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1.
Two experimental late fall-winter-spring grazing studies, each lasting two years, were conducted at the North Florida Research and Education Center (NFREC), Marianna, Florida to evaluate the organic constituents and macromineral concentrations of annual cool season pasture forages grazed by growing beef cattle. Eight 1.32 ha fenced pastures or paddocks were divided into two pasture land preparation/planting methods, four pastures for the sod seeding treatments and four for the prepared seedbed treatments. These pastures were planted with two different forage combinations: rye/oats mix with or without ryegrass for the first two years (Study 1), and oats with ryegrass or ryegrass only for the last two years (Study 2). Each of the four forage/land preparation combination treatments was assigned to two pastures each year, thereby giving two replicates per year. Forage samples were collected at the start of grazing and twice monthly thereafter until the end of grazing season for each year, pooled by month, and were analyzed for calcium (Ca), phosphorus (P), sodium (Na), potassium (K), magnesium (Mg), dry matter (DM) yield, crude protein (CP), and in vitro organic matter digestibility (IVOMD). Blood plasma samples were also collected from the tester cattle during the spring season of year 2 of Study 2 and were analyzed for Ca, P, and Mg. Month differences were observed in forage concentrations of P and K (P < 0.0001), and Mg (P < 0.05) in both studies, Ca (P < 0.01) in Study 1 only, and Na (P < 0.05) only in Study 2. Year affected P, K, and Mg concentrations in Study 1 and Ca, P, and Na concentrations in Study 2. In Study 2, forage type by month interactions on Ca, K, and Mg concentrations were noticed (P < 0.01). Forage Ca was lower (P < 0.05) than the critical level for all months from the oat plus ryegrass pastures, and for early winter months and late spring months from ryegrass only pasture. Forage Na concentrations were consistently low throughout the grazing season and unaffected by forage type or land cultivation methods used in both studies. Low Mg concentrations of both forage types in Study 2 (also with high K concentrations) were indicative of a potential risk of grass tetany (hypomagnesemia) for grazing ruminants. Forage DM yields were highly variable with fluctuations among the experimental months and were found to be highest in the spring months, with decreasing yields towards the end of the grazing season in both studies (P < 0.0001). The CP concentrations were greater than the required levels and both CP and IVOMD decreased gradually by month in both studies (P < 0.0001). Normal blood plasma concentrations of Ca and P obtained were indicative of a good overall status of these minerals in the animal's body. Plasma Mg concentrations were slightly above the critical level for cattle from both forage types. In summary, the macrominerals most likely to be deficient in North Florida during the cool season would be Ca, Na, and Mg. Special attention should be given to supplementation of Mg since forages reflected a marginal deficiency of this mineral and high K concentrations were found.  相似文献   

2.
Abstract

A two‐year study was conducted to determine the trace mineral status of cattle grazing forages (bahiagrass) and soils on a ranch in central Florida. Forage and soil samples were collected every month for two years. Month effect (P < 0.05) on soil trace mineral concentrations were observed in manganese (Mn) and zinc (Zn) in years 1 and 2, and in copper (Cu) and iron (Fe) only in year 2. All soil trace minerals studied showed higher (P < 0.05) concentrations in year 2. Month differences (P < 0.05) in forage trace mineral concentrations were found in cobalt (Co), Cu, Fe, Mn, molybdenum (Mo), selenium (Se), and Zn. The majority of forage trace minerals were higher in spring‐summer months. Year means were similar (P > 0.05) in forage trace mineral concentrations. Few and low correlation coefficients were observed between and within soil and forage trace minerals concentrations. Percentages of total forage collected with trace minerals below critical values (in parentheses) and suggestive of deficiency were as follows: in forage, Co (0.1 ppm), 93%; Cu (8 ppm), 98%; Fe (50 ppm), 75%; Mn (40 ppm), 41%; Mo (> 6 ppm), 0%; Se (0.2 ppm), 98%; and Zn (25 ppm), 84%; in soil, Cu (0.3 ppm), 77%; Fe (2.5 ppm), 7%; Mn (5 ppm), 91%; and Zn (1.5 ppm), 53%.  相似文献   

3.
Abstract

The experiment rationale was to determine forage micromineral concentrations as effected by biosolids fertilization. We determined the effects of two exceptional quality biosolids on bahiagrass trace mineral concentrations as related to beef cattle requirements. Twenty‐five 0.8‐ha pastures were divided into five blocks. Two biosolids were applied as normal and double agronomic rates. The control received NH4NO3. Forages were analyzed for total copper (Cu), iron (Fe), manganese (Mn), zinc (Zn), molybdenum (Mo), cobalt (Co), and selenium (Se), and soils were analyzed for Mehlich I extractable Cu, Mn, and Zn. Some significant increases (P<0.05) in forage Co, Cu, Fe, Zn, and Se were observed at various sampling times, but the increases were generally small and biologically insignificant. Although forage Mo samples from pastures with the Tampa biosolids applied were consistently higher than the control (P<0.05), at no time did they approach levels considered toxic. Similar results were seen in forage Mn concentrations, with treatment Baltimore‐2X elevating (P<0.05) Mn concentrations as well. Deficiencies of Co, Cu, Zn, and Se are common in this Florida region and slight elevations due to biosolids treatment could be beneficial. Biosolids applied at the highest rates improved soil Cu and Zn concentrations above control soils and soil Mn was increased over the control at both sampling times for Baltimore‐2X. In relation to beef cattle requirements, the majority of forages were deficient in Co, Cu, Se, and Zn. In summary, biosolids fertilization slightly improved the micromineral status of forage and soil, without creating toxicity.  相似文献   

4.
Abstract

A two‐year experiment was conducted at a north Florida farm to evaluate the mineral status of bahiagrass forages and soils. Forage samples were collected every 28 d throughout the grazing season, and soils evaluated twice yearly. The minerals calcium (Ca), sodium (Na), copper (Cu), cobalt (Co), selenium (Se), and zinc (Zn) were uniformly below the dietary requirements for growing beef cattle in both years. Forage magnesium (Mg), phosphorus (P), potassium (K), crude protein (CP), and manganese (Mn) were generally adequate throughout the grazing season, with the exception of low P concentration at the end of the growing season for both years. Extractable soil concentrations of Ca, P, K, Mg and Zn were adequate but low in Cu. Although CP was adequate (>7.0%) throughout the grazing season, IVOMD values were relatively low. There was a general trend for forage P, K, and IVOMD to decrease (P<0.05) with time.  相似文献   

5.
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.  相似文献   

6.
Abstract

A study was carried out to determine the mineral status of grazing cattle as affected by the eruption of the Cerro Negro Volcano in northwestern Nicaragua. A total of 14 composite soil and forage samples and 30 blood samples were collected at each collection period, before (August 1991) and after (August 1992) the volcanic eruption. Higher soil levels of calcium (Ca), sodium (Na), manganese (Mn) (P<0.01), zinc (Zn) (P<0.05), and lower organic matter (OM) (P<0.01) were found after the volcanic eruption. Phosphorus (P) was the only macromineral found deficient with 93 and 71% of the samples below a critical level before and after volcanic eruption, respectively. Forage Ca, potassium (K), magnesium (Mg), P, Zn, copper (Cu), and selenium (Se) concentrations did not vary between collections. Forage crude protein (CP), in vitro organic matter digestibility [(IVOMD) P<0.05], cobalt (Co), Mn, and Na (P<0.01) were lower after the eruption. Iron (Fe) was the only mineral in forages that increased (P<0.01) after the volcanic eruption. Of the six minerals evaluated in serum only Ca and Mg concentrations were higher (P<0.05) after the volcanic eruption. The macrominerals more likely to be deficient in this area are P and Mg. Trace elements most likely to limit cattle productivity are Zn, Mn, Cu, Se, and Co. Special attention should be given to supplementation of Cu, since both plant and animal tissue samples reflected a deficiency of this mineral.  相似文献   

7.
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).  相似文献   

8.
A shift in oat (Avena sativa L.) production from grain to forage (hay and grazing) is occurring in the southeastern USA. However, most available cultivars were developed for improved grain production, rather than forage yield. We field tested several standard and new oat releases over 2 years, using repeated clippings to determine forage yield, nutrient uptake, and the potential to match plant nutrients with cattle mineral dietary needs. There were no differences in total annual forage yield among the tested cultivars within years but there was a difference between years. Forage tissue phosphorus (P), magnesium (Mg), and calcium (Ca) were sufficient, potassium (K), sulfur (S), and manganese (Mn) were excessive, and iron (Fe), copper (Cu), and zinc (Zn) were occasionally or frequently deficient to meet daily cattle dietary mineral needs. Sulfur, Cu, Fe, Zn, and Mn may be the most challenging to regulate in U.S. Coastal Plain soils at concentrations that satisfy both, oat and cattle nutritional requirements.  相似文献   

9.
Abstract

The rationale for this experiment was to determine forage nutrient concentrations as affected by biosolids fertilization. We studied the effects of single applications of two exceptional quality biosolids to bahiagrass (Paspalum notatum) pasture with regard to satisfying beef cattle nutrient requirements. Twenty‐five 0.8‐ha pastures were divided into five blocks. Two biosolids were applied as normal and double agronomic rates. The control plot received NH4NO3. Forages were analyzed for calcium (Ca), phosphorus (P), magnesium (Mg), potassium (K), sodium (Na), crude protein (CP), and in vitro organic matter digestibility (IVOMD), and soils were analyzed for Mehlich I extractable Ca, P, Mg, and K. Single (agronomic or twice this) applications of biosolids to pastures had little effect on Ca, P, Na, and K forage concentrations, but forage Mg was elevated in several treatments late in the season. Crude protein concentrations were elevated above the control for all biosolids treatments late in the season, whereas only small differences were observed at early sampling times. Trends were similar for IVOMD. In general, all treatments were associated with soils with adequate Ca, P, and Mg concentrations, while soil K was uniformly low. In relation to grazing beef cattle requirements, all treatments resulted in generally adequate forage levels of Ca, P, Mg, K, CP, and IVOMD, however, Na (<0.06%) was deficient.  相似文献   

10.
Abstract

The in vitro organic matter digestibility (IVOMD), crude protein (CP) content, and mineral composition of 11 grasses were compared between seasons in Puerto Rico and evaluated in relation to grazing ruminant requirements. Digitaria eriantha was the highest in IVOMD for both seasons, being higher (P<0.05) than 6 of 10 forages in the long‐day season and 4 of 10 in the shortday season. No differences (P>0.05) in CP content were observed among accessions at both seasons. Mean macroelement content of the accessions was generally adequate in relation to grazing ruminant requirements with the exception of sodium (Na) and magnesium (Mg). Forage microelement concentrations of cobalt (Co), copper (Cu), and zinc (Zn) were generally under the grazing ruminant requirements for the accessions evaluated during both seasons. Iron (Fe) and manganese (Mn) content were high in relation to requirements, especially during the short‐day season. Molybdenum (Mo) was not in excess for the accessions evaluated. The Zn concentrations were similar to the results reported from other experiments with higher fertilization levels. The selenium (Se) concentrations presented an apparent seasonal variation higher in the short‐day season, which is similar to other experiments with high fertilization levels.  相似文献   

11.
Abstract

The in vitro organic matter digestibility (IVOMD), crude protein (CP) content and mineral composition of ten Panicum maximum accessions were compared between seasons in Puerto Rico and evaluated in relation to grazing ruminants requirements. On short days, PRPI 13605 was superior (P<0.05) in IVOMD to all the other accessions. In terms of the CP content, accession PRPI 3634 was above 11% in both seasons, however, without differing (P>0.05) from most accessions. The mean macroelement content of the accessions was generally adequate in relation to grazing ruminant requirements with the exception of Na and Mg. Phosphorus was less than the critical concentration (0.25%) for one‐half of the accessions in the short day season and 2 of 10 for the long day season. For all samples, Mn was high and Fe was generally adequate in relation to ruminant requirements. Most all samples contained deficient concentrations of Co, Cu, Se, and Zn. Forage Mo concentrations, therefore, did not result in conditioned Cu deficiencies. In this context, it is probable that Na, Se, Cu, Co, Zn, and perhaps Mg, will be needed even if intensive fertilization is practiced in the humid tropical region of Puerto Rico.  相似文献   

12.
Abstract

An experiment was conducted on a commercial farm located in the western part of Venezuela (10.5°N and 72°W; mean annual rainfall of 1000 mm; mean annual temperature of 28°C; sandy‐loam Alfisol with pH of 5.5). The purpose of the experiment was to evaluate the in vitro organic matter digestibility (IVOMD), crude protein (CP) content and mineral composition of four Leucaena leucocephala (Lam.) De Wit accessions under rotational grazing by heifers over a 6‐month period covering dry and rainy seasons, using a split‐plot experimental design with two replications. Neither accessions nor the accession x season interaction affected (P>0.05) any of the variables. The mean IVOMD was 68.6%, whereas CP content during the rainy season (26.5%) was higher (P<0.05) than in the dry season (24.3%). Average mineral content of the accessions were adequate in relation to grazing ruminant requirements with the exception of phosphorus [(P) 0.13%], sodium [(Na) 0.038%], copper [(Cu) 6.9 ppm], and zinc [(Zn) 19.7 ppm]. Forage P concentration may have been influenced by the low soil P content of the experimental site. The mean forage Ca:P ratio (11.3:1) was considerably wider than desirable. During the dry season, ash content increased (P<0.05), Na, iron (Fe), and cobalt (Co) decreased (P<0.05), but Fe and Co still remained above the critical levels. Mean concentrations of other elements were not affected (P>0.05) by season. Forage molybdenum (Mo) concentrations were low and, therefore, would not result in conditioned Cu deficiency. The four L. leucocephala accessions had similar feeding value for grazing ruminants and their quality was not markedly reduced in the dry season. Mineral supplementation of ruminants grazing this legume may be needed to correct specific deficiencies and imbalances.  相似文献   

13.
Abstract

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.  相似文献   

14.
Abstract

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.  相似文献   

15.
Abstract

Greater than 10 mg/kg molybdenum (Mo) concentrations in forage present increasingly challenging management of most classes of livestock. In 1950, 71 alfalfa fields were sampled in Kern County, California, to gain a better understanding of the extent and distribution of high Mo concentrations in forage. Similarly, a large number (82) of the same or nearby fields were resampled in 1985 to evaluate the changes which had occurred in the Mo levels. The number of samples, minimum, maximum and average Mo concentrations were 71, 1.4, 41.7, 10.78 and 82, 0.7, 9.6, 3.57 mg/kg for 1950 and 1985, respectively. Copper (Cu) concentration in 1985 ranged from 6.0 to 19.0 with an average of 10.23 mg/kg. Cu:Mo ratios in 1985 had a low of 1.19 up to 13.71 with an average of 4.25. Forage concentrations of sulfur (S), zinc (Zn), iron (Fe), and selenium (Se) were also determined. Suggested causes for the decline in forage Mo levels are: leaching of soluble salts with irrigation, acidification of soils by nitrogen fertilizers and crop removal. Molybdenosis in livestock is much less of a problem with the decline in molybdenum concentration of forages.  相似文献   

16.
Background and Objective  Largely influenced by the passage of the Swamp Land Act of 1849, many wetlands have been lost in the coastal plain region of southeastern United States primarily as a result of drainage to convert land for agriculture. While further wetland conversion or loss is universally acknowledged, the process continues with little public recognition of the causes or consequences. This study examined changes in soil carbon, pH, and Mehlich extractable nutrients in soils following conversion of wetland to beef cattle pasture. Methods  To better understand the chemical response of soils during wetland conversion to beef cattle pasture, soil samples were collected from the converted beef cattle pastures and from the adjoining reference wetland. Soil samples were collected from eleven sites in the beef cattle pasture, and from four in the adjoining reference wetland. Data that were collected from the reference wetland sites were used as the reference/baseline data to detect potential changes in soil properties associated with the conversion of wetlands to beef cattle pastures from 1940 to 2002. Results and Discussion  Compared with the adjoining reference wetland, the beef cattle pasture soils in 2002, 62 years after being drained, exhibited: (1) a decrease in organic carbon, TOC (-172.3 g kg-1), nitrogen, TN (-10.1 g kg-1), water soluble phosphorus, WSP (-5.1mg kg-1), and potassium, K (-0.7 mg kg-1); (2) an increase in soil pH (+1.8 pH unit), calcium, Ca (+88.4 mg kg-1), magnesium, Mg (+7.5 mg kgc), manganese, Mn (+0.3 mg kg-1), and iron, Fe (+6.9 mg kg-1); and (3) no significant changes in sodium (Na), zinc (Zn), copper (Cu), and aluminum (Al). In 2002, the amount of TOC and the concentration of soil organic matter (OM) in pasture fields were significantly lower than the concentration in the reference wetland with average values of 7.8 ± 8 g kg-1 and 36 ± 26 g kg-1 and 180.1 ± 188 g kg-1 and 257 ± 168 g kg-1, respectively. It appeared that conversion of wetlands was proceeding toward a soil condition/composition like that of mineral soils. Conclusion and Outlook  Overall, conversion of wetland had significant effects on soil carbon, pH, nitrogen, phosphorus, and extractable nutrients. Results of our study have shown a decrease in TOC, TN, WSP, and K and an increase in soil pH, Ca, Mg, Mn, and Fe. These results are important in establishing useful baseline information on soil properties in pasture and adjoining reference wetland prior to restoring and converting pasture back to its original wetland conditions as a major part of the restoration effort being underway.  相似文献   

17.
基施硒肥对莜麦产量和微量元素含量的影响   总被引：2，自引：2，他引：0  
在河南省黄河滩区,通过研究基施硒肥(亚硒酸钠)对莜麦青干草和果实产量以及微量元素含量的影响,探索提高莜麦产量以及微量元素含量的新途径。结果表明: 1）基施硒肥能提高莜麦的青干草产量, 当基施量为954 g/hm2的情况下,效果最佳,扬花期青干草产量提高9.33%（P0.05）,但基施硒肥对莜麦果实产量影响不显著; 2）莜麦对硒有较强的吸收和同化能力,可以从肥料中大量吸收无机硒,并大多转化为有机硒向上运输到茎叶和果实中; 3）基施硒肥能在不同程度上提高莜麦青干草中Cu、 Zn和Se的含量,而对Fe和Mn的含量影响不大,当硒肥基施量在954 g/hm2的情况下,扬花期青干草中Cu、 Zn和Se的含量分别提高 9.31%（P0.05）、 13.22% （P0.05）和281.25%（P0.05）; 4）基施硒肥能显著提高莜麦果实中Fe、 Cu、 Zn和Se的含量,而对Mn的含量影响不大,当硒肥基施量在954 g/hm2的情况下,Cu、 Zn和Se的含量分别比不施硒对照提高7.92%（P0.05）、 5.75%（P0.05）和18.75%（P0.05）,当硒肥基施量在765 g/hm2的情况下,莜麦果实中Fe的含量比对照提高10.19%（P0.05）。综上,莜麦对硒肥有较强的吸收和转化能力,适当地基施硒肥有利于提高扬花期青干草中Cu、 Zn和Se的含量和果实中Fe、 Cu、 Zn和Se的含量,适宜的硒基施量为765954 g/hm2。  相似文献   

18.
锰、硼对紫花苜蓿草产量和矿质元素含量的影响   总被引：4，自引：1，他引：3  
采用叶面喷施的方法,研究不同水平锰、硼对紫花苜蓿草产量和矿质元素含量的影响。结果表明,喷施锰、硼可增加紫花苜蓿产草量;施锰200 mg/kg（Mn2处理）和硼600 mg/kg（B3处理）效果最好,草产量比CK分别显著提高809.49和1065.35 kg/hm2。喷施锰肥能显著提高紫花苜蓿锌和锰的含量,适量喷施能显著提高磷、钴、硒、铁和钼的含量;但喷施锰肥降低了紫花苜蓿钙、铜和硼的含量,适量喷施能显著降低钙和铜的含量。紫花苜蓿锰含量与施锰量呈正相关,硒、铜含量与施锰量呈负相关,而铁、锌含量随施锰量增加呈先升后降趋势。喷施硼肥显著提高了紫花苜蓿锌和磷含量,显著降低了钙、钼、硒的含量,而适量喷施硼肥能显著提高钴、铁、锰、硼的含量,但喷施硼肥未显著降低紫花苜蓿铜的含量。紫花苜蓿锌、硼含量与施硼量呈正相关,铁、钙、钼、铜、硒含量与施硼量呈负相关,而锰、磷含量随施硼量增加呈先升后降趋势。  相似文献   

19.
Deficient trace elements concentration in soils, forages, and animals have been reported in several areas of Balkan region. Main challenge in overcoming low productivity of forage and animal production in this region is the lack of data on the nutritional status of the pastures and soils. This study examined the nutrient and pseudo total concentration of trace elements in soil and herbage plants, and the potential deficiency or excess with regards to crop and livestock production. Soil and plant samples from 100 sampling points were collected in the mountainous grasslands of Manja?a (between longitudes 16°56′ and 17°8′ east; and latitudes 44°33′ and 44°42′ north) and Vla?i? (between longitudes 17°14′ and 17°29′ east; and latitudes 44°25′ and 44°37′ north). Soil samples were analysed for soil texture, pseudo total concentration (5?ml HNO3) of trace elements (TE), pH, soil organic carbon (SOC), while plant samples were analysed for TE. The soil pH varied from strongly acidic to moderately alkaline. The concentration of SOC varied from 0.5% to 12.3%. Most of the soil samples were finer-textured soils high in silt content. The average concentrations of Na, P, Zn, Se, Cu, Co, and B were low in both soil and herbage plants. Plant K, Ca, Mg, Mo, and Mn concentrations were sufficiently high to meet the requirements of grazing animals, while Fe concentrations was elevated in certain areas. High levels of Mo were found in both soil and plants. The results suggest that imbalances observed in natural pastures of Manja?a and Vla?i? area, caused by low soil TE concentration and other soil and plant properties, could contribute to poor animal nutrition.  相似文献   

20.
锰与硼喷施对紫花苜蓿产量和矿质元素含量的影响   总被引：2，自引：0，他引：2  
采用叶面喷施的方法,研究不同水平锰与硼对紫花苜蓿草产量和矿质元素含量的影响.结果表明,喷施锰、硼促进了紫花苜蓿草产量的增加,适量则效果显著(P < 0.05),以施锰浓度200 mg·L-1(Mn2处理)和硼浓度600 mg·L-1(B3处理)效果最好,草产量比对照分别提高809.49和1 065.35 kg·hm-2;喷施锰肥能显著提高锌和锰的含量;适量则能显著提高紫花苜蓿磷、钴、硒、铁和钼的含量,喷施锰肥降低了钙和铜的含量,适量则影响显著;喷施锰肥,硼的含量略有降低;且锰含量与施锰量呈正相关,硒、铜含量与施锰量呈负相关;而铁、锌含量随施锰量增加呈先升后降趋势.喷施硼肥显著提高了锌和磷含量,显著降低了钙、钼、硒的含量,显著提高钴、铁、锰、硼的含量,喷施硼肥,铜的含量略有下降;且锌、硼含量与施硼量呈正相关,铁、钙、钼、铜、硒含量与施硼量呈负相关;而锰、磷含量随施硼量增加呈先升后降趋势.  相似文献   

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