Forage Mineral Concentrations Research Articles

Seasonal influence on mineral concentration of forages on flooded pastures in South Sumatra, Indonesia

This study was conducted to evaluate macro- and micro-mineral concentrations in forages growing on seasonally flooded native pastures in non-tidal swamps of South Sumatra, Indonesia and grazed by buffalo. The upper part of native forage plants from 5 species of Poaceae, 4 species of Leguminosae, 3 species of Cyperaceae and 1 species of Onagraceae were sampled by hand-plucking during flooded and dry seasons. The results showed that mineral concentrations of forages varied greatly between seasons. In general concentrations of most minerals were adequate to supply the dietary needs of grazing ruminants in both wet and dry seasons. Phosphorus (P) concentrations were low in all species in both wet and dry seasons but growing animals should select a diet adequate in P, while lactating females could benefit from P supplementation. In cut-and-carry situations, animals would probably respond to additional P in the diet. These hypotheses need testing in the field.

Case Study: Regional assessment of mineral element concentrations in Idaho forage and range grasses

ABSTRACT The objective was to quantify forage mineral concentrations in Idaho and evaluate changes due to seasonality and irrigation. Forage was sampled on rangeland and irrigated pastures in summer and fall from 35 locations in 9 counties and analyzed for Ca, P, K, Mg, S, Na, Zn, Fe, Mn, Cu, Mo, Co, and Se. Statistical analysis was by pasture type using mixed model repeated measures with fixed effects being county, season, and county × season. Location within county was a random effect. Samples were also analyzed by soil type with type of forage, season, and type × season as fixed effects and location within soil type as the repeated random effect. The macrominerals P, Mg, and Na were deficient in rangeland forage, and Na was deficient in irrigated forage. Potassium was deficient on fall rangeland. Deficient trace minerals for both pasture types were Cu, Se, and Zn. Cobalt was deficient on both types of summer pasture. Antagonistic minerals were Mo and Fe. Forage macromineral concentrations declined (P

Macro-mineral concentrations in soil and forage in three grassland sites at Zacatecas

Mineral concentration in forage is an important factor for extensive livestock production. Therefore, a study was performed in order to evaluate the soil mineral contents and their relationships with forage mineral concentrations taking into account three grassland sites located at Zacatecas state, México. Soil organic matter (OM) content and pH as well as soil and forage contents of Ca, P, Mg, Na and K were estimated. Soil OM contents were not different (P>0.05) among sites averaging 2.99 %. Soil pH of site 2 was higher (P£0.05) than those of sites 1 and 3. Soil of site 2 had higher P, Ca and Mg concentrations than the minimum contents used as references. Soil contents of Na and K were lower than the reference contents suggesting deficiencies in all three sites. Considering requirements for growing cattle, P, Ca and Na were at insufficient levels in forage from all three sites. Significant correlations (r Pearson) suggest a positive effect of soil P content on forage P and Mg concentrations. Soil P content could affect forage Ca concentration and Ca:P ratio. Other correlations suggest soil Ca negative effects on forage Ca concentration and Ca:P ratio.

Long‐Term Manure Applications Impact on Irrigated Barley Forage Mineral Concentrations

Agronomy Journal 105:1441–1450 (2013). doi:10.2134/agronj2012.0204 In the above article the authors have discovered errors in the title for Table 3 and captions for Fig. 1 and Fig. 2. The unit for the manure application rates should be Mg ha–1 yr–1, not kg ha–1 yr–1. In addition, the fertilizer application unit should be kg N ha–1 instead of kg ha–1. The units are correct everywhere else in the manuscript and these errors do not change the results and discussion. The correct title for Table 3 and captions for Fig. 1 and Fig. 2 are shown below. We apologize for the error in the publication. Table 3. Properties of the surface soil (0–15-cm depth) under the treatments investigated, including a check (CK); 100 kg N ha–1 NH4NO3 (FER); manure applied at rates of 60, 120, and 180 Mg ha–1 yr–1 (wet basis) for 37 continuous yr (M60, M120, and M180, respectively); and manure applied at rates of 60, 120, and 180 Mg ha–1 yr–1 for 30 continuous yr followed by 7 yr discontinued applications (D60, D120, and D180, respectively). Fig. 1. Soil inorganic N (NO3–N + NH3–N) concentrations in (A) 2003 and (B) 2008 under the treatments investigated, including a check (CK), 100 kg N ha–1 NH4NO3 (FER); manure applied at rates of 60, 120, and 180 Mg ha–1 yr–1 (wet basis) for 37 continuous yr (M60, M120, and M180, respectively), and manure applied at rates of 60, 120, and 180 Mg ha–1 yr–1 for 30 continuous yr followed by 7 yr after manure applications had been discontinued (D60, D120, and D180, respectively). Horizontal bars indicate the standard error. Bars with different letters for each depth and each year indicate a significant difference (P < 0.05, Bonferroni test). Fig. 2. Annual N and P recovery [removal from plant uptake, kg ha–1/(input + previous year balance, kg ha–1) from manure applications × 100] from 1974 to 2010 under the treatments investigated, including a check (CK), 100 kg N ha–1 NH4NO3 (FER); manure applied at rates of 60, 120, and 180 Mg ha–1 yr–1 (wet basis) for 37 continuous yr (M60, M120, and M180, respectively), and manure applied at rates of 60, 120, and 180 Mg ha–1 yr–1 for 30 continuous yr followed by 7 yr after manure applications had been discontinued (D60, D120, and D180, respectively).

Long‐Term Manure Applications Impact on Irrigated Barley Forage Mineral Concentrations

Long‐term manure use near livestock feedlot operations can result in soil nutrient imbalances. We investigated the impact of continuous (37‐yr) and discontinued (30‐yr continuous + 7 yr without applications) manure applications on soil properties and barley (Hordeum vulgare L.) yield and nutritive value under semiarid field conditions in southern Alberta, Canada. Feedlot cattle manure annual applications were 0, 60, 120, and 180 Mg ha–1 (wet weight) to an irrigated Chernozemic soil. After 37 yr, barley yields were not affected by manure applications, while forage crude protein (CP), NO3–N, P, K, and Zn concentrations increased (P &lt; 0.01). Forage Ca/P ratios decreased and K/(Ca + Mg) ratios increased with manure applications to critical levels of illness potential in ruminants. Discontinuing manure applications did not affect forage CP content; however, forage P and K concentrations declined (P &lt; 0.01) with decreases in soil P and K. This resulted in the return of forage Ca/P ratios within the recommended levels. Seven years after manure applications were discontinued, forage Zn concentrations were similar to concentrations from unmanured plots. Although forage nutrient balances for animal nutrition improved after manure applications were discontinued, soil nutrient recovery was small, and soil P, K, and Zn concentrations in the discontinued plots remained greater (P &lt; 0.01) than concentrations in the unmanured plots and well above those required for optimum crop growth.

Forage Mineral Concentrations in Grazed, Warm-Season Bahiagrass Pastures in Florida

AN243, a 4-page fact sheet by Bob Myer, Lee McDowell, Cheryl Mackowiak, and Ann Blount, discusses the concentrations of forage minerals in bahiagrass pastures for beef cattle, to determine adequate mineral levels and use of mineral supplements. Includes references. Published by the UF Department of Animal Science, July 2010.

Forage Mineral Concentrations and Mineral Status of Beef Cattle Grazing Cool Season Pastures in Northwestern Florida, Emphasizing Magnesium

A 68‐day study was conducted in North Florida to evaluate forage and beef cattle serum, liver, and urine mineral concentrations, emphasizing magnesium (Mg). Forty‐two Angus, Brangus, and Romosinuano cows in early lactation were divided into two groups and placed on ryegrass or oat pasture. Samples were collected every 2 weeks except for liver biopsies, which were collected only on day 68. Mineral concentrations were determined for forage, plasma, urine, and liver samples. All forage mineral concentrations except Mg, calcium (Ca), copper (Cu), cobalt (Co), selenium (Se), and zinc (Zn) were greater than critical levels for a beef cow in lactation. Forage Mg and Cu were severely deficient in both oats and ryegrass. All blood plasma mineral levels were greater than critical levels, but plasma Mg was borderline to slightly deficient. There should be special attention given to Mg supplementation because forages are deficient and contain excess potassium (K).

Effects of Aluminum from Water‐Treatment‐Residual Applications to Pastures on Mineral Status of Grazing Cattle and Mineral Concentrations of Forages

Aluminum (Al) applied to land in the form of water treatment residuals (Al‐WTR) can reduce soluble soil phosphorus (P). Two experiments (145 and 148 d) using 36 grazing Holstein steers were conducted to determine effects of Al‐WTR applications to pasture on mineral status of cattle and bahiagrass (Paspalum notatum). Four treatments were with and without Al‐WTR and P‐free mineral supplementation. Total pasture application of Al‐WTR over 2 years was 75.8 metric tons dry weight/ha. There were few treatment effects on weight gains and mineral tissue concentrations. Forage mineral concentrations were generally unaffected by treatment but were affected (P < 0.05) by collection dates. Most forage samples were deficient in sodium (Na), copper (Cu), selenium (Se), and cobalt (Co) and at various collections deficient in calcium (Ca), P, iron (Fe), and zinc (Zn). Applications of Al‐WTR are effective in reducing P contamination without affecting forage or cattle mineral concentrations.

A Study on Seasonal Variability of Trace Elemental Status of Forages for Grazing Ruminants

ABSTRACT An investigation was conducted to determine the trace- mineral concentrations of forages in relation to requirements of ruminants grazing in natural pastures in the province of Punjab, Pakistan during two different seasons. Animals were closely followed during grazing and forages corresponding to those consumed by the animals were taken and analyzed for copper (Cu), iron (Fe), zinc (Zn), manganese (Mn), and cobalt (Co) concentrations. The data on the trace- mineral concentrations showed that most of these minerals varied greatly as a function of seasons and sampling periods. The forage Cu, Fe, and Zn concentrations were affected by seasonal changes but no influence of season was observed on the concentrations of forage Mn and Co concentration. Forage Zn and Co, during both seasons and at some sampling intervals, and forage Mn during summer were at marginal deficient levels, and in contrast, all other forage trace-minerals were within the required range for ruminants during both seasons. Based on these results, the supplementation of Zn, Co, and Mn would seem most important to support optimum livestock productivity.

Forage Nutritive Value in an Emulated Silvopasture

Incorporating trees into pastures may alter forage nutritive value. The objective of this study was to determine nutritive value in response to trees and slope position in an emulated (no animals) silvopasture. In 1995, black walnut (Juglans nigra L.) and honey locust (Gleditsia triacanthos L.) trees were planted within three block plots of predominantly tall fescue (Lolium arundinaceum (Schreb.) Darbysh.) pasture. Soils on the site, (Unison and Braddock) are fine, mixed mesic Typic Hapludults, well drained, with moderately steep slopes (10–25%). Trees were planted down slopes in rows to create low‐, medium‐, and high‐tree densities at shoulder‐, mid‐, and toe‐slope positions. Forage from sampling sites (n = 54) under field treatment combinations was harvested May, June, and July in 2002 and 2003. Concentrations of neutral and acid detergent fiber (NDF, ADF), acid detergent lignin (ADL), crude protein (CP), total nonstructural carbohydrate (TNC) and Ca, P, Mg, and K were determined. Few differences due to treatment were observed for NDF and ADF concentrations. Concentrations of TNC decreased with greater tree density and appeared to follow tree leaf growth. Crude protein concentrations were typically greater under honey locust trees. Forage mineral concentrations frequently were greater with increased tree density. Trees appear to have both positive and negative effects on forage nutritive value, and their effects on animal performance warrants further research.

Dietary Cation Anion Difference of Five Cool‐Season Grasses

Forage‐based rations with a low dietary cation anion difference (DCAD) should be fed to dairy cows 2 to 4 wk prepartum to prevent hypocalcaemia or milk fever. We evaluated the DCAD of two to four cultivars of five grass species at three locations in Québec, Canada. Orchardgrass (Dactylis glomerata L.), meadow bromegrass (Bromus riparius Rehmann), tall fescue (Festuca arundinacea Schreb.), smooth bromegrass (Bromus inermis Leyss.), and timothy (Phleum pratense L.) were harvested twice a year during two production years. Forage mineral concentrations were measured and the DCAD was calculated with a short equation [DCADS = (Na+ + K+) − (Cl− + S2−)], and a long equation [DCADL = (Na+ + K+ + 0.15Ca2+ + 0.15Mg2+) − (Cl− + 0.6S2− + 0.5P3−). The five species had, respectively, DCADS of 656, 540, 510, 490, and 384 mmolc kg−1 DM (dry matter) in spring growth, and 633, 569, 496, 447, and 332 mmolc kg−1 DM in summer regrowth. Orchardgrass had the highest DCAD and timothy the lowest while the three other species were intermediate in both spring growth and summer regrowth. Species differences in DCAD were primarily related to differences in K concentration. Timothy was the only species that decreased significantly in DCADS (by 52 mmolc kg−1 DM) and DCADL (by 35 mmolc kg−1 DM) from spring growth to summer regrowth. Cultivars did not differ in DCADS and DCADL except for tall fescue. Locations did not differ in DCAD. Among the grass species in this study, and because of its low DCAD, timothy is the best suited for producing forages fed to dairy cows in the weeks preceding calving.

Minerals in Soils and Forages Irrigated with Secondary Treated Sewage Water in Sebele, Botswana

Production of forage using treated sewage water is a viable practice internationally. However, there is not much information on the heavy metal content of such forages. This study was conducted to determine the effect of sewage water on soils and forages irrigated with treated sewage water at Botswana College of Agriculture 's farm. The study was conducted for a period of 120 days using established forage pastures of rye grass (Lolium multiflorum) and lucerne (Medicago sativa). Heavy metals determined were Fe, Mn, Cu, Zn, Ni, Pb and Cd. Generally the treated sewage water contained relatively low levels of heavy metals. Zn, Ni and Mn concentration were below the detectable levels. In the sewage water while soils and plants had low levels of heavy metals. Comparatively the soil and plants heavy metal levels were much higher than those in the water and the difference was significant (p<0.05). There was some low correlation between trace element contents in the water and soil. In addition there was some significant difference (p<0.05) in heavy metal concentration in sewage water between the months during which the analyses were done. However, the sewage water, soils and forage mineral concentrations were within the internationally allowable heavy metal concentration with respect to irrigation, soil loadings and animal feeds. poor performance is largely attributed to low and variable effluent is generated per annum and discarded in rainfall as well as the occurrence of successive droughts. Gaborone alone as sewage . The use of sewage water for This calls for exploitation of other means of water sources irrigation is a positive way to dispose off sewage. Such to sustain the sector as underground water from huge volumes of water in a country with persistent boreholes, damming of rivers and sewage water. The latter droughts and unreliable rainfall can be of great agronomic being the most sustainable as it minimizes the cost of and economic importance. Irrigation with sewage water procuring portable or fresh water for agricultural use. can increase available water supply or release water for Concern for water quality denotes it's suitability and is alternative use. The utilization of sewage water also related to it's effect on the soil and plants and the contributes to cleaning of the environment, as the water management that may be necessary to control or is not discharged into water bodies that could otherwise compensate for a water quality related problem is the most get polluted. In addition to these direct economic benefits limiting factor in the use of sewage water for agricultural that conserve natural resources, this water contains a lot purposes. The principle for evaluating the quality of of nutrients and can serve as an alternative source to irrigation water deals with the total concentration and expensive chemical fertilizers. FAO estimated that typical composition of soluble salts in water . Soluble salts wastewater from domestic sources could supply all of the (2)

Mineral Content of Forages Grown on Poultry Litter-Amended Soils

Large quantities of poultry litter are applied each year to pastures in Arkansas and Oklahoma. Our objective was to monitor mineral concentrations in forages grown on poultry litter-amended soils and compare them with mineral requirements for gestating and early lactating beef cows. A total of 65 forage samples were gathered from four farms in northwest Arkansas and northeast Oklahoma from April 2000 to March 2002. Mean forage mineral concentrations were compared with beef cattle requirements using a two-tailed t test. Two-year average forage Ca, P, K, S, and Fe concentrations from each farm exceeded (P<0.05) gestation and lactation requirements, but forage Zn concentrations from one farm did not differ (P>0.05) from gestation and lactation requirements. On individual sampling dates, concentrations of Ca, P, K, and Zn rarely fell below lactation requirements. Mean forage Mg concentrations from one farm exceeded (P<0.05) lactation requirements, but those from the other three farms exceeded (P<0.05) gestation but not (P>0.05) lactation requirements. Mean tetany ratios from all farms were below (P<0.05) the tetany threshold of 2.2, but forage from two farms surpassed the tetany threshold during Spring 2000, and one sur-passed it during Spring 2001. Average forage Cu concentrations were below (P<0.05) requirements on one farm and did not differ (P>0.05) from the requirements on three farms. Forages from pastures fertilized with broiler litter may meet most but not all mineral requirements of beef cattle, and supplementation of specific minerals, particularly Mg and Cu, may be necessary.

In situ solubility of selected macrominerals from common bermudagrass fertilized with different nitrogen rates and harvested on two dates

Minerals are essential nutrients for animals as primordial elements for structural tissues and metabolic reactions. Forages are considered an important source of minerals for ruminants, but forage mineral concentrations may vary across the growing season due to several factors such as forage species and fertilization levels. Common bermudagrass [ Cynodon dactylon (L.) Pers.] growing on a poultry layer manure-amended site was fertilized with ammonium nitrate at four rates (0, 56, 112, and 168 kg N/ha) approximately 1 month before the first and third harvests (30 May and 18 August 2000, respectively) to evaluate those effects on forage concentration and ruminal disappearance of Ca, P, Mg, and K. Five crossbred ruminally cannulated steers (422±21.0 kg BW) were used to evaluate these forages in situ in a randomized complete block design with a 2×4 ( harvest date × N fertilizationrate ) factorial arrangement of treatments. Forage P content decreased ( P<0.01) with increasing N fertilization on 18 August, while forage Mg increased ( P<0.01) and forage Ca content tended ( P=0.08) to increase with increasing N fertilization on both harvest dates. Approximately, 992 g/kg of the K disappeared immediately (fraction A) from the bags compared with approximately 821, 718, and 476 g/kg of Mg, P, and Ca, respectively. Fraction A, fraction B (the fraction disappearing at a measurable rate), and effective ruminal disappearance of Ca, P, Mg, and K were affected by linear or quadratic interactions between N fertilization and harvest date. Effective P disappearance increased linearly ( P<0.05) on 30 May and decreased quadratically ( P<0.01) on 18 August, and effective Mg disappearance increased linearly ( P<0.01) on both dates with N fertilization rate. The intercepts of the regression of effective P, Mg, and K disappearance on N rate were greater ( P<0.05) on 30 May than 18 August, but the mean values for each date were >830 g/kg. Rate of Mg disappearance responded quadratically ( P<0.01) to N fertilization rate and was greater ( P<0.05) on 18 August compared with 30 May. Therefore, N fertilization rates affected the concentration and ruminal liberation of macrominerals from bermudagrass, and effective mineral disappearance was greater than 700 g/kg in all instances.

Adequate Soil Phosphorus Decreases the Grass Tetany Potential of Tall Fescue Pasture

Adequate Soil Phosphorus Decreases the Grass Tetany Potential of Tall Fescue Pasture

Comparison of collection methods for determination of forage nutritive status1

Forage samples were collected from pastures amended with one of five biosolids (municipal sludges) and fertilizer treatments (year one) or eleven treatments in year two. Forage samples were collected six times during each year, once every 28 d, beginning in mid‐June. Two methods of forage collection were compared, the cage method and the transect method. The transect method involved collecting samples at different areas of a pasture to more closely mimic what the animals appeared to consume. In year one, forage samples obtained using the cage method were collected from permanent cages (approximately 2 m diameter) randomly placed, but then fixed in position in each pasture. In year two, the cages were randomly moved to new spots following each sampling and mowing. During year one, copper (Cu), zinc (Zn), and iron (Fe) concentrations differed (P<0.05) by collection method several times, with microelement concentrations from cage samples routinely being higher than from transect samples. Differences were observed at fewer sampling times during year two for Cu and Fe, but Zn concentrations differed at each sampling time. The macroelements followed a similar pattern, with more differences due to collection method observed during year one than year two. The in vitro organic matter digestibility (IVOMD) and crude protein (CP) results suggest an effect of increasing maturity for the transect samples contributing to the differences observed in collection methods in year one. When forage collection methods differed in forage mineral concentrations, cage samples gave routinely higher units but this difference was reduced when cages were moved to new locations following sampling.

Mineral concentrations of forages grazed by small ruminants in the wet season in benue state, Nigeria. II. Trace minerals and forage crude protein1

A total of 71 forage samples were analyzed for trace mineral and crude protein concentrations in three Agricultural zones of Benue State, Nigeria. The zones consisted of the Northern, Eastern, and Central zones, each of which was made up of four Local Government Areas. In each Local Government Area, grazing animals were followed and forages corresponding to those consumed were collected during the peak of the wet season (June) and analyzed for the nutrient composition. Deficiencies were observed in copper (Cu) and cobalt (Co) concentrations in all classes of forage, and in forage Cu and zinc (Zn) in all Local Government Areas in the Northern zone. A higher (P<0.05) forage Cu concentration was observed in legumes compared to other classes of forage in the Eastern zone. Concentrations of iron (Fe) and manganese (Mn) were considered adequate and their contents were not affected (P>0.05) by class of forage or Local Government Areas. In the Eastern zone, the contents of selenium (Se) in grass and tree leaf hay were higher compared to leguminous forage, which in turn was higher compared to Se concentrations in crop wastes. Only about 18% of total forage samples showed protein concentrations below the critical value of 7%. Supplementation of Cu, Zn, and Co would seem to be necessary in the Northern zone, and to a lesser extent in the Eastern zone for optimum productivity of grazing animals.

Mineral Dynamics in Forages of the Northern Great Plains

Mineral concentrations of range grasses are often below that required by grazing livestock. Limited information is available on forage mineral concentrations for the Northern Great Plains and there is little data on factors influencing concentrations of forage minerals throughout the year. Therefore, a study was conducted to evaluate special and temporal variations in mineral concentrations of major forage species in the Northern Great Plains. Herbage was sampled from 4 replicates on each of 2 soils in July, August, and September 1991, April, June, July, August, and September 1992, and April 1993. Herbage was sorted by species grouping and by live and dead tissue classes. Analyses on herbage included Ca, P, Mg, K, Na, Zn, Cu, Mn, and Mo. For western wheatgrass [Pascopyrum smithii (Rydb.) Love] and annual bromes [Bromus spp.], Zn and all macrominerals except Na were greater in live than in dead tissue. Live tissues of all other species groupings contained greater amounts of P and K than did dead tissue. Live tissue Mg concentrations were greater than dead tissue concentrations for other cool-season and warm season grasses. Manganese concentrations were greater in live than dead annual brome tissues, while Cu was greater in dear than live tissue. Dead sedge tissue contained greater concentrations of Ca than live tissue. Soil type affected several nutrient but this was partially related to soil effects upon composition of species groupings and live:dead ratios. Minerals most likely to be found in quantities less than required for animal production were P, Na, K, Zn, and Cu.

Mineral concentrations of forages and soils in Benue State, Nigeria. I. Macrominerals and forage in vitro organic matter digestibility and crude protein concentrations

Abstract Macromineral composition of different forage species and soils and forage in vitro organic matter digestibility (IVOMD) and crude protein concentrations in three agricultural zones of Benue State were studied. The zones consisted of Tiv zone (Zone A), Igala zone (Zone B), and Idoma zone (Zone C), each of which was made up of three sites. Site I was Fulani cattle migration routes across the state, site II represented grazing sites within home proximity, and site III were grazing reserves. Grazing animals were followed and forages corresponding to that consumed by them, and the corresponding soil samples were collected during the peak of the dry season (December‐January) and analyzed for nutrient composition. Forage IVOMD ranged from 21% to 79%, with values obtained in grass being lowest due to pronounced overmaturity. Only 10% of forage samples (exclusively from grasses), showed protein levels below the critical value of 7%. Most forage samples, as well as their corresponding soil samples were suf...

Mineral concentrations of forages and soils in Benue State, Nigeria. II. Trace minerals, soil pH and organic matter

Abstract Trace mineral concentrations of forages and soils and soil pH and organic matter in three agricultural zones in Benue State were studied. The zones consisted of Northern zone (A), Eastern zone (B), and Central zone (C) corresponding to Tiv, Igala and Idoma territorial districts, respectively. Each zone was divided into three grazing environments. In each of the study environments, grazing animals were closely followed during grazing and forages corresponding to that consumed by the animals and their corresponding soil samples were collected and analyzed for nutrient concentrations. Deficiencies in forage copper (Cu) and zinc (Zn) were found in all classes of forages in each of the zones. Mean soil pH was similar at all sites in each zone, ranging from 6.4 to 8.7. In Tiv Zone, soils from leguminous forages contained the highest (8.9 ppm) amount of Fe which was higher (P < 0.05) than soils collected at tree leaf sites. At all sites, forage Cu and Zn were deficient in Tiv and Idoma Zones in regard t...