Conversion of Wheat-Maize to Vegetable Cropping Systems Changes Soil Organic Matter Characteristics
Conversion of Wheat-Maize to Vegetable Cropping Systems Changes Soil Organic Matter Characteristics
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DOI：
10.2136/sssaj2009.0222
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发表时间：
2010-07
影响因子：
2.9
通讯作者：
B. Lei;M. Fan;Qing Chen;J. Six;Fusuo Zhang
中科院分区：
文献类型：
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作者：
B. Lei;M. Fan;Qing Chen;J. Six;Fusuo Zhang
我们研究了从谷类粮田（GF）转变为温室蔬菜田（VF）对土壤剖面表层30厘米处土壤总有机碳（SOC）、总氮（TN）以及活性土壤有机质库（溶解性有机碳（DOC）、高锰酸盐可氧化碳（POC）、溶解性有机氮（DON）、矿质氮和微生物生物量碳（MBC））的影响。土壤样本采集自中国东北地区20组成对的土壤（温室蔬菜田与小麦[Triticum aestivum L.] - 玉米[Zea mays L.]轮作田）。与粮田相比，蔬菜田的土壤有机碳和总氮浓度分别增加了28%和58%。然而，总氮与土壤有机碳的积累速率导致蔬菜田的土壤碳氮比与粮田系统相比显著下降。粮田和蔬菜田之间碳氮比的最大差异出现在大团聚体（>2000μm）中。转变为蔬菜田导致溶解性有机碳、高锰酸盐可氧化碳和溶解性有机氮浓度增加，以及土壤有机碳中溶解性有机碳和高锰酸盐可氧化碳的百分比增加。然而，蔬菜田的pH值、微生物生物量碳以及土壤有机碳中微生物生物量碳的百分比低于粮田系统。此外，在蔬菜田系统中发现pH值和微生物生物量碳之间存在显著的正相关关系，而在粮田系统中微生物生物量碳与土壤总有机碳和高锰酸盐可氧化碳呈正相关。总之，结果表明当农田从小麦 - 玉米种植转变为蔬菜种植系统时，土壤有机碳固存增加与碳氮比下降和土壤酸化之间存在权衡。建议中国蔬菜生产系统改进土壤和作物管理，特别是避免过量施用氮肥和有机肥。
We investigated the effects of land use conversion from cereal grain fields (GF) to greenhouse vegetable fields (VF) on total soil organic C (SOC) and total N (TN) and the labile soil organic matter pools dissolved organic C (DOC), permanganate-oxidizable C (POC), dissolved organic N (DON), mineral N, and microbial biomass C (MBC) in the top 30 cm of the soil profile. The soil samples were collected in 20 sets of paired soils (greenhouse vegetable vs. wheat [Triticum aestivum L.]-maize [Zea mays L.] rotation fields) in northeast China. Compared with those in GF, the SOC and TN concentrations in VF increased by 28 and 58%, respectively. The accumulation rate ofTN vs. SOC, however, led to a significant decrease in soil C/N ratio in VF compared with GF systems. The greatest difference in C/N ratios between GF and VF was observed in the large macroaggregates (>2000 μm). Conversion to VF led to increased DOC, POC, and DON concentrations and an increase in the percentage of SOC as DOC and POC. The pH, MBC, and percentage of SOC as MBC, however, were lower in the VF than GF systems. Furthermore, a significant positive relationship was found between pH and MBC in the VF systems, while MBC was positively related to total SOC and POC in the GF systems. In conclusion, the results show tradeoffs between increasing SOC sequestration when agricultural land is converted from wheat-maize to vegetable systems and decreased C/N ratios and soil acidification. Improvements in soil and crop management for vegetable production systems in China, particularly the avoidance of excess N fertilizer and manure applications, are recommended.