Prediction of nutritive values,morphology and agronomic characteristics in forage maize using two applications of NIRS spectrometry

This study evaluates nutritive, morphological and agronomic characteristics of forage maize predicted by using a high-quality near-infrared (NIR) spectrometer and an NIR hyperspectral-imaging technique using partial least squares (PLS) regression models. The study includes 132 samples of dried milled whole-plant homogenates of forage maize with variation in maturity, representing two growing seasons, three locations in Sweden and three commercial maize hybrids. The samples were measured by a classical sample cup NIR spectrometer and by a pushbroom hyperspectral-imaging instrument. The spectra and a number of variables (crude protein, CP, neutral detergent fibre, starch, water soluble carbohydrates (WSC) and organic matter digestibility), morphological variables (leaves, stems & ears) and crop yield were used to make PLS calibration models. Using PLS modelling allowed the determination of how well maize variables can be predicted from NIR spectra and a comparison of the two types of instruments. Most examined variables could be determined equally well, by both instruments, but the pushbroom technique gave slightly better predictions and had higher analytical capacity. Predictions of CP, starch, WSC and the proportions of ears in the maize gave robust. The findings open new possibilities to further utilise the technology in plant breeding, crop management, modelling and forage evaluation.     

Effects of Drought on Nutritive Value of Kudzu

Kudzu (Pueraria montana), a vigorous, perennial warm-season invasive legume is widely spread in the southeastern United States and has the potential to be used as feed by ruminants during its growing season from May until first frost (usually in October). The purpose of this study was to determine the nutritive value of kudzu during a drought-prone growing season. Five samples of apical leaves and stems were harvested once a week from random locations within a 43-year-old kudzu infestation grown on a Cecil clay loam (fine, kaolinitic, thermic Typic Kanhapludults) at the Clemson University Experimental Forest (Clemson, S.C.). We report the effects of plant part, sampling date, mean air temperature (MAT), and precipitation on dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), calcium (Ca), magnesium (Mg), phosphorus (P), potassium (K), sulfur (S), zinc (Zn), copper (Cu), manganese (Mn), and iron (Fe) of the kudzu. Dry matter and CP were significantly greater in the apical leaf than in the stem; CP had a significant mean air temperature by plant part interaction. A significant temperature by plant part interaction also existed for Mg. Magnesium was greater in leaf than in the stem at the beginning of the growing season until the end of October, when small differences in Mg concentrations between stem and leaf were observed. Stem and leaf Ca concentrations were not significantly different. Calcium concentrations did vary across the dates (P?=?0.002). A significant temperature by plant part interaction existed for Mg concentrations (P?=?0.003), Ca to P ratio (P < 0.0001), P concentrations (P?=?0.0007), S (P < 0.0001), Zn (P?=?0.0053), Mn (P?=?0.0014), and Cu (P?=?0.006). Overall, kudzu's nutritive value as feed for ruminants during the growing season is highly variable; however, chemical composition was very comparable to other common forages. More frequent and intensive droughts predicted as a result of climate change may limit forage choices; however, kudzu maintains its forage potential for feeding both domestic and wild animals during drought-prone growing season.     

Use of Mefluidide to Alter Growth and Nutritive Value of Pearl Millet

Abstract

Pearl millet (Pennisetum americanum L. Leeke) has an inherent rapid growth rate that often presents management problems to achieve optimum utilization by livestock throughout the growing season. Both the rapid spring–summer growth rate and photoperiodism that diminishes growth in late summer—early fall creates the need to use both grazing and mechanical defoliation to have efficient use of forage production. The objectives of this 2‐year field study were to evaluate the effects of a growth regulator, mefluidide (N‐[2, 4‐dimethyl‐5‐([(trifluoromethyl) sulfonyl] amino) phenyl] acetamide), on growth characteristics and nutritive parameters of “Millex 24” pearl millet. Mefluidide was broadcast applied at different rates to determine the effect on dry matter (DM) yield and nutritive value of leaves and stems of pearl millet. Mefluidide reduced DM biomass at each weekly harvest, and at three weeks post‐treatment DM was reduced 3‐fold in Year 1 and 2‐fold in Year 2. Percent leaf, however, was nearly doubled by mefluidide application. Crude protein (CP) of leaves was not affected by mefluidide, however, CP of treated stems was significantly higher (P < 0.05) than untreated pearl millet. Fiber components were lowered (P < 0.05) in treated leaves and stems compared to untreated pearl millet. The 2‐year study showed that mefluidide enhanced nutritive value of pearl millet, but at the expense of DM.     

Effect of Selenium on Mineral Content and Nutritive Value of Melilotus officinalis L.

Plants of Melilotus officinalis L. were subjected to two different treatments: a) no selenium (Se), and b) addition of 3 mg Se L^?1 irrigation water for 45 days and samples of leaves, stems and roots were analyzed for Se, potassium (K), sodium (Na), magnesium (Mg), iron (Fe), copper (Cu), calcium (Ca), manganese (Mn) and zinc (Zn). Crude protein (CP) content, neutral detergent fiber (NDF), acid detergent fiber (ADF) and in vitro organic matter digestibility (IVOMD) were also estimated for the aerial plant tissues. In Se-treated plants Se mainly accumulated in leaf tissues, various changes in macronutrient concentrations were detected, while the micronutrient content decreased significantly. In addition, leaf CP, NDF and ADF content decreased, while IVOMD increased, possibly indicating ameliorated nutritive value. According to our findings, M. officinalis could be used either as a dietary supplement, in mixture with non-accumulator species, for livestock feed deficient in Se or for restoration of grasslands in seleniferous soils.     

Mineral concentrations in leaves and stems of various forages of the Colombian paramo

Abstract

A study was conducted to determine the elemental composition of two plant fractions (leaves and stems) of several forage species in three sheep farms of the paramo in Colombia. The elemental composition of the forage species, and the relationship between soil chemistry and the elemental composition of the forages were also determined. Sampling periods corresponded to the end of the rainy season (May‐June 1987), and the middle end of the dry season (February 1988). Leaves were higher (P<0.05) than stems in the following: calcium, phosphorus, magnesium, potassium, iron, molybdenum, crude protein, and IVOMD. Overall percentage of deficiencies were related to the requirements for sheep as follows: calcium (88%, 13%), phosphorus (50%, 27%), magnesium (85%, 41%), potassium (13%,3%), sodium (94%, 96%), iron (10%, 4%), copper (82%, 65%), manganese (7%, 0%), zinc (46%, 42%), cobalt (92%, 85%), selenium (77%, 65%), crude protein (45%, 8%) for stems and leaves, respectively.

Based on analyses, elemental, crude protein and IVOMD concentrations of forage species, tended to differ. Soil‐forage correlation coefficients of the same mineral for the rainy season were calcium (r = 0.81), magnesium (r = 0.89), potassium (r = 0.71), zinc (r = 0. 69). For the dry season, correlations were calcium (r = 0.61) and magnesium ( r = 0.58). Results indicated low correlation coefficients between most soil and forage elements, and that they are not of great value in assessing the elemental status of grazing sheep in the paramo.     

Production of the forage halophyte Atriplex amnicola in metal‐contaminated soils

Clean‐up of contaminated soils is a costly and slow process that requires long periods of time to be effective. Therefore, direct use of contaminated sites with appropriate management is often likely to be a more efficient use of such land. Consequently, the production of safe animal forages from contaminated soils was the aim of this research. Field studies were conducted to evaluate the growth and elemental composition of river saltbush (Atriplex amnicola) grown on a metal‐contaminated soil. The soil was amended with compost at rates of 0, 15 and 30 t/ha to assess its role on plant growth and metal uptake. Compost application significantly (P < 0.05) increased biomass yield, crude protein (CP) and ash content of river saltbush; in contrast, it decreased the Zn and Pb concentrations in shoot tissues. When 30 t/ha of compost was added, the Pb concentrations in the stems and leaves decreased by 32 and 38%, respectively. Despite the large total and extractable content of metals in the studied soil, shoot concentrations of these metals in A. amnicola were always maintained below potentially toxic levels. The biomass material of A. amnicola had a high nutritive value compared to conventional forage crops and could safely be used as animal forage. This work demonstrates that an Atriplex spp, A. amnicola, has significant potential for use as a safe forage crop in the sustainable on‐site management of contaminated soils.     

Monthly variation of forage and soil minerals in central Florida. I. macro‐minerals

Abstract

A two‐year study was conducted to determine the macromineral status of cattle grazed forages, mostly bahiagrass, and soils in central Florida. Soil and forage samples were collected every month for two years. Month differences (P < 0.01) were observed in all forage macrominerals and in crude protein (CP) for both years. No month effect (P > 0.05) was observed in IVOMD level during year 1. Year effects (P < 0.05) were observed in calcium (Ca), sodium (Na) and CP. Concentrations below the critical level were observed in all macrominerals studied. Higher forage macro‐mineral concentrations were found during spring‐summer months. In general, higher (P < 0.05) soil aluminum (Al), Ca, magnesium (Mg), phosphorus (P), and organic matter (OM) were observed during fall‐winter months, while Na was higher in winter. Soil Ca and Mg were adequate and potassium (K), Na and P were deficient. Year 2 showed higher (P < 0.05) soil macromineral concentrations. Correlation coefficients (r >|0.5|, P < 0.05) were present between forage K and forage CP (r = 0.557) and between forage P and forage CP (r = 0.554). Low correlations were found between soil and forage macrominerals. Percentages of total forage samples with macromineral and CP concentrations below critical levels (in parentheses) and suggestive of deficiency were as follow: in forage, Ca (0.30 ppm), 21%; Mg (0.18 ppm), 34%; K (0.60 ppm), 47%; Na (0.06 ppm), 89%; P (0.25 ppm), 85%; and CP (7%), 18%.     

Boron,molybdenum and selenium status in different plant parts in forage legumes and vegetable crops 1

This study was conducted in Prince Edward Island (P.E.I.), Canada to characterize the levels of B, Mo, and Se in the various plant parts of alfalfa (Medicago sativa L.), red clover (Trifolium pratense L.), broccoli (Brassica oleracea var. italica Plenck.), Brussels sprouts (Brassica oleracea var. gemmifera Zenker), cauliflower (Brassica oleracea var. botrytis L.), and rutabaga (Brassica napobrassica Mill). The three micronutrient anions were consistently highest in the leaves and lowest in the stems. The lower halves of the vegetable crops usually contained close to the highest amounts of B and Mo. In forage legumes, the B concentration was higher in the bottom than in the upper leaves, but B was lower in the bottom than upper stems. Since leaves consistently contained the highest amounts of B and Mo, it is recommended that most recently matured leaves in the Brassica species, and young leaves in forage legumes be sampled to characterize the B and Mo status of these crops. Selenium is of significance to livestock, but not in plant nutrition; therefore, only the parts fed to animals, e.g. the whole vegetative tops of forage legumes, should be used to determine the crop Se status.     

Responses of eastern gamagrass [Tripsacum dactyloides (L.) L.] forage quality to nitrogen application and harvest system

Eastern gamagrass is a warm-season perennial with good forage yield and quality, but both may be increased with nitrogen (N) fertilization. The effects of N and harvest management on neutral- and acid-detergent fibers (NDF and ADF), lignin, in vitro dry matter digestibility (IVDMD), and crude protein (CP) were studied. Nitrogen (0, 50, or 100 kg ha^?1) was applied by broadcasting or knife placement, and forage was harvested from 1- or 2-cut systems. Data were obtained during four years of N treatment, and three intervening years with no N treatment. Neutral- and acid-detergent fibers and lignin were usually lower, and IVDMD and CP were generally higher in the 2-cut than in the 1-cut system. Increasing N affected forage quality in minor ways, except for CP. When 100 kg ha^?1 was applied, CP was increased over no N by 0.14 in the 1-cut system and by 0.25 in cut 1 of the 2-cut system.     

Cool‐Season annual legume effects on wheat forage nutritive value

Hard red winter wheat (Triticum aestivum L. emend. Thell.) is an important cool‐season winter forage used primarily for increasing weight gain on growing beef cattle in the southern Great Plains. ‘Karl’ hard red winter wheat grown alone or grown with either hairy vetch (Vicia villosa Roth) or pea [(Pisum sativum L. subsp. arvense) var. ‘Austrian winter'] was sampled for forage nutritive value. The interplanted legume forage was also sampled for forage nutritive value. Ruminally degradable nitrogen (RDN):ruminally degradable organic matter (RDOM) ratios were highest for legume forage and exceeded the National Research Council (NRC) recommendation of 26.13 g RDN: 1 kg RDOM for peak ruminai microbial efficiency during March, April, and May sample periods over the 2‐year study. Wheat grown alone met the NRC requirement only during March. Wheat grown with either hairy vetch or pea had higher (P<0.05) RDN:RDOM ratios and crude protein (CP) values when compared to wheat grown alone during May. There were no differences (P>0.05) in dry matter (DM) yield between wheat grown alone or grown with the legumes except when analyzed by individual date, and then only for 1 of 6 sample dates. Undegraded intake protein (UIP) was generally higher (PO.05) for wheat compared to the legumes and higher (PO.05) for wheat grown alone during May compared to wheat grown with the legumes during May. The decline of the RDN:RDOM values to 40% below the NRC recommendation of wheat grown alone during May indicates a possible need for protein supplementation for growing beef cattle grazing wheat during this period. These data also indicate that interplanting legumes with wheat may enhance animal performance by providing forage of higher nutritive value. More information regarding grazing tolerance of these selected cool‐season annual legumes and subsequent animal performance is required.     

Effect of nitrogen and phosphorus fertilizers on some components of nutritive value of dwarf elephantgrass

Abstract

Crude protein (CP), calcium (Ca), and phosphorus (P) concentrations and in vitro dry matter digestibility (IVDMD) of leaves, stems, and whole plants of sprinkler‐irrigated dwarf elephantgrass (Pennisetum purpureum) cv. Mott as affected by the factorial combinations of nitrogen (N) (0, 150, 300, and 450 kg N ha^‐1 year^‐1) and P (0, 50, and 100 kg P₂O₅ ha^‐1 year^‐1) fertilization rates were evaluated in a tropical dry forest in the State of Zulia, western region of Venezuela. A randomized complete block design with three replications was used. Soil was a low‐fertility sandy‐loam Alfísol (Udic Paleustalf) with pH of 6.1. Data from eight cuttings carried out at 45‐day intervals were used. Only Ca and P concentrations in stems were affected by N fertilization. Phosphorus fertilization influenced (P>0.05) PC and P contents in leaves, IVDMD in stems, and Ca and P concentrations in both stems and whole plants. Overall mean IVDMD and CP, Ca, and P contents were: leaves, 62.9, 8.75, 0.39, and 0.30%; stems, 64.1, 7.38, 0.20, and 0.38%; and whole plants, 61.3, 8.13, 0.26, and 0.33%, respectively. Even though CP values were not very high, moderate production levels can be expected from ruminants fed this species since other components of its nutritive value can be regarded as adequate.     

不同高粱种质对污染土壤中重金属吸收的研究

利用重金属含量较高的污水污染土壤,以未污染土壤作对照,种植8个甜高粱品种、2个饲用高粱品种和1个粒用高粱品种,检测8种重金属在高粱植物体内不同器官的含量,以研究不同高粱种质对重金属的吸收特性。结果表明:甜高粱对汞(Hg)、镉(Cd)、锰(Mn)和锌(Zn)的吸收在两种土壤间差异显著,对钴(Co)、铬(Cr)、铅(Pb)和铜(Cu)的吸收差异不显著。Mn在甜高粱体内含量表现为未污染土壤高于污染土壤;而Zn含量在不同器官之间存在差异,未污染土壤叶中含量远高于穗,穗中含量远高于茎和根。不同重金属在甜高粱体内的储存部位不同,污染土壤上Hg、Cd、Co、Cr和Zn在根中积累量较高,Cu、Mn和Pb在穗中的积累量较高。甜高粱、饲用高粱和粒用高粱对重金属的吸收、运输及储存在品种之间差异较大,同一品种对不同重金属的吸收也存在差异。饲用高粱表现为叶部对Cr和Zn的储存量较高,而粒用高粱‘晋中0823’则显示了茎对多种重金属的储存能力。高粱根对土壤中重金属的富集系数较高,为0.02(Pb)~0.23(Cd),转移系数变幅为0.21(Co)~3.42(Pb)。对同一种重金属的吸收量品种间差异较大,甜高粱‘西蒙’根对Co、Cr、Cu、Mn、Pb和Zn具有高富集系数,粒用高粱‘晋中0823’茎对Hg、Cd、Mn、Pb和Zn富集系数较高。高粱对重金属的吸收能力与转移能力不同步,甜高粱‘绿能1号’具有对多种重金属的高转移能力,粒用高粱‘晋中0823’只对Zn有较高的转移能力。因此本文认为甜高粱对不同重金属的吸收和转移有选择性。对Zn吸收并转移到地上部后,首先储存在叶和穗中,当吸收量足够大时,茎和根也成为储存器官;对Mn的吸收与其他重金属的吸收存在竞争作用,Hg吸收后很少向地上部转移;而对Cu、Mn和Pb吸收后在穗部的储存量较大。饲用高粱与甜高粱相比对重金属的吸收未显示明显的不同,甜高粱‘西蒙’根对多种重金属具有强储存能力,而粒用高粱‘晋中0823’的茎秆显示了比甜高粱更强的储存能力,甜高粱‘绿能1号’对多种重金属的转移能力较强。所以,选择富集和转移能力均强的高粱品种能更有效地吸收土壤中的重金属,达到修复污染土壤的目的。     

Effects of Lead on the Content,Accumulation, and Translocation of Nutrients in Bean Plant Cultivated in Nutritive Solution

Increasing contents of lead (Pb; from 0 to 10 mg L^?1) as contaminant were added in Clark's nutritive solution to evaluate the effects on content, accumulation, and translocation of macronutrients [phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S)] and micronutrients [copper (Cu), manganese (Mn), zinc (Zn), and iron (Fe)] in different parts of the bean plant (Phaseolus vulgaris L.). Experiments were built using an entirely randomized statistical arrangement and measurements were performed after 60 days of exposure to Pb. The contents of almost all nutrients decreased when Pb was added, except for P in root, Mg in fruits, and S in root and fruits. Reduction in accumulation of all nutrients in the three parts of plants was determined, and an increase in the translocation index was observed for the following nutrients: Mg and Zn in fruits and S in fruits and leaves. For the remaining nutrients, the translocation index diminished.     

向日葵幼苗对Pb、Cu富集能力与耐受性研究

采用室内培养技术研究了向日葵幼苗对Cu、Pb的富集能力与耐受性。结果表明:向日葵幼苗对Pb、Cu具有很强的富集能力,根是主要的富集器官,Cu由根向茎叶运输能力大于Pb。低浓度Pb、Cu刺激了幼苗营养生长;在高浓度条件下,除Pb组外,其它处理均抑制向日葵幼苗的营养生长。Pb、Cu抑制了幼苗根系活力,刺激了幼苗茎叶脯氨酸的生成,改变幼苗茎叶、根蛋白质含量分配水平。Pb与Cu交互作用对幼苗营养生长和生理生化反应具有协同作用。向日葵属于重金属富集植物,对Pb具有很强的耐受性,可以用于修复被Pb污染的土壤。     

In situ labeling of legume residues with a foliar application of a 15N‐enriched urea solution

Abstract

Conventional methods for labeling of legume residues with ¹⁵N for the measurement of the transfer of nitrogen (N) to a succeeding crop are inadequate for zero‐tillage management where the residue is chemically desiccated. The study tests the feasibility of in situ labeling of legumes with ¹⁵N for the study of N transfer to a succeeding crop. A single foliar application of ¹⁵N‐labeled urea was misted onto the stems and leaves of second cut red clover and alfalfa in the field in 0.75 x 0.75 m microplots. Nitrogen content and ¹⁵N enrichment were determined for above‐ and below‐ground plant parts. Overall, recovery of the foliar applied ¹⁵N in the forage was 30% and 57% for the alfalfa and red clover, respectively. Of the nitrogen recovered, approximately 70% and 30% were recovered in the above‐ and below‐ground plant parts, respectively, for both forage species. Atom % ¹⁵N was similar for the red clover and alfalfa for each of the above‐ground plant parts and was slightly lower in the crown and roots for the red clover than for the alfalfa. Values of atom % ¹⁵N ranged from 0.5 for fine roots to 1.5 for leaves above 0.20 m from the ground. Labeling of the plant material was not uniform between plant parts but was adequate for many studies of N transfer to a succeeding crop.     

Effects of organic solid cattle manure application on nutritive value of winter cereal forages

Nutritive value of winter cereal forages is one of interested subjects of farmers for animal feeding. Field experiments were established in 2007–2008 and 2008–2009 growing seasons in northeast Turkey to investigate the effect of organic solid cattle manure application (0, 10 and 20 Mg ha^?1 yr^?1) on nutritive value of three annual cereals for forage. The winter cereal forages were: wheat (Triticum aestivum L.), oat (Avena sativa L.) and rye (Secela cereale L.). ADF (acid detergent fiber), NDF (neutral detergent fiber) CP (crude protein), nitrogen, phosphorus, potassium, sulfur, calcium, copper, iron, magnesium, manganese, sodium, zinc and boron (N, P, K, S, Ca, Cu, Fe, Mg, Mn, Na, Zn and B) concentrations were researched in this study. Wheat had the highest CP, N, Ca, Cu, Na and Zn concentration, whereas oat had the lowest ADF and NDF and the highest K, Fe and Mn concentrations. The greatest Mg and P concentrations were determined in rye. Organic solid cattle manure applications had no effect on N and CP contents, but it decreased ADF and NDF contents. However, in most cases it positively affected the P, B, Cu, Fe, Mg and Na concentrations, whereas it decreased K, Ca, Mn and Zn concentrations. The results showed that wheat and oat are more nutritive species than rye in terms of animal feeding and the organic solid cattle manure, in some cases increased the nutritive values of wheat, oat and rye under organic agriculture conditions.     

Evaluation of Diversity among North American Accessions of False Indigo (Amorpha fruticosa L.) for Forage and Biomass

False indigo (Amorpha fruticosa L.) is a perennial leguminous shrub native to North America. The species could potentially be used for livestock forage, biomass energy, reclamation of degraded environments, or as green manure. Future work with the species will depend upon knowledge of available accessions. Our objectives were to determine (1) the range of diversity among accessions, (2) the correlations among traits across locations, and (3) the distribution of variation among accessions. We studied 21 accessions grown at two locations and a subset of 15 accessions grown at a third location. We measured 47 morphological, agronomic, and phenological traits. All traits were influenced by accession in at least one location (p < 0.05). The mean dry matter (DM) biomass yield of accessions in August ranged from 53 to 1515 g plant⁻¹ and was correlated across locations. False indigo had a high second-year leaf concentration, averaging 660 g kg⁻¹ DM at one location in August. Forage quality of false indigo leaves was high, with average crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF) concentrations in July of 205, 226, and 235 g kg⁻¹, respectively. Accession means of forage quality traits were poorly correlated across locations, indicating that it would be difficult to improve forage quality through selection. Diversity among accessions was often related to geographic origin. The two southern accessions were distinct from all other accessions, indicating that accessions from distant geographic regions will likely contribute valuable diversity to a plant breeding program.     

Nutrient Distribution and Stem Length in Flowering Stems of Protea Plants

A study of nutrient distribution in the flowering stem of proteas was carried out in commercial protea plantations of each of the cultivars ‘Scarlett Ribbon’, ‘High Gold’, ‘Veldfire’, and ‘Sunrise’ of Leucospermum cordifolium, and of the species L. patersonii located in a subtropical zone (La Palma Island, Canarian Archipelago). Flowering stems were cut into different parts: flower bud, leaves from half proximal stem to the flower bud, leaves from half distal stem to the flower bud, half proximal stem to the flower bud, and half distal stem to the flower bud. Nutrient content of the different parts of the flowering stems of the cultivar and the species gave significant differences in some cases, depending on the nutrient and the cultivar. Occasional dissimilarities among the levels of nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), sodium (Na), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) were determined in comparisons among half proximal stems and half distal stems, independent of the cultivar. The same trend was observed when nutrient contents of the leaves from the half distal and the half proximal stems were compared. Phosphorus exhibited the lowest concentrations of all macronutrients in the different organs. Flower buds presented the smallest levels of macro-and micronutrients, while the leaves of the half distal and half proximal stems showed the highest values. The influence of nutrients of leaves from the half proximal stems on the stems length varied among cultivars.     

ACCUMULATION AND TRANSLOCATION OF SILICON IN RICE AND BEAN PLANTS USING THE 30SI STABLE ISOTOPE

The ³⁰Si silicon isotope stable was used for assessing the accumulation and translocation of Si in rice and bean plants grown in labeled nutritive solution. The isotopic silicon composition in plant materials was determined by mass spectrometry (IRMS) using the method based on SiF₄ formation. Considering the total-Si added into nutritive solutions, the quantity absorbed by plants was near to 51% for rice and 15% for bean plants. The accumulated amounts of Si per plant were about 150g in rice and 8.6g in bean. Approximately 70% of the total-Si accumulated was found in leaves. At presented experimental conditions, the results confirmed that once Si is accumulated in the old parts of rice and bean plant tissues it is not redistributed to new parts, even when Si is not supplied to plants from nutritive solution.     

日粮营养素水平对东北肉鹅生长性能及血液生化指标的影响（1-28日龄）

本试验选用216只1日龄东北肉鹅,采用四因素三水平L9(34)正交试验设计,探讨0-28日龄东北肉鹅日粮代谢能、粗蛋白、钙和非植酸磷水平对东北肉鹅生长性能、部分血液生化指标及激素水平的影响。结果表明：日粮代谢能水平极显著影响肉鹅的日增重、采食量及料肉比( P < 0.01),粗蛋白显著影响料肉比( P < 0.05)。能量水平对高密度脂蛋白(HDL)、低密度脂蛋白(LDL)和胆固醇(CHO)含量影响显著( P < 0.05),对尿酸的影响极显著( P < 0.01);肉鹅日增重与T3呈较强的正相关,能量水平显著影响血清生长激素(GH)、胰岛素样生长因子-1(IGF-1)的含量( P < 0.05),并且日增重与血清中GH和IGF-1的含量、GH与IGF-1的含量呈显著的正相关。