【作者】 林清火；

【导师】 屈明； 罗微； 林钊沐；

【作者基本信息】 西南农业大学 ， 土壤学， 2004， 硕士

【摘要】 肥料是农业生产中最重要的生产资料之一。据统计目前我国肥料利用率氮肥仅为20％～50％、磷肥为15％～25％、钾肥为30％～35％。每年所施化肥的一半左右由各种途径损失。因此，化肥养分的损失是一个严重的问题，它不仅浪费肥料资源，降低施肥效益，而且给我们的环境带来不良后果。在化肥损失过程中，淋溶损失是重要途径之一。特别是在降雨量大、高渗透性、低阳离子交换量的土壤上，淋失作用是导致化肥利用率低的主要原因。 海南省砖红壤分布的地区年平均气温23～24.5℃，年平均降雨量1400～2700mm。这种气候条件使砖红壤成为强酸性土壤，阳离子交换量和盐基饱和度低，铝饱和度高，化肥通过淋溶损失过程就更为突出。要提高化肥在砖红壤中的利用率，研究其淋溶及转化特征则显得极为重要，如淋失速度、淋失量、转化途径等，然而迄今为止，在砖红壤上这方面研究报道较少，且主要是针对砖红壤中矿化出来的营养元素，而缺乏对化肥在砖红壤上淋失特征的研究。 本研究通过室内土柱模拟和盆栽试验，探讨不同施肥量、肥料品种以及种植模式等对化肥在砖红壤上淋失的影响，并建立相应模型，预测肥料养分在砖红壤中的损失趋势。其试验结果如下： 在不同尿素施用量情况下，各处理中20cm处渗漏液中NH₄⁺-N最高浓度值与施肥量密切相关，但60cm和120cm处渗漏液中NH₄⁺-N浓度与施肥量关系不大。对不同氮肥品种NH₄⁺-N淋失特征研究表明：各处理渗漏液中NH₄⁺-N最高浓度值，尿素最高，复合肥最低，复混肥和碳铵大致相等；根据种植作物（玉米）处理与对照（未种作物）比较，种植玉米可以显著的减少NH₄⁺-N的淋失；各施肥处理中NH₄⁺-N淋溶过程以抛物线方程Y_l^1/2=a+bt的拟合效果最优；各种氮肥NH₄⁺ -N的淋溶率，尿素＞复混肥＞碳铵＞复合肥。西南农业大学硕士学位论文摘要-鱼旦.月阵亘.口归.口...口 在不同尿素施用量情况下，各处理渗漏液中20cm处入O三一浓度变化趋势相似;60c“处渗漏液中各处理N0三一N最高浓度值均显著高于对应的Zoom处;120cm处渗漏液中各处理No歹一N浓度在39d前无显著变化，之后迅速上升并且随着施肥量的增加而增大，其最高浓度值与施肥量的关系可用方程y=0 .5257x十138.2来表示·从12ocm处N0丁一N累计淋失量来看，其累计淋失量与施肥量的关系可以用下式来表示:y=0 .478x+204.26:用方程进行拟合NO三一N淋失量Y:（gN）与时间t（d）的关系，其中处理1用直线方程Yt二a+bt拟合效果最好，处理2、处理3和处理4用幂函数方程inyt:a+bln拟合效果最适宜。 各氮肥品种在砖红壤中转化形成No牙一N的过程可分为三个阶段:前期平缓阶段、中期上升阶段和后期下降阶段。将No歹一N淋溶量Y:（gN）与时间t（d）的关系进行拟合，结果表明尿素、碳按和复合肥以抛物线方程Y、’‘2二a+bt拟合效果最好，而复混肥以双曲线方程l/丫=a+bl/t的拟合效果最优;从种植玉米处理各氮肥品种以N0丁一N形态的淋溶总量来看，尿素、碳按、复合肥和复混肥淋溶总量分别为1.67、1.58、1.79和2.76gN，分别占施入的氮素的42.1钱、39·oo%、45·2溅和69. 70%，但在本试验条件下，种植玉米与未种植处理N0至一N淋溶总量无显著差异。 钾在砖红壤表层土中运移速度较快，灌水30Inln即3d后，ZOc.处即有肥料中K’的淋出;6Oc口处渗漏液中K’浓度在39d后随着时间的推移逐渐下降，淋失浓度与施肥量表现出正相关:45d后120cln处渗漏液中K+浓度才随着施肥量的增加而上升，推侧其运移速度为2.7。m/d。K-在120cm处的累计淋失量与施肥量成正相关，其施肥量与累计淋失量可用下式来表示:y=35.58+0.0328x。应用方程Iny:=a+blnt可拟合钾肥在砖红壤中120em处的淋失过程。 从不同氮肥品种对钾在砖红壤中淋溶影响的结果来看，渗漏液中K+浓度的大小顺序为复混肥>碳馁>尿素>复合肥;从不同种植模式来看，休闲处理渗漏液中K+浓度均高于对应的种植玉米处理。对各处理渗漏液中K’淋溶量丫.随时间t的变化用方程进行拟合，结果表明CK、碳按和复混肥处理，以双曲线方程l/Y二a+bl八拟合效果最好，而尿素和复合肥处理则以抛物线方程Y，’/2=a十bt拟合效果最好。更多还原

【Abstract】 Fertilizer is one of the most important factors to the agriculture development. According to the current statistics the efficiency of N, P and K fertilizer utilization in the our country is only 20%-50%, 15%-25% and 30%-35%.There are almost half of the applied fertilizer lost by every kind of path annually. Therefore, the loss of fertilizer nutrient is a serious problem. It not only waste fertilizer resources, lower fertilizer utilization ratio, but also give some bad consequence to our environment. Published have reported that in high rainfall .highly permeable, low-cation exchange capacity(CEC) regions, rapid losses of native and applied fertilizer through leaching are believed to be a major cause of the low efficiency of fertilizer utilization.Mean annual temperature and mean annual rainfall at latosol region in Hainan are 23-24.5℃ and 1400-2700mm. This climate make latosol usually as acidic, low levels cation exchanges capacity and low lever base cations, high levels of exchange Al ,with a high potential for leaching of plant nutrients. To increase the fertilizer utilization in the latosol, studying the fertilizer leaching and conversion characteristic ,such as leaching velocity Reaching amount, conversion path etc, seem to be extremely important. However, hitherto the study of fertilizer nutrient leaching characteristic are scanty, only some on the mineral nutrient derived from latosol.The objective of this study was to estimate the losses of nutrients in the labgoratory by leaching soil columns containing disturbed soils, measuring the impact of different quantity fertilized applied .different fertilizer sorts and plant system, establishing the comparative model .evaluating fertilizer leaching tendency . Some results are as follows:The highest concentration of NH 4+ -N in leachate is closely related with Urea quantity applied at 20cm depth, but not different significantly related at 60cm and 120cm depth. The leaching characteristics of NH 4 -N with different nitrogen fertilizer sorts are studied, results are as follows: Planting com can significantly decrease the leaching amount of NH4+-N from fertilizer nutrient; Comparing the tallest concentration of NH4+ -N in the leachate with different nitrogen fertilizer sorts, Urea is the tallest, composed fertilizer is the lowest, ammonium-bicarbonate and complex mixed fertilizer are the same and in the midst. The relationship between the accumulation amount of NH4+-N leaching and the time could be expressed as equation Yt1/2=a+bt with fertilizer applied treatment. Comparing the leaching ratio of different nitrogen fertilizer sorts, Urea > complex mixed fertilizer > ammonium-bicarbonate > composed fertilizer.The concentration of NO 3- -N transformation tendency in the leachate at 20cm depth is similarity in different Urea quantity applied; The highest concentration of NO 3--N in leachate at 60cm depth with different treatment is significantly higher than the corresponding ones at 20cm depth; The concentration of NO 3- -N in the leachate at 120cm depth is not significantly different before 39 days, then quickly ascending correspondingly with the Urea quantity applied. The relation between the highest concentration of NO3--N and fertilizer quantity applied can be expressed with regression equation y=0.478x+204.26; The relation between the accumulation amount of NO3--N leaching with time could be expressed by equation model Yt=a+bt best with treatment 1 and could be expressed by equation model lnYt=a+bln best with treatment 2, treatment 3 and treatment 4.Leaching of NO3- -N with different fertilizer sorts can be divided into three stages: equilibrium, ascending, descending. Used dynamics equation to express the relation between the accumulation amount of NO 3 -N leaching and time: Urea, ammonium-bicarbonate and composed fertilizer can be expressed as equation Yt1/2=a+bt, complex mixed fertilizer can be expressed as equation 1/Y=a+bl/t. The accumulation leaching quantity of NO 3- -N with Urea, ammonium-bicarbonate, composed fertilizer and complex mixed更多还原