Manure was supposed to return to the soil Livestock production and water environment from 1970s to 2000s

Manure was supposed to return to the soil Livestock production and water environment from 1970s to 2000s

From the 1970s to the 2000s, Japanese livestock production rapidly increased in scale against the backdrop of changing dietary habits and growing demand. Traditionally, livestock waste had been circulated within the community as fertilizer that was returned to farmland, but as the number of animals kept increased, the amount generated exceeded the land's capacity to accept it, and proper treatment could no longer keep pace. As a result, open piles and simple storage of manure became the norm, and untreated wastewater flowed into groundwater and rivers during rainfall. In particular, groundwater contamination by nitrate-nitrogen became a serious problem in rural areas, and the use of well water for drinking and the health risks to infants became a social issue. In addition, eutrophication in rivers and lakes led to abnormal growth of algae and prolonged degradation of the ecosystem. 1999 saw the enactment of the Livestock Waste Management Law, which mandated the construction o
f treatment facilities, but the high cost of investment and lack of support tended to delay the implementation of such measures. This problem demonstrates the contradiction between the philosophy of resource recycling and the overproductive livestock production structure, and it continues to cast a shadow as a structural issue that causes environmental burdens to accumulate in the region.