Agriculture Reference
In-Depth Information
14.5.3.3 China
Conservation agriculture for soil conservation: China is paying more attention to
tilled soils being more susceptible to water and wind erosion. The best solution to
control water and soil erosion is to eliminate tillage. Practices that improve water
use efficiency and natural resource management by reducing runoff and erosion are
of great importance. Therefore, the adoption of CA practices, providing more resi-
due cover and less soil disturbance, has received considerable attention. Since their
beginnings in response to issues from the American “dust bowl” era, several decades
of development have demonstrated that CA systems are a valuable means of reducing
erosion by both water and wind (Uri et al. 1998) because of low soil disturbance and
soil surface protection with crop residues.
Conventional tillage (CT) in dryland farming areas of northern China includes
moldboard plowing to a depth of about 20 cm, followed by harrowing, hoeing, roll-
ing, and leveling. All the residues in the fields are removed for animals or as fuel
before plowing. In some parts of northern China, particularly in the North China
Plain, burning crop residue has increased during the last decades.
Long-term moldboard plowing and residue removal/burning have increased the
risks of wind and water erosion and the formation of hardpan in the deep soil layer. It
has also resulted in poor soil physical and chemical properties, as well as high inputs
of energy and labor, which apparently lead to low farmer incomes. To address these
TABLE 14.3
Magnitudes of Soil Sediment Transport in Comparisons of CA and CT
Region
Testing Site
Collection Time
CA (g)
CT (g)
Reduction (%)
Loess Plateau of
China
Yanggao, Shanxi
March 25, 2004-
April 3, 2004
8.4
15.1
44.7
Northeast ridge
tillage areas
Lingyuan,
Liaoning
March 25, 2004-
April 3, 2004
16.3
10.2
37.3
North China
Plain
Fengning, Hebei
March 22, 2002-
April 21, 2002
12.7
42.5
70.0
Zhangbei, Hebei
April 8, 2002-
May 8, 2002
12.7
42.5
70.0
Changping,
Beijing
March 28, 2005-
April 17, 2005
16.7
19.0
12.1
Yanqing, Beijing
March 16, 2005-
March 20, 2005
4.2
5.0
17.0
Farming—
pastoral areas
Chifeng, Inner
Mongolia
April 22, 2003-
May 3, 2003
4.7
7.1
34.2
Zhenglanqi,
Inner Mongolia
March 23, 2003-
April 27, 2003
11.3
25.0
54.8
Wuchuan, Inner
Mongolia
March 26, 2003-
April 6, 2003
2.9
7.4
61.6
Northwest China
Hetian, Xinjiang
March 16, 2004-
April 27, 2004
7.4
105.5
92.9
 
Search WWH ::




Custom Search