Spatial variability of stoichiometric characteristics of soil carbon

nitrogen and phosphorus and its influence factors were systematically analyzed through classical statistics analysis and geostatistics analysis methods in Rapeseed Planting areas of Jiangxi Province. The results showed that the averaged values of soil organic carbon (SOC)

total nitrogen (TN) and total phosphorus(TP) contents were 16.99 g/kg

1.44 g/kg and 0.50 g/kg respectively

and soil C:N

C:P

and N:P were 12.28

38.31 and 3.27 respectively. The ecological stoichiometric ratios were 33.86:2.88:1

and the ratios were at a relatively low level

indicating that there existed variation coefficients and spatial variability with a moderate degree

which also suggested the spatial variability of soil C:N

C:P and N:P were determined by the co-effects of structural and random factors in Jiangxi Province

and the structural factors played a more important role. From the characteristics of spatial distribution

SOC

TN

and TP content trend to be high in northeast and low in southwest. The high-value region of soil C:N mainly distributed in the north of Jiangxi Province and the distribution area was small

while the low-value region was mainly distributed in West Jiangxi

Northwest Jiangxi

Southwest Jiangxi and East Jiangxi. Soil C:P and N:P had the same spatial distribution characteristics as well

the high-value region was located on Southwest Jiangxi and Northeastern Jiangxi sporadically; The low-value region was mainly distributed in Northwest Jiangxi and South Jiangxi. Regression analysis showed that soil parent materials

soil types

topography

climate condition and cropping system had very significant impacts on soil C:N

C:P and N:P ratios (P<0.01). The soil parent materials were able to explain 16.6%

3.7% and 7.0% of soil C:N

C:P and N:P spatial variability

respectively. The topography factors could explain 3.5%

2.9% and 4.2% of the spatial variability

respectively. The explanatory power of cropping system were 9.7%

4.4%

and 7.6%. The annual fertilizer Nitrogen application explained 3.9%

4.4% and 7.6% of soil C:N

C:P and N:P spatial variability

respectively. However

The explanatory power of soil types and climate condition were 16.8%

5.1%

9.0% and 13.4%

9.8%

15.2%

respectively

which suggested that soil types and climate condition were the dominant factors in controlling the spatial variability of soil C:N

C:P and N:P.