The author defends that the conversion of rangelands to maize fields in Argentina has enabled the formerly rare field mouse to expand . The mouse is both a host and vector for the virus that causes Argentine hemorrhagic fever . She reminds us that water logging and salinization of soils are major causes of deterioration in croplands around the world . She believes that chemical fertilizers have been responsible for the increase in world food production and are now intricately linked to agriculture . One of the major fertilizer ingredients, phosphorus, binds to soil particles and is carried away with surface runoff.
Nitrates are major plant nutrients in the soil but serious pollutants in drinking water supplies.
They have been linked to the increases in lymphatic cancer , and, at high levels in drinking water, nitrates can cause a type of anaemia in infants. According to Yvonne the soil is a complex and richly diverse ecosystem , but mostly treated as dirt - poisoned , ploughed, scraped and still having to support any plant sown into it. She says that creating a few centimetres of new top soil from disintegrating bedrock and organic decay can take several hundred or thousand of years , meaning that lost soil is not a renewable resource on an any time scale. It is the interactions between the soil and plant and animal communities that create and maintain the characteristic soils of a region. She believes that changes in biodiversity aboveground can alter not only the subterranean environment but also the resources flowing into it.