Nutrient concentrations of turfgrass and soil test levels as affected by soil media and fertilizer rate and placement

Abstract

There has been a trend toward using sandier growing media on highly trafficked turf areas to combat the detrimental effects of compaction on soil physical properties. Use of sand to modify, or even replace, existing soil also affects the nutrient status of these turf areas and could lead to both macronutrient and micronutrient deficiencies. Greenhouse experiments were conducted to determine the effects of natural organic fertilizer (Milorganite) or micronutrient supplement (Esmigran) applied to the surface or incorporated at several rates on the nutrient concentration of ‘Pennfine’ perennial ryegrass (Lolium perenne L.) grown on quartz sand, a sand‐peat topdressing mix, and a silt loam soil. Effects of Milorganite rate were most apparent on sand and topdressing, and, with at least one soil for one harvest period, increased rates of Milorganite resulted in increased tissue concentration for phosphorus (P), potassium (K), calcium (Ca), sulfur (S), manganese (Mn), iron (Fe), copper (Cu), and zinc (Zn). With Esmigran, increases in tissue concentration due to rate were found for Mn, boron (B), and Zn. Interactions among soil, rate, and application method made it difficult to generalize concerning nutrient availability from these fertilizers. Effects tended to be most obvious with sand and were more apparent with surface applications in some cases and with incorporation in others. Tissue analysis was superior to soil testing for assessing the nutrient status of a turfgrass stand.     

Long-Term Inorganic Fertilization Effect on the Micronutrient Density in Soil and Rice Grain Cultivated in a South Korean Paddy Field

Soil fertility exerts a direct influence on the essential micronutrient contents of food crops. The focus in this study was on the role that long-term inorganic fertilization (nitrogen (N), phosphorous (P) and potassium (K)) plays in increasing the micronutrient output of the paddy cropping system. After more than 45 years of inorganic fertilizer application, the combined application of fertilizers (PK > NP > NK) substantially increased As (arsenic), B (boron), Cd (cadmium), Co (cobalt), Cr (chromium), Cu (copper), Fe (iron), Mn (manganese), Mo (molybdenum), Ni (nickel), Se (selenium), V (vanadium) and Zn (zinc) density in the soil and rice grain. Optimized and continuous application of PK fertilizers increased the overall micronutrient densities in rice milling fractions (grain and bran). Micronutrient concentrations were usually the highest in bran. Both grain and bran were rich in Fe, Mn and Zn. Correlation analysis indicated that soil pH and organic matter exert a significant and direct effect on the micronutrient concentration of rice. Although long-term fertilization enhanced the proportion of micronutrients in rice grain, the levels were still much lower than the recommended dietary intake levels for micronutrients. We therefore suggest high consumption levels of brown rice (with micronutrient-dense bran layer) because they may increase the daily intake level of micronutrients and meet the nutritional requirements that people need for sound health.     

Micronutrient needs ‐ which,where, on what ‐ in the United States

Abstract

A summary of four micronutrient surveys conducted between the years 1961 and 1967 revealed that one or more of the six micronutrient elements are recommended in every state. Micronutrient recommendations may be found for all the major field, forage, vegetable, fruit and nut crops grown in the United States. Forty‐three .states recognize and make recommendations for B, 16 for Cu, 23 for Fe, 31 for Mn, 24 for Mo and 39 for Zn. Most of the recognized micronutrient deficiencies occur in specific areas and on specific crops. Cu seems to be the only micronutrient for which this is not true. The tonnage of all micronutrient fertilizers sold in 1968 represents only 0.25% of the total NPK tonnage, although its dollar value is about 2% of total dollar value of all NPK fertilizers sold.     

长江中游农田土壤微量养分空间分布特征

为了更好地掌握长江中游土壤肥力状况,运用地统计学和Arc GIS技术相结合的方法,对湖北、湖南、江西三省41 943个土壤样品的微量养分(铁Fe、锰Mn、铜Cu、锌Zn、硼B)含量的分布特征和空间变异进行研究。结果表明,长江中游土壤有效态Fe、Mn、Cu、Zn、B的平均含量分别为88.0、27.2、3.05、1.71、0.41 mg kg-1。空间分布特征表现为Fe、Mn均以江汉平原区较低,Zn以湖南省较低,Cu、B空间分布较为不均;与第二次土壤普查结果相比,土壤微量养分含量均有所提高,其中Fe、Mn、Cu含量为缺乏或严重缺乏的面积比例分别降至0.1%、2.2%和0.1%,而Zn和B分别为30.8%和17.7%。不同的土地利用类型、土壤类型和成土母质对土壤微量养分均有不同程度的影响。随着微量养分在农业生产中的贡献越来越突出,亟须根据土壤微量养分的分布特征进行分区管理。     

长期不同施肥对南方黄泥田水稻子粒与土壤锌、 硼、 铜、 铁、 锰含量的影响

在福建黄泥田长期定位施肥试验的第26年,研究了不同施肥模式对水稻子粒与土壤微量元素含量的影响。结果表明,与不施肥（CK）相比,化肥+牛粪（NPKM）、 化肥+秸秆还田（NPKS）及单施化肥（NPK）处理的水稻子粒Zn、 B、 Cu含量均有不同程度的提高,并尤以NPKM处理最为明显,三种微量元素含量分别提高14.3%、 25.1%、 465.2%,均达差异显著水平。NPKM与NPKS处理还不同程度地提高了子粒Mn含量,但各施肥处理的子粒Fe含量均显著降低。各施肥处理尤其是NPKM与NPKS均显著提高了子粒微量元素吸收量。NPK处理的土壤有效B、 Fe、 Zn、 Cu含量与CK相比均呈下降趋势,且有效Zn、 Mn含量较试验前土壤分别降低了36.4%与24.6%,而NPKM与NPKS处理缓解了下降趋势,且NPKM处理的土壤有效Zn、 B、 Mn含量分别较CK提高46.6%、 52.0%、 43.0%,均达差异显著水平。土壤有机质与子粒B、 Cu、 Zn含量呈显著正相关,子粒必需氨基酸、 粗蛋白与子粒Zn含量呈显著正相关。以上结果说明,长期化肥配施牛粪或秸秆还田有利于提高水稻子粒Zn、 B、 Cu等微量元素含量和产量,改善子粒营养品质,一定程度上又可缓解土壤有效微量元素含量的下降,是适合南方黄泥田的施肥模式。     

Direct and Residual Effects of Micronutrients on Crops in a Pattern in Floodplain Soil

ABSTRACT

Different micronutrients have variable residual effects in the soil. Again, crops have variability in their response to applied micronutrient. An experiment was conducted in floodplain soil of Bangladesh using cauliflower, maize, and rice in a pattern to explore differential effects of micronutrients on crops. Seven treatments following additive element trial technique including a control were used in the study. Micronutrients were applied @ 3 kg Zn, 2 kg B, 2 kg Cu, 3 kg Mn, 5 kg Fe and 1 kg Mo per hectare. Cauliflower as the first crop of the pattern responded to direct application of both zinc and boron whereas significant residual effects of these elements were observed in the second crop (maize). In rice as the third crop, no significant residual effects were estimated. In floodplain soil, zinc and boron fertilizers are needed to apply in each third crop of a pattern where the second crop is nutrient exhaustive like maize.     

土壤作物微量养分含量与营养诊断指标

本文针对黄土地区微肥施用中存在的问题,研究了土壤、作物微量养分含量与施肥效应,提出了土壤、作物微量养分分级指标。初步拟定了土壤缺素临界值:有效锌、有效铜和水溶硼为0.5ppm,有效锰为7ppm,有效钼为0.05ppm,有效铁为2.5ppm。植株缺素临界值与毒害指标:锌为20ppm和400ppm,锰为30ppm和1,000ppm,硼为20ppm和500ppm。防治土壤,作物缺素的主要措施是:施用微肥,大量施用有机肥和有选择地灌溉污水也有一定作用,大量施用氮、磷化肥时应配合施用微肥。     

Long-Term Effects of Straw and Manure on Crop Micronutrient Nutrition under a Wheat-Maize Cropping System

Management practices have significant effects on crop micronutrient contents. This study examined effects of applying chemical fertilizers of nitrogen (N), phosphorus (P), and potassium (K) (NPK), alone or supplemented with straw or manure, under a wheat-maize cropping system in a 18-year experiment, on the crops’ iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) contents throughout the crops’ development. The micronutrient contents of both wheat and maize were above critical values during vegetative development, but Zn contents of maize ear leaves were sub-sufficient under all treatments. The wheat grain Mn, Cu, and Zn contents were lower under fertilized treatments than in unfertilized controls. Nutrient balance calculations showed that NPK application alone or with straw resulted in deficits of the four micronutrients, but not application of NPK supplemented with manure. Hence, application of micronutrients, such as Zn, through organic or inorganic fertilizers is recommended for this cropping system.     

Effect of manures and fertilizers on soil physical properties,build-up of macro and micronutrients and uptake in soil under different cropping systems: a review

Combined application of manures and fertilizers played a pivotal role in the improvement in soil physico-chemical properties, macro and micronutrients distribution and their transformations under different cropping systems. Based on a cropping system, the different levels of manures and fertilizers were used to study improvement in physico-chemical properties of soil. The aim was to explore the appropriate application of organic manures and inorganic fertilizers for improved sustainable yields of a cropping system. Intensive cropping systems lead to N, P, K, Zn, Cu, Fe, and Mn deficiencies in surface and subsurface soil, which could be refreshed with combined application of manures and fertilizers. The application of manures and fertilizers controls the pH and electrical conductivity of soil. Moreover, manures and fertilizers showed improvement is soil physical conditions viz. bulk density, particle density, porosity, and water holding capacity etc. Manuring coupled with fertilization helped to great extent for macro and micronutrient transformations in the soil. Under these transformations, the soil solution and water soluble component (fractions/pools) of soil is enriched with macro and micronutrients. There was a consistent declining trend of DTPA-extractable Zn, Cu, Fe, and Mn in the sub-surface soil in comparison to the surface layer, which may be ascribed to increase in pH with increase in depth and decrease of organic matter with depth. Similarly, manures reduced the concentration of residual macro and micronutrients in soil. Recently, integrated nutrient management system (INMS) is gaining importance vis-a-vis maintaining the soil fertility with conjunctive use of chemical fertilizers plus organic manures.     

Comparison of MnSO4 and MnEDTA for soybeans grown on two soils in the greenhouse

Abstract

A greenhouse experiment was conducted to compare MnSO₄ and MnEDTA as Mn sources. Four soil‐applied rates of each source were applied to two Coastal Plain soils, a Leefield s (pH 6.3) and an Alapaha is (pH 7.0). Plants were grown for 40 days and dry tissue weights were recorded along with leaf contents of Mn, Zn, Fe and Cu. The same ions were extracted from the soil with DTPA. The chelate source caused no differences in either extractable soil Mn or plant Mn between soils or among rates even when added at its highest rate of 2 μgMn/g. The sulfate source increased extractable soil Mn and plant Mn over the various rates but more so for the Alapaha soil than for the Leefield. Plant weights were not different between sources except on the averages for the Leefield soil. However, for the Leefield soil and the sulfate source, plant weights were lower for the check than for intermediate Mn rates due to Mn deficiency and lower for the high Ma rate (50 μg/g) presumably due to toxicity. A correlation coefficient of 0.866** was obtained for soil‐extracted Mn versus plant Mn concentration indicating that the DTPA was a good extractant for these two soils. High correlations between plant and soil Mn versus plant and soil Zn, Fe, and Cu for the chelate source showed that the MnEDTA affected metal ion availabilities other than just Mn. It was concluded that the MnSO₄ was the better source at the rates used and that for these soils the best rate was S μgMn/g applied to the soil.     

The relationship between phosphorus and copper concentrations in wheat

Abstract

Poorly managed kaolinitic soils are often too low in P and K for optimum agronomic crop production. Even though many of these soils have relatively high phosphate fixing capacities, P applied at sufficient rates to increase soil P to acceptable levels may induce micronutrient deficiencies. The purpose of this study was to evaluate the effects of applied and residual P on Mn, Zn, and Cu uptake by field grown wheat (Triticum aestivum). Treatments were a one‐time application of P (0, 64, 128, 256, and 384 kg/ha P) and K (0, 110, 220, 440, and 660 kg/ha K) rates arranged in a 5×5 complete factorial. The treatments were applied in October, 1977 and the study was continued through June, 1979. Potassium and P × K interactions did not have a significant effect on Mn, Zn, or Cu uptake. Phosphorus did not affect Mn concentration in the wheat tissue but Zn and Cu concentrations generally decreased as applied and residual soil P levels increased. The tissue Zn concentration at the various plant growth stages did not decrease below defined critical levels. The Cu concentration decreased linearly with applied P and curvilinearly with residual P. The tissue Cu levels often decreased below suggested critical levels. Total Cu in the wheat tissue indicated that the decrease in Cu concentration as P levels increased was not a simple dilution effect resulting from increased plant growth as applied and residual soil P increased.     

Sonic dispersion of soil DTPA solution suspension as an extraction procedure for DTPA micronutrient test

Abstract

To examine sonic dispersion as an extraction procedure for DTPA micronutrient test, soil DTPA solution suspensions were sonicated to extract Fe, Zn, Mn, and Cu. The elements extracted after 15 or 60 seconds sonication were compared with those extracted after 1/2 or 2 hours shaking.

The mean differences between Fe, Zn, Mn, or Cu extracted after 15 seconds sonication and those extracted after 1/2 hour shaking were not significant. However, the extractions obtained after 2 hours shaking were significantly higher than those obtained after 15 or 60 seconds sonication.

The elements extracted after 15 or 60 seconds sonication correlated significantly with those extracted after 1/2 or 2 hours shaking. Therefore, 15 or 60 seconds sonication can replace 2 hours shaking in the extraction procedure for DTPA micronutrient test. However, 15 seconds sonication is more convenient than 60 seconds and does not require cooling of soil solution suspension during sonication. Therefore 15 seconds sonication ‐ a replacement for 2 hours shaking to extract Fe, Zn, Mn, and Cu ‐ is recommended.     

Application of micronutrients to citrus trees through microirrigation systems

Using conventional soil and foliar spray applications to correct micronutrient deficiency in citrus has not been completely satisfactory. Therefore, this study was developed to test the effectiveness of micronutrient application through microirrigation (fertigation) at rates similar to those recommended for foliar spray application. Three field experiments were conducted on ‘Valencia’ orange [Citrus sinensis (L.) Osb.] trees to study the absorption of Fe, Mn, Zn, and Cu by periodically analyzing leaf samples. The effectiveness of fertigation with micronutriems was found to depend on the fertilizer source. Application of chelated Fe, Mn, and Zn through irrigation systems increased the concentrations of these micronutrients in the leaves. The nitrate forms of Fe, Mn, and Zn were ineffective, as was the sulfate form of Zn. The sulfate form of Mn was occasionally effective, but the sulfate form of Cu was very effective. The application of chelated micronutrients through fertigation shows promise in central Florida.     

Influence of sulfur and nitrogen fertilzer on the uptake of iron,manganese, and zinc by corn plants grown in calcareous soil

Abstract

A pot experiment was conducted with a coarse‐textured calcareous soil (pH‐H₂O 8.3) to study the effect of single and combined application of N and S fertilizers on soil pH, Fe, Mn, Zn, and P mobilization, and on growth and micronutrient uptake by com (Zea mays L.). Increasing amounts of elemental sulfur were mixed with the soil. To stimulate S oxidation, the treated soils were incubated for six weeks at field capacity. Nitrogen was applied as NH₄NO₃ (100, 200, and 400 mg N/kg). After six weeks, dry matter yields were recorded and shoots were analyzed for Fe, Mn, Zn, and P. At the end of the experiment, soil pH and the DTPA‐extractable micronutrients were determined. The results showed that: a. Soil pH was decreased by 0.2, 0.5, and 0.9 unit as a result of increasing S applications.

b. Applied sulfur and N fertilizer had increased the availability of micronutrients to following crops.

c. Application of N and/or S resulted in increased dry matter yields.

d. Manganese uptake tended to be higher as amounts of N applied increased; this was most evident at the higher S application rates. This effect was, however, reversed for Fe, Zn, and P uptake.

e. Under our experimental conditions, promising results were achieved on improving micronutrient availability and uptake when 400 mg N/kg was combined with 3 g S/kg.

     

Effect of sulfur additions on soil and the nutrition of wheat

Abstract

A field experiment was conducted for two years to determine the effects of four sulfur (S) sources applied at various rates on the elemental composition of Coker 747³ wheat and on the soil S concentration. The concentration of S in plants increased by all sources of applied S. Increased S in the soil from S application decreased P concentrations in plants regardless of the S source used. Sulfur additions did not significantly affect the concentrations of Cu, Ca, Mg, or N in plants. The concentrations of Mn, Zn, and Fe in plants either increased or decreased depending on S source used. Analysis of the silt loam soil to a depth of 90 cm revealed that applied S moved readily from the surface to the lower depths and that the elemental form of S moved less rapidly than the more soluble forms of applied S.     

Micronutrients in the Kootenai river valley of Northern Idaho. I. Effect of soil chemical properties on micronutrient availability

Abstract

Crops grown on soils of the Kootenai River Valley of northern Idaho are showing an increasing tendency for micronutrient deficiencies. These soils are generally high in organic carbon (OC) and slightly alkaline. Soil pH has been increasing at the rate of 0.2 units every 10 years for the last 30 years. Normal soil sampling and testing procedures have failed to identify potential deficiencies of micronutrients prior to planting crops. Consequently, a different way to predict the tendency of micronutrient deficiencies is desired. The objectives of this study were to: (1) evaluate the effects of soil pH and OC on DTPA‐extractable Cu, Mn, and Zn, (2) establish relationships between pH, OC, Cu, Mn, and Zn and soil mapping units and geographic areas (drainage districts), and (3) predict tendencies for deficiencies or sufficiencies of evaluated micronutrients. One hundred fifty‐four soil samples were collected from the surface 30 cm of fields in the Kootenai River floodplain during 1989 and 1990. Six soil mapping units and eleven drainage districts were sampled. Soil pH, OC and DTPA‐extractable Cu, Mn, and Zn were determined on each sample. AU collected data were analyzed with the GLM procedure of SAS and quartile reference was used to separate the data. Manganese availability was negatively correlated with pH and OC. Significant correlations were also found between Cu and soil pH, and Zn and OC. The pH x OC interaction significantly affected both Mn and Zn availability. Soil pH, OC, and DTPA‐extractable Cu, Mn, and Zn were used to categorize soil mapping units and drainage districts into low, medium, and high tendencies for micronutrient availability. This categorization can be used as a tool for growers and consultants for soil micronutrient management     

Spatial variability and evaluation of status of micronutrients in selected soils around Taihu Lake, China

Background, aim, and scope  Soil micronutrients are essential for plant growth and human health. Spatial variability and evaluation of soil micronutrient status are the research hotspot. The plain of northern Zhejiang Province, around Taihu Lake, China, is a key agriculture production area. With the rapid development of agriculture in Zhejiang Province, the management of soil micronutrients is of increasing concern to sustain crop productivity and human health. Soil-available micronutrients in the study region have not previously been studied in detail. Primary objective of this research was to examine the spatial distribution and evaluation of soil-available micronutrients in the arable land in this agriculturally important region using geostatistics. The controlling factors for the spatial variability of available micronutrients were interpreted. The research findings attained in the present study are of fundamental significance in providing a guideline for precise agriculture management practice and sustaining food security. Materials and methods  Amounts of available Fe, Mn, Cu, Zn, B and Mo in 1893 soil samples taken from the arable land in nine counties in northern Zhejiang Province, around Taihu Lake, were measured and their spatial distribution patterns were investigated. Available Mn, Fe, Cu, and Zn were extracted with DTPA and analyzed by inductively coupled plasma–atomic emission spectroscopy. Available B was extracted with boiled water, then determined by inductively coupled plasma–optical emission spectroscopy. Available Mo was extracted with Tamm reagent and was then determined by inductively coupled plasma-mass spectrometry. Geostatistics was conducted for the data processing. Results  More than 50% of the arable land were deficient in available Mo, while more than 70% had extremely low amount of available B. Amounts of available Cu, Zn and Mn were relatively high, whereas the soils are extremely sufficient in available Fe. The geostatisticical data shows that Mn, Cu, Zn, and Mo were best fit with an exponential model, while Fe and B were best fit with a spherical and linear model, respectively. Copper and Mo had strong spatial dependency, which is attributable to the effects of natural factors including parent material, topography, and soil type; Fe, Mn, and Zn had medium spatial dependency; however, B had weak spatial dependency, indicating an involvement of anthropogenic factors. Nevertheless, the six micronutrients studied all show spatial distribution trend to a certain extent. Discussion  Based on the provincial classification standard of soil micronutrients and the results of the present study, regionalized management of soil micronutrients was recommended. We divided the soil micronutrients investigated in the present study into three types: Type I (Fe), Type II (Mn, Cu, and Zn) and Type III (B and Mo). Type I is sufficient, and its amount needs to be controlled; otherwise, it will be toxic to crops. Type II is enough and its amount does not need to be increased currently through micronutrient fertilization. However, Type III is deficient in substantial areas in the region studied and its cause of deficiency needs to be investigated; its availability needs to be improved to sustain the crop production and food quality. The availability of B and Mo in the north of Zhejiang Province should be regionally managed. Over the past two decades, the spatial variability of soil-available micronutrients in the study region was attributable to the soil formation factors as well as anthropogenic activities such as fertilization, cultivation, and other soil management practices. The lower available B and Mo concentrations in the arable land were apparently due to continuous cropping and intensive applications of fertilizers without adequate supply of micronutrients. The high available Fe and Mn concentrations in the soils were attributed to increasing soil acidification and relatively high soil organic matter contents. The high available Cu and Zn levels of the soils in this region were attributed to intensive utilization of animal manure as fertilizers. Conclusions  Based on the provincial classification standard and the results from the present study, regionalized management of soil micronutrients was recommended. Moreover, the present study would provide an insight into understanding the basis for the development of innovative strategies for land management practices such as precision farming and environmental risk assessment. Recommendations and perspectives  The research findings attained in the present study would help to improve our understanding of spatially variable availability of soil micronutrients and providing a quantitative basis for decision and policy making to develop innovative agricultural management strategies to sustain micronutrient nutrition. Further research should be conducted to elucidate the relationship between soil micronutrient and plant growth and human health.     

长期施肥对潮土耕层土壤和作物籽粒微量元素动态的影响

Micronutrient status in soils can be affected by long-term fertilization and intensive cropping.A 19-year experiment (1990-2008) was carried out to investigate the influence of different fertilization regimes on micronutrients in an Aquic Inceptisol and maize and wheat grains in Zhengzhou,China.The results showed that soil total Cu and Zn markedly declined after 19 years with application of N fertilizer alone.Soil total Fe and Mn were significantly increased mainly due to atmospheric deposition.Applications...     

Methods of adding micronutrients to a NPK formulation and maize development

Micronutrients are essential for plant development; however, micronutrient content in soil often is not sufficient. This study compared availability of boron (B), copper (Cu), manganese (Mn), and zinc (Zn) in the soil and their effect in developing maize plants, supplied from a physical mixture of nitrogen, phosphorus, and potassium (NPK) granules and micronutrients or from a granulated mixture of NPK coated with these micronutrients. The experiment was conducted in a greenhouse, with a Rhodic Acrustox soil and the formulation 4-30-10 [nitrogen-phosphorus pentoxide-potassium oxide (N-P₂O₅-K₂O)] with 0.1% B, 0.2% Cu, 0.2% Mn, and 0.3% Zn. A randomized block design with four replicates was used and the NPK formula doses used were 0, 150, 300, 600, 1200, and 2400 kg/ha. Coated NPK increased Zn levels in soil in 0.5 mg/dm³ in relation to its initial content, also causing an increase in plant dry matter. Compared with mixture, this increase was more than three times greater. Cu and Zn accumulation and Zn absorption were greater when their supply was made via coated granules. The larger dose of B via coated granules resulted in a greater B accumulation in comparison to the mixture. No differences were observed for the other variables when comparing both sources. Coating NPK granules with micronutrients was better than the mixture when comparing B, Cu, and Zn concentrations in the soil. Dry matter production of maize shoots and the accumulation of B, Mn, Cu, and Zn in it was greater when the fertilizer was coated with micronutrients.     

Overcoming Fe deficiency in guava (Psidium guajava L.) by co-situs application of controlled release fertilizers

Abstract

Among micronutrient deficiencies, Fe deficiency is the most difficult nutritional disorder to prevent in the fruits of trees growing on calcareous soils. In this study, a pot experiment was carried out to evaluate the potential of co-situs application of controlled release fertilizers (CRF) in alleviating Fe deficiency and improving the growth of fruit trees growing on calcareous soil (pH 9.3). Guava (Psidium guajava L.) seedlings were used as test plants because of their sensitivity to Fe deficiency. Treatments consisted of the following: (1) broadcast application of readily soluble Fe, Zn, Cu, B and Mn fertilizers (Control) or (2) co-situs application of CRF containing N, P, K, Mg, Fe, Zn, B, Cu and Mn (Co-situs). For the Control treatment, CRF containing only N, P and K was used. Both treatments received the same amount of all nutrients. Plants were more chlorotic in young leaves under the Control treatment and the Fe content of young leaves was significantly (least significant difference [LSD_0.05]) higher under the Co-situs treatment. Dry matter production of shoots under the Co-situs treatment was 5.2-fold higher than under the Control treatment, and the total accumulations of macro and micronutrients were much higher under the Co-situs treatment than the Control treatment. Total accumulations of N, P, K, Ca and Mg were 5.0, 4.1, 9.6, 3.2 and 2.2-fold higher, respectively, under the Co-situs treatment compared with the Control treatment, and Fe, Zn, Cu and Mn accumulations were 3.2, 4.1, 6.0 and 3.7-fold higher, respectively. Iron deficiency in guava seedlings was successfully alleviated by the co-situs application of controlled fertilizer, proving the high potential of this method in alleviating Fe deficiency in fruit trees growing on calcareous soils.