Application of High Copper and Zinc Compost and Its Effects on Soil Properties and Growth of Barley

Abstract

A compost of high copper (Cu) and zinc (Zn) content was added to soil, and the growth of barley (Hordeum vulgare L.) was evaluated. Four treatments were established, based on the addition of increasing quantities of compost (0, 2, 5, and 10% w/w). Germination, plant growth, biomass production, and element [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sodium (Na), magnesium (Mg), iron (Fe), Cu, manganese (Mn), and Zn] contents of soil and barley were determined following a 16‐week growing period. Following harvesting of the barley, analysis of the different mixtures of soil and compost was performed. Micronutrient contents in soils as affected by compost additions were determined with diethylene–triamine–pentaacetic acid (DTPA) (Cu, Mn, Fe, and Zn) or ammonium acetate [Ca, Na, Mg, K, cation exchange capacity (CEC)] extractions, and soils levels were compared to plant uptake where appropriate. Increasing rates of compost had no affect on Ca, Mg, or K concentration in barley. Levels of Cu, Zn, Mn, and Na, however, increased with compost application. High correlations were found for DTPA‐extractable Cu and Zn with barley head and shoot content and for Mn‐DTPA and shoot Mn content. Ammonium acetate–extractable Na was highly correlated with Na content in the shoot. High levels of electrical conductivity (EC), Cu, Zn, and Na may limit utilization of the compost.     

Nutrient status of the lowbush blueberry,Lac‐Saint‐Jean area,Québec,Canada

Abstract

The lowbush blueberry (Vaccinium angustifolium Ait.) is an important commercial crop of the Lac‐Saint‐Jean area (Quebec, Canada). The major blueberry fields are located on sandy soils relatively poor in available mineral nutrients. The nutrients originate from a thin organic layer found on the top of these sandy soils. The leaf mineral contents (N, P, K, Mg, Ca, Mn, Fe, Cu, Zn and B) were measured in five blueberry fields during 1984 and 1985. Soil pH and soil available P, K, and Mg were also assessed. The results show that the leaf mineral contents are generally adequate. However, K and Zn might be occasionally deficient when compared to the actual established standards. The available Mg in soil was significantly correlated with the leaf Mg concentration. The data also suggest that the increase of the pH following the burn pruning seems to influence the nutrition of this species.     

Distribution and redistribution of mineral nutrients and dry matter in grain sorghum as affected by soil salinity

A study was made of the effects of soil salinity on dry matter production, grain yield, and the uptake, distribution and redistribution of mineral nutrients in irrigated grain sorghum. Soil salinity (EC, 3.6 mS/cm) reduced seedling establishment by 77%, and dry matter and grain yields per plant by 32%; grain yield/ha was reduced by 84%. Salinity reduced grain number per head, but not individual grain size. The accumulation of dry matter and most nutrients was reduced by salinity, but the distribution and redistribution of nutrients within the plant were largely unaffected. Redistributed dry matter provided 52 and 31% of the grain dry matter for control and salt‐affected plants, respectively. Salt‐affected plants had a greater proportion of their sulfur (S), magnesium (Mg), sodium (Na), and chloride (Cl) in stems and leaves than control plants at maturity. Grain had 50–90% of the nitrogen <N), phosphorus (P), S, and Mg, 20–50% of the potassium (K), manganese (Mn), zinc (Zn), and copper (Cu), but < 20% of the calcium (Ca), Na, Cl, and iron (Fe) contents of the whole plant. Over 65% of the N and P, and from 20 to 30% of the K, S, Mg, Cu, and Zn was redistributed from the stem and leaves to grain. There was no redistribution of Ca, Na, Cl, Fe, and Mn. Leaves were more important than the stem as a source of redistributed N, but the leaves and stem were equally important as sources of redistributed P, K, S, Mg, and Cu. Redistribution from the stem and leaves provided 80% of the K and 20–50% of the N, P, S, Mg, Zn, and Cu accumulated by grain. Concentrations of Na, and especially Cl, were high in vegetative organs of salt‐affected plants, but not in grain. It was concluded that although moderate salinity was detrimental to the establishment and yield of grain sorghum, it had little effect on patterns of distribution and extents of redistribution of mineral nutrients.     

Application of near‐infrared spectroscopy in analysis of soil mineral nutrients

Abstract

The feasibility of using near‐infrared reflectance spectroscopy (NIRS) was investigated for the analysis of pH, electrical conductivity (EC), phosphorus (P), sulfur (S), calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), iron (Fe), and manganese (Mn) in 28 Canadian soil samples from three boreholes down to 10 m in depth. Field moist soil samples were scanned for pH and EC, and air‐dry samples were scanned for the analysis of the elements. Calibrations were developed between the near‐infrared spectral data and results obtained by conventional analyses. The NIR‐predicted values were highly correlated to the measured values obtained by the conventional methods (r²>0.9) for P, Ca, Mg, K, Fe, and Mn, and almost as highly correlated (r²>0.8) for S and Na Results for pH were somewhat less successful (r²>0.6), and appeared to be useful only for screening purposes, whereas EC was not successfully predicted by NIRS in this study. It appeared that NIRS could be a useful method for the rapid, non‐destructive, simultaneous analysis of elemental concentrations in dry soils, useful in routine analysis.     

Evaluation of Ammonium Bicarbonate–Diethylene Triamine Penta Acetic Acid as a Multinutrient Extractant for Acidic Lowland Rice Soils

Abstract

Simultaneous extraction of nutrients using ammonium bicarbonate–diethylene triamine penta acetic acid (ABDTPA) extractant has been successful for highland soils, but its potential for lowland soils is still uncertain. This study evaluated the suitability of ABDTPA extractant to determine available phosphorus (P), potassium (K), sodium (Na), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) in lowland rice soils of Sri Lanka. Available nutrients were analyzed both by conventional and ABDTPA methods, using the original ABDTPA (1∶2 soil–extractant) method as well as a modified (1∶4 soil–extractant) method. Conventional methods tested were Olsen, Bray 1, and FeO strip for available P; neutral NH₄OAc extraction for exchangeable Ca, Na, K, and Mg; and DTPA extraction for available Zn, Cu, Fe, and Mn. Nutrient content and uptake by plants were determined by a pot experiment with rice (Oryza sativa). Nutrients extracted by the conventional methods and ABDTPA methods correlated well, in general, for all nutrients. Highly significant correlations were observed between plant uptake and extractable nutrients by 1∶2 and 1∶4 ABDTPA methods for P (r=0.85***and 0.73***, respectively), K (r=0.79*** and 0.66***, respectively), Na (r=0.86*** and 0.78***, respectively), Zn (r=0.66*** and 0.60***, respectively), Mn (r=0.72*** and 0.84***, respectively), and Fe (r=0.74*** and 0.68***, respectively). Calcium and Mg extracted by ABDTPA showed a poor relationship with their respective plant uptake. The ABDTPA method was as effective as or even better than the conventional methods in evaluating fertility status of lowland rice soils with respect to most nutrients. Replacing the conventional methods by the single ABDTPA multielement extractant will reduce the time and cost of soil analysis.     

Influence of salinity in irrigation water on forage sorghum and soil chemical properties

Abstract

Soluble salts found in wastewater can be toxic when used for irrigation of forages. Thus, two greenhouse experiments were conducted to investigate effects of saline [CaCl₂NaCl (3:1, w:w)] treatments on soil chemical properties and ‘Dekalb FS‐5’ forage sorghum [Sorghum bicolor(L.) Moench]. Treatments for the first experiment consisted of a nonsaline control or 500 mL of a solution with an electrical conductivity (EC) of 10 dS m^?1 applied once. In the second experiment, treatments were salinity levels of 1.7,3.5,5.2,8.5, and 12.2 dS m^?1, applied in non‐nitrogenous Hoagland's solution as the sole source of irrigation. Both experiments were replicated four times. For both experiments forage sorghum was seeded in pots containing 7 kg of air‐dried Amarillo fine sandy loam soil. Sorghum survivability and plant height were measured. In the second experiment, water use by sorghum was also measured. Plants were harvested 7 wk after seeding, weighed, dried at 55°C, weighed, and ground for subsequent mineral analysis. After harvest, soil salinity, pH, and in the second experiment, extractable soil elements were determined. Soil salinity increased, while soil pH decreased, with the salinity treatments. Extracted soil calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), manganese (Mn), and cadmium (Cd) increased while sulfur (S), iron (Fe), and copper (Cu) decreased, and aluminum (Al) and zinc (Zn) exhibited no change with increasing salinity. Sorghum aerial plant and root production decreased with increasing salinity. Plant Ca, strontium (Sr), Mn, and Cd levels increased with increasing salinity. In contrast, sorghum K, P, and S levels declined with increasing salinity.     

Effect of elemental sulphur and sulphur containing waste in a calcareous soil in Turkey

The effect of elemental sulphur (S) and S containing waste applications on soil pH treated with 0–2,000 kg ha^‐l elemental S, and 0–100 tons ha‐¹ of waste was determined in the field and the pots. Sorghum (Sorghum bicolor L.) was grown in a Lithic Xerorthent soil which was taken from where the field experiment was conducted in pots receiving 5 kg soil. Plants were harvested 20 weeks after planting or 30 weeks after the applications for determination of dry matter yield and phosphorus (P), iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu) uptake by shoots. EC, NaHCO₃‐extractable P, and DTPA‐extractable Fe, Zn, Mn, Cu also were measured in pot soil at the 5th, 10th, and 30th weeks. All treatments led to a decrease in soil pH though pH tended to increase again during course of time in both field and pot experiments. The both elemental S and waste applications in pot experiment caused an increase in dry matter yield and P, Fe, zinc (Zn), Mn and Cu uptake (mg pot^‐1) by shoots in sorghum plant. There was also an increase in EC of soil due to both applications of S. The concentration of available P extracted by NaHCO₃ in the pot soil, though not significantly different, was slightly higher compared with the control. Waste applications increased DTPA‐extractable Fe content of the soil, DTPA‐extractable Mn and DTPA‐extractable Cu. DTPA‐extractable Zn content, however, was reduced by the same applications.     

Effects of mes [2(n‐morpholino)‐ethanesulfonic acid] and ph on mineral nutrient uptake by mycor‐rhizal and nonmycorrhizal maize

Mycorrhizal (+VAM) and nonmycorrhizal (‐VAM) maize (Zea mays L.) plants were grown in sand culture in a greenhouse to determine effects of MES [2(N‐morpholino)‐ethanesulfonic acid] (2.0 mM) and pH (4.0, 5.0, 6.0, and 7.0) on mineral nutrient uptake. Plants were inoculated with the vesicular‐arbuscular mycorrhizal (VAM) isolate Glomus intraradices UT143. Shoot and root dry matter yields were lower in plants grown with MES (+MES) than without MES (‐MES), and decreased as pH increased. Shoot concentrations of N, Ca, Mg, Mn, and Zn were generally higher in +MES than in ‐MES plants, and nutrient contents of most nutrients were generally higher in + MES than in ‐MES plants. Concentrations of N, Ca, Mg, and Mn increased and P, S, and Fe decreased, while contents of all measured nutrients except Mn and Zn decreased as pH increased. Concentrations of Mn, Fe, Zn, and Cu were higher in +VAM than in ‐VAM plants, and contents of P and Ca were higher in ‐VAM than in +VAM plants and Zn content was higher in +VAM than in ‐VAM plants. MES had marked effects on mineral nutrient uptake which should be considered when MES is used to control pH of nutrient solutions for growth of maize.     

Critical nutrient concentrations and antagonistic and synergistic relationships among the nutrients of NFT‐grown young tomato plants

Critical concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn), and manganese (Mn) with respect to dry matter yield end antagonistic and synergistic relationships among these nutrients were studied in which tomato (Lycopersicon esculentum L.) was grown in recirculating nutrient solution (NFT). Increments of nutrient elements in the nutrient solution increased the proportional rate of the corresponding nutrient elements. Increasing levels of N negatively correlated with plant P and positively correlated with Ca, Fe, and Zn. Iron and Mn contents of the plants were increased and N, K, Ca, and Mg were decreased as a function of P applied. Increases in K in the nutrient solution caused increases in the concentrations of K, N, P, and Zn, and decreases in the concentration of Ca and Fe. Applied Ca increased the concentrations of Ca and N, and decreased the concentrations of P, Mg, Fe, Zn, and Mn. Potassium, Ca, and Fe contents of the plants were decreased and Zn increased, while N, P, and Mn were not affected by the increasing levels of external Mg. Iron suppressed the plant Mg, Zn, and Mn contents. Synergism between Zn and Fe was seen, while P, K, Ca, Mg, and Mn contents were not affected by Zn levels. Potassium, Ca, Mg, and Fe were not responsive to applied Mn, however, N and P contents of the plants were decreased at the highest levels of Mn.     

Sewage sludge incinerator ash effects on soil chemical properties and growth of lettuce and corn

Abstract

Incineration reduces sewage sludge volume, but management of the resulting ash is an important environmental concern. A laboratory incubation study and greenhouse pot experiments with lettuce (Lactuca sativa L.) and corn (Zea mays L.) were conducted to examine the potential for recycling elements in sewage sludge incinerator ash in agricultural systems. Ash rates in both the laboratory and greenhouse were 0, 0.95, 3.8, 15.2, and 61.0 g/kg soil (Typic Hapludoll). Ash was also compared to equivalent rates of citrate soluble P from superphosphate fertilizer in a soil‐less growth medium. During soil: ash incubation, Olsen P and DTPA extractable copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) increased with incubation time at the higher ash rates. Release rates diminished rapidly, however, and the limited release of these elements after 280 days was associated with decreasing pH. In the greenhouse, ash amendment increased extractable soil P, plant tissue P, and the growth of lettuce and corn. Ash was a less effective P source than superphosphate fertilizer in the soil‐less growth medium and Olsen P levels were more consistent with these differences than Bray P. Ash increased extractable soil levels and plant tissue concentrations of calcium (Ca), magnesium (Mg), sodium (Na), Cu, and Zn, but extractable soil manganese (Mn) and plant tissue Mn decreased. Ash increased soil pH and extractable SO₄‐S. DTPA extractable Cd and Pb increased, but chromium (Cr) and nickel (Ni) decreased. Lettuce accumulated higher amounts of these trace metals than corn, but tissue concentrations were at control levels or below detection limits in both crops.     

Effect of acid modification of biochar on nutrient availability and maize growth in a calcareous soil

The nutritional quality of acid‐modified poultry manure biochar is unclear, so a better understanding of its properties and agronomic potential is needed. The biochar was modified with phosphoric acid (H₃PO₄) and nitric acid (HNO₃) and a combination of the two, before and after pyrolysis. After characterization of biochar samples and determination of total and water‐soluble mineral element concentrations, biochars were applied to a calcareous soil at a rate of 0.5% (w/w) to find out their effects on the mineral nutrition and growth of maize. Treatment with H₃PO₄+ HNO₃ enriches the biochar with phosphate, nitro groups and nitrate. The experimental results suggested that biochar modified with HNO₃ and/or HNO₃+H₃PO₄ after pyrolysis increased the water‐soluble phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn), copper (Cu) and manganese (Mn) concentrations and increased plant‐available nutrients and plant growth by positively affecting the absorption of plant nutrients. The highest plant dry weight was obtained from biochar post‐treated with HNO₃+H₃PO_4, and this was followed by HNO₃‐ and H₃PO₄‐modified biochars. Premodification with HNO₃+H₃PO4 also significantly increased plant dry weights. The results of this study revealed that poultry manure biochar modified with HNO₃ and H₃PO₄ can be used effectively in calcareous soil for the improvement of plant mineral nutrition.     

A comparison of the chemical composition of the corn leaf and the grain sorghum leaf

Abstract

Leaf samples were taken from corn and grain sorghum being grown in adjacent fields with the same soil type and with the same cultural practices insofar as possible. The samples were analyzed for N, P, K, Ca, Mg, Fe, Zn and Mn. Results show that the nutrient composition of the leaves of corn and grain sorghum were consistently different for most nutrients. The differences were sufficiently great and consistent to strongly suggest that critical nutrient levels need to be established for grain sorghum instead of using diagnostic criteria established for corn.     

Soil properties and tree growth along an altitudinal transect in Ecuadorian tropical montane forest

In tropical montane forests, soil properties change with increasing altitude, and tree‐growth decreases. In a tropical montane forest in Ecuador, we determined soil and tree properties along an altitudinal transect between 1960 and 2450 m asl. In different vegetation units, all horizons of three replicate profiles at each of eight sites were sampled and height, basal area, and diameter growth of trees were recorded. We determined pH and total concentrations of Al, C, Ca, K, Mg, Mn, N, Na, P, S, Zn, polyphenols, and lignin in all soil horizons and in the mineral soil additionally the effective cation‐exchange capacity (CEC). The soils were Cambisols, Planosols, and Histosols. The concentrations of Mg, Mn, N, P, and S in the O horizons and of Al, C, and all nutrients except Ca in the A horizons correlated significantly negatively with altitude. The C : N, C : P, and C : S ratios increased, and the lignin concentrations decreased in O and A horizons with increasing altitude. Forest stature, tree basal area, and tree growth decreased with altitude. An ANOVA analysis indicated that macronutrients (e.g., N, P, Ca) and micronutrients (e.g., Mn) in the O layer and in the soil mineral A horizon were correlated with tree growth. Furthermore, lignin concentrations in the O layer and the C : N ratio in soil affected tree growth. These effects were consistent, even if the effect of altitude was accounted for in a hierarchical statistical model. This suggests a contribution of nutrient deficiencies to reduced tree growth possibly caused by reduced organic‐matter turnover at higher altitudes.     

Availability and extractability of soil manganese in a liming experiment

Abstract

The availability of soil Mn to corn in relation to extractability of soil Mn by EDTA, Mg(NO₃)₂, CH₃COONH₄, hydroquinone, H₃PO₄, and NH₄H₂PO₄ as affected by liming was evaluated under field conditions on a single soil type. EDTA, Mg(NO₃)₂ and CH₃COONH₄‐extractable Mn were related inversely to available Mn. No useful relationships were found between hydroquinone, H₃PO₄, and NH₄H₂PO₄‐extractable soil Mn and Mn uptake by sweet corn.     

Ranges of nutrient concentrations in Quercus ilex leaves at natural and urban sites

The leaf nutrient concentrations and the N‐to‐nutrient ratios were analyzed to evaluate the nutritional status of holm oaks (Quercus ilex L.) experiencing various anthropogenic pressures. Leaves (1 year old) of Q. ilex and surface soil (0–5 cm) surrounding the trees were collected at seven natural and seven urban sites in Campania Region (Southern Italy) and analyzed for the concentrations of macro (C, N, P, S) and micronutrients (Mn, K, Na, Cu, Mg, Ca, Fe, Zn). The available soil fraction of micronutrients was also evaluated. The nutrients showed different concentration ranges for the natural and the urban sites in the soil (total and available) and in the leaves, that we reported separately. Organic‐matter content and macronutrient concentrations were higher in the natural soils, while the highest leaf N, S, and P concentrations were found at some urban sites. Concentrations of Cu, Na and Zn both in leaves and soil, and Mg and Fe in leaves from the urban sites appeared to be affected by air depositions. Manganese was the only micronutrient to show higher concentrations at the natural than at the urban sites, both in soil and leaves. For this nutrient, in addition, a relationship between leaf and available soil concentrations was found at the natural sites. The ratios between the concentrations of N and each studied nutrient in the leaves highlighted a different nutritional status between the plants from the natural and urban sites.     

巨桉人工林叶片养分交互效应

在四川巨桉栽培区设立了60个标准地,采用相关分析和矢量诊断法进行分析,以了解巨桉人工林养分的相互作用关系。结果表明,巨桉人工林叶片的养分交互作用较为复杂。N可促进P、K、Ca、Mn等的吸收,但易受到Fe、Zn、高Ca、高Mg的拮抗,而且高N抑制了Mn的吸收;P可促进K、Mg、Mn等的吸收,但易受Zn、Fe、高Mn、高K、高Ca、高Mg的拮抗,而高浓度的P将抑制K、Zn、Fe等的吸收;K对其他养分元素均没有明显的促进作用,但高浓度K限制P的吸收;Ca、Mg之间可相互促进吸收。同时,低浓度的Ca和Mg有利于Fe、Zn的吸收,高浓度的Ca和Mg将对N、P、Fe、Mn、S、B等养分产生拮抗,限制吸收;S可促进Zn的吸收,但易受高Ca、高Mg拮抗;Cu、Zn、Fe、Mn之间主要以拮抗为主。B相互作用较少,对其他养分几乎没有明显的促进作用。     

Spatial and Fractal Characterization of Soil Chemical Properties and Nutrients across Depths in a Clay-Loam Soil

Researchers assessed the spatial distribution of soil chemical properties and nutrients at four depths in a clay loam soil cropped to corn and soybean at Freeman farm of Lincoln University. Soil samples were taken at depths of 0–10, 10–20, 20–40, and 40–60 cm in a 4.05-ha field and analyzed for acidity or basicity (pH), cation exchange capacity (CEC), total carbon (TC), organic matter (OM), base saturations on the CEC, ammonium (NH₄⁺), nitrate (NO₃^?), phosphorus (P), potassium (K), calcium (Ca), sulfur (S), magnesium (Mg), sodium (Na), manganese (Mn), copper (Cu), iron (Fe), and zinc (Zn). Results showed that coefficients of variation (CV) ranged between 5 and 30%, except for TC, NO₃^?, and Zn, which had greater CVs. Soil chemical properties and nutrients responded to exponential, linear, Gaussian, and spherical variogram models with nugget-to-sill ratios ≤ 1.0 and effective ranges from 4 to 56 m. Fractal analysis showed that CEC in all depths belonged to the 1.99 ≥ D3 ≥ 1.90 group, which suggests great disorder and antipersistence in the spatial structure.     

Effect of soil pH on cation and anion solubility

Abstract

The effect of soil pH on the exchangeability and solubility of soil cations (Ca, Mg, Na, K, and NH₄‐N) and anions (NO₃‐N, Cl, and P) was investigated for 80 soils, spanning a wide range in physical and chemical properties and taxonomic groups. This information is needed from environmental and agronomic standpoints to estimate the effect of changes in soil pH on leachability and plant availability of soil nutrients. Soils were incubated with varying amounts of acid (H₂SO₄) and base (CaCO₃) for up to 30 days. Although acid and base amendments had no consistent effect on cation exchangeability (as determined by neutral NH₄OAc), amounts of water‐soluble Ca, Mg, Na, K, NH₄‐N, and P decreased, while NO₃‐N and Cl increased with an increase in soil pH. The increase in cation solubility was attributed to an increase in the negative charge of the soil surface associated with the base addition. The change in surface electrostatic potential had the opposite effect on amounts of NO₃‐N and Cl in solution, with increases in N mineralization with increasing soil pH also contributing to the greater amount of NO₃‐N in solution. The decrease in P solubility was attributed to changes in the solubility of Fe‐, A1‐, and Ca‐P complexes. The logarithm of the amount of water‐soluble cation or anion was a linear function of soil pH. The slope of this relationship was closely related (R² = = 0.90 ‐ 0.96) to clay content, initial soil pH, and size of the cation or anion pool maintaining solution concentration. Although the degree in soil pH buffering increased with length of incubation, no effect of time on the relationship between cation or anion solubility and pH was observed except for NO₃‐N, due to N mineralization. A change in soil pH brought about by acid rain, fertilizer, and lime inputs, thus, affects cation and anion solubility. The impact of these changes on cation and anion leachability and plant availability may be assessed using the regression equations developed.     

Water and nutrient dynamics of a paddy soil of Bangladesh

The objectives of the study were the changes in water tension, redox potential, and the pH value of a silty Eutric Gleysol from young river sediments near Mymensingh, the nutrient concentration of soil solution, as well as the supply of nutrients by rain, irrigation and fertilizing, and the uptake of nutrients by rice during the year. In the case of nitrogen, a moderate loss was observed, caused by the leaching of NH₄, and significant losses due to volatilisation and denitrification. Fertilized P was enriched in the soil. The leaching of Ca, K, Mg, Na, Cu, Fe, Mn, and Zn was clearly higher than the addition by rain, irrigation and fertilization. It is concluded, that the loss of nutrients was caused by weathering.     

Nitrogen rate and source affects leaf elemental concentration and plant growth in muscadine grapes

Leaf concentrations of nitrogen (N), phosphorus (P), potassium (K), iron (Fe), and manganese (Mn) in ‘Sterling’ muscadine grapes (Vitis rotundifolia Michaux) grown for two years in sand culture were not influenced by different N‐fertilizer sources. Leaf zinc (Zn) and copper (Cu) were higher with ammonium nitrate (NH₄NO₃)than ammonium sulfate [(NH₄)₂SO₄]. Shoot growth was greatest with NH₄NO₃. Leaf Ca, Mg, Mn, and Cu content decreased and leaf N increased as N‐fertilizer rates were raised. Plant growth was positively correlated with leaf N, but was negatively correlated with leaf Ca, Mg, Fe, Cu, and Mn content. Percent Mg in the leaves was reduced when N levels, regardless of N source, were raised from the low (1.8 mM) to the middle (5.4 mM) rate. High leaf‐N levels were correlated with lower Ca and Mg in the leaves, indicating a relationship between N fertilization and the late‐season Mg deficiency often observed in muscadine grapes.