Loss of soil organic matter and related soil properties under long-term sugarcane production on two contrasting soils
Loss of soil organic matter and related soil properties under long-term sugarcane production on two contrasting soils
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DOI：
10.1007/s00374-002-0538-5
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发表时间：
2002-11-01
影响因子：
6.5
通讯作者：
van Antwerpen, R
中科院分区：
文献类型：
--
作者：
Dominy, CS;Haynes, RJ;van Antwerpen, R
在南非夸祖鲁-纳塔尔糖业带的沙质沿海棕壤(Glenrosa土)和红色Rhodic Ferralol(Hutton土)的0~10 cm土层中，研究了甘蔗单作(收割前焚烧管理)下增加时期对土壤有机质含量和相关土壤性质的影响。在未受干扰的植被下，两个样地的有机碳含量在40~50gC kg(-1)之间。随着甘蔗种植年限的增加，这一指标呈指数下降。对于格伦罗萨遗址来说，它在大约3040年后达到了一个新的平衡水平。甘蔗种植20~30年后，赫顿土壤有机碳含量降至33g kg(-1)左右，格伦罗萨土壤降至17g kg-1左右。赫顿土壤保持较高的有机质含量主要归因于粘土对有机质的保护，因为赫顿土壤的粘土含量为62%，而格伦罗萨土壤的粘土含量为18%。出于同样的原因，赫顿土壤的团聚体稳定性也普遍高于格伦罗萨土壤。甘蔗下土壤有机质的流失导致土壤微生物量碳、有机碳在微生物量中所占比例、基础呼吸作用、二乙酸荧光素水解性和团聚体稳定性的下降。在Glenrosa站点，土壤中的自然增量(13)C丰度被用来计算森林来源的自然土壤C的损失和伴随的甘蔗来源C的输入。甘蔗来源的有机C随着时间的推移而增加，直到在甘蔗下种植超过50年的土壤中占到表层10 cm有机C的61%左右。结果表明，甘蔗生产可导致土壤有机质含量大幅下降，应推广绿色收获、免耕和种植绿色作物等措施，以帮助缓解这一问题。
The effects of increasing periods under sugarcane monoculture (managed with preharvest burning) on soil organic matter content and related soil properties were investigated in the 0- to 10-cm layer of a sandy coastal Ochric Cambisol (Glenrosa soil) and a red Rhodic Ferralsol (Hutton soil) from the sugar belt of the South African province of KwaZulu-Natal. The organic C content at both sites under undisturbed vegetation was between 40 and 50 g C kg(-1). This declined exponentially with increasing years under sugarcane. For the Glenrosa site it reached a new equilibrium level after about 3040 years. After 20 30 years of sugarcane, organic C content had declined to about 33 g kg(-1) for the Hutton soil and 17 g kg-1 for the Glenrosa soil. The higher organic matter content maintained at the Hutton site was attributed mainly to clay protection of organic matter since the clay content of the Hutton soil was 62% compared to 18% for the Glenrosa soil. For the same reason, aggregate stability was also generally higher in the Hutton than Glenrosa soil. The loss of soil organic matter under sugarcane resulted in a concomitant decline in soil microbial biomass C, percentage of organic C present as microbial biomass, basal respiration, fluorescein diacetate hydrolytic activity and aggregate stability. At the Glenrosa site, the natural delta(13)C abundance in soils was used to calculate the loss of forest-derived, native soil C and the concomitant input of sugarcane-derived C. Sugarcane-derived organic C increased over time until it accounted for about 61% of organic C in the surface 10 cm in soils that had been under sugarcane for greater than 50 years. It was concluded that sugarcane production can cause a large decline in soil organic matter content and that practices such as green cane harvesting, zero tillage and use of green crops should be promoted to help ameliorate the problem.