Soil Improvement and Reclamation

Proper soil health is crucial to ensure that cropping systems provide essential ecosystem services, including food and fiber production. When soil properties are not adequate for crop production and limit yields, we should improve soil conditions and in extreme cases reclaim affected fields. First, the causes behind the loss of soil health should be identified so specific treatments to improve the soil functionality can be implemented. This chapter reviews the main causes affecting soil degradation and proposes solutions to maintain and recover soil health. Low content of soil stable organic matter (SOM) is one of the main issues associated with cultivated soils and can lead to multiple problems including reduction of nutrient fertility, soil water holding capacity, and soil aggregate stability that may lead to cultivation restrictions. Strategies to maintain or build up SOM rely in a mass balance between losses and biomass inputs. Soil physical properties such as compaction, stoniness, or structural degradation require specific corrections relying on mechanical operations and/or management practices (i.e., tillage intensity, cover cropping). Reclamation of soils affected by chemical issues (salinity, sodicity, and acidity) is conducted by the application of amendments and/or leaching that relies on chemical equilibria revised in this chapter. Finally, the concept of regenerative agriculture is defined and exemplified by a case study.