ORGANIC-CARBON EFFECTS ON AVAILABLE WATER CAPACITY OF 3 SOIL TEXTURAL GROUPS
ORGANIC-CARBON EFFECTS ON AVAILABLE WATER CAPACITY OF 3 SOIL TEXTURAL GROUPS
复制标题
DOI：
10.2136/sssaj1992.03615995005600010038x
复制
发表时间：
1992-01-01
影响因子：
2.9
通讯作者：
BLACK, AL
中科院分区：
文献类型：
--
作者：
BAUER, A;BLACK, AL
侵蚀造成土壤生产力损失的一个主要原因是土壤持水特性的变化或植物生根带厚度的减少。本研究的目的是测量管理引起的土壤有机碳（OC）浓度的变化对影响土壤有效水容量的土壤特性的影响。四个站点中粗（桑迪），中，中细或细（细）土壤进行了采样，在四个增量为0.457米内的两个农田管理系统（传统耕作和残茬覆盖）和两个原始草地管理系统（放牧处女和残遗处女）。测定了扰动土样田间持水量（FC）和永久萎蔫点（PWP）的重量含水量（P（w））。堆密度随OC浓度的增加而降低。变化的幅度是最大的桑迪和至少在中等质地的土壤。对于所有土壤相结合，砂部分的变化占约75%的P（w）的变化在FC和PWP。FC时P（w）的变化大于PWP。在桑迪土壤中，有机碳浓度的单位变化导致FC处的P（w）变化大于PWP处的P（w）变化，但在中细土中，FC处的P（w）变化基本上与PWP处的变化相一致。OC浓度的增加并没有改变桑迪组的有效水容量，并降低它在中等和精细质地组。在北方大平原，土壤侵蚀引起的土壤生产力损失可能与养分和生物活性下降的关系比与可用水容量变化的关系更密切。
A major cause of soil productivity loss through erosion is attributed to changes in soil water-holding properties or a reduction in thickness of the plant rooting zone. The objective of this study was to measure the effect of management-induced changes in soil organic carbon (OC) concentration on soil characteristics affecting the available water capacity. Four sites each of moderately coarse (sandy), medium, and moderately fine or fine (fine) soils were sampled in four increments to 0.457 m within each of two cropland management systems (conventionally cultivated and stubble mulched) and each of two virgin grassland management systems (grazed virgin and relict virgin). Measurements of the water concentration by weight (P(w)) at field capacity (FC) and permanent wilting point (PWP) were made on disturbed soil samples. Bulk density decreased with increasing OC concentration. The magnitude of change was greatest in sandy and least in the medium-textured soils. For all soils combined, a change in sand fraction accounted for about 75% of the change in P(w) at both the FC and the PWP. The change in P(w) was greater at FC than the PWP. A unit change in OC concentration in the sandy soils caused a greater change in P(w) at FC than at the PWP, but in the medium and fine soils the change in P(w) at FC essentially paralleled the change at the PWP. An increase in OC concentration did not change the available water capacity in the sandy group and decreased it in the medium and fine textural groups. Loss of soil productivity induced by erosion in the northern Great Plains is probably more closely associated with a decline in nutrients and biological activity than from a change in available water capacity.