Chinese cropping system not only provides people grains
vegetables
etc.
but also takes an important role in soil conservation. First
crops reduce soil erosion through increasing soil penetrability and reducing runoff. Second
Chinese farmers invented many of measures for soil conservation in the long term of farming practice
such as terrace
check-dam
contour farming
straw mulch
etc.
all of these are proved effective in soil conservation and crops yield improvement. According to the calculated results in the paper
the weight of soil conserved by Chinese cropping system is 101.910~8 t per year
and cropping systems in Southwestern China
Loess Plateau and Northeastern China are outstanding in soil conservation. Monetary value of soil held by Chinese cropping system is also calculated by methods of market price
opportunity cost and shadow cost. The results show that the total monetary value is 4 626.6610~8 yuan per year
which accounts for 32.08% of the mean output value of Chinese cropping production during 20002002. The values of keeping soil nutrients
reducing soil abandon and alleviating sedimentation are 4 408.5010~8 yuan/a
164.0910~8 yuan/a and 53.7410~8 yuan/a
respectively. The monetary value in Northeastern China
Loess Plateau and Southwestern China are greater
and sum of them is 2 851.810~8 yuan/a and accounts for 61.6% of total monetary value of soil conservation service provided by Chinese cropping system.