Polyculture chemicals into the environment such as eutrophication of fresh water or the presence of excess atmospheric nitrogen are greatly reduced in polycultures. Other negative impacts of modern agriculture are similarly reduced. Excessive tillage occurs in most modern agricultural practices, but removes essential microbes and nutrients from the soil that are conserved in polycultures, especially permacultures. Agricultural machinery not only uses fossil fuels and creates waste, but is more costly to farmers. Because polyculture relies on natural systems of crop maintenance these costs can be eliminated as well. Modern agriculture is also dependent on a very limited number of plant species.
Korean natural farming enhanced SI within 2 cropping cycles. KNF posits three primary stages of plant growth. Each stage requires a different balance of nutrients. In the growth phase, the plant extends its roots, branches and foliage. The key nutrient in this stage is nitrogen. KNF prefers the use of a preparation of fish amino acids for this phase. After the plant has reached sufficient size, the plant diverts its energy into making flowers to attract pollinators. The key nutrients in this stage are calcium and phosporous. KNF prefers the use of a preparation of fermented plant juice and other amendments for this