【作者】 刘占军；

【导师】 周卫； 申建波；

【作者基本信息】 中国农业大学 ， 植物营养学， 2014， 博士

【摘要】 我国南方低产水稻土类型多、面积大、分布广,具有较大的增产潜力。阐明典型低产水稻土的养分特征及障碍因素,对于指导科学培肥和提高水稻产量有重要意义。目前有关土壤质量评价多侧重于对土壤物理和土壤化学性状的研究,对土壤生物学性状的研究相对较少；有关区域尺度上对高产、中产和低产水稻土的质量特征缺乏系统的研究。本研究以黄泥田、反酸田、冷浸田、白土和潜育化水稻土五大类南方低产水稻土为研究对象,通过对不同生产力水稻土物理、化学和生物学性状分析与质量评价,从区域尺度上揭示不同类型低产水稻土的主要障碍因素。取得的主要进展如下：(1)我国南方水稻土养分总体特征为有机质和全氮含量高；碱解氮和有效锌明显高于临界水平；西南稻区大面积为低磷区域(<10mg kg1),土壤有效磷表现为亏缺；土壤pH、速效钾、CEC和有效硅均表现为东南低、西南高；东南稻区水稻土缺钾明显,pH和CEC偏低。(2)黄泥田土壤质量评价的最小数据集包括全氮、速效钾、有效硅、微生物量碳和菌根真菌(AMF)。整个黄泥田研究区域,土壤有效磷、有效硅和有效锌均表现为盈余,速效钾则表现为亏缺。较低水平的全氮、速效钾和有效硅是低产黄泥田的主要产量限制因子。(3)潜育化水稻土质量评价的最小数据集包括全氮、速效钾、微生物量碳、β-葡萄糖苷酶、总细菌和AMF。整个研究区域土壤碱解氮和有效磷表现为盈余,速效钾则表现为亏缺。较低水平的全氮、速效钾和微生物活性是低产潜育化水稻土的主要产量限制因子。(4)反酸田土壤质量评价的最小数据集包括微生物量碳、有效锌、pH、有效硅和全氮。整个反酸田研究区域,土壤有效磷和有效锌均表现为盈余,土壤速效钾和有效硅则表现为亏缺。较低水平的pH、有效硅和全氮被认为是低产反酸田的主要产量限制因子。(5)白土质量评价的最小数据集包括脱氢酶、全氮、pH、有机质和AMF。整个研究区域,土壤有效磷、有效硅和有效锌含量均表现为盈余,土壤速效钾则表现为亏缺。较低水平的有机质、全氮、速效钾和pH是低产白土的主要产量限制因子。(6)冷浸田质量评价的最小数据集包括全氮、总细菌、磷酸酶、有效磷和AMF。整个研究区域,碱解氮、有效硅和有效锌表现为盈余,有效磷则表现为严重亏缺。较低水平的全氮、有效磷和速效钾是低产冷浸田的主要产量限制因子。更多还原

【Abstract】 The low-yield paddy soil in south China has a large potential of increasing crop production because of its various types and large area. The improved knowledge of soil quality assessment involving nutrient characteristics and limiting factors is crucial to designing more effective farming systems and thus improving rice production. Many previous studies evaluated soil quality status using physico-chemical properties, but rarely focused on soil biological properties. Moreover, little information is available for a systematic research of soil quality assessment involving high-, medium-and low-productivity paddy soil at a regional-scale. Therefore, the present study focuses on evaluation of low-yield paddy soils including yellow clayey paddy soil, acid sulfate paddy soil, water-logged paddy soil, albic soil and gleyed paddy soil, and the key soil physical, chemical and biological properties were measured to make the soil quality assessment more comprehensively and accurately, and find out the constraints limiting the rice production. The main results and progress are listed as follows:(1) The paddy fields in south China have following characteristics:soil organic matter (SOM) and total nitrogen (TN) exhibit high levels in soils; the concentrations of alkali-hydrolyzable nitrogen (AN) and available zinc (AZn) are significantly higher than their critical levels, indicating an obvious surplus; a large area of southwest China shows a deficiency of available phosphorus (AP)(<10mg kg-1); Soil pH、available potassium (AK), cation exchange capacity (CEC) and available silicon (ASi) exhibit the similar trends in spatial distributions with high concentrations in the southwest China and low concentrations in the southeast. Paddy fields in southeast China are characterized by severe AK deficiency and low status of pH and CEC.(2) The refined minimum data set (MDS) for soil quality assessment of yellow clayey paddy soil included the following indicators:TN, AK, ASi, microbial biomass carbon (MBC) and arbuscular mycorrhizal fungi (AMF). The whole study area is characterized by sufficient AP, ASi and AZn, but deficiency in AK. Low levels of TN, AK and ASi are considered to be the major constraints limiting the rice production of yellow clayey paddy soil.(3) The refined MDS for soil quality assessment of gleyed paddy soil included the following indicators:TN, AK, MBC, β-glucosidase, total bacteria (TB) and AMF. The whole study area shows a surplus of AN and AP, but deficiency in AK. Low levels of TN, AK and soil microbial activity are considered as the primary constraints limiting the productivity of gleyed paddy soil.(4) The refined MDS for soil quality assessment of acid sulfate paddy soil included the following indicators:MBC, AZn, pH, ASi and TN. The whole study area is sufficient in AP and AZn, but deficiency in AK and ASi. Low levels of pH, ASi and TN are regarded as the important constraints limiting the productivity of acid sulfate paddy soil.(5) The refined MDS for soil quality assessment of albic soil included the following indicators: dehydrogenase, TN, pH, SOM and AMF. The whole study area is characterized by high concentrations of AP, ASi and AZn, but deficiency in AK. Low levels of pH, TN, SOM and ASi are considered to be the major constraints limiting the rice production of albic paddy soil.(6) The refined MDS for soil quality assessment of water-logged paddy soil included the following indicators:TN, TB, AP, phosphatase and AMF. The whole study area is rich in AN, ASi and AZn, but deficiency in AP. Low levels of TN, AP and AK are considered as the major constraints limiting the rice production of water-logged paddy soil.更多还原