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吉林省主要耕作土壤中钾的固定与释放 总被引:4,自引:0,他引:4
通过X—射线衍射、室内模拟实验及常规分析研究了吉林省主要耕作土壤中钾的固定与释放。结果表明,土壤对钾的固定与释放与土壤的矿物组成有关,3种土壤的固钾量均随钾加入量的增加而增大,而固钾率则随施钾量的增加而逐渐下降。随钾加入量的增加,固钾量和固钾率均有黑土>白浆土>黑钙土的趋势。土壤释钾量有黑钙土>黑土>白浆土的趋势。相关分析表明,蒙脱石、蛭石为主要的固钾矿物,而伊利石为主要的释钾矿物。 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(22):2661-2675
The reserve of nonexchangeable potassium (K), threshold levels for release and fixation of intermediate K, and the Gapon exchange selectivity coefficient for K to calcium (Ca) and magnesium (Mg) exchange were studied in soils of widely varying properties, with a view to optimize the efficiency of native as well as added fertilizer K for plant uptake. The illite-dominated soils recorded greater reserve of nonexchangeable K and showed greater cumulative K release. The threshold values of soil K parameters for release and fixation of intermediate K were found to vary with the change in background electrolyte concentration. The soils dominated by illite were found to possess greater K threshold release and fixation values. In general, the fixation threshold level was greater than release threshold level. The Gapon exchange selectivity coefficient for K to Ca exchange revealed that K ions were more tightly held in the specific sites than in planar sites. 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(12):1404-1414
Potassium (K) release and kinetics were studied in soils of north western India varying in soil properties. Mathematical equations were tested for their applicability to describe K release in the alluvial soils. The major portion of total K was released within 1 h of the reaction. The initial rapid K release was followed by a slower rate of K release. The linear equation adequately described the K release kinetics. The next best fit to satisfactorily describe the reaction rates of K release was the first order equation. There existed two separate first order equations indicating different rates of K release. Soils having higher native potassium and clay released higher amounts of K and at a faster rate. However, the first order equation showed that the faster rate of reaction might be inhibited by higher amounts of clay, probably because of the restrictive properties of illites. 相似文献
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Potassium (K) release from sources that are not initially exchangeable is attributed to depletion of interlayer K of micas and clay minerals or weathering of feldspars. The aim of the present study was to estimate the K release from interlayer K. Soil samples from 17 field experiments in ley on a range of mineral soils in Norway were used in the study. The change in K‐fixation capacity was used as an estimate of depletion of interlayer K. It was assumed that the increase in K‐fixation capacity during 3 yr of cropping was equivalent to the amount of K depleted from the interlayer positions. Mean K fixation increased in the majority of the soils during 3 yr of grass cropping both with and without K application. The increase in K fixation indicated that without K application, the K uptake from interlayer K amounted to 43%, 28%, and 26% of the K yield for clay soils, high‐K sandy soils, and low‐K sandy soils, respectively. Including K uptake from exchangeable K in the topsoil and from subsoil, the explained K uptake amounted to 79%, 69%, and 81% for the three groups of soil, respectively. Simple linear‐regression analyses showed that the change in K fixation during 3 yr of grass cropping was best explained by the percentage of clay in the soil. 相似文献
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广东不同母质水稻土供钾特性的评价 总被引:1,自引:1,他引:1
应用生物耗竭法并结合模拟试验综合评价了广东5种主要母质发育水稻土的供钾特性。研究结果表明:(1)2mol/L冷HNO3法提取的有效钾与水稻吸钾量间的相关性最好,建议用2mol/L冷HNO3法提取的钾来评价土壤的供钾状况。(2)1mol/L沸HNO3法提取的非交换性钾含量在耗竭后高于耗竭前的水平,与水稻吸钾量相关性很小或呈负相关,不适宜用来评价耗竭土壤。(3)广东5种主要母质发育的水稻土供钾能力大小顺序为:三角洲沉积物发育水稻土>花岗岩发育水稻土>砂页岩发育水稻土>石灰岩发育水稻土>玄武岩发育水稻土。该试验结果可供水稻合理施用钾肥作参考。 相似文献
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《Land Degradation \u0026amp; Development》2017,28(5):1696-1703
An 8‐month greenhouse experiment with ryegrass (Lolium perenne L.) examined the relationship between the dynamics of potassium (K) reserves in soil and changes in clay minerals, using X‐ray diffraction. The capacity of soil to release K was consistent with its ability to supply it and was the highest in the soil samples collected from Laiyang (H1T2a), Harbin (H1T1) and Beibei (H2T4), followed by the sample from Jiangyan (H1T2b), and the lowest in the samples from Gao'an (H2T3a) and Wangcheng (H2T3b). Removal of soil K decreases the intensity of reflections for illite and increases that for interstratified clay minerals. The centre of gravity values of the clay fractions was significantly negatively correlated to the depletion of soil K reserves, as ascertained through chemical extraction or through plant action. The quantitative regression equations between the centre of gravity values and the dynamics of soil reserves of K can be used for predicting the release and plant availability of K even without growing a crop. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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Akram FATEMI 《土壤圈》2017,27(6):1105-1115
Knowledge on potassium ion(K~+) release from soils makes K fertilizer recommendation more efficient and profitable.Kinetics of K~+release under continuous fertilization of no fertilizer(CK), urea(N), triple superphosphate(P), and urea + triple superphosphate(NP) without K fertilizer was investigated in calcareous(chloritic and kaolinitic) soils on the Miandarband Plain in Kermanshah Province of Iran.The results showed that the kinetics of K~+release included an initial reaction and a slow reaction.The phosphateand NH_4~+-induced K~+release followed the same rate process during the rapid(2–192 h) and slow release periods(192–1 090 h).There were no significant differences in the cumulative K~+released from the chloritic and kaolinitic soils among all the treatments.The cumulative K~+released was positively correlated with P adsorption capacity for the chloritic(r = 0.461, P 0.05) and kaolinitic soils(r = 0.625, P 0.01), and negatively correlated with K fixation potential for the chloritic(r = 0.720, P 0.01) and kaolinitic soils(r =-0.513, P 0.01).There was a significant(P 0.001) interactive effect of K fixation potential × P adsorption capacity on the cumulative K~+released for both soil groups.The initial release rate(IRR) index(a·b, where a and b are the rate coefficients of the power function equation) for the chloritic soils was significantly(P 0.05) higher under applications of P and NP than N and CK.The IRR index values among different fertilization treatments were in the order of NP = P N = CK for the chloritic soils, and N =P NP CK for the kaolinitic soils.This study showed that K fixation potential and P adsorption capacities controlled K~+release from soils.This information will be helpful for precise fertilizer recommendations for the studied soils. 相似文献
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Nitrogen Fractions and Release in the Sediments from the Shallow Lakes in the Middle and Lower Reaches of the Yangtze River Area, China 总被引:3,自引:0,他引:3
Shengrui Wang Xiangcan Jin Lixin Jiao Fengchang Wu 《Water, air, and soil pollution》2008,187(1-4):5-14
Different nitrogen (N) fractions from 14 sediments from the shallow lakes in the middle and lower reaches of Yangtze River area before and after N release experiments were investigated, and the content of different N fractions, and contribution of different N fractions to the N released from sediments were also studied. Ion-exchangeable form (IEF–N), carbonate form (CF–N), iron-manganese oxide form (IMOF–N) and organic matter-sulfide form (OSF–N) accounted for 2.72~17.67%, 0.47~4.43%, 1.18~3.49% and 31.05 to 71.61% to total N, respectively. The N released was higher than 50% from IEF–N, approximately 35% from OSF–N, 6 and 8% from CF–N and IMOF–N on the average. Approximately 27.32~70.02% of IEF–N, 10.37~32.11% of CF–N, 11.37~33.43% IMOF–N and 2.02~8.19% OSF–N were released. For the sediments that were slightly polluted, IEF–N was the main N fraction that may be released and its contribution to total N released was more than 63.07%, for the sediments that TN was higher than 3,540.27 mg·kg?1, OSF–N would become the main N fraction that can be released and its contribution to total N released was more than 45%. 相似文献
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Laboratory Experiments on Phosphorous Release from the Sediments of 9 Lakes in the Middle and Lower Reaches of Yangtze River Region, China 总被引:1,自引:0,他引:1
Xiangcan Jin Shengrui Wang Qingyun Bu Fengchang Wu 《Water, air, and soil pollution》2006,176(1-4):233-251
Phosphorus (P) has been recognized as the most critical nutrient limiting lake productivity. In addition, P release from sediments may have a significant effect on the water quality and may result in continuous eutrophication in eutrophic lakes. In this study, P release kinetics from sediments and their relationship with sediment composition were investigated, eutrophication risk index (ERI) and degree of phosphorus saturation (DPS) were used to evaluate the eutrophication risk of the studied sediments, and their influencing factors were also discussed. The results show that total P (TP), organic matter (OM), Al2O3+Fe2O3 and the percentage of sand particles were the most important factors affecting the ability of P sorption. P release process was similar for all studied sediments, consisting of the quick and slow reaction processes. The quick reaction mainly occurred within 0.5 h, and slow reaction after 0.5 h. P release occurred within 20 h and then reached the dynamic equilibrium. P release process was slower than P sorption process. Three models (Power function model, Parabolic diffusion model and Simple Elovich model) can satisfactorily describe the P release kinetics. P release was mainly affected by TP, OM, sorbed total phosphorus (STP), DPS and sand particles, and quick P release was mainly a physical process. For the slightly polluted sediments, Al2O3+Fe2O3 mainly restrained P release. But for the heavily polluted sediment both OM and Al2O3+Fe2O3 promoted P release. Both DPS and ERI can be used to evaluate the P-induced lake eutrophication risk, and their threshold values were 6.6% and 25%, respectively. Based on the assessment by DPS and ERI, most of the studied sediments were in eutrophication risk for the studied sediments. For the heavily polluted sediments, Al2O3+Fe2O3 was significantly correlated with DPS. But for the slightly polluted sediments it was significantly negatively correlated with DPS and OM, and the sand particle percentage was negatively related to ERI. 相似文献
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华北与西北地区典型土壤固钾能力差异研究 总被引:1,自引:0,他引:1
试验在我国华北和西北小麦玉米种植地区进行,研究了几种典型土壤在连续13年的K肥施用及小麦秸秆还田条件下耕层土对外源K素的固定能力差异.结果表明:相比常年只施NP肥处理,连续施用K肥或秸秆还田可显著降低土壤对外源K素的固定量,土壤固K量随环境溶液中K素浓度的增加而增加,但固定率下降.随土层变深,各定位点土壤固K量和固K率均随之增加,华北两定位点相对明显.轮作地区各处理0 ~ 20 cm土层土壤对外源K素的固定量(率)均远高于原始土壤,而单作区土壤的固K量(率)稍高或低于原始土.土壤固K能力表现出地带性规律,整体看取自华北两个定位点的土壤对外源K的固定能力强于取自西北两个定位点的土壤. 相似文献
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石羊河流域中下游沙漠-河岸过渡带土壤特征研究 总被引:2,自引:0,他引:2
对石羊河中游断流段(DS)、泉水溢出段(SOS)及下游水库以上丰水段(WSA)和水库以下干涸段(DSB)沙漠-河岸过渡带0-200cm土层土壤理化性质进行了调查和分析.结果表明:土壤含水量的大小顺序为WSA>SOS>DSB>DS.雨季降水对WSA段土壤含水量的影响很小,对其他河段土壤含水量影响较大,其对土壤水分的贡献主要在10-40cm土层;土壤容重大,且表层大于下层.pH值7.70~8.55,表层低于下层.pH值从上游至下游依次减小,其变化与有机质含量和盐分组成及总量有关;土壤养分贫瘠,有机质、全氮、速效磷含量低,速效钾含量高.WSA段土壤有机质和全氮含量最大,DS段土壤速效磷和速效钾含量最大;土壤含盐量从上游至下游依次增大.WSA和DSB段土壤已盐化,盐化类型分别为氯化物-硫酸盐盐化土和硫酸盐-氯化物盐化土.由于同时受水力和风力的影响,石羊河中下游沙漠-河岸过渡带土壤性质变异大,各河段之间的差异大多都不显著. 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(16):2013-2022
ABSTRACTPotassium (K) plays several key roles in plant metabolism and crop productivity. Non-exchangeable K (NEK) makes K available in soil and to the crops. Impact of integrated use of organic and inorganic fertilizers on NEK release was studied in an ongoing long-term fertilizer experiment (LTFE) under rice-wheat cropping system. The experimental plots in the field were laid out following a randomized complete block design (RCBD) with eight treatments and three replications. Addition of K increased the release of NEK, but integrated use of manure with fertilizers increased K release of NEK from soils than the use of inorganic K alone. The maximum NEK (102 × 10–2 cmol kg?1 of soil) was released under 100% NPK with Farm Yard Manure (FYM) treatment and the minimum (93.9 × 10–2 cmol kg?1 of soil) under 100% NP-treated soils. Four kinetic models, parabolic diffusion, first order, power function, and Elovich, were tested for characterizing K release data and Elovich model provided the best fit (R2 = 0.96–0.97). Available K status in soils, rice yield, and plant K uptake increased significantly with the increase in NEK release rate. Our research outcomes suggest that the addition of K through integrated fertilization is needed to improve plant nutrition and productivity of the intensive rice-wheat cropping systems. 相似文献
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水稻秸秆钾与化肥钾释放与分布特征模拟研究 总被引:10,自引:2,他引:10
通过室内恒温(25℃)培养试验,研究了不同用量水稻秸秆钾和化肥钾在水-土体系中的释放与分布特征。结果显示,施用水稻秸秆钾300 mg/kg处理,表层水溶液pH经历了一个弱酸化到弱碱化的过程,而化肥钾的施用则降低了表层水溶液的pH。稳定态时相关分析表明,pH与水稻秸秆钾用量正相关(R2 = 0.938**),与化肥钾负相关(R2 = 0.993**)。试验开始当天外加300 mg/kg化肥钾处理表层水溶液钾浓度达到最大值,为50.64 mg/L,随后呈下降趋势。5天时土壤缓效钾含量达到最大值414.51 mg/kg,并保持相对稳定,而速效钾钾含量继续升高,25天后变化较小。外加300 mg/kg水稻秸秆钾处理表层水钾浓度在第3天达到最大值,为52.70 mg/L,之后呈下降趋势,但在相同时期时,秸秆钾处理表层水溶液钾含量高于化肥钾处理。不同钾素用量结果表明,施钾量为150 mg/kg时,两种来源钾主要以交换态钾存在,其次是水溶态钾;随着钾素用量的增加,钾离子被土壤固定,且在等量条件下,水稻秸秆钾处理的交换态钾比例高于化肥钾处理,而非交换态钾所占比例则相反。因此,在一定钾素用量范围内,土壤对秸秆钾和化肥钾的固定没有显著差异,而当用量超过阈值时,秸秆的投入会降低土壤对钾素的固定。 相似文献
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玛纳斯河流域中下游平原地区水化学特征及其影响因素 总被引:1,自引:0,他引:1
通过Piper三线图示法、系统聚类等方法对玛纳斯河中下游28个地表水样品离子化学成分进行了分析,研究了玛纳斯河流域冲积平原的水化学分布特征及影响因素。结果表明:1)研究区水体样品pH值差异较小,但矿化度和各离子组成的差别明显,从淡水到高盐矿化度水均有分布。阳离子浓度Na+Ca2+Mg2+K+;阴离子浓度SO42-Cl-HCO3-。水样中K+和HCO3-的变异系数相对较小,Cl-和Na+变异系数最大。2)玛纳斯河流域冲积平原地区水化学类型主要有Ca2+-HCO3-,Na+-SO42-,Ca2+-SO42-,Na+-Cl-四种。其中Ca2+-HCO3-型占总水样的78.6%,其中仅有3个样品为Na+-SO42-型,2个样品为Ca2+-SO42-型,1个样品为Na+-Cl-型。聚类分析的结果表明玛纳斯河流域地表水化学特征表现出较为明显的空间分异性。总体来看,玛纳斯流域地表水中部分水样的水化学类型改变,主要是由于水体蒸发强度的差异以及玛纳斯河流域土壤中盐分离子被淋洗,增加了水体中的盐分离子含量从而导致水化学类型呈现出差异性。 相似文献
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为了探究土壤侵蚀演变机制,以澜沧江中下游流域为研究区域,利用改进的土壤流失方程(RUSLE)模型,开展流域内土壤侵蚀时空演变特征研究,引入随机森林算法探讨了流域内土壤侵蚀因子的相对重要程度。结果表明:澜沧江中下游流域2005—2015年土壤侵蚀量为0~1.89万t/(km2·a),平均土壤侵蚀模数为0.252万t/(km2·a),中下游子流域平均土壤侵蚀模数处于较低风险以上和中风险侵蚀以下级别。自2005年以后,澜沧江中下游流域土壤侵蚀空间分布特征呈现中度侵蚀风险区域扩张,高度和低度侵蚀风险收缩的趋势。随机森林算法结果发现植被覆盖管理因子和地形因子是影响澜沧江中下游流域土壤侵蚀的主要因素,土壤可蚀性因子、降雨侵蚀因子和水土保持措施因子的相对重要程度偏低,均未超过20%。可见,土壤侵蚀的时空异质性主要是由于植被覆盖和地形影响改变了局部气候而导致的。 相似文献
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汾河中下游河道生态需水量研究 总被引:1,自引:0,他引:1
汾河中下游流域地处我国黄土高原干旱、半干旱地区,水资源短缺与生态环境矛盾十分突出,从水资源开发利用中的生态环境问题出发,构建了适合汾河中下游生态需水量计算模型。河流生态需水量是一个随着时段、河段的不同而发生变化的动态值,把汾河中下游以水文站分成5段,分别计算了不同水文频率年各河段生态需水量,把河道生态需水量分为河道蒸发、渗漏、自净、输沙需水量和基础流量,并根据它们之间的相互关系,界定了总生态需水量。结果表明,汾河中下游20%,50%,70%和95%水文频率年河道生态需水量分别为6.17×108m3,3.78×108m3,2.37×108m3,1.59×108m3;占流域代表年径流量的百分比分别为55.43%,61.97%,61.27%,88.15%,且占多年平均流量的百分比分别为73.68%,45.10%,28.27%,18.92%。要实现汾河流域的可持续管理,必需采取切实有效的措施进行水资源开发调控,分时段分河段地进行水资源的合理利用。 相似文献