Alfalfa Phytoestrogen Content: Impact of Plant Maturity and Herbage Components

Legumes contain a range of non‐nutritional phytochemicals that may have health‐promoting effects in humans. In this study, we determined the concentrations of four phytoestrogens (coumestrol, apigenin, luteolin and quercetin) in field‐grown alfalfa (Medicago sativa L.). Differences between plants of different stages of maturity, between plant parts, and different canopy segments were assessed. The concentration of individual phytoestrogen in whole herbage varied between 15 and 225 μg g^?1 dry matter (DM) and was strongly affected by stage of maturity. Coumestrol and apigenin concentrations were highest at early vegetative stages, luteolin and quercetin at early vegetative and late flowering stages. All phytoestrogens were found in lowest concentrations at the early flowering stage (average 68 μg g^?1 DM); stage at which alfalfa is usually harvested when used as a forage source for animals. At vegetative stages, apigenin was the predominant phytoestrogen in herbage followed by coumestrol, the reverse being observed upon initiation of flowering; luteolin and quercetin were found at all stages in similarly lower concentrations. Concentrations of luteolin, quercetin and apigenin were 225, 410 and 690 % greater, respectively, in flowers than in leaves or stems; coumestrol concentration was similar between plant parts. In flowers and stems the predominant phytoestrogens were apigenin and quercetin, followed by coumestrol and luteolin. Similar concentrations (average 26 μg g^?1 DM) of each of the four phytoestrogens were found in leaves. Concentrations through the herbage canopy varied and were greatest at >60 cm from the soil surface for apigenin and coumestrol, but greatest at >60 and 0–20 cm for quercetin and at 0–20 cm for luteolin. The results suggest that if alfalfa is to be used as a source of phytoestrogens and is harvested for the production of herbal supplements or nutraceuticals, management will need to be adapted.     

Effect of ensiling whole crop oat with lucerne in different ratios on fermentation quality,aerobic stability and in vitro digestibility on the Tibetan plateau

The objective of this study was to determine the effect of ensiling different ratios of whole crop oat to lucerne on fermentation quality, aerobic stability and in vitro digestibility of silage on the Tibetan plateau. Four experimental treatments were produced varying in the ratio of forages on a fresh matter (FM) basis: 1) 100% oat (control, dry matter (DM) content: 317 g/kg), 2) 90% oat + 10% lucerne (OL10, DM content: 316 g/kg), 3) 80% oat+ 20% lucerne (OL20, DM content: 317 g/kg) and 4) 70% oat+ 30% lucerne (OL30, DM content: 318 g/kg). All treatments were packed into laboratory‐scale silos and ensiled for 60 days and then subjected to an aerobic stability test for 15 days. Further, the four experimental treatments were incubated in vitro with buffered rumen fluid to study the nutrient digestibility. All silages were well preserved with low pH and NH₃‐N contents, and high lactic acid contents and V‐scores (evaluation of silage quality). Increasing the lucerne proportion increased (p < 0.05) crude protein (CP) content of silage, whereas neutral (NDF) and acid (ADF) detergent fibre contents were not affected. Under aerobic conditions, the control silage showed higher (p < 0.05) yeast counts (>10⁵ cfu/g FM) followed by OL10 silage, and OL10 silage improved aerobic stability for 74 h. OL20 and OL30 silages showed fewer (p < 0.05) yeasts (<10⁵ cfu/g FM) and markedly (p < 0.05) improved the aerobic stability (>360 h). After 48‐h incubation, OL30 silage increased (p < 0.05) in vitro dry matter digestibility (IVDMD) and neutral detergent fibre digestibility (IVNDFD) compared with the control silage. These results suggest that replacing oat with lucerne had no unfavourable effects on fermentation quality of silage, but improved CP content, aerobic stability IVDMD and IVNDFD. OL30 silage was the best among the three mixed silages.     

Selection for increased forage yield in alfalfa at different NaCl levels

Summary Alfalfa (Medicago sativa L.) forage yield may be reduced by moderate levels of salinity. Increasing forage yield in saline environments through plant breeding could partially ameliorate this problem. However, prior indirect selection either in cell culture, at germination, or during seedling growth has not resulted in agronomically relevant levels of salt tolerance. This study was conducted to determine whether mean forage yield of alfalfa grown in saline environments could be increased. To reduce the number of possible selection schemes, forage yield data for five harvests from Sonora and its parental cultivar African grown in a greenhouse and irrigated with 0, 30, 60, or 80 mM NaCl were used to simulate one cycle of selection at each NaCl environment. Greatest gains in forage yield were expected under non-saline conditions with decreased gains under saline conditions. Selection based on yield in regrowth harvests was also predicted to be more efficient than that based on seedling harvest. Experimental populations were developed from Sonora and African at each NaCl level using phenotypic selection for increased mean forage yield for harvests 3 to 5. After each of two cycles of selection, forage yield from selected, control (plants selected randomly under non-saline conditions), and parental populations was evaluated at 0, 30, 60, and 80 mM NaCl. Gains in forage yield were observed in African when the selection and evaluation environments were the same, but in Sonora this was observed only at 0 NaCl. Selection at 0 NaCl did not increase forage yield at 60 or 80 mM NaCl in either germplasm source. This suggests that selection for increased forage yield may be successful at low to moderate NaCl levels in germplasm with ample variation for yield when grown in saline environments, while selection for increased forage yield in non-saline conditions may be ineffective.     

陇中黄土高原不同草田轮作模式土壤碳组分的差异研究

通过田间定位试验,研究黄土高原西部旱农区多年生苜蓿草地(L-L)及苜蓿耕翻轮作处理苜蓿-休闲(L-F)、苜蓿-小麦(L-W)、苜蓿-玉米(L-C)、苜蓿-马铃薯(L-P)、苜蓿-谷子(L-M)对土壤总有机碳(TOC)、易氧化有机碳(ROC)、轻组有机碳(LFOC)及重组有机碳(HFOC)的影响。结果表明,在0200 cm土层,不同轮作模式下土壤总有机碳含量及土壤各有机碳组分均表现为随土层加深呈波动下降趋势,其中TOC、ROC、HFOC含量最高值和最低值分别出现在苜蓿连作表层(05 cm) 和苜蓿轮作(小麦)中层(3050 cm) ,LFOC最高值和最低值分别出现在苜蓿轮作(马铃薯)表层(05 cm)和苜蓿轮作(玉米)底层(170200 cm)。与苜蓿连作模式相比,苜蓿轮作(小麦、玉米、马铃薯、谷子)会降低TOC、ROC、HFOC含量,增加LFOC含量,其中TOC含量分别降低17.44%,9.25%,18.40%和9.34%;ROC含量分别降低28.10%,8.52%,29.75%和23.17%;HFOC含量分别降低18.80%,10.06%,20.53%和12.50%;LFOC分别增加7.41%,5.56%,22.22%和57.41%。可见,苜蓿种植多年耕翻轮作粮食作物后降低了土壤总有机碳水平,且对有机碳各组分的影响存在显著差异。     

Effect of various plant factors on the expression of creeping-rootedness in lucerne (Medicago sativa L. complex)

Although agronomically interesting, selection of creeping-rootedness inlucerne, that is, the ability to form adventitious shoots on horizontal,spreading roots, remains difficult because of the complex and still unclear geneticcontrol of this character, coupled with the possible occurrence of external factorsthat affect unpredictably its expression. Two experiments were undertaken onprogenies of creeping-rooted plants, to verify previous findings and inferences,and test novel hypotheses, concerning the effect of various plant factors on theexpression of creeping-rootedness. The ultimate aim was to provide information onthe most appropriate germplasm, procedures, or indirect selection criteria, that wouldimprove the efficiency of breeding for this character. The factors here examinedincluded genotype, age, kind of progeny, vigour, spreading ability, and undergroundmorphology. Some genotypes appeared to be good donors of the character, whereasothers did not. The proportion of creeping-rooted plants increased in allcases with the plant age. Selfing consistently depressed the expression ofthe character compared with clonal propagation or crossing. It is suggestedthat the effect of age and selfing on the penetrance of creeping-rootedness ismediated through their effect on plant vigour. Both aerial and root vigour showedindeed an effect per se on the presence of the character. Beside thevigour, possible indirect selection criteria were identified in the frequenciesof swollen zones and latent stem primordia on horizontal roots. Proportion ofcreeping-rooted plants in progenies after one year of growth appeared as a simple anduseful criterion to predict future trends. Consistent with previous conclusions, theresults provided evidence that a combination of family and individualselection may enhance the character expression.     

紫花苜蓿与禾草混播草地生长动态研究

在河南省黄河滩区土壤和气候条件下,对紫花苜蓿与无芒雀麦和羊茅二种多年生禾草的混播草地特点进行了研究,并对其地上、地下生物量的时空间动态进行了详细的分析与研究。结果表明,紫花苜蓿混播牧草地上和地下生物量季节动态均呈双峰曲线,地上生物量峰期分别在完熟期以及果后营养中期;地下生物量的峰期分别在种子完熟期和果后营养后期。地上部分生物量增长最快在抽穗期(现蕾期)到完熟期期间,紫花苜蓿与无芒雀麦以及羊茅的混播牧草的生长强度为11.92gDM/(m2·d)和14.13gDM/(m2·d);地下部分增长最快分别在分蘖期(分枝期)到拔节期(抽茎期),紫花苜蓿与无芒雀麦以及羊茅的混播牧草根系生长强度分别为8.53gDM/(m2·d)和8.94gDM/(m2·d)。     

Demography of Abutilon theoprasti and Setaria faberi in three crop rotation systems

Field experiments were conducted to characterize the demography of Abutilon theophrasti and Setaria faberi in a conventionally managed 2‐year (maize/soya bean) rotation, and in 3‐year (maize/soya bean/triticale + red clover) and 4‐year (maize/soya bean/triticale + lucerne/lucerne) rotations managed with 72% and 79% lower herbicide inputs respectively. Rates of weed seedling recruitment, seedling survival and adult plant fecundity were determined for populations in each phase of each rotation and used to calculate annual rates of weed population change, Δ. In both years of the study, Δ for A. theophrasti populations declined or remained stable in all three rotation systems. Despite greater rates of seedling survival and fecundity in maize and soya bean in the 3‐ and 4‐year rotations, increases in Δ for A. theophrasti populations were prevented in these systems because of low fecundity in triticale and low seedling survival and fecundity in lucerne. For Setaria faberi populations, Δ remained stable in the 2‐year rotation, increased in the 3‐year rotation in both years, and increased in the 4‐year rotation in 1 year. The results of this study indicate that when herbicide use is reduced, rotations that include triticale and lucerne can facilitate the suppression of A. theophrasti. Rotations that include lucerne can contribute to restraining S. faberi population growth, given adequate levels of seedling mortality in this crop.     

Forage chain arrangement for sustainable livestock systems in a Mediterranean area

Mediterranean forage systems suffer from limited availability of fresh forage because of water deficits and extreme temperatures. Consequently, fresh forage is unavailable for at least 6–7 months a year, and farmers must buy feed to support livestock production. With the aim of overcoming these limitations, a 2‐year trial was conducted on three distinct sites in Sicily (at 10, 600 and 1200 m elevation) with thirty‐four varieties of forage species belonging to nine biennial/perennial and thirteen annual species. Results showed that by integrating grasses and legumes, species from environments with different climatic conditions enable the season of forage production to be extended from mid‐April to mid‐November. Quality traits of forage in different areas varied in relation to species and varieties. In general, the sown‐forage quality was better than in pastures and fallows in the same areas commonly used to feed animals. This also leads to a reduction in the use of supplementary feeds. Among the tested species, Lolium multiflorum and Medicago sativa emerged as the most promising for filling the forage‐deficit periods, and Trifolium spp. and Vicia sativa were found to be superior for increasing forage quality. The results are discussed in the context of adapting Mediterranean forage supplies for ensuring greater sustainability of livestock production in mountain, hill and plain areas. The proposed forage chain arrangement represents part of local potential adaptation to climate limitations and climate change.     

A two-year comparison on nutritive value and yield of eight lucerne cultivars and one red clover cultivar

Red clover (Trifolium pratense) and lucerne (Medicago sativa) are among the most common legume species used for ruminant feeding systems. Besides the greater nutritive quality and first-year ley yield compared to lucerne, red clover decreases its yield over the years. However, under unfavourable soil conditions the persistency of lucerne can be compromised, not performing as expected. This study compared yield and chemical composition of eight lucerne cultivars and one tetraploid red clover cultivar, with similar growth capacity as lucerne, replicated over two years. In the second year, four lucerne cultivars and the red clover cultivar were analysed for crude protein (CP) fractions, dry matter and neutral detergent fibre (NDF) digestibility. A randomized block design was used with three field blocks per cultivar for the multiple comparisons within each year. There were differences in DM yield, concentrations of CP and NDF and CP fractions among the lucerne cultivars, but the differences were inconsistent between years and between growth cycles within year. The red clover cultivar had lower CP and NDF concentrations than a majority of the lucerne cultivars, and greater in vitro organic matter digestibility compared to all of the lucerne cultivars. Also, the red clover cultivar had greater rumen undegradable-to-degradable CP ratio but confirmed its lower yield persistency compared to the lucerne cultivars.     

不同磷水平对紫花苜蓿产量和品质的影响

不同磷水平对苜蓿产量和品质的影响研究表明 ,在苜蓿充分供应氮、钾等其它营养的情况下 ,施用磷肥能显著增加植株生长高度和侧枝数 ,增加植株生长高度 8 2～ 10 1cm ,增加植株侧枝数 0 9～ 1 8个/株 ;能大幅度提高苜蓿鲜草产量 ,增产 30 8%～ 70 2 % ;对反映苜蓿品质的各营养成分含量影响不明显 ,但能增加单位面积牧草营养成分总产量 ;增施磷肥不仅可以显著增加苜蓿对磷的吸收 ,而且能不同程度地促进苜蓿对钾和钙的吸收 ;本试验条件下的经济最佳施磷 (P2 O5)量为 10 2 4kg/hm2 。