They need to know because landscaping provide common and popular experience with soils. Homeowners and farmers alike test soils to determine how they can be maintained and improved. Plant nutrients such as nitrogen, phosphorus, and potassium are tested for. If specific soil is deficient in these substances, fertilizers may provide them. Extensive academic research is performed in an effort to expand the understanding of agricultural soil science.

Earth sheltering is the architectural practice of using soil for external thermal mass against building walls. The principle is that earthen material undergoes slow temperature changes and thus presents a fairly constant surface temperature at the wall. In higher latitudes with low average annual air temperature, the potential for heat leaching requires floor and base wall insulation. Earth-based, wall-construction materials include adobe, chirpici, cob, mudbrick, rammed earth, and sod. An earthen wall facing the mid-day sun can be designed as a trombe wall. A trombe wall is glazed on the exterior to enhance heat gain. Heat is vented to the interior at night.

Organic soils, especially peat, serve as a significant fuel resource. Peat deposits are found in many places around the world. The majority of peatlands are found in high latitudes; approximately 60% of the world’s wetlands are peat. Peatlands cover around 3% of the global land mass or 3,850,000 to 4,100,000 km². Peat is available in considerable quantities in Scandinavia: some estimates put the amount of peat in Finland alone to be twice the size of North Sea oil reserves.[8] Peat is used to produce both heat and electricity, often mixed with wood. Peat accounts for 6.2% of Finland’s yearly energy production, second only to Ireland.[9] Peat is arguably a slowly renewable biofuel but is more commonly classified as a fossil fuel.[9]

Waste management often has a soil component. Using compost and vermicompost are popular methods for diverting household waste to build soil fertility and tilth. The technique for creating Terra prêta do índio in the Amazon basin increasingly appears to have started from knowledge of soil first gained at a household level of waste management. Industrial waste management similarly relies on soil improvement to utilise waste treatment products. Compost and anaerobic digestate (also termed biosolids) are used to benefit the soils of land remediation projects, forestry, agriculture, and for landfill cover. These products increase soil organic content, provide nutrients, enhance microbial activity, improve soil ability to retain moisture, and have the potential to perform a role in carbon sequestration.

Compost and digestate are the finished products of treatment. Soil performs a more direct treatment role when it comes to septage effluent and in land application of industrial waste water.

Septic drain fields treat septic tank effluent using aerobic soil processes to degrade putrescible components. Pathogenic organisms vulnerable to predation in an aerobic soil environment are eliminated. Clay particles act like electrostatic filters to detain virus in the soil adding a further layer of protection. Soil is also relied on for chemically binding and retaining phosphorus. Where soil limitations preclude the use of a septic drain field, the soil treatment component is replaced by some combination of mechanical aeration, chemical oxidation, ultraviolet light disinfection, replaceable phosphorus retention media and/or filtration.

For industrial wastewater treatment, land application is a preferred treatment approach when oxygen demanding (putrescible) constituents and nutrients are the treatment targets. Aerobic soil processes degrade oxygen demanding components. Plant uptake and removal through grazing or harvest perform nutrient removal. Soil processes have limited treatment capacity for treating metal and salt components of waste.

Well it’s very important if they intend to grow crops. Crops need rich soil to flourish. Farmers need to know about the PH levels in the soil, etc., because each crop they grow requires different types of soil – i.e. grapes are very often grown on sloping soil – all this has to be taken into consideration by farmers.

Different crops deplete different nutrients. Some even put some nutrients back into the soil. Sensible crop rotation is used to keep a field usefully productive. Without a knowledge of soil, a field will become unproductive due to depletion of nutrients.

They need to know the mineral composition of the soil to determine the crop to plant. Since corn and beans absorb different minerals, farmers practice”crop rotation” and also Field rotation to allow the soil to recover.

Farmers need to know about soil because you can’t just plant anything in any soil. They need to know how much acid is in it. They need to know if they should fertilize it. There are many reasons.

the nutrient in the soil are important to plant growth different nutrients produce food differrently

for wine makers it’s everything the soil the climate all has a hand in the outcome

Permaculture! The cheapest best place to store water is in the soil. Farmers can design their land on Permaculture principles. Yeoman’s Keyline plan has a scale of permanence, in this order: climate, land shape (which is created by the action of water) roads, trees and building soils. Keyline is about reshaping landscapes so that surplus run off water is stored in the soil in dams and used to irrigate the land it is stored on. This builds soil fertility and reduces future run off which leaches minerals from the soils. When you reform the landscape you create dams, diversion channels and irrigation chanels. Key line is contour at the key point, this is the best place to store water. The geography of keyline is key. There is a main ridge, a primary valley, a primary ridge and a secondary valley. A keyline only exists in the primary valley. Contour mapping shows water levels. It is like forensic evidence which allows the land shape to show itself. If water has run on the contour before, it will again. The contour line itself joins points of equal height. For example the water line of a pond is a contour line. Key line cultivation is where you plant the clover (nitrogen fixer) and grasses, these live and die to feed the soil. Only chisel ploughs are used to prepare for tree planting. The contours spread water flow from valleys to ridges if you plough downwards away from the valley. Planting trees, is also essential to prevent water logging or over illumination of soils and soil salting in the long term. Particularly planting fruit trees in shelter belts prevents overuse of water. Leaf drop self mulches reducing the need for artificial watering and adds additional compost. Pitting, swales (absorption beds) and water spreading all assist in getting water to storage for long term use. Swales are all built on contour lines and do not allow water flow. They just hold water. Shelter belts are planted using the principles of sectoring, this takes into account wind direction and sunlight. The wind tunneling effect is minimized by sectoring but the shelter belt does not cast shade because of it’s deliberate orientation. The shelter belt improves the microclimate, reduces wind chill and reduces evaporation too. Soil structure improvement (building soil) is done with mulching including green manures. This prevents further water logging in winter and overdrying of soil in summer, which reduces the need for land drainage and watering. It also reduces the need for fertilizer inputs. Water harvesting is also a priority as this can be used for farm irrigation particularly under deep mulch which further reduces evaporation.

Soil and what’s in it has a lot to do with whether a crop will grow successfully or not.

because they want to know salts and products in the soil so that they choose the right soil for their products