【摘要】 [目的]了解广西滨海农田土壤养分现状、时间变化特征,以及与我国主要滨海地区土壤养分性质的差异,服务广西滨海农田土壤养分综合评价与地力提升,丰富我国海岸带土壤地理学研究。[方法]选取广西滨海主要农田类型甘蔗、木薯、菜园、水稻田和抛荒水稻田为研究对象,分析其土壤有机质、全氮、全磷、全钾、碱解氮、有效磷和速效钾养分现状特征,并将其与该区第二次土壤普查、我国主要滨海地区(环渤海、黄海、东海)农区土壤养分性质对比分析,探讨该区土壤养分性质30余年的变化和在我国滨海农田土壤养分特征中的地位。[结果]广西滨海农田土壤养分含量整体较低、变异程度高,除有效磷含量为土壤养分等级中的丰富水平外,有机质、全氮、全磷、全钾、碱解氮和速效钾含量均为缺乏及以下级别,并整体表现农田系统高于旱地系统。与第二次土壤普查结果相比,该区旱地、水田系统及其各土壤养分指标变化各异,旱地系统中全磷含量显著增加,增比为126.73%,但全钾和速效钾含量降比分别达58.29%、38.48%;水田系统的土壤全磷含量有微小增加,但其余养分指标均明显降低,且其降比均达20%以上,呈现出退化趋势。我国沿海地区土壤肥力整体偏低,各地区各养分指标存在较大差异,且各指标在各区的分布也具有较强的变异性(变异系数为15.30%～197.37%),4个比较区中,广西滨海农田土壤有最高的有机质含量(22.21 g/kg)、碱解氮含量(58.77 mg/kg)和有效磷含量(74.78 mg/kg),浙东海积平原区全氮含量(1.33 g/kg)最高,环渤海区速效钾含量(202 mg/kg)最高。[结论]我国滨海地区土壤养分状况较差,人类耕作活动和成土母质是导致现阶段广西滨海农田及其与我国主要滨海地区土壤养分状况差异的主要原因,应加强我国滨海区土壤地理学、土壤养分形成与演变机理以及高效培肥模式研究,以充分发挥滨海土地后备耕地资源效益,同时防止海岸带区面源污染。更多还原

【Abstract】 [Objective]The research aimed to investigate the soil nutrient status, temporal change of the coastal farmland of Guangxi, compare it with soil nutrient properties in the coastal area of the Bohai Sea, Yellow Sea and East Sea. It is benefit for the soil quality increase and soil geography research of the coastal area. [Method] The content of soil organic matter, total nitrogen, total phosphorus, total potassium, available nitrogen, available phosphorus and available potassium of sugarcane field, cassava field, vegetable field, paddy field and abandoned paddy field were tested. Soil nutrient properties in 1980 s of the study area and the Bohai Sea, Yellow Sea, East China Sea were collected from the literature. Based on the statistical methods, the soil nutrient status, temporal change of the coastal farmland of Guangxi, and the difference among the coastal area of the Bohai Sea, Yellow Sea and East China Sea were analyzed. [Result] The soil nutrient were characterized by low contents and high heterogeneity. Most of the contents of soil nutrient were lack even below lack class, including soil organic matter, total nitrogen, total phosphorus, total potassium, available nitrogen and available potassium, only the available phosphorus is rich class. Soil nutrient of paddy field system was higher than that of the dry land system. Compare to soil nutrient of the second nation-wide soil survey, soil nutrient degraded in the past 30 years. In the dry land system, the total phosphorus content increased significantly with a ratio of 126.73%, however, total potassium and available potassium decreased by 58.29%, 38.48% respectively. In the dry land system, all the soil nutrient properties decreased more than 20%, except the total phosphorus content increased slightly. Generally, soil fertility in coastal areas of China was low and different among Beibu Gulf, Bohai Sea, Yellow Sea and East China Sea(coefficient of variation was between 15.3% and 197.37%). The coastal farmland of Guangxi had the highest soil organic matter content(22.21 g/kg), available nitrogen content(58.77 mg/kg) and available phosphorus content(74.78 mg/kg). The coastal soil of East China Sea had the highest nitrogen content(1.33 g/kg). And the soil available potassium content(202 mg/kg) of the Bohai Sea coastal area was the highest. [Conclusion] It has a poor soil nutrient in coastal areas of China. Human farming activities and soil parent materials play a main role in affecting the modern soil nutrient properties and the difference among different coastal areas. It is important to study on the soil geography, soil nutrient formation and evolution mechanism, and high efficiency fertilization patterns in coastal areas for high utilization efficiency of coastal soil, which is an important reserved land resource. Also, it is benefit for the non-point source pollution control in coastal areas.更多还原