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1.
砂质黏性紫色土遇水极易崩解是导致西南山区土壤侵蚀流失等水土灾害的重要原因,为揭示其崩解规律和机制,改善土体的崩解性,采用自制崩解测量仪对不同初始干密度、含水率及颗粒级配条件下的紫色土进行浸水崩解试验,并从非饱和有效应力角度分析了其崩解演化机制,在此基础上,通过扫描电镜（Scanning Electron Microscope,SEM）探讨利用微生物诱导碳酸钙沉积（Microbial Induced Calcite Precipitation,MICP）加固技术对紫色土崩解性的改善效果。结果表明：1）紫色土浸水崩解全过程包含排气吸水期、平衡期、崩解发展期、崩解残余期4个阶段;2）崩解率与平均崩解速率随初始干密度及含水率的增大而减小,且细颗粒含量越高,平均崩解速率越大;3）紫色土浸水后非饱和有效应力的衰减过程受初始饱和度的影响较大,平均崩解速率随初始饱和度的增大呈指数函数衰减;4）MICP加固土的崩解率和平均崩解速率相较于素土分别下降了73～97个百分点和84%～99%,固化沉积的碳酸钙晶体使土体结构中的微裂隙与大孔隙大幅减少,形成较为致密的孔隙结构,大幅增强了粒间胶结强度,使土体抗崩解性能明显提升。MICP技术可以作为西南山区紫色土水土灾害防治的有效措施。 相似文献
2.
紫色土坡耕地埂坎裂隙发育对土壤入渗的影响 总被引：2，自引：2，他引：0
为揭示埂坎裂隙发育程度对土壤入渗性能的影响,该研究选取了3种裂隙发育程度（重度发育、中度发育、轻度发育）的埂坎为研究对象,利用双环入渗试验揭示裂隙发育的埂坎土壤入渗规律并采用入渗模型进行模拟。结果表明：1）不同裂隙发育程度下,埂坎土壤入渗率变化趋势均为先迅速下降后逐渐趋于稳定。有裂隙埂坎各时段的入渗率均大于对照组无裂隙埂坎,但其差值均随入渗时间的增加而减小;2）随着埂坎裂隙发育程度的增加,土壤初始入渗率、平均入渗率、稳定入渗率和累积入渗量均增大,其中初始入渗率的增幅最高（98.72%）;3）控制初始含水率条件下,裂隙深度和面积-周长比仍与初始入渗率、平均入渗率及120 min累积入渗量呈显著正相关（P＜0.05）,裂隙面密度仅与平均入渗率呈显著正相关（P＜0.05）;4）Kostiakov模型和Mezencev模型对不同裂隙发育程度下埂坎入渗过程拟合效果较好（R2为0.84～0.99）,但Kostiakov模型只有在一定时间范围条件下才能有效描述裂隙埂坎入渗过程。研究结果可为紫色土区坡耕地埂坎的建设、维护管理和合理利用及水土保持提供参考。 相似文献
3.
沙质土壤改良剂对科尔沁地区风沙土物理性质及玉米产量的影响 总被引：2，自引：1，他引：1
一次性在沙地施加沙质土壤改良剂,研究了其在不同年份对科尔沁沙地风沙土土壤团聚体含量、土壤贮水量以及玉米产量影响的长效机制。结果表明,各处理均能显著提高0—40cm土层间粒径大于0.25mm的团聚体含量,能促进粒径0.1~0.25mm小团聚体逐渐向粒径为0.25~0.5mm和粒径大于2mm的大团粒结构转变,其中以第4a的0—10cm土层处理表现最为明显,粒径0.1~0.25mm小团聚体较CK减少了34.55%,粒径0.25~0.5和大于2mm的大团粒结构分别较CK增加了1.63和12.31倍;在贮水量方面,施入土壤改良剂第3a,第4a,第2a以及第1a分别较CK提高了42.21%~48.48%,32.48%~38.11%,28.35%~34.3%和19.15%~29.47%;在产量方面,各处理间差异均显著,各处理较CK增产幅度在15.1%~59.62%。施加沙质土壤改良剂在前3a可逐年改善土壤团粒结构、贮水能力和提高产量,说明其具有显著的改土和增产效果。 相似文献
4.
不同母质土壤-水稻系统Cd吸收累积特征及差异 总被引：1，自引：0，他引：1
通过选取土壤有效态镉(Cd)含量相近、母质不同的水稻土河沙泥(河流冲积物发育)和紫泥田(紫色砂页岩母质发育),添加不同浓度的外源Cd(0,0.5,1,2,5mg/kg)模拟Cd污染稻田土壤进行盆栽试验,研究不同母质稻田土壤Cd胁迫条件下水稻不同生育期对Cd吸收累积的差异,并推算出土壤Cd环境安全临界值。结果表明,水稻生育期2种土壤有效态Cd含量均在分蘖期最高,河沙泥有效态Cd含量平均为0.47mg/kg,紫泥田平均为0.36mg/kg,同一外源Cd水平下,河沙泥土壤有效态Cd含量高于紫泥田。对河沙泥而言,随着外源Cd浓度的增加,水稻总生物量呈现先增加后下降的趋势,当外源Cd浓度为1mg/kg时达到最大生物量,为47.11g/pot;而紫泥田水稻生物量呈现逐渐增加的趋势,但各处理间差异不显著(P0.05)。2种土壤中水稻糙米、谷壳、茎叶、根Cd含量均随外源Cd浓度的增加而增加,整体分布特征为根茎叶谷壳糙米,且河沙泥高于紫泥田;河沙泥水稻平均Cd累积量为51.71μg/pot,紫泥田平均Cd累积量为42.56μg/pot,2种土壤成熟期水稻Cd累积量对比分蘖期分别增加1.45,1.07倍。回归分析表明,河沙泥和紫泥田稻米Cd超标的土壤Cd安全临界值分别为2.03,3.14mg/kg。水稻对Cd的吸收累积特征及土壤Cd安全临界值因土壤母质不同而存在显著差异。 相似文献
5.
Short- and long-term effects of subsoiling four soils were closely related to variations in soil structure and consistence. Penetration resistance decreased when shear failure was accomplished by fracturing. Plastic failure in a near saturated, clayey subsoil did not affect penetration resistance. Penetration resistance of a firm, clayey subsoil with weak to moderately strong structure was lower than presubsoiling levels 2 years after subsoiling. In soils with strong structure, fracturing may occur between peds, which in time settle back to their approximate original configuration. More intra-pedal fracturing probably occurs in soils with weaker structure, thus reducing average ped size and increasing interpedal macropore volume, even after settling. Subsoiling of a loose, sandy soil decreased penetration resistance for at least 4 months, but after 4 years no residual effect was found.Only in the sandy soil did subsoiling have any noticeable effect on soil moisture content. Vertical filling of the blade and mole channels with A1 horizon material resulted in increased moisture content in the mole channel 4 months after subsoiling. After 4 years, moisture content in the A1 horizon remained higher in the vicinity of the channel. This may be due to increased upward movement of water through the more highly organic A1 horizon material that had infiltrated along the blade channel. 相似文献
6.
DCD 在不同质地土壤上的硝化抑制效果和剂量效应研究 总被引：5，自引：0，他引：5
通过硝化抑制剂抑制土壤硝化作用是实现作物铵硝混合营养和提高氮肥利用率的重要途径之一。本试验采用室内模拟的方法, 在人工气候室(25 ℃)黑暗培养条件下, 应用新疆石灰性土壤研究了不同剂量的双氰胺(dicyandiamide, DCD)在砂土、壤土、黏土3 种不同质地土壤中对土壤硝态氮、铵态氮转化的影响及DCD 的剂量效应和硝化抑制效果。处理30 d 内, 各剂量DCD 处理对砂土的硝化抑制率为96.5%~99.4%(平均值为98.3%), 在黏土上为66.9%~85.6%(平均值为77.6%), 在壤土上为49.3%~79.4%(平均值为67.7%), 总体硝化抑制率表现为砂土>黏土>壤土。在砂土上DCD 的剂量效应不明显, DCD 用量从纯氮的1.0%增加到7.0%时, 土壤中硝态氮含量仅增加1.9~10.7 mg·kg-1(培养30 d 时); 而在壤土和黏土中, 土壤硝态氮含量随DCD 浓度的增加而显著下降, 存在明显剂量效应。这说明施用DCD 可显著抑制新疆石灰性土壤的硝化作用过程, 在砂土、壤土、黏土中DCD 的最佳浓度分别为纯氮用量的6.0%、7.0%和7.0%, 并在培养30 d 内发挥显著作用。 相似文献
7.
Lenir Fátima Gotz Nerilde Favaretto Gabriel Barth Paulo Sergio Pavinato Volnei Pauletti 《Soil Use and Management》2023,39(1):606-617
The benefits of manure as a source of nutrients for plants and to improve soil quality are well-known. Monitoring of manure application is needed if environmental issues are to be prevented. In particular, the availability and accumulation of phosphorus (P) has to be subject to rigorous monitoring. This study aims to both evaluate the efficacy of the resin method in extracting inorganic labile P in soils under the long-term application of dairy liquid manure (DLM), and verify the influence of DLM on the recovery of applied P and soil legacy P. To realize our objectives, two long-term field experiments were established under a no-tillage system with annual DLM application on sandy clay loam (sandy Oxisol) and clayey (clayey Oxisol) soils. Treatment consisted of DLM applications (0, 60, 120, 180 m3 ha−1 year−1), independent of mineral fertilizer. Soil samples were taken from the 0–5, 5–10 and 10–15 cm layers after 10 years from the beginning of the trial. A single extraction with resin underestimated inorganic labile P; however, successive extractions were able to take up 43% and 26% of the total P in sandy and clayey Oxisols, respectively, whereas in a single extraction the take-up was 17% and 8% from the same soils, respectively. The resin method was more effective in extracting P from the sandy Oxisol. Thus, when interpreting soil P contents for fertilizer planning, the soil texture should be taken into account. DLM application decreased P recovered from applied P, ranging from 54% to 83% (sandy), and 43% to 67% (clayey), and substantially increased soil legacy P. 相似文献
8.
本文采用振荡平衡法研究了紫泥田、河沙泥、灰泥田及红黄泥4种稻田土壤对铵的矿物固定的动力学及热力学特性。结果表明,供试土壤对添加铵的矿物固定速度很快,随着固铵量增多,固铵速度下降,反应后24小时固定基本上达到平衡,不因土壤种类而异。数学拟合结果表明,以一级动力学方程和E lovich方程描述供试土壤对铵的矿物固定资料最优,抛物扩散方程也能较满意地描述实验结果,以零级方程的拟合效果最差。供试土壤对铵的矿物固定的热力学资料均能用一元Langmu ir吸附等温式、Freund lich吸附等温式和Temk in吸附等温式拟合,拟合结果均达极显著水平,但以一元Langmu ir吸附等温式的拟合结果最优,由一元Langmu ir吸附等温式可以求得土壤对铵的矿物固定的热力学平衡常数、最大固铵量以及固铵过程中的自由能变△G°。供试土壤固铵过程的自由能变△G°均为负值,说明供试土壤对铵的矿物固定为一自发过程,4种土壤固铵强度依次为紫泥田>河沙泥>灰泥田>红黄泥。 相似文献
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10.
Dymphie J. Burger Florian Schneider Sara L. Bauke Timo Kautz Axel Don Wulf Amelung 《European Journal of Soil Science》2023,74(6):e13426
Deep-ploughing far beyond the common depth of 30 cm was used more than 50 years ago in Northern Germany with the aim to break root-restricting layers and thereby improve access to subsoil water and nutrient resources. We hypothesized that effects of this earlier intervention on soil properties and yields prevailed after 50 years. Hence, we sampled two sandy soils and one silty soil (Cambisols and a Luvisol) of which half of the field had been deep-ploughed 50 years ago (soils then re-classified as Treposols). The adjacent other half was not deep-ploughed and thus served as the control. At all the three sites, both deep-ploughed and control parts were then conventionally managed over the last 50 years. We assessed yields during the dry year 2019 and additionally in 2020, and rooting intensity at the year of sampling (2019), as well as changes in soil structure, carbon and nutrient stocks in that year. We found that deep-ploughing improved yields in the dry spell of 2019 at the sandy sites, which was supported by a more general pattern of higher NDVI indices in deep-ploughed parts for the period from 2016 to 2021 across varying weather conditions. Subsoil stocks of soil organic carbon and total plant-available phosphorus were enhanced by 21%–199% in the different sites. Root biomass in the subsoil was reduced due to deep-ploughing at the silty site and was increased or unaffected at the sandy sites. Overall, the effects of deep-ploughing were site-specific, with reduced bulk density in the buried topsoil stripes in the subsoil of the sandy sites, but with elevated subsoil density in the silty site. Hence, even 50 years after deep-ploughing, changes in soil properties are still detectable, although effect size differed among sites. 相似文献
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12.
Short-term changes in the spatial distribution of microorganisms in soil aggregates as affected by glucose addition 总被引：1，自引：0，他引：1
We studied the location of microorganisms in soil aggregates by low temperature scanning electron microscopy and by confocal laser microscopy (direct counts of bacteria) on dissected aggregates. We compared a sandy and a clayey soil and studied the effect of adding glucose on the spatial distribution of microorganisms. In the sandy soil, pores with diameters between 6 µm and 30 µm were the most abundant. In the clayey soil, the pores were <0.2 µm in diameter. In the sandy soil, microorganisms were present both on the surface and inside aggregates, whereas they were concentrated on the surface of clayey soil aggregates. Glucose addition increased the amount of bacteria and fungi on the surface of clayey soil aggregates but not inside them. For the sandy soil, microbial numbers were increased dramatically both inside and on the surface of the aggregates after glucose additions. This study thus evidenced contrasting microbial habitats in soil aggregates. 相似文献
13.
《CATENA》2001,43(2):137-156
The aim of this paper is to explain soil genesis and spatial variability in the soil cover of a flat landscape in the southern part of Argentina's semiarid region. Soil survey data indicate random differences in the properties of soils lying within a few hundred meters of one another, as reflected in an intricate distribution pattern which cannot be explained by the climatic theory of soil genesis in a single pedogenetic cycle. This pattern is unrelated to the actual vegetation cover. The soil parent materials consist of a <2-m mantle of aeolian Holocene sediments overlying a thick plio-Pleistocene “tosca” layer (calcrete, caliche). The undulations in the tosca layer are indicative of a paleomicrorelief levelled up to the present surface after the deposition of the Holocene sediments. Soils with fine-textured sandy loess and strong development (Meridiano soil: A–Bw–Ck–2Ckm) occupied a higher position within paleomicrorelief of the tosca layer. Adjacent soils on border or intermediate positions of the petrocalcic paleosurface have more complex profiles with a relict calcic horizon (Vizcachera soil: A–C–2Ck–3Ckm) and coarser texture (silty clayey sand) in the topsoil. In the lower positions of the paleomicrorelief of the tosca layer, the silty clayey sand directly overlie the petrocalcic horizon (El Khazen soil: A–C–2Ckm). The intricate distribution pattern is due to the coexistence of older polypedon (Meridiano soil), remnants of an earlier erosion cycle complexed with two younger soils, one from partial erosion (Vizcachera soil) and the other where total erosion of earlier soils was followed by successive pulses of aeolian deposition (El Khazen soil). The distribution pattern of the three soils thus reflects a complex history involving at least three stages of landscape evolution. 相似文献
14.
钾镁锌硼钼肥对椪柑产量和品质的影响 总被引：4，自引：1，他引：4
在成龄椪柑桔园连续3年施肥试验结果表明,施用钾、镁、锌、硼和钼肥对椪柑产量和品质有不同程度的影响。在红泥土和河沙土上氮磷钾平衡施较不施钾显著增加椪柑产量,分别增产14.3%和13.5%。在施用氮磷钾基础上施镁、锌、硼和钼肥,可使红泥土上椪柑果实产量依次平均增产8.6%、7.9%、7.4%和2.7%,可使河沙土上的椪柑果实产量依次平均增产4.3%、4.2%、3.1%和2.2%。施钾能增加果实的维生素C、全糖和可溶性固形物含量,而能降低全酸含量和糖/酸比。在施用氮磷钾基础上施镁、锌和硼能增加椪柑果实的维生素C、全糖和可溶性固形物含量。施钼肥导致果实中全酸含量的提高和糖/酸比的降低。在红泥土和河沙土上施钾使椪柑果皮增厚,施镁使果皮变薄,施锌硼对果皮影响甚微,施钼能明显地使果皮增厚。 相似文献
15.
元谋干热河谷辣木人工林地灌水后不同覆盖措施对土壤水分及辣木物候的影响 总被引：1，自引：0，他引：1
根据元谋干热河谷气候特点,2010年初步研究了旱坡地辣木人工林地灌溉后地表盖草和覆膜的土壤水分及其变化状况,研究结果得出:(1)在地面覆盖物作用下,无论是沙土、沙壤土还是黏土样地,耕作层0-20cm、20-40cm土壤水分高于未覆盖样株的土壤水分,辣木生育期比未覆盖提前。总体表明,盖膜土壤水分增加最多,在0-20cm土层,2龄辣木树10d的土壤水分高于对照1.2%～4.6%,幼龄辣木树(栽植8个月)10d的土壤水分高于对照1.8%～4.7%。其次是草覆盖,在0-20cm土层,2龄辣木树10d的土壤水分高于对照2.6%～3.4%,幼龄辣木树(栽植8个月)10d的土壤水分高于对照1.8%～4.6%。土层20-40cm下土壤水分变化较小。(2)由于土壤质地差异,无论是灌水量的多少与处理的不同,沙土蒸发均高于沙壤土,而且变化较大,沙壤土变化均匀,黏土较保水。深层土壤水分总体趋势是随土壤深度增加而增加,增加幅度随之减少。 相似文献
16.
磷钾硼锌肥对百合、白术产量和养分吸收的影响 总被引：1，自引：0，他引：1
在田间试验条件下研究了不同营养元素对百合、白术产量和养分吸收的影响。两年结果表明,在河沙土和灰泥土上,施用磷、钾、硼和锌肥的百合产量分别平均增产5.1%、33.5%、22.3%、16.3%和16.2%、12.5%、2.1%、6.1%,在灰泥土上,白术产量分别平均增产8.6%、34.6%、9.1%、5.8%,百合施用钾、硼和锌肥的增产效果大于白术,而白术施磷的增产效果大于百合。施磷肥能促进百合和白术对氮、磷、钾和硼的吸收,而降低对锌的吸收;施钾、硼和锌肥能增进百合和白术的氮、磷、钾、硼和锌养分的吸收量。百合和白术吸收的养分量表现出钾>磷>锌>硼。百合和白术吸收的氮、磷、钾和锌主要分配在鳞茎和根状茎部分,吸收的硼主要集中在茎叶部分。平衡施肥可提高药用部分(鳞茎和根状茎)的磷、钾和锌养分的分配比率。 相似文献
17.
喷灌强度对滨海盐碱地土壤水盐运移特征的影响 总被引：3，自引：1，他引：3
为研究一维条件下喷灌强度对滨海盐碱地土壤湿润峰运移、水分再分布特征及盐分淋洗的影响,选用滨海盐碱地黏质重度盐碱土和砂质重度盐碱土2种土壤,设置5个喷灌强度(分别是1.72、3.13、5.27、8.75、10.11mm/h),进行室内喷灌条件下土柱模拟试验。结果表明,喷灌强度与土壤黏粒含量显著影响湿润锋运移。湿润锋推进速度随着喷灌强度增加而增大,而湿润深度随之减小,且土壤黏粒含量越高,越不利于湿润锋运移;随着土壤水分再分布过程的推进,黏质重度盐碱土在3.13mm/h喷灌强度下同一深度体积含水率较其他处理大,砂质重度盐碱土在1.72mm/h喷灌强度条件下土柱具有较高的保水性;采用喷灌淋洗,可使上层土壤脱盐,盐分均累积至下层土壤,并使其急剧增加且达到最大值。对于黏质重度盐碱土,3.13mm/h喷灌强度下,盐分淋洗效果较好,而对于砂质重度盐碱土,8.75mm/h喷灌强度淋洗效果优于其他处理。该研究可为喷灌技术合理和可持续开发利用滨海盐碱地提供参考。 相似文献
18.
网格式生物埂对坡面土壤养分分布特征的影响 总被引：1，自引：0，他引：1
网格式生物埂作为将水土保持生物措施与工程措施相结合的一种新型护坡技术, 对土壤养分特征和坡面分布规律有较大影响。本文采用野外调查和室内分析方法, 研究建设1~4年的黄花网格式生物埂对坡面土壤养分分布特点和分布规律的影响。结果表明: (1)网格式生物埂对土壤有机质含量和pH有显著改善作用, 随着建设年限的增加, 土壤pH逐渐降低, 而土壤有机质含量逐渐增大; 在不同坡位之间有机质含量表现为: 坡上>坡中>坡下, 与对照裸坡呈相反规律; (2)随着网格式生物埂建设年限的增加, 土壤全氮呈现先降低后增加的趋势, 且生物埂对于改善上坡位氮素含量效果较显著; 土壤碱解氮与全氮含量变化呈显著正相关, 且不同建设年限间生物埂土壤碱解氮含量在坡上和坡下位置差异均较显著; (3)生物埂建设1~3年, 相同年限的生物埂不同坡位的土壤全磷含量之间显著差异性规律不同, 但建设4年生物埂土壤全磷的坡面分布规律与对照完全相反, 表现为坡下>坡中>坡上, 且不同坡位差异达极显著水平(P=0.000); 有效磷含量随生物埂建设年限增加表现出一定的波动性, 变异系数达31.37%, 但相比对照平均值提高1.15~3.30倍, 而坡面分布随建设年限没有明显的变化规律; (4)网格式生物埂土壤全钾含量相比对照提高9.7%~28.2%, 但随着网格式生物埂建设年限的增加, 土壤全钾含量呈降低趋势; 生物埂能显著增加土壤有效钾含量, 且达到一定建设年限, 坡面不同位置土壤有效钾含量差异性显著增加。 相似文献
19.
Critical limits of the degree of compactness and soil penetration resistance for the soybean crop in N Brazil 总被引：1，自引：0，他引：1 
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下载免费PDF全文 Pedro Daniel De Oliveira Michel Keisuke Sato Herdjania Veras de Lima Sueli Rodrigues Alvaro Pires da Silva 《植物养料与土壤学杂志》2016,179(1):78-87
In agricultural fields soil compaction is a major cause of physical degradation. Degree of compactness (DC) is a useful parameter for characterizing compaction and the response of crops for different soils. The objectives of this study were: (1) to identify the critical DC and PR values for soybean [Glycine max (L.) Merrill] using plant growth variables and (2) to verify the relationship between DC and PR, and assess which parameter is recommended for the evaluation of soil compaction. The study was conducted in a greenhouse in a completely randomized factorial design of 4 textures × 5 compaction levels for sandy loam and sandy clay loam soils, and 3 compaction levels for the clayey and very clayey soils. Soil samples were collected from the surface of a Xantic Kandiudox from the NE region of the State of Pará, Brazil. The DC was calculated from the maximum bulk density obtained by the Proctor test, and the PR curve was determined in undisturbed samples equilibrated in different matric potentials. The growth and development of the soybean was favored in the DC range of 80 to 85%, regardless of soil texture. The critical degree of compactness for the growth of soybean was around 98% regardless of soil texture, while the critical values for penetration resistance at field capacity varied according to soil texture and bulk density and were 28.2, 5.6, 3.5, and 5.2 MPa for the sandy loam, sand clay loam, clayey and very clayey soils, respectively. The root length was the plant growth variable most susceptible to soil compaction. Change in soil penetration resistance was poorly related with change in degree of compactness showing that one parameter cannot be replaced by the other. Because PR is quickly determined in field and have a direct relationship with plant growth, for the soils evaluated in this study we recommend the use of soil PR to assess the state of soil compaction. 相似文献
20.
高钾用量和根区施肥可提升皖南不同质地土壤烟叶钾含量 总被引：1，自引：0，他引：1
钾是烟叶的品质元素之一,提升烟叶钾含量一直是我国烟草行业关注的重点之一。本文选取安徽烤烟主产区皖南宣城市砂土与黏土两类典型土壤,以云烟97为试验材料,研究田间条件下不同高钾用量水平与施肥方式对烟叶钾含量的影响。研究结果表明,在耕层土壤全层混施方式下,随着施钾量增加(0、300、600、900、1 200、1 800、2400mg/kg,以纯K计),两种质地土壤烟叶钾含量均显著上升,呈先快速增加而后缓慢增加的趋势。在钾肥用量低于1 200 mg/kg时,每增加钾肥用量100 mg/kg,砂土和黏土烟叶不同部位钾含量分别平均增加2.4 g/kg和1.0 g/kg。更高钾肥用量可使砂土烟叶钾平均含量提升到44.0 g/kg,黏土则只能提升到26.2 g/kg。两类土壤钾肥效果差异极大的原因与土壤固钾能力有关,土壤速效钾含量与烟叶钾含量呈线性相关,而黏土钾肥固定率平均为71%,远高于砂土的25%,这是两种质地土壤钾肥肥效差异的根本原因。在常规同等钾肥用量条件下(K2O25kg/667m2),氮磷钾根区集中施用较常规条施显著促进了烟叶对钾的吸收,提升了烟叶钾含量,而且砂土的效果要好于黏土,其原因也与根区施肥可显著提升烟叶根区土壤速效钾含量有关。以上结果表明,选择固钾能力弱的土壤,提高钾肥用量并改进施肥方法可以有效提升皖南烟叶钾的含量。 相似文献