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不同土壤施用钾肥对小麦生长和土壤钾含量的影响 总被引:2,自引:1,他引:2
本研究在人工气候室中对几种不同土壤施钾,观察其对小麦生长和土壤钾含量的影响。盆载试验结果表明,在砂土小麦植株达最高生长量的施钾量(K)为120mg/kg,其它土壤为60mg/kg。钾肥施用越多,土壤有效钾化不施钾处理增加越多。同时对两种有效钾浸提测定方法进行了相关性研究,表明阳离子交换膜(CEM)浸提的钾与醋酸铵(NH4OAC)浸提的钾呈显著的正相关。 相似文献
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Soil and tissue analyses are usually used in identifying potassium(K) deficiencies and predicting K fertilizer requirements of crops.The critical levels of both soil and fresh leaf tissue at seventh leaf stage were developed and assessed for canola,chickpea and sunflower grown on two saskatchewan,soils,with six rates of K fertilizer supply.in a growth chamber experiment.The available potassium in soils was detemined by two methods:1)resin strip extraction,and 2)NH4OAC extraction.The potassium in fresh leaves was determined at seventh leaf stage by a simple procedure using a common garlic press and injector to extract the plant sap and testing the sap with a handheld ion selection electrode meter,The results showed significant relationships between the resin strip extractable K and NH4OAC extractable K,and between the plant uptake of total K and the supple of available K in the soils determined by the two methods.Good relationships were also found between the potassium in fresh leaves and the plant uptake of totak K for canola,chickpea and sunflower.The resin strip extraction for K was calibrated using common NH4OAC extraction,and recommended for routine analyses because of its simplicity and sensitivity. 相似文献
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采用两种化学连续提取法及连续耗钾实验,研究了几种耕作土壤非有效性钾释放特性及有效性。结果表明,供试土壤非交换性释放特性和有效性与粘土矿的密切相关,富含伊利石的土壤非交换性钾的释放量大,速率快,有效性高,黑麦草吸收该土壤的非交换性钾量及总吸钾量高,生物量大。而富含高岭石或蒙脱石的土壤非有效性钾有效性明显较低,非交换性钾的释放量和速率,黑麦草吸收该土壤的非交换性钾量,总吸钾量及生物量的均值分别仅为富含 相似文献
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用阳离子交换树脂膜法和传统化学提取法评估土壤有效钾 总被引:3,自引:0,他引:3
Four testing methods using cation exchange membrane (CEM),ammonium acetate,ASI(0.25mol L^-1 NaHCO3 0.01mol L^-1 EDTA 0.01 molL^-1 NH4F) and 1.0molL^-1 boiling nitric acid,respectively,were used to evaluate soil available K.The soil K tested by CEM was significantly correlated with that by the other (conventional)methods(r^2=0.43^**-0.95^***).The soil K tested by CEM saturated with NH4HCO3(15min extraction)was most closely correlated with that by the other methods(r^2=0.60^**-0.95^***),Potassium availability,as predicted by soil test,was comparable to actual K uptake by canola and wheat grown on the soils in growth chamber.Regression analyses showed that plant K uptake was more closely correlated wiht K extracted by CEM(r^2=0.56^**-0.81^***)than that by the conventional methods(r^2=0.46^***-0.81^***),most colsely correlated with that by NH4HCO3-saturated CEM for 15 min (r^2=0.81^***).and worst correlated with that by HNO3(r^2=0.45^**-0.72^***) 相似文献
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山东主要土壤供钾能力和非交换性钾释放的研究 总被引:8,自引:1,他引:7
用生物耗竭方法,研究和比较了山东省主要农业土壤:棕壤、褐土和潮土的供钾能力。结果表明,以土壤交换性钾、缓效钾含量和耗竭过程中作物吸钾总量和吸收来自土壤非交换性钾的数量、比率及土壤非交换性钾释放速度和数量为依据,评价土壤供钾能力有褐土>潮土>棕壤的总趋势。 相似文献
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设施蔬菜栽培对土壤阳离子交换性能的影响 总被引:10,自引:0,他引:10
以辽宁省沈阳市于洪地区设施菜地及其相邻旱田土壤为研究对象,测定土壤的有机质、阳离子交换量、交换性盐基离子组成和土壤盐基离子饱和度,分析设施蔬菜栽培对土壤阳离子交换量及交换性盐基离子组成的影响。结果表明:(1)与旱田土壤相比,设施土壤有机质含量明显增加,上下层土壤有机质平均含量分别为35.6 g kg-1和18.0 g kg-1,分别是旱田上下层土壤有机质含量的2.1倍和1.8倍;设施土壤阳离子交换量呈上升的趋势,土壤阳离子交换量与有机质含量呈极显著正相关关系(r=0.603**,n=50,r0.01=0.361)。(2)与旱田土壤相比,不同层次设施土壤交换性盐基总量均有所增加,交换性盐基离子中除交换性Ca2+含量变化不大之外,交换性K+、Mg2+、Na+含量均显著增加;不同层次设施土壤交换性K+、Mg2+、Na+饱和度显著高于旱田土壤,但交换性Ca2+饱和度和盐基饱和度呈下降趋势。 相似文献
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环境因素对小麦根系非选择性阳离子通道(NSCCs)转运钾的影响 总被引:2,自引:0,他引:2
以石家庄8号小麦作为研究对象,通过添加钾载体抑制剂和钾专性通道抑制剂的方法,探讨了温度变化和重金属镉、铜对植物根系的非选择性阳离子通道(NSCCs)转运钾离子的影响。结果显示,NSCCs转运钾的最适温度在35℃左右,低温和高温都会使NSCCs的吸钾速率下降。较高的温度(40℃)对NSCCs转运钾的影响大于对专一性钾通道的影响;而较低温度(20℃)对专一性钾通道活性的抑制比对NSCCs的抑制更强。重金属镉和铜均对小麦的钾吸收速率产生影响,浓度越大,抑制作用越强。其中,根系NSCCs对镉的敏感度相对于专一性钾通道来说要低,而对铜的敏感度相对较高。说明不同重金属对两类通道蛋白的影响机制不一样。 相似文献
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通过田间试验研究了淮北平原砂姜黑土地区小麦施钾的增产效应。结果表明,增施适量钾肥具有显著的增产效果,小麦子粒产量提高9.6%-25.0%,平均增产15.5%。小麦钾肥的增产效应与土壤有效K含量和施K量有极大关系。应用逐步回归分析方法,建立了钾肥(K2O)施用量x1、土壤有效K含量x2与小麦单位钾肥增产量y之间的多元线性回归方程:y=17.678-0.0446x1-0.0963x2。当前生产水平下,淮北平原砂姜黑土地区小麦钾肥适宜施用量为K2O 130kg/hm^2左右。 相似文献
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山西褐土长期施钾和秸秆还田对冬小麦产量和钾素平衡的影响 总被引:24,自引:10,他引:24
在山西石灰性褐土一年一作条件下,通过16年的田间定位试验,研究了长期施钾和秸秆还田对小麦产量和土壤钾素平衡的影响。结果表明,只施用氮、磷肥,冬小麦年平均产量5.5 t/hm2,土壤钾素养分严重亏缺,年平均亏缺104.3 kg/hm2,与试验前的初始值比较,土壤速效钾和缓效钾含量分别下降23.6%和14.3%。在施用氮、磷肥的基础上每年施用钾肥(K2O 150 kg/hm2),平均增产10.2%以上;小麦秸秆还田平均增产6.6%以上,二者配合平均增产17.6%,年平均吸钾量提高32.0 kg/hm2。与试验初始值比较,土壤速效钾、缓效钾分别提高38.6%和11.0%。在施用氮、磷肥的基础上,长期施用钾肥和秸秆还田在显著增加冬小麦的经济产量、生物产量和吸钾量的同时,也减少年度间因气候因素等影响引起的产量变异,提高年度间产量和植物吸钾量的稳定性。 相似文献
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红壤酸化及石灰改良影响冬小麦根际土壤钾的有效性 总被引:7,自引:1,他引:7
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Using support vector machines to predict cation exchange capacity of different soil horizons in Qingdao City,China 下载免费PDF全文
Agricultural, environmental and ecological modeling requires soil cation exchange capacity (CEC) that is difficult to measure. Pedotransfer functions (PTFs) are thus routinely applied to predict CEC from easily measured physicochemical properties (e.g., texture, soil organic matter, pH). This study developed the support vector machines (SVM)‐based PTFs to predict soil CEC based on 208 soil samples collected from A and B horizons in Qingdao City, Shandong Province, China. The database was randomly split into calibration and validation datasets in proportions of 3:1 using the bootstrap method. The optimal SVM parameters were searched by applying the genetic algorithm (GA). The performance of SVM models was compared to those of multiple stepwise regression (MSR) and artificial neural network (ANN) models. Results show that the accuracy of CEC predicted by SVM improves considerably over those predicted by MSR and ANN. The performance of SVM for B horizon (R2 = 0.85) is slightly better than that for A horizon (R2 = 0.81). The SVM is a powerful approach in the simulation of nonlinear relationship between CEC and physicochemical properties of widely distributed samples from different soil horizons. Sensitivity analysis was also conducted to explore the influence of each input parameter on the CEC predictions by SVM. The clay content is the most sensitive parameter, followed by soil organic matter and pH, while sand content has the weakest influence. This suggests that clay is the most important predictor for predicting CEC of both soil horizons. 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(5):393-397
Abstract Commercial protease and cellulase treatment of dried and milled plant roots decreased their cation exchange capacity to varying degrees, indicating that protein and cellulose contribute to the exchange mechanism in addition to pectin. Membranes isolated from two roots proved to be epidermal cells; these had a significant cation exchange capacity when thought of as an interface between the soil and the root, but not when compared to the root as a whole. Methylation of the membranes reduced their exchange capacity to zero. 相似文献