Testing foliar nutritional changes in space and over time in greenhouse tomato

The aim of this trial was to study the spatial and temporal variability of the leaf nutrient concentration in tomato intensive crop under greenhouse, to know the number of sub-samples needed to be taken to obtain a representative sample and the influence by the position in the greenhouses. The experiment consisted on the selection of 20 sample points over the greenhouse with one tomato plant per sample point. One fully expanded leaf by sample point with an interval of a week were taken. Nitrogen (N), phosphorus (P), potassium (K), sulfur (S), sodium (Na), and chloride (Cl) were determined in each sample. According to these results, N, P, K, S, Cl, and Na concentration showed no variation over the time. The spatial variability of N, P, and K could be related with the light intensity and yield. The suggested number of leaf sub-sample ranging from 25 to 126 depending on nutrient.     

Spatio-temporal variations in nutrient concentration in soil solution under greenhouse tomato

The aim of this trial was to study the spatio-temporal variability in solution nutrient concentration under intensive greenhouse tomato production, to determine the number of suction-cups needed to obtain a representative sample and the influence by the position in the greenhouses. Twenty sampling points were selected within the greenhouse with one suction-cup per sampling point. One soil solution were sampled per point at weekly intervals to analyze for pH, electrical conductivity, chloride, nitrate, phosphate, sulfate, sodium, potassium, calcium, and magnesium (EC, Cl^?, NO₃^?, H₂PO₄^?, SO₄^2—, Na⁺, K⁺, Ca²⁺, and Mg²⁺) concentrations. The pH, Cl^?, H₂PO₄^?, and SO₄^2? concentrations showed no spatio-temporal variation but EC, NO₃^?, and K⁺ showed temporal variation. The spatial variability in EC, K⁺_, Na⁺, Mg²⁺, and Ca²⁺ can be influenced by microclimate and topography. The numbers of suction cups required for a representative sample ranged from 1 to 10 depending on nutrient.     

Nitrogen application rates for greenhouse tomato based on real-time diagnosis of petiole sap: Effects of soil nitrate contents before cultivation

(pp. 825–831)

This study was carried out to clarify the effects of soil nitrate before cultivation and amounts of basal-dressed nitrogen on additional N application rate and yields of semi-forced tomato for three years from 1998 to 2000. The amounts and timing of additional N dressing were determined based on diagnosis of petiole sap nitrate. The top-dressing was carried out with a liquid fertilizer when the nitrate concentration of a leaflet's petiole sap of leaf beneath fruit which is 2–4 cm declined below 2000 mg L^?1.

For standard yield by the method of fertilizer application based on this condition, no basal-dressed nitrogen was required when soil nitrate before cultivation was 150 mg kg^?1 dry soil or higher in the 0–30 cm layer; 38 kg ha^?1 of basal-dressed nitrogen, which corresponds to 25% of the standard rate of fertilizer application of Chiba Prefecture, was optimum when soil nitrate before cultivation was 100150 mg kg^?1 dry soil; 75 kg ha^?1 of basal-dressed nitrogen, which corresponds to 50% of the standard, was optimum when soil nitrate before cultivation was under 100 mg kg^?1 dry soil. A standard yield was secured and the rate of nitrogen fertilizer application decreased by 49–76% of the standard by keeping the nitrate concentration of tomato petiole sap between 1000–2000 mg L^?1 from early harvest time to topping time under these conditions.     

Evaluation of the Nutrients Variability in Sap of Different Petiole Samples in Tomato Plant

The aim of this trial was to study the variability of anions and cations concentrations in the different petiole samples: young leaves (YL), mature leaves (ML) and aged leaves (AL). The experimental design consisted of four blocks and four plants per block being each plant one replication. In each plant, petiole samples were collected at 135 days after transplanting (DAT) to determine chloride, nitrate-nitrogen, phosphate-phosphorus, sulfate-sulfur, sodium, potassium, calcium, and magnesium (Cl^?, NO₃^–N, H₂PO₄^–P, SO₄^2–S, Na^+, K⁺, Ca²⁺ and Mg²⁺) concentrations. Our results showed that the selection of sample petiole in the tomato crop did not modify the Ca²⁺, Cl^?, SO₄^2–S and Na⁺ concentrations, while NO₃^–N, K⁺, Mg²⁺ and H₂PO₄^–P concentrations showed a great variability due to the selection of the sample petiole, therefore it is necessary to be careful with the sample selection.     

Polyhalite as a sulfur source for fresh market tomato production in Brazil

Abstract

Polyhalite (PH), a naturally occurring multinutrient fertilizer containing potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S), has improved tomato (Solanum lycopersicum L.) production in Brazil but a specific response by tomato to the S in PH is not confirmed. We compared four S sources – PH, sulfate of potash (SOP), sulfate of potash magnesia (SOPM), and single super phosphate (SSP) – applied at a target application rate of 40?kg?S?ha^?1 to fertilizers with no S (muriate of potash, MOP), and no K or S at commercial application rates in three commercial fields in Brazil with nitrogen (N), phosphorus (P), and K applied at recommended rates of 355, 500, and 200–300?kg?ha^?1, respectively. Consistent across locations, PH increased total yields over the control, MOP, and SSP, with SOP and SOPM higher than the control but not MOP or SSP. Only PH increased marketable yields compared to the control. Yields increased linearly with fruit numbers per plant which were higher for PH than the control or MOP, indicating higher fruit set in PH contributed to yield differences. While fertilizers increased leaf K and S concentrations and soil test K and SO₄–S, yield differences did not appear to be related solely to either K or S fertilization, nor to Mg fertilizers to which there was no response. Leaf and fruit Ca concentrations were higher in PH than the control and MOP at some locations suggesting Ca improved fruit set in PH. Results suggest tomato likely responded to the multinutrient content or solubility pattern of PH.     

Anionic relationships in leaf petiole sap of tomato and capsicum plants growing in a glasshouse

The nitrate, chloride and sulphate content and their interaction effects in capsicum and tomato plants growing in glasshouse under fertigation systems was studied. Using leaf petiolesap concentrations as an index of the uptake rhythm, it was found that nitrate‐chloride and nitrate‐chloride plus sulphate relationships are regulated by potential or logarithmical laws. Nitrate‐sulphate interactions only appear clear in capsicum plants, but not for tomato.

The utilization of these interaction curves may permit the use of waters with a relatively high saline level for the irrigation of the both capsicum and tomato plants, by suitable planning of the nitrate supply in the fertigation program.     

Response of tomato to polyhalite as a multi-nutrient fertilizer in southeast Brazil

Abstract

Limited information on the agronomic performance of polyhalite (K₂SO₄.MgSO₄.2CaSO₄.2H₂O) motivated us to establish two field trials in Sao Paulo, Brazil. The objective was to evaluate the comparative responses of tomato to muriate of potash (MOP), sulfate of potash, potassium magnesium sulfate, and polyhalite at different graded doses of potassium (K) application supplying varied amount of secondary nutrients. Under very low soil K conditions, polyhalite resulted in significantly higher marketable fruit yield, and higher foliar and fruit K and sulfur (S) concentrations than other K sources. This was not the case under medium soil K levels, that is, 101?mg?kg^?1. Likewise, polyhalite enhanced postharvest residual soil calcium (Ca), magnesium (Mg), and S than other evaluated sources. Depending on soil nutrient status and the cost of polyhalite, tomato farmers of Brazil could consider polyhalite as an option to meet crop K and secondary nutrient requirements.     

磷、钾与钙配合对保护地番茄钙吸收的影响

采用随机区组设计方法研究了石灰性土壤磷、钾与钙配合对保护地番茄钙吸收的影响,并利用差值法计算了钙的利用率。研究结果表明,CaP1和CaK2处理最佳,可以显著提高保护地番茄总吸钙量和果实吸钙量,提高钙的利用率;与单纯施钙处理相比,钙的利用率分别提高10.3和16.1个百分点,同时,CaP1和CaK2处理能明显改善保护地番茄生物学特性,显著提高番茄果实产量;与单施钙处理相比,番茄的果实产量分别提高了16.1%和22.9%。研究结果同时证明钙磷配合或钙钾配合施用可以提高番茄果实中Vc的含量、糖分含量,降低酸度含量和脐腐病果的数量,明显地改善果实的品质。     

日光温室番茄的氮素追施与反馈调控

在施用足量有机肥的基础上,以山东寿光当地的常规氮肥追施措施为对照,通过结合硝酸盐速测技术对日光温室秋冬茬番茄不同生育时期的氮素供应进行实时动态调控,以确定合理的追肥数量。结果表明,同当地农民的常规处理相比,采用实时调控处理的氮素投入总量减少了N170kg.hm2,但对番茄的生长(株高、茎粗、果实发育速度等)、产量和品质等指标没有任何影响。根据追肥前根层土壤氮素的供应水平(0—30cm土壤NO3--N含量+氮素追施数量)的监测,可初步确定日光温室秋冬茬番茄在第一穗果膨大期、第二穗果膨大期和第四穗果膨大期时的氮素供应目标值最多为N296kg.hm2、216kg.hm2和191kg.hm2。与此同时,将每个时期所确定的目标值应用在同期生长的其它3个日光温室的番茄氮素追施调控,结果发现与相应的农民常规处理相比,实时调控处理对作物的生长同样没有影响,这表明在日光温室秋冬茬番茄生产过程中,结合植株和土壤硝酸盐速测技术,通过施肥调控满足作物在不同生长时期的氮素供应水平是可行的。     

Effects of Wood Ash Dose and Formulation on Soil Chemistry at Two Coniferous Forest Sites

Harvesting stem biomass from the forest inevitably involves exporting nutrients from the ecosystem. The amount exported is increased when the logging residues are also removed for use as fuel. Recycling of the resulting wood ash has been advocated as a measure to compensate for the nutrient losses and to sustain future forest production. The physical formulation of the wood ash may have an important influence on its effects on soil properties. In this paper, we report effects of two different types of wood ash (one self-hardened and crushed, the other pelleted), with differences in solubility, on soil chemistry in the humus layer and upper 15 cm of the mineral soil, at two coniferous sites in south-central Sweden, 5 yr after their application. The crushed ash was applied at three doses (3, 6 and 9 ton ha^–1), while the pelleted ash was applied at only one dose (3 ton ha^–1). At both sites the soil was podzolized. The two sites differed with respect to soil conditions, despite being situated only a few kilometers apart. The application of wood ash increased both soil pH and base-cation content in the humus layer at both sites. In the mineral soil, the effects were less pronounced. Treatment effects on soil chemistry did not differ between the two ash formulations. The retention (i.e. the extractable amount of nutrients found in the soil that could be attributed to the ash application) of nutrients varied strongly between the two sites, and K retention (ca. 10%) was generally lower than that of Ca and Mg.     

荔枝、龙眼叶片中钾、钙、镁交互作用指标诊断标准的建立

植物钾、钙和镁3种养分之间存在交互作用,因此于2016~2019年在华南荔枝、龙眼主产区22个妃子笑荔枝园和8个储良龙眼园采集末次梢老熟期和果实膨大期叶片样本,测定叶片钾、钙、镁元素含量,用充足范围法研究荔枝、龙眼不同生育期的钾、钙、镁交互作用指标[K/Ca、K/Mg、K/(Ca+Mg)及Ca/Mg]的诊断标准值。结果表明,荔枝、龙眼叶片中钾、钙、镁交互作用指标在同一年份同一生育期的不同树之间、不同年份的同一生育期之间以及同一生长周期的不同生育期之间的差异均很大。但是,荔枝、龙眼高产群体的上述指标在不同年份的同一生育期的差异明显较小,而同一生长周期内不同生育期的差异仍为极显著(P<0.001),表明不同生育期应有不同的诊断标准。利用充足范围法,在荔枝叶片钾、钙、镁含量处于适宜范围的基础上,末次梢老熟期叶片K/Ca、K/Mg、K/(Ca+Mg)和Ca/Mg的适宜水平分别为3.1~4.2、4.1~4.9、1.8~2.2和1.15~1.54,果实膨大期的分别为0.51~0.92、1.63~2.81、0.40~0.73和2.62~3.66;在龙眼叶片3种养分含量为适宜水平的前提下,末次梢老熟期叶片K/Ca、K/Mg、K/(Ca+Mg)和Ca/Mg的适宜水平分别为1.55~2.06、8.9~10.2、1.32~1.69和5.1~6.2;果实膨大期的分别为0.46~0.61、5.3~7.5、0.42~0.56和11.1~12.8。上述指标为诊断荔枝、龙眼叶片中钾、钙、镁营养的平衡状态及指导3种养分的平衡施用提供了数据参考。     

Concentrations and uptake of macronutrients by oat and pea in intercrops in response to N fertilization and sowing ratio

Intercropping is of increasing interest in temperate-arable farming systems. The influence of nitrogen (N) fertilization and sowing ratio on concentrations and uptake of calcium (Ca), potassium (K), magnesium (Mg) and phosphorus (P) by oat and pea was assessed in three substitutive intercrops on a fertile soil in eastern Austria. N decreased Ca in oat grain and increased P in pea grain as well as Ca and Mg in oat residue and Mg and P in pea residue. Intercropping did not affect nutrient concentrations of oat grain, whereas a lower pea share in intercrops increased P in pea grain. In residue, Ca, K and Mg concentrations were higher in oat and Ca and K partly lower in pea with a lower share of each crop. The oat-dominated intercrops could partly achieve a slightly higher total grain nutrient yield than pure stands at no or low N; however, these benefits diminished with a higher pea share and N input. In comparison to pure stands, higher residue nutrient yields were obtained by intercropping in all sowing ratios and fertilization levels. Consequently, oat–pea intercropping can be a strategy for increasing the macronutrient yield of grain and especially of residue for ruminant feeding.     

Correlation of petiole sap nitrate-nitrogen concentration measured by ion selective electrode,leaf tissue nitrogen concentration,and tomato yield in Florida

The effectiveness of measuring petiole sap nitrate-nitrogen concentration (PSNC) using ion selective electrode (ISE) has been scrutinized due to claims that PSNC poorly predicts leaf tissue nitrogen concentration (LTNC) or crop yield. This study evaluated the relationship among PSNC, LTNC, and marketable yield of tomato (Solanum lycopersicum L.). Two tomato trials were conducted using seepage irrigation and controlled-release fertilizer (CRF) in fall 2011 and 2012. At 15 days intervals, six most recently mature leaves were collected to measure PSNC and LTNC. PSNC and LTNC declined throughout the growing seasons, but PSNC was affected by weather. PSNC and LTNC were correlated (P = 0.0001, r = 0.38), though not meaningfully. PSNC and LTNC correlated negatively and positively with crop yield in most correlations, respectively. Correlations of CRFs and soluble fertilizers (SFs) separately, did not improve relationships. Measuring LTNC may be a more reliable nutrient management tool compared to PSNC measured using an ISE.     

增施钾肥对日光温室番茄产量和品质的影响

研究了增施钾肥对日光温室番茄产量和品质的影响。结果表明，在农民习惯施肥的基础上，合理增施钾肥可提高日光温室番茄的单果重和单株结果数，大幅度提高番茄产量；合理增施钾肥可显著增加农民种植番茄的纯收入；番茄的含糖量、Vc含量随钾肥的增施有升高的趋势，NO3^--N含量随钾肥的增施有降低的趋势。在增施钾肥的基础上，适当减少氮肥用量可提高番茄含糖量。在农民习惯施肥的基础上（即每公顷施45m^3鸡粪，N600kg，P205300kg，K20300kg），每公顷增施K2O 150kg比较适宜。     

Short-term variation in the concentration of selected ions within individual tropical rainstorms

Rainwater was collected at the campus of the University of Brunei Darussalam in Bandar Seri Begawan, Brunei Darussalam, using a funnel-in-bottle sampler. Polypropylene bottles were changed at intervals during rainstorm events. The pH and conductivity were determined immediately after collection on aliquots of the sample. Samples were refrigerated at 5°C for subsequent chemical analysis. Analyses for Na, Mg, Ca, Zn and Fe were carried out by means of inductively coupled plasma atomic emission spectroscopy (ICP-AES); Cu and Mn were analysed by graphite furnace atomic absorption spectroscopy (GFAAS); K was analysed using flame atomic emission spectroscopy (FAES); and Cl^–, NO₃ ^– and SO₄ ^2– were analysed by ion chromatography (IC). Concentration versus time profiles are reported for three rainstorm events. All ions exhibited a decrease in concentration during the rainstorm. The first sample contained the highest concentration of ions, consistent with a first-flush effect. The contribution of the initial stages of the shower to the total quantity of ion deposited during the entire rainstorm is quite overwhelming; in many cases 20 to 30% of the mass was deposited in less than 5% of rainstorm duration. On the other hand, the pH and conductivity variation during rainstorms did not exhibit a consistent pattern.     

Effects of biosolids from tomato processing on soil fertility and wheat growth in a Greek alfisol

The effects of biosolids from tomato processing on soil properties and wheat growth were investigated in an Alfisol from central Greece. Biosolids were mixed with soil from the surface (Ap) or subsurface (Bt) horizon in plastic containers at rates of 1%, 5%, and 10% by dry weight (d.w.; equivalent to 10, 50, and 100 Mg ha^–1). Biosolid treatments were compared to an NH₄Cl application (50 mg N kg^–1) and an untreated control in (1) a 102 d incubation experiment at 28°C to determine biosolid nitrification potential and (2) a 45 d outdoor experiment to evaluate effects on soil fertility and wheat growth. Mineralization of biosolids in the incubation experiment resulted in accumulation of nitrate‐N and indicated that biosolids were able to supply N that was in excess of crop needs in treatments of 5% and 10%. After 45 d of wheat growth, available soil nutrients (N, P) and P uptake by wheat were distinctly lower in the Bt than in the Ap horizon. However, soil pH, electrical conductivity, organic matter, total N, nitrate‐N, extractable P, and exchangeable K increased with increasing rate of biosolid application in both soils. These were followed by corresponding increases in wheat nutrient uptake and biomass production, thus demonstrating the importance of this organic material for sustaining production in soils of low immediate fertility. Compared to the NH₄Cl treatment (50 kg N ha^–1 equivalent), biosolid application rates of 5% and 10% had higher available soil nutrients, similar or higher nutrient uptake and higher wheat biomass. But only an application of 10% biosolids provided sufficient N levels for wheat in the surface soil, and even higher applications were required for providing sufficient N and P in the Bt horizon.     

Effects of ammonium and inorganic carbon enrichment on growth and yield of a hydroponic tomato crop

Effects of varying the proportions of NO₃^— and NH₄⁺ in the growth medium on seedling growth and tomato fruit yield (Lycopersicon esculentum L. cv. Trust F1) were investigated in greenhouse hydroponic experiments. The presence of NH₄⁺ as the sole N source (11 mM) was toxic: it curtailed growth and decreased chlorophyll content of the leaves. However, at low concentration (10 % of total N), the presence of NH₄⁺, with or without added dissolved inorganic carbon (DIC), increased vegetative growth and fruit yield by ˜ 15 %, and enhanced taste/flavor of the fruits. In DIC‐enriched treatment, pH was maintained at 5.8 by addition of KHCO₃ or as CaCO₃. The presence of NH₄⁺, at 10 % of total N, inhibited NO₃^— uptake rates by ˜ 27 %. The rates of uptake of NO₃^— and NH₄⁺ were comparable (13.3 and 14.2 mmol plant^—1 d^—1, respectively, in the presence of DIC, and 14.7 and 14.0 mmol plant^—1 d^—1, respectively, in the absence of DIC), despite such a large difference in their concentrations in the nutrient feed solution. A higher proportion of NH₄⁺ (up to 50 % of total N) had no further significant effect upon early vegetative growth, but in a long‐term experiment resulted in a high incidence of blossom end‐rot (BER) disease, thereby severely curtailing fruit yield. The presence of even 1.1 mM NH₄⁺ reduced Ca²⁺ and Mg²⁺ accumulation in the leaves as well as in fruits.     

滴灌条件下控释专用肥对设施番茄氮钾吸收及其残留的影响

【目的】设施蔬菜生产中水肥的过量投入不仅引发环境污染问题,而且增加生产成本。因此迫切需要通过调整肥料养分释放速率,在满足作物营养充分供应的同时,降低肥料和劳动投入,提高产出。为此,本文研究了习惯施肥与3种番茄控释专用配方肥对京郊番茄产量、品质、氮钾吸收以及土壤中硝态氮和钾残留的影响,以期为番茄的合理施肥提供依据。【方法】采用蔬菜大棚内小区试验的方法,试验设对照（不施氮肥,CK）、 有机肥（只施有机肥,MN）、 习惯施肥（施N 300 kg/hm2,TN）、 控释专用肥Ⅰ（CN1）、控释肥专用肥Ⅱ（CN2）和控释肥专用肥Ⅲ（CN3）共6个处理。3个专用肥的氮由80%的控释氮与20%速效氮构成,作为基肥一次性施入,用量与习惯施肥相同,除CK外其他处理的有机肥用量均为8 t/hm2。 控释肥为自制的聚合物包膜尿素（含N 42%）和包膜硫酸钾（含 K2O 47%）。包膜尿素3种,2个为延迟释放型,1个为直线释放型;2种包膜钾肥均为直线释放型。按不同比例组成3种专用肥。试验采用自压式滴灌系统,每畦安装一条滴灌管,共灌水6次,各小区等量灌溉,分别在移栽及移栽后第44、65、73、79和89 d灌水,每次分别为45、37、35、28、30和27 mm,每小区总量均为202 mm。小区面积为24 m2,每个处理3次重复,随机排列。高畦栽培,畦宽1.4 m,双行定植,行距40 cm,株距40 cm。【结果】 各处理番茄鲜果产量为79.2~87.1 t/hm2,其间无显著差异。CN3处理果实的硝酸盐含量增加,但Vc含量却下降,果实品质有所降低。3个控释肥处理的S型控释肥表现为前控后促的供氮趋势,在果实膨大期无机氮供应达到N102247 kg/hm2,与习惯施肥处理多次追肥形成的供氮规律相似。控释钾肥仅释放23.2%~36.0%,环境温度对于控释钾肥的释放促进作用很小。收获后土壤硝态氮的残留主要集中在表层（020 cm）和次表层（2040 cm）,占0100 cm土层的87.1%;060 cm土层内,CN3处理的NO-3\|N残留量与习惯施肥相当,而CN1和CN2处理的NO3--N残留比习惯施肥减少37.3%~55.0%,有效降低了硝态氮向下淋洗。施肥增加了各处理表层土壤中的钾含量,表层以下各处理的钾含量差别不大。【结论】3个专用肥处理中控释肥一次性施用不仅节约了施肥时间和劳动成本,而且在果实膨大期提供了充足的氮素供应,实现了与作物氮素吸收的同步。控释专用肥配方1和配方2可以提供合理的氮素供应,在降低劳动投入和节水的情况下,番茄产量和果实品质不降低,并减少了硝态氮的淋洗损失。     

山东省种植区地下水硝酸盐污染空间变异及分布规律研究

近年来,我国部分地区地下水硝酸盐污染态势十分严峻,特别是集约化种植区由于施用大量氮肥导致的硝酸盐污染更为严重。为控制污染,应掌握地下水硝酸盐污染的空间变异规律与分布特征。采用地统计学方法,对山东省种植区地下水硝态氮含量数据进行空间变异分析。结果表明,不同区域地下水硝态氮含量存在一定的差异,存在明显的趋势效应以及变异性,且含量随地下水深度增加而减少。通过相关性分析,获得与地下水硝态氮含量相关性最高的两个因子（土壤有机质含量和全氮含量）,并作为协克里金（Cokriging）插值方法中的协同因子,对山东省地下水硝酸盐污染进行插值。经比较分析,协克里金法比普通克里金法（Ordinary Kriging）的精度高,减少了80%的平均误差。协克里金法空间插值结果表明,空间分布规律表现在从西南到东北逐渐升高的方向性效应,而地下水硝态氮含量较高的区域主要分布在潍坊、青岛、烟台种植区,如青岛的平度、莱西,潍坊的寿光等农业较发达的种植区。     

水培条件下加入钾和硅减轻甘蔗盐胁迫效应

A hydroponics experiment was conducted to evaluate the role of potassium (K) and silicon (Si) in mitigating the deleterious effects of NaCl on sugarcane genotypes differing in salt tolerance. Two salt-sensitive (CPF 243 and SPF 213) and two salt-tolerant (HSF 240 and CP 77-400) sugarcane genotypes were grown for six weeks in ? strength Johnson’s nutrient solution. The nutrient solution was salinized by two NaCl levels (0 and 100 mmol L-1 NaCl) and supplied with two levels of K (0 and 3 mmol L-1) and Si (0 and 2 mmol L-1). Applied NaCl enhanced Na+ concentration in plant tissues and significantly (P ≤ 0.05) reduced shoot and root dry matter in four sugarcane genotypes. However, the magnitude of reduction was much greater in salt-sensitive genotypes than salt-tolerant genotypes. The salts interfered with the absorption of K+ and Ca2+ and significantly (P ≤ 0.05) decreased their uptake in sugarcane genotypes. Addition of K and Si either alone or in combination significantly (P ≤ 0.05) inhibited the uptake and transport of Na+ from roots to shoots and improved dry matter yields under NaCl conditions. Potassium uptake, K+/Na+ ratios, and Ca2+ and Si uptake were also significantly (P ≤ 0.05) increased by the addition of K and/or Si to the root medium. In this study, K and Si-enhanced salt tolerance in sugarcane genotypes was ascribed to decreased Na+ concentration and increased K+ with a resultant improvement in K+/Na+ ratio, which is a good indicator to assess plant tolerance to salt stress. However, further verification of these results is warranted under field conditions.