【作者】 王小利；

【导师】 周建斌；

【作者基本信息】 西北农林科技大学 ， 植物营养学， 2003， 硕士

【摘要】 速效性肥料施入土壤后虽然养分可以直接为作物吸收利用，但肥效持续时间短，一次施用容易伤害作物；另外，未被作物吸收利用的养分容易发生淋溶、挥发、固定等损失，影响肥效，污染环境。通过物理、化学等方法对速效性肥料进行处理得到的控释肥料，具有养分释放与作物吸收养分相协调的特点，是提高肥料利用率的有效途径之一。肥料成本高、养分释放与作物吸收养分尚未有效协调，是目前多数控释肥料面临的突出问题。本研究在对不同肥料养分释放特性评价及其与环境条件关系研究基础上，采用回归混料设计，通过室内模拟和盆栽试验方法，系统地研究了不同肥料及其配比养分的释放特性及肥效，旨在为研制既可达到协调肥料养分的释放，又能降低肥料成本，因土因作物施用的控释肥料提供理论依据。研究取得了如下主要结论： 1．供试7种包膜控释肥料养分初期溶出率均＜12.0％，微分溶出率在0.26％～2.49％之间，符合国际公认标准。其中两种控释肥料（Sample₁和Sample₂）的养分微分溶出率较低，单独施用可能会造成作物生育前期供肥不足。 2．温度与水分对普通尿素和包膜尿素氮素释放均有明显影响。温度对包膜控释肥料养分释放的影响因含水量不同而不同，而普通尿素培养处理差异不显著。一定温度范围内，温度升高包膜尿素处理土壤NH₄⁺-N浓度也升高，而普通尿素处理土壤NH₄⁺-N浓度反而下降。高含水量时普通尿素处理NH₄⁺-N浓度高峰期持续时间相对较长，低含水量时两种肥料在培养结束时土壤中仍能维持一定浓度的NH₄⁺-N。水分对土壤NO₃^--N浓度变化的影响因温度和肥料不同而存在显著差异。高含水量下土壤矿质氮浓度在培养5～20d内明显下降。 3．不同释放特性的氮肥配合，土培期间各处理土壤NH₄⁺-N含量均随时间逐渐降低，而NO₃^--N和矿化N含量随时间逐渐增加。不同处理相比，整个培养期内单施尿素处理土壤NH₄^--N、NO₃⁺-N及矿质态氮含量最高；两种控释肥单施或配施土壤NH₄⁺-N、NO₃^--N及矿质态氮含量最低；尿素与控释肥配施，土壤NH₄⁺-N、NO₃^--N及矿质态氮含量界于二者之间。不同时期内土壤NH₄⁺-N的来源不同，0～20d内，尿素对土壤NH₄⁺-N含量贡献最大；30～50d内，土壤NH₄⁺-N主要来自控释肥料D60；整个培养期内尿素对土壤NO₃⁺-N和矿质态N的贡献均最大。肥料配比中随着尿素比例的减少，土壤NH₄⁺-N、NO₃^--N及矿质态N均逐渐减少。 4．控释肥料及其配比养分释放特性可用一级动力学方程描述。常数k既可反映控释肥料氮素释放速率的大小，也可描述肥料的配比效应。与单施控释肥处理相比，尿素与控释肥配施，氮素释放速率增加96.0％～180.0％，释放期缩短20d～79d。 5．与单施速效肥或控释肥相比，速效肥料与控释肥料配施明显增加了玉米的前期生长量。生育后期施用控释肥或速效肥料与控释肥料配施比单施速效肥料处理的生物学和经济学产量均显著增加。与单施速效肥相比，速效一控释肥配比施用，还增加了植株叶面积、根系长度和根系活力，提高叶片的光合能力和作物对氮磷钾养分的吸收量。速效肥料与控释肥料配施玉米籽粒产量与单施控释肥处理相近，但由于降低了控释肥的用量，无疑可以降低肥料成本。 在前人研究的基础上，本文有以下创新或新见解: 1.首次将混料设计方法用于控释肥料的研究，根据得到的回归方程，对不同肥料的养分释放特性进行了比较。提出了等值线图示法和计算机寻优法两种确定最佳肥料配比的方法。 2.提出了“肥料接力法”的概念，这一方法通过将养分释放特性不同的肥料（速效一控释肥）相混合的方法，来有效地调节肥料供肥与作物需肥的关系。其优点表现在可以根据土壤营养状况及作物需肥特性等，灵活调整控释肥料配方，调控养分供应的强度和数量，调节养分供应的形态，如N比一和NO3一N的供应比例，满足不同情况下的养分供应;同时又减小了控施肥料的用量，可以降低肥料成本。更多还原

【Abstract】 The availability of traditional chemical fertilizers is high, and can be readily uptake by crops. However, high application of the fertilizers may damage the growth of plants, and the duration of nutrient supply is also limited. When the nutrients added to soil are not absorbed by crops, they may lose from the soil through leaching, volatilization, and fixation, inducing low recovery of fertilizer and polluting the environment. Controlled-release fertilizers (CRFs), manufactured from traditional chemical fertilizers by physical or chemical methods, have been defined as a kind of fertilizer whose nutrient release could match the crop need, and are considered as an effective way to increase the nutrient efficiency. The high cost and the poor nutrient match are two problems for most of CRFs. In this study we used different incubation methods and pot experiments to evaluate the nutrient release characteristics from different CRFs, and determine the effects of temperature and water in soil on the release of CRFs. The mixture design was also used to determine the nutrient release characteristics from normal fertilizer (urea) and different CRFs. The main goals are to decrease the cost of fertilization with CRFs and to produce fertilizer-plant-well-matched CRFs. The main results are as follows:1. The initial solubility of seven kinds of CRFs was lower than 12.0%, and their differential solubility was in the range of 0.26% - 2.49%, which match the international standards.2. There were interactions between temperature and water content on nitrogen released from both urea and polymer-coated urea. The effect of temperature on nutrient release of CRFs varied with the water content in soil; yet for urea the effect of temperature was not obvious. As the increase of temperature, the NH 4+ in soil with CRFs increased; on the contrary, the NH4+ in soil with urea decreased. When water content in soils was high, the high level of NH4+ in soil remained a long time during incubation; when water content in soil was low, the NH4+ remained in soil for all treatments even at the end of incubation. The nitrate concentration in soil was related with temperature and fertilizers. The concentration of soil mineral nitrogen decreased significantly during the 5th to 20th days in the incubation.3. The NH4+ in soil of all treatments designed with the simplex centroid designmethod decreased in the incubation period, and soil nitrate and mineral nitrogen increased. The contents of ammonium, nitrate and mineral nitrogen in soil added with urea were highest among all treatments, and lowest contents of their kinds of N were found in the treatments when only two kinds of CRFs were added separately or together. When urea was added with CRFs the contents of ammonium, nitrate and mineral nitrogen in soil were between with urea and CRFs during the whole incubation. Soil ammonium mainly came from urea during the first 20 days, and during the 30th to 50th days the NH4+ was considered from CRFs (D60). And soil nitrate and mineral nitrogen mostly came from urea during the whole incubation; and their contents decreased while the proportion of urea in the fertilizer mixture was decreased.4. The first-order kinetic equation could be used to fit the nutrient release characteristics of different treatments. Both the nitrogen release rate and their combinational effectiveness can be reflected by velocity coefficient (k). In comparison with only application of CRFs, applying urea combined with CRF significantly increased the rate of nitrogen release, with an increase from 96.0% to 180.0%, and shortened the nitrogen release period from 20 to 79 days.5. Compared to the single application of readily available fertilizers or CRFs, the application of the combination of readily available fertilizers and CRFs significantly increased the crop biomass in the early growth period. In the late growth period, the application of CRFs or the combination of readily available fertilizers and CRFs increas更多还原