Restoring Soil Fertility on Degraded Lands to Meet Food, Fuel, and Climate Security Needs via Perennialization

Abstract

A continuously growing pressure to increase food, fiber, and fuel production to meet worldwide demand and achieve zero hunger has put severe pressure on soil resources. Abandoned, degraded, and marginal lands with significant agricultural constraints—many still used for agricultural production—result from inappropriately intensive management, insufficient attention to soil conservation, and climate change. Continued use for agricultural production will often require ever more external inputs such as fertilizers and herbicides, further exacerbating soil degradation and impeding nutrient recycling and retention. Growing evidence suggests that degraded lands have a large potential for restoration, perhaps most effectively via perennial cropping systems that can simultaneously provide additional ecosystem services. Here we synthesize the advantages of and potentials for using perennial vegetation to restore soil fertility on degraded croplands, by summarizing the principal mechanisms underpinning soil carbon stabilization and nitrogen and phosphorus availability and retention. We illustrate restoration potentials with example systems that deliver climate mitigation (cellulosic bioenergy), animal production (intensive rotational grazing), and biodiversity conservation (natural ecological succession). Perennialization has substantial promise for restoring fertility to degraded croplands, helping to meet future food security needs.

Restoring Soil Functions and Agroecosystem Services Through Phytotechnologies

“…Soil contamination with heavy metals can reduce soil fertility, modify microbial processes such as carbon mineralization and nitrogen transformation, and reduce crop production (23). Soil fertility is a critical component of food and water safety, and the ever-growing pressure to increase food, fiber, and fuel production to meet worldwide demand and achieve zero hunger has put severe pressure on soil resources (11,24). Losses of carbon and essential nutrients from the agricultural system have resulted in nutrient deficient food for human consumption.…”

“…There is growing evidence, however, that degraded lands can be restored while remaining productive (82). Central to this restoration is the incorporation of perennial crops and forages in long rotations (24,83). Perennial plants that have a higher root-to-shoot ratio (24), higher root biomass production (84-86), and higher rootassociated C input through exudation and turnover (87,88) can improve soil properties that are closely linked to soil fertility, such as soil aggregation, water-holding capacity, and microbial biomass and diversity.…”

“…Central to this restoration is the incorporation of perennial crops and forages in long rotations (24,83). Perennial plants that have a higher root-to-shoot ratio (24), higher root biomass production (84-86), and higher rootassociated C input through exudation and turnover (87,88) can improve soil properties that are closely linked to soil fertility, such as soil aggregation, water-holding capacity, and microbial biomass and diversity. In addition, perennial plants are known to make better use of nitrogen, as their deeper and more extensive root systems optimize inorganic N and P retention in the soil, thus reducing leaching of these elements (81,(89)(90)(91)(92).…”

“…In addition, perennial plants are known to make better use of nitrogen, as their deeper and more extensive root systems optimize inorganic N and P retention in the soil, thus reducing leaching of these elements (81,(89)(90)(91)(92). In addition, some species contribute to N retention by translocating N in their belowground biomass, such as in rhizomes at the end of the growing season (24). Further to this perenniality concept in restoring soil fertility is the diversification concept.…”

Can artificial ecological corridors be used for ecological restoration of cultivated land in Chinese Mollisols?

“…Different land-use patterns may affect the accumulation pattern of nutrients in the soil ecosystem by affecting the growth rate of plants, the distribution pattern of soil nutrients and the quality of soil nutrients (Lugo, 1992;Hobbie, 1996). 3) The accumulation of soil nutrients results from the mutual exchange and accumulation of soil, plants and animals in the soil ecosystem (Mosier et al, 2021).…”