水保所知识产出(1956---)知识库

基于作物产量和表层（0～20 cm）土壤有机碳密度（SOCD）数据，利用GIS 技术研究了县域尺度（青海乐都县）小麦产量时空
变化特征及其与农田表层SOC 关系。结果表明，乐都县小麦单产和SOCD 在空间分布上具有显著区域特征，地形、土地利用方式等
结构性因素影响SOCD 和作物产量的相关关系。20 世纪80 年代和2000 年以后，乐都县小麦单产与SOCD 在空间上呈相反分布，
高产区SOCD 最低，低产区SOCD 最高。这两个时间段，高产区小麦单产增幅仅为0.5%，SOCD 增幅却达11.5%；中、低产区小麦单
产均呈增加趋势，增幅分别为12.9%、18.9%，SOCD 却呈降低趋势，降幅分别为24.6%、29.8%。

Soil property and plant growth exist spatial and temporal variations due to the unevenness of effects of natural and human factors
across a region. This study investigated the spatio-temporal variations in wheat production and soil organic carbon density（SOCD）in surface
soil（0～20 cm）at a county scale（Ledu, Qinghai Province）. Wheat yield and SOCD had significant spatial patterns at county scale.
However, they showed an opposite spatial distributions in the 1980s and 2000s：the lowest SOCD found in the high-yield fields and the
highest SOCD observed in the low-yield fields. From the 1980s to the 2000s, wheat yield had a slight increase of only 0.5%, while SOCD
increased by 11.5% in the high-yield fields; wheat yield was increased by 12.9%, but SOCD were decreased by 24.6% in the middle-yield
fields; and wheat yield was elevated by 18.9% while SOCD were lowered by 29.8% in the low-yield fields. Topography and land use were
the dominant factors influencing the relationships between SOCD and crop yields at county scale.