Water pollution Oxygen-depleting substances may be natural materials such as plant matter (e.g. leaves and grass) as well as man-made chemicals. Other natural and anthropogenic substances may cause turbidity (cloudiness) which blocks light and disrupts plant growth, and clogs the gills of some fish species. Alteration of water's physical chemistry includes acidity (change in pH), electrical conductivity, temperature, and eutrophication. Eutrophication is an increase in the concentration of chemical nutrients in an ecosystem to an extent that increases the primary productivity of the ecosystem. Depending on the degree of eutrophication, subsequent negative environmental effects such as anoxia (oxygen depletion) and severe reductions
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