抄録
A study on nutrient cycling and nutrient balances at different scales in the autonomous region of Guangxi was carried out. Using data from a survey in representative cropping systems in different counties and nutrient input: output calculations based on published data, the agricultural statistics revealed a detailed knowledge about the nutrient inputs from organic and inorganic resources to the main cropping systems on lowland and upland. The overall consumption of N and K was not sufficient to cover the demand of the crops whereas the P balance showed a positive value. In lowlands, N inputs clearly exceeded outputs whereas on the uplands the balance of N was negative, leading to overall negative balance for nitrogen. Substantially more potash fertilizer is required to overcome the negative balance and the severe K deficit observed. The prediction for future mineral fertilizer consumption indicates 7-10%annual increase to meet the growing demand and to establish balanced nutrient budgets in the farmlands.
