摘要
【目的】研究小麦-玉米轮作体系长期有机无机肥配施对(土娄)土土壤水稳性团聚体分布及其有机碳、无机碳含量的影响,以了解(土娄)土碳固存机制对施肥的响应。【方法】依托21年长期肥料定位试验,采集不施肥(CK)和施用有机无机肥(MNPK)处理0—10、10—20和20—30 cm土层土样,利用湿筛法分析不同大小水稳性团聚体的质量百分比、原土和团聚体中有机碳和无机碳含量。【结果】长期有机无机肥配施显著降低各个土层>1 mm团聚体百分含量,显著增加0—20 cm土层0.25—1 mm团聚体百分含量。长期有机无机肥配施较对照显著降低了所有土层平均重量直径(MWD),3个土层分别降低26.6%、38.3%和62.4%。显著降低了20—30 cm土层几何平均直径(GMD),但对0—20 cm土层GMD值没有影响。有机无机肥配施较不施肥显著增加原土所有(土娄)土层有机碳含量,3个土层有机碳含量分别增加150%、97%和42%;也增加了0—10 cm和10—20 cm(土娄)土层所有级别团聚体有机碳的含量,其中0—10 cm土层>2、1—2、0.5—1、0.25—0.5以及<0.25 mm土壤团聚体有机碳含量增加幅度分别为163%、160%、111%、86%和61%,10—20 cm的增加幅度分别为97%、109%、118%、39%和45%,团聚体有机碳含量随团聚体增大而增加。长期有机无机肥配施显著增加20—30 cm土层无机碳含量,增加幅度为28.2%。另外,0—10 cm土层有机无机肥配施土壤大团聚体无机碳含量较对照有降低的趋势,其中>2 mm和0.25—0.5 mm团聚体无机碳含量显著降低;10—20 cm土层影响不显著;而20—30 cm土层有机无机肥配施均显著增加了各团聚体无机碳含量,增幅为22.1%—36.6%。土大于50%的有机碳储存在<0.25 mm的微团聚体中,1—2 mm团聚体储存最少(<10%)。长期有机无机肥配施降低了>2 mm和<0.25 mm团聚体有机碳分配比例,其中0—10 cm土层分别降低了4.33%和13.78%,10—20 cm土层分别降低10.24%和7.81%。显著
【Objective】The objective of this study is to investigate the effect of long-term application of organic manure combined with chemical fertilizers on distribution of water-stable aggregates and their organic carbon（SOC） and inorganic carbon（SIC） in a tier soil under winter wheat and summer maize rotation system, and to get deep insight into the mechanisms of soil carbon sequestration in tier soil.【Method】 Soil samples with an increment of 10-30 cm were collected from a 21-year long-term field experiment. Collected soil samples of two treatments, of which one receiving no fertilizer（CK） and the other, receiving organic manure plus N, P and K fertilizers（MNPK）, were separated into 5 aggregate-sizes classes by wet sieving. And then both organic and inorganic carbon contents in each size of aggregates and bulk soils were determined.【Result】Compared to CK, MNPK significantly reduced the proportion of aggregates that 1 mm at all three soil horizons, while increased the 0.25-1 mm aggregates at 0-20 cm soil layers. MNPK significantly decreased the mean weight diameter（MWD） at 0-10, 10-20 and 20-30 cm soil horizons by 26.6%, 38.3% and 62.4%, respectively. MNPK also decreased the geometric mean diameter（GMD） at 20-30 cm soil depth, but had no effect on it at 0-20 cm soil layers. In comparison to CK, MNPK significantly increased the SOC contents of bulk soils by 150%, 97% and 42%, respectively, for above three soil layers; and enhanced SOC in aggregates 2 mm, 1-2 mm, 0.5-1 mm, 0.25-0.5 mm and 0.25 mm by 163%, 160%, 111%, 86% and 61%, respectively at 0-10 cm; by 97%, 109%, 118%, 39% and 45%, respectively at 10-20 cm soil horizons. Organic carbon concentration of aggregates generally tended to increase with the increasing size of aggregates. MNPK greatly improved the SIC of bulk soils by 28.2% at 20-30 cm soil depth. However, the SIC of the macro-aggregates showed a tendency of decreasing on MNPK over CK at 0-10 cm soil horizons, where it decreased drastically in 2 mm and 0.25-0.5 mm sizes f
出处
《中国农业科学》
CAS
CSCD
北大核心
2015年第23期4678-4689,共12页
Scientia Agricultura Sinica
基金
国家公益性行业(农业)科研专项(201203030)
农业部农业科研杰出人才及其创新团队培养计划
关键词
长期施肥
(土娄)土
平均重量直径
几何平均直径
水稳性团聚体
碳分配比例
long-term fertilization
tier soil
mean weight diameter
geometric mean diameter
water-stable aggregate
distribution of carbon
