腐殖酸钾对生姜生长、钾素吸收及钾肥利用率的影响

研究了腐殖酸钾对生姜生长、钾素吸收及钾肥利用率的影响。结果表明,生姜植株干物质积累量和钾素积累量随生姜生长发育而增加,变化动态可以用Logistic方程拟合。施用腐殖酸明显提高了根系活力,增加了植株钾素吸收量和干物质积累量,比空白对照增产8．88％。施用腐殖酸钾显著促进了根系生长发育,提高了钾素积累速率和钾素积累量,并最终提高产量,比空白对照增产61．29％,比等量氧化钾对照增产9．92％。施用腐殖酸钾显著提高了钾肥农学利用率和钾肥吸收利用率,而钾素干物质生产效率和钾素收获指数都有所降低。     

施钾时期对甘薯产量及钾肥利用率的影响

为了明确不同时期施用钾肥对甘薯块根产量及钾肥利用率的影响,以济徐23为材料,进行大田试验。研究钾肥施用时期对甘薯块根干物质积累特性、干物质分配、钾肥利用率的影响。结果表明,不同时期施用钾肥均可提高块根产量,基施增产幅度最大,为26.09%,封垄期追施次之,高峰期追施最小。与对照处理相比,施用钾肥提高了块根膨大速率,基施和封垄期追施处理块根膨大前期增幅较大,而高峰期追施钾肥块根膨大后期增幅略高;基施处理显著降低全时期甘薯茎叶鲜重与块根鲜重的比值(T/R值),而封垄期追施处理显著降低生长中后期T/R值;施肥处理均可提高收获期块根干物质分配率,基施钾肥处理达到显著水平。基施钾肥处理钾肥产块根效率、钾肥收获指数、钾肥农学利用率和钾肥偏生产力显著高于其他施钾处理。基施钾肥通过提高钾肥农学利用率、偏生产力和钾肥收获指数,降低T/R值,促进块根膨大,最终获得高产。     

控释钾肥对玉米产量、钾肥利用率和土壤速效钾的影响

通过玉米—小麦轮作条件下连续2年的大田定位试验,以钾空白(CK)、普通氯化钾常量(K1)、普通氯化钾高量(K2)为对照处理,研究通过控释氯化钾常量(CRK1)、控释氯化钾高量(CRK2)、氯化钾与控释氯化钾等比掺混常量(BBF1)、氯化钾与控释氯化钾等比掺混高量(BBF2)处理对玉米产量、钾肥利用率和土壤速效钾的影响。结果表明:(1)BBF2玉米-小麦季产量分别为11 697.8kg/hm2和11 921.1kg/hm2,增产和增收效果最好,较K1分别显著增产13.3%和15.7%,较K1分别显著增收16.6%和19.6%;(2)BBF2钾肥农学利用率较K1分别显著提高了49.0%和41.9%,生理利用率较K1分别显著提高了17.6%和34.8%;BBF1钾肥表观利用率最高,玉米—小麦分别为23.73%和35.22%;(3)施用钾肥显著提高了玉米的株高和茎粗;BBF2提高了玉米吐絮后期至成熟期的株高;CRK1、CRK2、BBF1、BBF2均提高了玉米吐絮后期叶片SPAD值。本试验条件下,控释氯化钾与普通氯化钾掺混施用可满足玉米整个生育期的钾素需求,提高玉米产量和钾肥利用率,BBF2处理为玉米最佳钾肥施用方案。     

不同钾肥用量对生姜生长和营养品质的影响

采用田间试验研究不同施钾量对生姜生长、钾素吸收、营养品质及经济效益的影响。结果表明,施用适量钾肥能明显促进生姜生长发育,提高块茎产量、植株含钾量和钾素吸收量,改善营养品质,提高施肥经济效益。2年2地试验结果表明,施钾生姜块茎产量增长13.0%~27.2%和22.3%~37.7%,平均增产22.5%和28.7%,中等钾肥用量的K450处理获得了最高产量;块茎产量与施钾量间呈一元二次抛物线关系。施用不同数量钾肥后,生姜茎叶、姜块和全株含钾量分别提高33.4%~210.7%、2.9%~70.8%和18.4%~139.9%,钾素吸收量增加64.5%~342.2%、31.3%~118.7%和48.5%~209.0%。施用适量钾肥后,生姜块茎粗蛋白质、Vc和可溶性糖含量相应提高,K450处理最高。施钾增收13 626~23 286元/hm2,施用钾肥的产投比高达(2.27~12.60)︰1。     

根区施用钾肥对烤烟产量、钾含量及钾素吸收的影响

为了探讨根区施用钾肥对黄淮烟区石灰土烤烟产量和钾素吸收利用的影响,采用田间试验,研究根区枸溶性钾肥与硫酸钾配施对烟叶产量、钾含量以及钾素吸收利用的影响。试验共设9个处理,分别为CK、CP_1、CP_2、WP_1、WP_2、CW_(1-50%)、CW_(2-50%)、CW_(1-75%)与CW_(2-75%)(CK表示对照,CP表示只施用枸溶性钾肥,WP表示只施用硫酸钾,CW表示枸溶性钾肥与硫酸钾配施;数字1、2表示施用量分别为225、300 kg/hm~2,百分数表示硫酸钾的配施比例)。结果表明,烟叶钾含量随生育期推进呈下降趋势,不同施肥处理各时期烟叶钾含量均高于CK;不同施肥处理下土壤钾素在垂直和水平方向上迁移距离较小,根区钾肥施用可直接有效的增加根区土壤速效钾含量;施钾(K_2O)300 kg/hm~2与225 kg/hm~2相比,可显著提高烟叶钾含量和钾肥利用效率(P0.05);CW_(2-75%)处理下烟叶钾含量、土壤速效钾含量和钾肥利用率最高,而CW_(2-50%)处理下烟叶产量最高。综上所述,根区施用含75%硫酸钾的枸溶性钾肥300 kg/hm~2(CW_(2-75%)处理)可有效改善黄淮烟区石灰土钾素养分,提高该区烤烟产量、钾含量与钾肥利用效率,达到优质高产。     

施钾对不同肥力土壤玉米钾素吸收、分配及产量的影响

采用田间试验, 研究了吉林省高(榆树市)、低肥力(公主岭市)肥力条件下不同钾肥用量对玉米产量、钾素吸收和分配的影响。结果表明, 榆树试验点和公主岭试验点的最高产量施钾量分别为83.3 kg·hm^-2和113.9 kg·hm^-2, 最佳经济施钾量分别为75.1 kg·hm^-2和103.1 kg·hm^-2。公主岭低肥力试验点比榆树高肥力试验点的最高产量和最佳经济产量分别提高了3.70%和3.68%。施用钾肥可有效提高玉米干物质最大积累速率和钾素最大吸收速率, 并能提前干物质最大积累速率和钾素最大吸收速率出现的天数。当施钾量超过60 kg(K₂O)·hm^-2时, 公主岭低肥力试验点的干物质最大积累速率和钾素最大吸收速率均高于榆树高肥力试验点。适宜的钾肥用量有利于提高钾养分由营养体向籽粒的转运量、转运效率及籽粒养分比例, 榆树高肥力试验点籽粒养分比例低于公主岭低肥力试验点, 幅度为0.5%~1.7%。除施钾量60 kg(K₂O)·hm^-2处理外, 公主岭低肥力试验点的钾肥农学利用率、偏生产力和利用效率等指标均高于榆树高肥力试验点, 分别提高7.3~8.8 kg·kg^-1、4.4~8.3 kg·kg^-1、1.6%~6.2%。综合考虑提高玉米产量、效益及钾肥利用效率, 高肥力土壤适宜施钾量为75 kg·hm^-2, 低肥力土壤上适宜施钾量为103 kg·hm^-2。     

钾肥对烤烟体内钾素分配及微量元素含量的影响

本文用三种典型的植烟土壤研究了不同的钾肥用量对烟株含量及分配的影响，结果表明，烟叶含钾量随钾肥用量的增加而增加，两者符合二次曲线的关系。充分供钾时，钾在烟株体内的含量顺序为芽＞叶＞茎＞根，烟叶不同部位为下部＞中部＞上部；当烟株缺钾时，上部烟叶含钾量高于中下部。无率在哪种土壤上，钾在烟株中的分配比例顺序为烟叶＞茎＞根＞芽，当中部烟叶含钾量达到２．４％时钾在烟株中的分配趋向一稳定值，即在烟叶、茎、根、     

钾肥和腐殖酸互作对烤烟有机钾盐指数的影响

以烤烟品种金神农1号为材料,采用钾肥与腐殖酸双因子大田试验,分析了不同钾肥和腐殖酸水平及其互作对烤烟干物质量、化学成分、香味物质及有机钾盐指数的影响。结果表明:在同一钾肥水平下增施腐殖酸及在同一腐殖酸水平下增施钾肥均可增加烤烟前期的总干物质和烘烤后烟叶的总香味物质量,改善烟叶化学成分,提高有机钾盐指数;钾肥和腐殖酸互作对烟叶还原糖、总氮、氮碱比、钾及有机钾盐指数均有显著的正效应,而对烤烟干物质量及其余化学成分指标的影响则未达到显著水平;较高水平的钾肥和腐殖酸配施相对于较低水平两者配施有利于改善烤烟品质,提高烟叶钾含量和有机钾盐指数。     

钾肥用量对甜荞麦产量和钾素利用效率的影响

以甜荞麦大粒荞品种为材料,设4个钾素水平（K2O 0、 22.5、 45和67.5 kg/hm2）,通过两年田间试验,研究了钾肥用量对甜荞麦产量、 钾素吸收和利用特性的影响。结果表明,甜荞麦籽粒产量、 籽粒钾素累积量随施钾量的增加先增加后降低,在施钾量为K2O 45 kg/hm2 时达最高。通过二次曲线模拟,在施钾量为K2O 46.2 kg/hm2（2009年）和46.3 kg/hm2（2010年）时产量达到最高。钾素生理效率、 钾素利用效率、 钾肥农学利用率、 钾肥生理利用率、 钾肥效率和钾肥利用效率均随钾肥用量的增加而下降。在本试验条件下,施K2O 22.545 kg/hm2时,通辽市库伦旗甜荞麦可获得较高的钾肥利用率,并获得高产。     

不同施钾方式对甘薯钾素吸收及产量的影响

【目的】钾素是调控块根类作物生长和产量的关键因子,特别是对淀粉型甘薯后期块根膨大及产量形成尤为重要。本试验选择胶州(砂姜黑土)和即墨(风沙土)两个不同土壤质地类型的试验点布置田间试验,探究不同施钾方式在两种不同类型土壤条件下对甘薯钾素吸收、 钾肥利用率以及产量形成的影响,以期对甘薯生产提供理论指导。【方法】借助水肥一体化技术能够实现甘薯钾营养的精细化调控,提高钾肥利用率和促进甘薯生长。试验共设置4个处理: K0(不施钾肥,CK)、 K1(钾肥基施)、 K2(钾肥1/2基施+1/2封垄期追施)和K3(钾肥全部封垄期追施)。【结果】与CK相比,三种不同施钾方式均显著提高了甘薯生物量、 养分吸收量及产量(P0.05)。与K3和 K1处理相比,砂姜黑土条件下K2分别增产18.7%和10.4%,但K3和 K1处理之间的产量差异不显著; 风沙土条件下K2增产幅度分别为35.3%和17.3%,其中K1处理的产量显著高于 K3处理(P0.05)。与K1处理相比,K2处理显著提高了甘薯生长中后期(115天~150天)钾素积累量和地下部生长速率,同时提高了钾收获指数、 钾肥偏生产力、 钾效率、 钾肥农学利用率。与K1 和K3相比,砂姜黑土条件下K2处理的钾肥表观利用率分别提高了12.5%和8.8%,风沙土条件下K2处理的钾肥表观利用率分别提高了13.9%和13.2%。不同土壤类型条件下同一施钾方式相比较,砂姜黑土条件下氮钾积累量、 生物量和产量均高于风沙土,但K2处理的钾素日积累速率、 钾素利用率与增产效应均表现为风沙土高于砂姜黑土。【结论】在供钾量较低的风沙土上采用分期施钾(1/2基施+1/2封垄期追施)能显著提高钾肥利用率和增加甘薯产量,是甘薯合适的施钾方式。     

钾肥用量对瘠薄地甘薯产量和钾肥利用率的影响

为探索瘠薄地条件下甘薯的最佳钾肥用量,以淀粉型甘薯品种济薯25为试验材料,设3个处理:CK(不施钾肥)、K1(K₂O,150 kg·hm^-2)、K2(K₂O,300 kg·hm^-2),研究钾肥用量对瘠薄地甘薯产量和钾肥利用率的影响。结果表明,施钾显著提高了鲜薯和薯干产量,K1增产幅度较大,鲜薯和薯干产量分别较CK增加22.84%和32.13%,K2分别较CK增产11.39%和20.30%。施钾促进了甘薯块根的膨大,K1和K2的块根膨大速率均显著高于CK,T/R值均显著低于CK。施钾促进干物质的积累,K1和K2的叶片、叶柄、茎和纤维根干重以及总生物量显著高于CK,且K1优于K2。施钾显著增加了甘薯各器官的钾素积累量,且整体表现为施钾量越多,各器官的钾素积累量越高。钾肥利用率随施钾量的增加而降低,K1的钾素产块根效率、产干物质效率、钾肥吸收利用率、钾肥农学利用率和钾肥偏生产力均显著高于K2。在本试验瘠薄地条件下,钾肥的最佳用量为150 kg·hm^-2。本研究为瘠薄地甘薯田间施肥提供...     

Potassium Uptake and Utilization Efficiency Among Selected Nitrogen-Fixing Tree Legumes Over Time

Nutrients released from tree prunings sustain alley cropping. Potassium (K) uptake and utilization efficiency were monitored over 16 months in Gliricidia sepium, Leucaena leucocephala, and Albizia lebbeck. Tree interspecific variation arose in biomass yields and K nutrition. Tissue potassium concentration narrowed within 0.68–1.15% and varied little among tree parts and species over time. Potassium accumulation increased steadily with tree age and significant differences among trees occurred at all ages. Gliricidia sepium had a higher yield than the others over the first 8 months, after which the uptake pattern declined drastically to become the lowest at harvest. Differential K partitioning within trees occurred as K in leaves, stems, and roots amounted to 18, 35, and 47% in Albizia; 28, 25, and 47% in Gliricidia; and 27, 42, and 31% in Leucaena, respectively. Higher K allocation into Leucaena stems and its low partitioning into Albizia leaves were drawbacks for alley cropping. Potassium utilization efficiency decreased inversely to biomass yield and K uptake over time. It differed significantly among trees with Albizia being the most efficient. Low K returns from tree prunings in alley cropping could be due to its uptake potential and partitioning impairment in each species.     

Efficacy of Potassium Humate and Chemical Fertilizers on Yield and Nutrient Availability Patterns in Soil at Different Growth Stages of Rice

Potassium humate (PH) is a promising natural resource to be utilized as an alternative for increasing crop production. A pot experiment was conducted during 2009 and 2010 to assess the efficacy of application of potassium humate (0, 5, and 10 mg kg^?1 soil) alone and in combination with chemical fertilizers (75% and 100% recommended dose of nitrogen–phosphorus–potassium) on yield and nutrient availability patterns in soil at different growth stages of rice. Two doses of zinc, viz. 0 and 12.5 mg kg^?1, were also applied. Sole and combined application of potassium humate with nitrogen–phosphorus–potassium (NPK) and zinc significantly (p < 0.05) improved the yield and availability of nitrogen, phosphorus, potassium, sulfur, zinc, and dehydrogenase activity in soil. Application of 10 mg kg^?1 potassium humate along with 100% NPK and 12.5 mg kg^?1 zinc sulfate proved significantly superior when compared to 75% and 100% of NPK alone.     

腐植酸钾对土壤铅化学形态、生物可给性及健康风险的影响

通过重金属分级提取和生物可给性体外模拟试验,研究了腐植酸钾对污染土壤中铅化学形态组成、生物可给性及基于生物可给性的健康风险评价的影响。结果表明,不同比例的腐植酸钾均可显著提高铅污染土壤的pH值和有机质含量,且随着添加量的增大而升高;添加腐植酸钾可显著降低土壤中弱酸提取态铅和可还原态铅含量,增加可氧化态铅和残渣态铅含量,其影响随添加量的增大而增强;土壤中铅的生物可给性随腐植酸钾添加量的增加而显著降低;基于生物可给性的人体健康风险评价显示,经口摄入铅污染土壤造成的危害水平随着腐植酸钾添加量的增大而显著降低,且儿童危害商(非致癌风险)高于成人,约为成人的1.8倍;土壤中铅的安全含量限值随腐植酸钾添加量的增大而增大,非敏感用地高于敏感用地。研究表明,腐植酸钾可有效降低铅污染土壤中铅的健康风险和生态风险,可用于铅污染土壤的修复。     

不同供磷水平对旱作条件下水稻生长、根系形态和 养分吸收的影响

通过盆栽试验,比较分析了磷素对旱作条件下不同水稻品种苗期生长、根系形态及磷素吸收利用效率的影响。结果表明,施用磷肥促进水稻地上部和根系的生长,低磷胁迫显著增大了植物的根冠比,且品种间差异明显,丛矮2在低磷水平和高磷水平下的根冠比比值为1.982,而黄华占相应的比值为1.096;随供磷浓度的增加,水稻植株含磷量增加而磷素生理利用率降低,在3种磷水平下,3345的磷素吸收效率均高于其他4个品种,磷素生理利用率却低于其他4个品种。根系形态参数与磷素吸收、利用效率的相关性分析表明:根系总长对水稻植株吸磷量影响最大。总之,适当地施用磷肥能更好地协调根系与地上部的关系,促进根系的生长和根系对磷素的吸收。     

Relative Phosphorus Utilization Efficiency,Growth Response,and Phosphorus Uptake Kinetics of Brassica Cultivars under a Phosphorus Stress Environment

Abstract

Plants grown in highly weathered or highly alkaline calcareous soils often experience phosphorus (P) stress but never a P‐free environment. Thus, applications of mineral P fertilizers are often required to achieve maximum yield, but recovery of applied P fertilizers is notoriously low. Phosphorus deprivation elicits a complex array of morphological, physiological, and biochemical adaptations among plant species and genotypes to enhance P acquisition and utilization efficiency. Ten Brassica cultivars were grown hydroponically to investigate their relative efficiency to utilize deficiently (20‐µM) and adequately (200‐µM) supplied P, using Johnson's modified solution. Cultivars differed significantly (P<0.001) in biomass accumulation. Orthophosphate concentration and uptake in shoot and root, absolute and relative growth rate, and P‐utilization efficiency (PUE) were also significantly different among various Brassica cultivars. Root‐shoot ratio and specific absorption rate were substantially increased in plants subjected to low P supply. Shoot and root dry‐matter yield as well as total biomass production correlated significantly (P<0.01) with their total P uptake and PUE. Cultivars, which were efficient in P utilization, were also efficient accumulators of biomass under adequate as well as deficient levels of P supply. As part of the study, kinetic parameters of P uptake were evaluated for six contrasting Brassica cultivars in PUE, grown in nutrient solution. The kinetic parameters related to P influx were maximal transport rate (Vmax), the Michaelis–Menten constant (Km), and the external concentration when net uptake is zero (Cmin). Lower Km and Cmin values were indicative of P‐uptake ability of the cultivars, evidencing their adaptability to P‐stress conditions. In another experiment, six cultivars were exposed to no P nutrition for 27 days after initial feeding on optimum nutrition for 14 days. All the cultivars retranslocated P from aboveground parts to their roots during growth in P‐free conditions, the magnitude of which was variable in different cultivars. Phosphorus concentration at 41 days after transplanting was higher in developing leaves than developed leaves. Translocation of absorbed P from metabolically inactive sites to active sites in plants growing under P‐stress conditions may have helped the tolerant cultivars to establish a better rooting system, which provided basis for tolerance against P‐deficiency stress and increased PUE.     

Nitrogen Application in Winter Wheat Grown in Mediterranean Conditions: Effects on Nitrogen Uptake,Utilization Efficiency,and Soil Nitrogen Deficit

ABSTRACT

Nitrogen (N) is one of the most growth restricting nutrients in cereal grain and represents one of the highest input costs in agricultural systems; therefore, environmental and economic considerations require the effective use of N fertilizer in plant production. This study was conducted for three years to better understand wheat plant response to optimize N fertilizer and how to reduce the risk of ground water pollution.

Two of the most important durum wheat cultivars in Southern Italy and four N fertilization levels (0, 60, 120, and 180 kg N ha^{? 1}, indicated as N0, N60, N120, and N180, respectively) were compared in this experiment. During plant growth, fresh and dry matter, plant nutritional state (SPAD readings and stem nitrate content), and N uptake were determined. At harvest, plant N content, N uptake, grain yield, yield components and quality were determined, allowing the calculation of the pre- and postanthesis N uptake and the N utilization efficiency indices. Furthermore, at the beginning and at the end of each year, soil mineral N was measured to calculate mineral N deficit in the soil.

The results indicated that the treatment with 120 kg N ha^{? 1} of fertilizer ensures a good balance between yield and N utilization. In fact, N180 and N120 showed similar yield (3.01 and 3.07 t ha^{? 1}, respectively) and protein content (13.7 and 13.5 %). Meanwhile, throughout the three-year experiment, N180 presented the highest final mineral N content in the soil at the end of the cropping cycles, increasing the amount of N available for leaching. The N120 treatment showed the same values of N utilization indices as compared to N180, indicating that further doses of N fertilizer did not increase wheat N utilization. Plant N status shows that it is possible to modify the N fertilization to reach its optimum level during plant growth, in accordance with variable weather conditions, and consequently the plants requirements. The mean treatments of the preanthesis N uptake were about 67.5% of the total N uptake, and it was significantly and positively correlated with wheat yield. On the contrary, the postanthesis N uptake showed positive correlation with grain protein content, confirming the importance of late N supply in grains quality. The variation of weather conditions affected winter wheat yield, quality, N utilization and plant N status, but any difference throughout years was found between N180 and N120, confirming that higher N rate did not influence wheat growth, yield, and N uptake.     

Effect of Potassium Fertilizers on Cotton Yield and Nitrogen Uptake Efficiency in an Aridisol

A field experiment was carried out to study the effect of different rates of potassium (K) fertilizer [0, 50, 100, and 150 potassium oxide (K₂O) ha^–1] in the presence of increased supply of nitrogen (N) (120, 180, and 240 kg N ha^–1) on cotton (Gossypium hirsutum L.) yield and the N and K use efficiencies using the ¹⁵N isotopic dilution technique. Potassium fertilizer increased cotton yield, which was significant and more pronounced with the application of N in the high level (N3). The greatest cotton yield (6442 kg ha^–1) was obtained in N2K3 treatment with an increase of 14% over the control. In addition, K fertilizer significantly increased N uptake efficiency in the N2 and N3 treatments. The greatest N uptake efficiency (98%) was in N2K3 treatment. The greatest K uptake efficiency (42%) was occurred in N3K1 treatment. In conclusion, the use of K fertilizer could be useful when growing cotton in soils of moderate to high N content to improve N uptake efficiency and consequently increase cotton yield.