【作者】 杨曾平；

【导师】 张杨珠；

【作者基本信息】 湖南农业大学 ， 土壤学， 2006， 硕士

【摘要】 通过野外调查采样和室内分析测定，研究了湖南省几个典型高产稻作区稻田土壤的立地条件和主要肥力特性；并以湖南省醴陵市的高产健康稻田土壤——河沙泥和红黄泥为供试土壤，以早稻品种湘早籼17号、晚稻品种金优207为供试作物，采用盆栽试验，研究了在不合理施肥条件下健康稻田土壤的退化过程。主要结果如下： 1．供试健康稻田土壤均分布在海拔40-90m之间的地势低平、开阔的丘陵谷地和冲积平原；其成土母质分别为石灰岩风化物、河流沉积物和第四纪红色粘土；土壤质地均为中壤土至轻粘土，砂粘适中。供试土壤总体养分状况良好，尤以有机质和氮素含量高于其他耕地土壤，但土壤有效硅含量大部分属中低水平，其中醴陵的浦口和白兔潭、浏阳永安的土壤有效硅含量均低于缺硅临界值。不同母质发育的土壤相比，以石灰岩风化物发育的水稻土肥力水平较河流沉积物和第四纪红色粘土发育的水稻土高。在剖面土壤中，养分和粘粒含量分布呈现随深度增加而降低的趋势，质地上重下轻，pH值则由上而下呈升高趋势。 2．合理和适量施肥是提高河沙泥和红黄泥土壤养分含量，增强土壤供肥能力的有效措施。过量施肥不但导致肥料浪费，还对水稻生长产生负面影响并造成环境污染。盆栽试验各处理土壤有效硅含量较低这一结果表明，水稻生产中施用硅肥已是必需措施。 3．不合理施肥措施均会促进河沙泥和红黄泥土壤氮素、磷素、钾素养分的渗漏损失，尤以化学肥料的不合理施用更甚。土壤氮素养分的渗漏损失主要发生在插秧后60天以内，磷的渗漏损失主要发生在插秧后15天之内，钾的渗漏损失主要发生在插秧后30天内。因此，化肥的不合理施用是造成农田生态系统养分淋失和水体富营养化的重要因素，施用有机肥后经渗漏造成磷素垂直移动而导致对水环境的威胁尤其应引起注意。 4．对于河沙泥，N、P、K的配施有提高水稻每穗粒数和成穗率的作用，偏施N肥则会降低每穗粒数；磷肥的施用可以增大水稻生物量；钾肥的施用有提高水稻株高、穗长、生物量和籽粒产量的作用；而过量施用化肥和不施肥处理中，水稻有效穗和分蘖数均减少：有机肥(稻草)的施用可提高水稻株高、穗长、每穗粒数、经济系数、成穗率、生物量和籽粒产量，而对有效穗、千粒重、结实率没有明显的促进作用。 5．对于红黄泥，施肥可提高水稻生物产量和籽粒产量，尤其是有机肥的配合施用效果更好，不施肥则导致生物产量和籽粒产量均下降；N、P、K肥配施有提高水稻株高、穗长、每穗粒数、千粒重的作用，偏施N肥则使株高降低；而过量施用化肥和不施肥处理均使有效穗、分蘖数、结实率和经济系数降低；偏施肥或不施肥可使水稻千粒重下降；有机肥(稻草)的施用能提高水稻株高、穗长、每穗粒数、经济系数、结实率、成穗率、生物量和籽粒产量，对千粒重没有明显的促进作用。更多还原

【Abstract】 By field investigation and sampling, and laboratory analysis, this paper was an attempt to study the local conditions and fertility properties of paddy soils of several typical areas of rice production in Hunan Province. Two of the tested soils, alluvial sandy earth and reddish yellow clayey earth, were used to study the degradation process of the paddy soils in relation to irrational fertilization practices with pot experiment. The main results are as follows:1. The paddy soils are developed from the weathering product of limestone, the river alluvium and Quaternary Red Clay, respectively. The soil texture ranges from medium loamy to lightly clayey, and it is suitable to crop growth. The nutrient status of the soils were good on the whole, the contents of organic matter, nitrogen, phosphorus and potassium were all on the higher level, and especially the contents of organic matter and nitrogen were much higher than that of other cultivated soils. However, content of available silica was at the lower level. Among them the paddy soil developed from the weathering product of limestone has much higher nutrient contents than the paddy soils developed from river alluvium and Quaternary Red Clay does. In the profile, the content of nutrient in most soils always decreases with the increase of depth except pH.2. Fertilization is one of the efficient measures to increase the soil nutrient content, improve the soil capacity to supply nutrient. Excessive fertilization is wasteful and would do harm to rice growth and pollute the environment. The low available silica content in the soils of various treatments indicates that silica application in rice production is necessary.3. All irrational fertilization treatments facilitate leakage loss of N, P, and K nutrient. N leaching appears within 60 days after transplanting rice; P leaching appears within 15 days, and K leaching, within 30 days mostly. Application of inorganic fertilizer is one of the important factors that can lead to water eutrophication. It is noticeable that serious P vertical leaching caused by application of organic manure is threatening to water environment.4. In alluvial sandy earth, combined application of N, P and K fertilizer can increase grains per panicle and effective panicle percentage of rice; preferential application of N fertilizer can decrease grains per panicle of rice; application of P fertilizer can increase biomass production of rice; application of K fertilizer can increase plant height, panicle length, biomass production and grain yield of rice; the treatments with excessive application of chemical fertilizer or no fertilization can decrease effective panicle and tillers number; application of organic manure (straw) can increase plant height, panicle length, grains per panicle, harvest index, effective更多还原