<p class="first" id="d8972192e150">Soil acidification is a major problem in intensive
agricultural systems and is becoming
increasingly serious. Most research has reported the soil acidification of cereal
crops, forests, and grasslands. However, there is no information about soil acidification
under tea cultivation on a national scale. Therefore, we conducted a nationwide survey
of soil acidification in the major tea-planting areas of China and used two nationwide
surveys in three Chinese counties to evaluate changes in soil acidity over the past
20-30 years. Finally, the acidity of soil from forests and traditional and organic
tea plantations was compared to evaluate the effects of agricultural management on
soil acidification in tea plantations. Our results show that: (1) the average soil
pH was 4.68 nationally and ranged from 3.96 to 5.48 in different provinces. Overall,
46.0% of the soil samples had a pH <4.5, which is too acidic for tea growth and
only
43.9% had a soil pH of 4.5-5.5, which is optimal for tea growth. (2) In the past 20-30 years,
the greatest soil acidification was observed in tea plantations; the pH decreased
by 0.47 to 1.43, which is much greater than the decrease seen in fruit and vegetable
systems (0.40 to 1.08) and cereals (0.30 to 0.89). (3) Compared with forests, tea
cultivation with chemical fertilizer application caused serious soil acidification,
while no significant acidification was observed at organic tea plantations. In conclusion,
serious soil acidification occurs nationally in China, and organic management is an
adaptive choice for sustainable tea growth.
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