supplies.
  • Improve water quality.
  • Increase wildlife habitat.
  • Reduce damages from floods and natural disasters.

Major Programs Today

Today, soil conservation programs are divided into two major categories: Working Land and Land Retirement. In the case of working-land programs, conservation practices are put into use on productive agricultural land. Under these programs, the land must stay in active production for the entirety of its enrollment period.

Land Retirement programs require that certain land is removed from agricultural production due to its vulnerability or high-erosion risk. Land sent into retirement then adopts conservation practices designated under the program the land is enrolled in.

Up until 2000, 90% of conservation programs focused on land retirement. Since then, the focus of the NRCS has shifted with the realization that working land needs as much, or more, protections.

Conservation Reserve Program (CRP)

This land retirement program serves to remove millions of acres of sensitive land that is susceptible to erosion from agricultural production. With 27 million acres lost to soil erosion, this program aims to reduce the damaging effects caused by agricultural production. Under this soil conservation service resides the Farm Service Agency which administers CRP in 10-year contracts under the NRCS.

Agricultural Conservation Easement Program (ACEP)

A working land program, the ACEP provides financial and technical assistance for agricultural land and wetlands to promote their conservation and the benefits both provide.

Also under this program is the Agricultural Land Easements. This component assists the NRCS in promoting Native American tribes, state and local governments, and non-government organizations to protect working land and prevent non-agricultural use of said land. The Wetlands Reserve Easements is yet another component that works to restore, protect, and enhance wetlands.

Environmental Quality Incentives Program (EQIP)

Another working-land program, EQIP may provide cost-share payments to producers and landowners to encourage them to put into place management practices to conserve and protect. Under this program reside four other programs with focused intent, which include the Conservation Innovative Grants, Ground and Surface Water Conservation, Klamath River Basin, and Colorado River Basin Salinity Control programs

The Conservation Security Program (CSP)

This working lands program offers financial incentives and technical assistance to agricultural producers. The program rewards producers who promote conservation efforts and work to improve soil, water, air, energy, plant, and animal life. This program is one of the most promising as it could eventually affect US agricultural policy.

Since the 1930s, and not that far into the 20th century, the U.S. recognized that just as the environment affected agriculture, so agriculture affected the environment. The implementation of several soil conservation programs under USDA oversight illustrate the efforts that need to be made to prevent or at least minimize the damage of soil erosion. 

World population has more than tripled since 1935, with now over seven billion humans on the planet that are fed and clothed through agriculture. As changing weather patterns produce storms and create unpredictability, agricultural producers and landowners must be more vigilant than ever.

Today there are many more programs filled with incentives and education to raise awareness and promote conservation efforts, a step in the right direction. Manufacturers are fulfilling the demand for substrates and sod-forming material to combat erosion and runoff. The National Resources Conservation Program has made strides forward to minimize the damage from soil erosion to include working land and land sent into retirement equally in the efforts to combat the effects of human activity and growth.

Soil Moisture and Soil Erosion: What You Need to Know

Soil is formed partly from the effects of wind and rain. Throughout soil’s lifetime, it continues to be affected by the same elements. The effects of moisture on soil are determined by the moisture content for a given region and by taking into account the topography of the land. Current climate conditions have a significant impact on soil as land and sea temperatures continue to rise.

Erosion is a natural occurrence, yet when human-related activities (agriculture and development) change the structure of the land and therefore the soil, consequences take place. Determining whether an area is experiencing a drought or will experience one is measured by the soil’s moisture content. If the moisture content is too high, the risk of soil compaction rises. Soil that is dry or in arid climates may experience drought although that may change as climate does.

What Is Soil Moisture?

The level of moisture in the soil is often determined by variables in climate systems. Surface temperatures affect moisture levels through precipitation and evaporation. Drought and floods have severe impacts on soil moisture content in addition to the effects of climate change. As these conditions affect moisture content, they also indicate vulnerability to runoff and erosion.

Jamali Baruti, in a recent study of soil moisture in relation to soil erosion, explains: “Available water capacity (AWC) is the amount of water that the soil can store. It is the amount of water that is available for use by plants and is normally expressed as volume fractions or percentage.’ People have an adverse effect on soil’s AWC. Activities such as compacting soil with heavy equipment will decrease the amount of water soil can hold. Lower AWC makes soil more prone to drought.

Climate Change and Soil Moisture

The moisture content of soil has increased over the last 30 years: a trend that has coincided with rising temperatures due to climate change. As temperatures rise and rainfall increases, there is less chance for evaporation or for the soil to dry enough to lessen its water content.

Changes to the climate drive the global hydrologic cycle and intensify it. This cycle starts with oceanic evaporation that is lifted and cooled, then condensed into water vapor to forms clouds. Moisture is carried until it is deposited back to earth in the form of precipitation. As this cycle is disrupted, it opens the door for increases in ET or evapotranspiration which is the process of moisture up — then down — in the hydrologic cycle.

What Is Soil Erosion?

Soil erosion takes place when one or more contributing factors are in place, water not being the least. Soil erosion from water can be devastating as it strips the top layer of soil while diminishing the integrity of underlying soils. Debris and sediment are carried away and can change the soil’s composition resulting in loss of fertility or new plantings.

Soil Moisture and Erosion Combined

A combination of soil moisture and soil erosion can work to create a superlative amount of damage to an area. Erosion accounts for economic, environmental, and human health risks.

”Soil erosion rates vary widely over the landscapes, over a field and even along a slope profile within the field. To understand soil erosion over a particular area it is necessary to assess erosion at different landscapes for which various techniques are available,” says Mr. Baruti. 

Understanding moisture content is imperative to know what the health of the soil is at any given time and if steps can be taken to avoid drought or erosion. Testing soil for its moisture content with various soil moisture testing devices or techniques is recommended to minimize the impacts of erosion and moisture imbalances.

How to Test Soil Moisture

Gravimetric

By far the oldest method to measure soil moisture, the gravimetric process is lengthy and time-consuming. Soil samples are collected and weighed, then dried in an oven and weighed again, and compared for differences to estimated water content. The gravimetric method may prove difficult to apply if samples need to be taken from greater depths. Disruptions in the soil might also account for soil compromise as numerous samples might need to be collected for analysis.

Hand auger

These devices come with shaft extensions and are commonly used for deeper samples. Augers can be applied to depths up to 55 feet. The auger is turned by its handle which pushes its cylinder into the soil. The auger is then raised, and the cylinder’s barrel is emptied by striking it to free the sample. The gravimetric method can then be applied to the deeper sample.

Tensiometer

This device determines how much force a growing plant needs to absorb moisture from the soil. A tensiometer consists of a ceramic cup (porous point) connected to a measuring device. The cup is filled with water, and the water in the cup finds its balance with the soil. As the soil dries, water flows out of the cup to indicate greater tension. As soil becomes wet and its tension reduces, water flows back into the cup. Changes in these tensions are indicated on the instrument’s measuring device. Temperature can affect tensiometers as the gradients between the device’s porous point and the soil might cause variations in its measurements.

Moisture sensors or probes

Soil moisture sensors test for moisture volume through electrical resistance, dielectric constant, or through interactions with soil neutrons. These instruments run the spectrum from a low-end do-it-yourself type up to more sophisticated devices that can also measure soil pH and determine soil temperature. Simply insert the probe into the soil, and the instrument does the rest.

Soil erosion is a serious consequence of agriculture and development. A warming planet is disrupting its cycles to create balance in soil’s moisture content. As these imbalances increase or fail to stabilize, drought, runoff, or erosion might result.

Testing soil for its moisture volume is one way to find out what’s coming. Take measures to increase soil’s ability to infiltrate or drain to avoid conditions that contribute to adverse consequences. Working to prevent problems now can positively affect two important factors — agriculture and development.

How Soil Erosion Can Affect Soil pH

Soil erosion is generally caused by one of two elements: wind or water. These two elements distribute soil sediments differently during erosion. Depending on the conditions surrounding the erosion, there could be economic and environmental losses. Water and wind erosion affect soil content and may reduce microbe induction while raising soil’s acidity, or pH level, which interferes with growth and yield.

Knowing soil’s pH can provide insight into problems such as crop loss and low yield. When a grower knows and understands these issues, they can take action and prevent further economic losses.

What is pH?

A crucial factor for soil health lies in its pH level. pH, or potential hydrogen, measures the concentration of hydrogen ions in soil. These concentrations determine whether soil is acidic or alkaline. pH levels of 5.5 and under are desirable for producing healthy crops. Subsoils should measure 4.8 or lower for more alkaline soil. The lower the pH level, the less acidity is in the soil.

Soil’s acidity or alkalinity determines whether crops will see their full yield, or be reduced unhealthy, acidic crops. pH levels decide the stability of the land for crop production by the measure of nutrients available for both soil and plant health.

While low pH should not result in production losses, high pH concentrations and acidity disturb the induction of microbes into the soil, which will weaken its overall structure.

What is Soil Erosion

Sheet and gully erosion caused by water can strip topsoil of its nutrients and change soil’s structure so that its underlying subsoils are also compromised. Saltation, an effect of wind erosion, tosses soil particles into the air and carries them great distances. These particles can cause upper respiratory conditions to flare while they blanket homes and roadways, and smother crops.

The environmental impacts of soil erosion are felt in loss of crop yields due to soil compromise and nutrient unavailability. Loss of animal habitat is felt as insects and microbes are partly responsible for soil’s structure and integrity.

Agriculture suffers overall as it is this land stripped bare of its vegetation. It is bare land that is most vulnerable to erosion and resulting acidity. Development also suffers losses as infrastructure is weakened by erosion.

How Does Soil Erosion Affect Soil pH?

Soil that is maximized to maintain its value as a resource to produce healthy, thriving crops is lower in pH for alkaline soil. Reducing high acidity in soil is needed to produce strong crops and prepare the land for the next growing season. 

As erosion occurs, it takes more than just soil. Erosion carries fertilizers and pesticides along with it as it flows or blows. These sediment deposits might affect surrounding soils and spread (or cause) acidity to nearby areas. Because acidic soil is responsible for nutrient deficiencies and toxicities found in plants, balancing pH is a crucial component to economic health.

As erosion contributes to a rise in the water table, and because pH is usually higher in moist soils, water erosion poses serious consequences to soil’s balance and stability. As acidity accumulates, it might affect surrounding areas by furthering the imbalance and making it that much more difficult to correct or offset the damage.

Managing Acidic Soils

Once pH levels are high in topsoils, underlying subsoil horizons might also be affected. If the parent layer, or O horizon, becomes too acidic, the fight to bring back balance intensifies. Knowing the pH levels of planting ground before the first crops go in is a wise move to prevent unexpected disaster.

Fortunately, there are methods a grower can use to reduce soil acidity and bring pH levels to their ideal levels for their incoming crops.

  • Applying the proper amount of nitrogen and sulfur fertilizers can have a positive effect on pH and lower its levels over time. The key is adding the proper amounts of fertilizer at the appropriate time depending on the crop’s needs.
  • Liming is a tried-and-true method of lowering soil pH. However, this method has proven to be time-consuming and labor-intensive. Moreover, not every farm can afford to purchase lime to control pH. Liming’s effects tend to last a short time and may contribute to nutrient deficiencies in the soil. Liming may also trigger a decline in microbes, compromising soil’s crucial make-up.
  • Cropping practices that improve soil’s organic matter and soil’s overall health is the ideal method of reducing soil pH. Geotextiles in natural fibers like coir can be used in strip planting and terracing to serve double duty: reduce effects of erosion and balance soil pH. Coir’s neutral pH makes it an ideal accompaniment for soil to maintain its overall structure and integrity.

How to Test Soil pH

Testing soil pH is relatively simple and can be performed with various measurement techniques. Be sure to test soil in more than one location for an accurate pH range.

  • PH kit with pH paper: Look for kits that contain a relatively broad pH level scale of 1-14. Some kits may concentrate the range with reading levels between 4.5-10. This method tests soil by adding in a little water then dipping the strip in the soil to take a pH reading. 
  • Soil pH meter: These meters are used by pushing the probe into the soil to read the meter’s measurement. 

How to Prevent pH Imbalances in the Soil

Reducing runoff and erosion are key components in maintaining soil’s ideal pH. Protecting bare land with added vegetation and the use of geotextiles is warranted and recommended to reduce the effects of soil nutrient loss. Additionally, frequent soil testing can alert growers to potential problems before they plant the first seeds.

Soil is composed of many elements for a reason. A living, evolving material, soil’s make-up can be compromised by excessive erosion or runoff that not only affects the growing topsoil but the supporting horizons beneath. Soil pH doesn’t have to be complicated to maintain, and with a little diligence and regular testing, soil will sound the alarm when there may be something wrong.