Which techniques and practices should be applied to combat soil degradation?

Soil degradation is caused by too much erosion. Often this is due to poor agricultural and industrial processes. One's land should be treated with care. Hilly acreage should be left as pasture so that the soil is not left barren for any length of time. Terraces are useful as well, as this slows runoff, but does not entirely eliminate it. In recent years many farmers have turned to no-tilling their row crops; this reduces the amount of soil exposed to the wind and rain and still allows for good crops. Farmers even report having to fertilize less with this method. Many mining companies plant trees and shrubs over areas that they have mined in order to control toxic runoff into streams.
It is also important not to take all the nutrients out of soil. Controlling erosion will help the soil stay fertile, but it is also important not to grow the same crop in a field every year as it can sap nutrients. Corn is especially bad for this, as it takes a great deal of nitrogen to grow a good corn crop. Many farmers use a green manure crop, such as winter wheat as both a soil cover in the winter and as nutrients in the spring when the wheat is turned under by the plow.

Soil is mostly degraded through erosion, agricultural activities, and industrial activities. Soil erosion occurs when it rains on areas with loose soils. Soil degradation occurs through agricultural and industrial activities because of the chemicals applied to or released in the soil.
Soil erosion can be controlled by growing some vegetative cover on the soil. The plants will stop soil degradation by holding the soil together and preventing soil erosion. Plants will also slow down the surface runoff caused by rain water. Building gabions in areas suffering extreme soil erosion will help stop the degradation.
Soil degradation caused by agricultural activities can be controlled by ensuring farmers use the correct types and amounts of agrochemicals. Constructing terraces in hilly areas can also prevent excessive surface runoff and erosion.
Soil degradation caused by industrial activities can be remedied through the restoration of utilized areas such as quarries. Stronger regulations and restrictions can also be imposed to control the industrial dumping of wastes, which contaminate the environment.
https://www.worldwildlife.org/threats/soil-erosion-and-degradation