Yield and Nutritive Values of Semi- and Non-Fall Dormant Alfalfa Cultivars under Late-Cutting Schedule in California’s Central Valley

California is one of the major alfalfa (Medicago sativa L) forage-producing states in the U.S, but its production area has decreased significantly in the last couple of decades. Selection of cultivars with high yield and nutritive value under late-cutting schedule strategy may help identify cultivars that growers can use to maximize yield while maintaining area for sustainable alfalfa production, but there is little information on this strategy. A field study was conducted to determine cumulative dry matter (DM) and nutritive values of 20 semi- and non-fall dormant (FD) ratings (FD 7 and FD 8 - 10, respectively) cultivars under 35-day cut in California’s Central Valley in 2020-2022. Seasonal cumulative DM yields ranged from 6.8 in 2020 to 37.0 Mg·ha−1 in 2021. Four FD 8 - 9 cultivars were the highest yielding with 3-yrs avg. DM greater than the lowest yielding lines by 46%. FD 7 cultivar “715RR” produced the highest crude protein (CP: 240 g·Kg−1) while FD 8 cultivar “HVX840RR” resulted in the highest neutral detergent fiber digestibility (NDFD: 484 g·Kg−1, 7% greater than the top yielding cultivars) but with DM yield intermediate. Yields and NDFD correlated positively but weakly indicating some semi- and non-FD cultivars performing similarly. These results suggest that selecting high yielding cultivars under 35-day cutting schedule strategy can be used as a tool to help growers to maximize yield while achieving good quality forages for sustainable alfalfa production in California’s Central Valley.

Effects of Mixture Sowing on Forage Yield and Interspecific Competition of Alfalfa and Orchard Grass

[ Objective] To explore the mixture sowing effects and optimal mixture ratio of alfalfa and orchard grass. [ Method] The alfalfa and orchard grass were sowed at different ratios （1 ： 0, 3： 1, 1 ： 1, 1 ： 3 and 0：1 ）. They were grouped and named as CK1, A1, A2, A3 and CK2., respectively. The forage yield, relative yield total （RYT） and the competition rate （CR） of alfalfa and orchard grass in each group were determined, respectively. [ Result] In the A3 treatment group, the total forage yield was the highest （4 827.67 kg/hm2） and significantly different from that of other treatment groups （ P 〈 0.01 ）. In every treatment group, the RYT was higher than 1, and the alfalfa was more competitive than the orchard grass in the mixed-seeding pasture. [ Conclusion] Our studies may provide a basis for the establishment of high yield and high quality artificial mixture pasture.

Yield Evaluation of Twenty-Eight Alfalfa Cultivars in Hebei Province of China

Cultivar selection is important for alfalfa （Medicago sativa L.） hay production. From 2009 to 2012, a field study was conducted to evaluate the dry matter yield （DMY） of 28 cultivars in Cangzhou District of Hebei Province, China, and to determine the most suitable cultivars for this province and other zones with similar climate conditions. 28 alfalfa cultivars were sown in late March of 2009 and were harvested for hay four times in each subsequent year. The results showed that the climatic conditions resulted in significant differences in annual DMY among years, with the second year being the highest and the first year the lowest. The top five cultivars with the highest total DMY were L2750 （62.75 t ha^-1）, Hom （62.72 t ha^-1）, 86-266 （61.55 t ha^-1）, German （61.44 t ha^-1） and Zhongmu 1 （61.18 t ha^-1）, respectively. Across all four years, first harvest had the highest ratios to annual DMY except the cultivar of Rambler, while the fourth harvest had the lowest ratio. There were positive correlation relationships between DMY of each harvest and annual DMY, and the correlation coefficients were all significant in four years. And the path coefficients of first harvest were always the highest in four years. The qualities showed small variations among these cultivars and the cultivar L3750 presented the highest crude protein in both years. Crude protein had significant positive correlation with relative feed value （RFV） in both years while crude fiber had significant negative correlation with RFV and crude fiber.

Effects of Cutting Interval between Harvests on Dry Matter Yield and Nutritive Value in Alfalfa

Understanding the relationship between dry matter yield and nutritive value throughout the growing season will help optimize the cutting intervals between harvests in alfalfa (Medicago sativa L.). The Ogallala Aquifer is a very important water source when growing alfalfa in Southwest Kansas and unfortunately, the water level of the Ogallala Aquifer is shrinking. The objective of this study was to determine the optimum cutting interval that optimizes dry matter yield and nutritive values of alfalfa. Alfalfa was harvested with different cutting intervals, i.e., every 28, 35, 42 and 49 day, which was equivalent of 5, 4, 4, and 3 cuttings per year, respectively in 2013 and 2014. Based on 2-yr total yield, by delaying alfalfa harvest by 21 days, i.e., from every 28th day to 49th day, alfalfa yield increased by 2.25 Mg/ha whereas by 5.58 Mg/ha by delaying cutting intervals from every 28th day to 42nd day. Although harvesting alfalfa every 42nd day had the same cutting frequency as the 35th day treatment (i.e., 4 cuttings per year), the treatment harvesting every 42nd day had significantly higher alfalfa yield than 35th day cutting interval. Alfalfa yield increased by approximately 20% by delaying one week for harvesting alfalfa from 35th to 42nd day interval, based on dry matter yields of 2013 and 2014. As cutting interval increased from every 28th to 49th day, crude protein (CP) content decreased. In contrast to CP, acid detergent fiber and neutral detergent fiber increased as the cutting interval and stage of maturity increased in 2013 and 2014. The results suggest that alfalfa producers in Southwest Kansas possibly could reduce the cutting frequency from 5 to 4 per year. Cutting interval of every 42nd day between harvests appears to be the optimum when considered a dry matter yield and nutritive values in alfalfa.

Correlation between Root Trait and Yield of Alfalfa

Growth traits of root system of 13 autumn-sowing alfalfa cultivars were analyzed. The results indicated that there were significant difference in growth pa- rameters of root system among alfalfa cultivars （ P 〈 0.05 ）. The cultivars, Prime and WI323, showed the highest root biomass （ higher than 32 g） ; cuhivar WI323 had the largest lateral root number （17.8 branches）. Cultivars Prime, WI323, Super7 and L90 had better root traits than other cultivars based on comprehensive evaluation. Among three times of mowing within a year, root growth and development of alfalfa had mutual promotion with the first and second time growth of abovegraund part, but had competition with the third time growth. Overwintering alfalfa root restricted the grass yield in the following year, especially the third-cut yield in the next year.

Effects of Mixed Fertilizer Applications on Hay Yield of Alfalfa

[ Objective] To study the effects of combined application of different elements on alfalfa hay yield. [ Medthod] Potassium sulfate, ammonium chloride, superphosphate and magnesium oxide were applied to alfalfa field in the experiment, and quaternary quadratic regression orthogonal combination was used to examine the effects of the experiment factors on hay yield of alfalfa. [ Result] The order of targets based on the effects on hay yield is as follows： potassium sulfate 〉 ammonium chloride 〉 magnesium oxide 〉 superphosphate. Among them, the potassium sulfate had a significant impact on alfalfa hay yield. The interaction between potassium sulfate and magnesium oxide also had a significant impact on alfalfa hay yield. [ Conclusion] The optimal cultivation measures for alfalfa hay yield of more than 19 224.6 kg/hm^2 are as follows： potassium sulfate, 163.253 - 181.679 kg/hm^2 ; ammonium chloride, 155.877 - 174.258 kg/hm^2 ; superphosphate, 566.177 - 632.924 kg/hm^2 ; and magnesium oxide, 30.060 - 33.628 kg/hm^2.

Harvest Time and Fertility Effects on Yield and Quality of Forage from Alfalfa, Hybrid Bromegrass and Their Mixture

A field experiment with 24 treatments consisting of three perennial forage crops [alfalfa (Medicago sativa L. cv. AC Longview), hybrid bromegrass (Bromus riparius Rehm & Bromus inermis Leyss. cv. AC Success) and their mixture], four Cut 1 dates (approximately June 20, July 10, July 30 or August 20), and two fertilizer levels (unfertilized and fertilized) was established in late May 2014, on a Black Chernozem [Udic Boroll] silty clay soil. Forage dry matter yield [DMY], and concentration (g·kg−1 DM) of crude protein [CP], total digestible nutrients [TDN] and acid detergent fiber [ADF] data were collected over 3 years from 2015 to 2017. The fertilizer treatments were imposed in 2016 and 2017. Forage crops were initially cut at four Cut 1 dates, and again cut [Cut 2] in autumn (September 2 in 2015, November 7 in 2016 and October 5 in 2017). For all three forage crops, forage DMY usually increased when Cut 1 was delayed. Delaying Cut 1 reduced forage DMY for Cut 2. Total DMY (Cut 1 + Cut 2) for all three forage crops was highest from the combination of July 10 and late Autumn cuts. Alfalfa-bromegrass mixture produced higher DMY than bromegrass or alfalfa alone. Fertilizer application resulted in a significant increase in Cut 1 and total DMY for bromegrass. The CP concentration in Cut 1 forage usually declined as the forage crops matured. The CP concentration was highest for alfalfa, followed by alfalfa-bromegrass mixture, and much lower for bromegrass. There was little or no effect of forage crop maturity on the TDN and ADF concentrations in forage. The TDN concentration was higher and ADF concentration was lower in forage from alfalfa or alfalfa-bromegrass mixture than bromegrass. Fertilizer application significantly increased CP concentration for alfalfa-bromegrass mixture. Delaying harvesting for Cut 1 increased ADF yield and TDN yield until Late July, but CP yield generally decreased with crop maturity. The ADF yield and TDN yield were higher for alfalfa-bromegrass mixture than bromegrass or alfalfa alone, and CP yield was similar for alfalfa and alfalfa-bromegrass mixture but considerably higher than bromegrass. Fertilizer application increased CP yield and ADF yield for bromegrass and alfalfa-bromegrass mixture, and TDN yield only for bromegrass. In conclusion, total DMY (Cut 1 + Cut 2) was highest for a combination of Early July and Autumn cuts. Forage yield was highest for alfalfa-bromegrass mixture, followed by alfalfa and lowest for bromegrass. The CP and TDN concentrations were higher, and ADF concentrations were lower in forage from alfalfa or alfalfa-bromegrass mixture than bromegrass.

不同苜蓿品种叶片特征、光合生理特性与产量性状的比较

以国内外引进的8个紫花苜蓿(Medicago sativa L.)品种为试验材料,对比研究不同品种的叶片特征、产量性状和光合生理特性,采用相关性分析和通径分析法,探讨其与产量的关联性,以期为高产紫花苜蓿种质的筛选提供依据。结果表明:供试紫花苜蓿品种单株干重的变幅为0.88~1.21 g;各性状与单株干重的相关性按大小排序依次为:单株叶干重>比叶重>蒸腾速率>单株叶片数>叶形指数,单株叶干重是最突出的叶片特征指标。对单株干重的影响程度从大到小依次为:比叶重>气孔导度>可溶性蛋白>株高>蔗糖>可溶性糖>叶绿素总量,其中,比叶重是单株干重的主要决定因子。综上,高产紫花苜蓿种质筛选的重要指标包括:单株叶干重和比叶重,8个紫花苜蓿品种中‘甘农9号’、‘WL319HQ’和‘SG501’的单株干重、单株叶干重和比叶重均较大,可作为高产种质在育种工作中加以研究利用。

天山北坡平原荒漠灌区9个紫花苜蓿品种生产性能综合评价

【目的】筛选出适宜在天山北坡平原荒漠区推广种植的紫花苜蓿品种。【方法】采用单因素随机区组设计,测定9个紫花苜蓿品种的株高、草产量、品质等指标,并利用灰色关联法对9个品种进行综合评价。【结果】随种植年限增加,供试材料的鲜草和干草产量均呈下降趋势,其中第1年的干草产量占比较高,平均为37.77%;佰苜341的株高积累量最大,为939.8 cm,显著高于其他品种;骑士T干草总产量、粗蛋白含量和相对饲喂价值最高,分别为61602.03 kg/hm^(2)、16.83%和119.16%;灰色关联度综合评价结果由高到低的顺序为:骑士T>佰苜202>大银河>阿迪娜>佰苜341>佰苜371>挑战者>佰苜401>康赛。【结论】骑士T的综合表现较好,建议在天山北坡平原荒漠灌区引种种植。

食用菌渣堆肥还田对苜蓿产量和品质的影响研究

食用菌渣是有机废弃物,也是可回收利用的优质农业资源,食用菌渣的高效资源化利用对于发展可持续农业有重要意义。以苜蓿为试验材料,设计不同堆肥施用方案(3 000 kg/hm^(2)、4 500 kg/hm^(2)和6 000 kg/hm^(2)),辅以两种补充灌溉量,观测食用菌渣堆肥还田对苜蓿产量和品质的影响。结果表明,4 500 kg/hm^(2)菌渣肥料协同240 mm补充灌溉量有利于苜蓿增产提质,该组合下熵权系数评价值达到0.81,可作为食用菌渣资源高效利用方案。

氮肥与复硝酚钠复配施用对紫花苜蓿生理特性及种子产量的影响

本试验以‘新牧4号’紫花苜蓿(Medicago sativa L.‘Xinmu No.4’)为试验材料,研究在盛花期喷施氮肥(N)、复硝酚钠(CSN)、氮肥和复硝酚钠复配(N+CSN)对紫花苜蓿生理特性、种子产量及产量构成因子的影响,发现喷施N,CSN,N+CSN能够提高紫花苜蓿叶片可溶性糖、淀粉、可溶性蛋白含量、SOD、POD和CAT活性。喷施N+CSN优于单施N和CSN,其中,N+CSN显著提高紫花苜蓿二级分枝数/生殖枝、荚果数/花序、种子数/荚果和千粒重,从而提高种子产量;与对照相比,单施N和CSN后种子产量提高了6.84%~38.49%,N+CSN施用后种子产量提高了44.39%~57.76%。根据相关性分析,不同处理下种子产量与可溶性糖、淀粉和可溶性蛋白含量,以及SOD、POD和CAT活性、千粒重、种子数/荚果、荚果/花序、小花数/花序、结荚率、二级分枝数/生殖枝都呈显著正相关关系。综上所述,隶属函数综合分析得出N+T2(0.5%N+6 mg·L^(-1)CSN)是提高种子产量和优化种子产量构成因子最优组合。

脱硫石膏与粉煤灰配施对碱化土壤改良及苜蓿生长的影响

【目的】筛选适宜新垦龟裂碱化土壤改良和苜蓿生长的脱硫石膏和粉煤灰配比。【方法】采用小区试验,试验设置CK(脱硫石膏0、粉煤灰0)、T1(脱硫石膏30 t/hm^(2)、粉煤灰15 t/hm^(2))、T2(脱硫石膏30 t/hm^(2)、粉煤灰30 t/hm^(2))、T3(脱硫石膏30 t/hm^(2)、粉煤灰45 t/hm^(2))、T4(脱硫石膏45 t/hm^(2)、粉煤灰15 t/hm^(2))、T5(脱硫石膏45 t/hm^(2)、粉煤灰30 t/hm^(2))、T6(脱硫石膏45 t/hm^(2)、粉煤灰45 t/hm^(2))共7个处理,研究脱硫石膏和粉煤灰配施对土壤pH值、碱化度和可溶性盐量及苜蓿生长影响。【结果】脱硫石膏和粉煤灰配施显著改善龟裂碱化土壤物理性质,与CK相比,T3处理土壤体积质量降低7.69%,土壤孔隙度和田间持水率分别提高9.69%和18.70%;脱硫石膏和粉煤灰配施对0~40 cm土层土壤化学性质改良效果较好,T4处理0~10、10~20 cm土层土壤pH值分别降低10.51%、11.66%,碱化度分别降低56.76%和50.27%;T4处理0~10、10~20、20~40 cm土层土壤可溶性盐量分别下降32.33%、52.55%、3.04%;T4、T1处理苜蓿增产效果较好,与CK相比,苜蓿鲜质量分别提高61.76%、43.21%,干物质量分别提高48.80%、30.72%;但脱硫石膏和粉煤灰配施量过大则会造成减产,T6处理苜蓿鲜质量和干物质量分别较CK降低19.69%、10.24%。【结论】脱硫石膏和粉煤灰配合施用能有效降低龟裂碱化土壤的体积质量、pH值、碱化度和可溶性盐量,提高土壤孔隙度、田间持水率,从而有利于苜蓿的生长和发育,其中45 t/hm^(2)脱硫石膏与15 t/hm^(2)粉煤灰为最优配比组合。

南疆风沙区不同保护播种模式紫花苜蓿的产量、品质及综合效益研究

新疆南疆地区种植的紫花苜蓿因苗期生长缓慢、受风沙影响成活率低,普遍采用小麦保护紫花苜蓿播种的方式。为探索一种资源利用率高、经济效益好且适合当地推广发展的最优种植模式,本研究以新疆南疆地区紫花苜蓿主要种植模式为切入点,选择当地常见的紫花苜蓿5种种植模式,研究了不同种植模式下紫花苜蓿干物质产量、营养价值及经济效益。结果表明:在2020年播种青贮玉米,2021年实施春小麦套种紫花苜蓿的种植模式(M5)在紫花苜蓿干物质总产量、粗蛋白含量以及经济效益方面的增益效果更为明显,适合当地推广种植。

紫花苜蓿种子产量与大小相关性状全基因组关联分析

紫花苜蓿(Medicago sativa L.)作为一种营养价值高、适口性好的豆科牧草,在我国种植面积不断扩大,其优质种子的需求量也逐年增多。因此,提高单位面积的种子产量对我国紫花苜蓿产业的发展具有重要意义。为挖掘调控种子产量与外形的相关基因,本研究中,利用从世界各地收集的220份紫花苜蓿种子材料,对其种子重量(Seed weight,SW)、种子面积(Seed area,SA)、种子周长(Seed perimeter,SP)进行全基因组关联分析(Genome-wide association study,GWAS)。表型分析表明3个性状存在不同程度的变异,变异系数分别为10.96%(SW),8.31%(SA),4.43%(SP)。通过GWAS,共在7条染色体上发现20个与3个性状相关的单核苷酸多态性(Single nucleotide polymorphism,SNP)位点,单倍型分析证实了优异等位基因的数量与SW,SA和SP之间存在正相关性。对这20个显著SNP上下游各20 kb范围内的基因进行搜索注释,最终筛选到4个与种子产量和大小相关的候选基因。本研究的结果可为优化紫花苜蓿种子大小,提高种子产量的分子育种提供新的标记与候选基因。

不同奶牛粪水还田量对苜蓿生长及土壤理化性质的影响

为探讨规模化奶牛养殖场粪水还田对苜蓿生长及土壤理化性质的影响,本研究设计了5种(0、150、300、450、600 m^(3)/hm^(2))经固液分离发酵后的奶牛粪水还田量的试验。通过测定不同还田量下的苜蓿产量、品质、土壤养分含量及重金属含量变化,结果表明:粪水还田能显著提高苜蓿干草产量,随着还田量的增加,产量增加显著,600 m^(3)/hm^(2)的处理下苜蓿全年干草产量达到19369.0 kg/hm^(2);施用粪水不会降低苜蓿的粗蛋白和相对饲喂价值;粪水还田会显著增加土壤的pH和含盐量,同时会提高土壤有机质含量,在全年不施肥的条件下,各处理土壤中有效氮、速效磷和有效钾均表现为下降水平,随着粪水还田量的增加,下降幅度越小,仅靠粪水还田不能满足全年的苜蓿生长需要,应结合施肥效果更佳。粪水还田会增加土壤中铜、镉、砷、铅、铬等重金属的含量,各重金属含量均以600 m^(3)/hm^(2)的水平下增加最大。综合考虑,建议奶牛粪水还田量控制在300~450 m^(3)/hm^(2)范围内,以实现对苜蓿产量和土壤质量的双重改善。

不同灌溉下限对科尔沁沙地紫花苜蓿生产性能的影响

为了探究不同灌溉下限对科尔沁沙地紫花苜蓿(Medicago sativa L.)产量、品质及水分利用效率(Water use efficiency, WUE)的影响,本文以雨养(CK)作为对照,设置了70%~75%田间持水量(Field capacity, FC)(W1),60%~65%FC (W2),50%~55%FC(W3) 3个灌溉下限,试验结果表明:随着灌溉下限的增加,苜蓿耗水量与年产量均显著增加,但WUE显著降低,且耗水量与年产量、WUE间均呈抛物线关系;相比于W1,W2仅减产5.5%,但可节水22.7%且WUE提高14.5%;不同灌溉下限对粗蛋白含量(Crude protein, CP)无显著性影响,但灌溉下限的降低会引起相对饲喂价值(Relative feed value, RFV)明显升高。基于灰色关联度分析,结合产量、品质及WUE的表现,推荐60%~65%FC为科尔沁沙地苜蓿水分管理的灌溉下限。

盐胁迫对紫花苜蓿生长发育及营养品质影响的研究进展

我国耕地资源紧张和优质饲草料严重短缺,利用盐碱地发展饲草产业既符合国家草牧业发展战略又能改变优质饲草料缺乏的局面。盐胁迫是重要的非生物胁迫之一,严重影响了植物的健康生长发育。了解盐胁迫对紫花苜蓿生长发育、产量及营养物质的影响有利于实现盐碱地资源的开发与利用,减轻日益增加的粮食压力。文中总结了盐胁迫对紫花苜蓿种子萌发、气孔导度及发芽状态等生理变化,探讨了盐胁迫对紫花苜蓿产量、碳水化合物、蛋白质含量的调控作用,并对今后的研究进行了展望。

磷添加对紫花苜蓿生物量、根系特性及化学计量特征的影响

采用盆栽试验研究不同施磷深度(距离表土5、10、15、20 cm,分别记为D5、D10、D15、D20)和施磷水平(0、52、104、156、208 kg/hm^(2),分别记为P0、P1、P2、P3、P4)对紫花苜蓿生物量、根系特征及叶片碳(C)、氮(N)、磷(P)含量的影响,以期为紫花苜蓿科学施磷提供理论依据。结果表明:施磷处理的紫花苜蓿地上生物量、地下生物量、总生物量均显著高于不施磷对照(P<0.05),其中,地上生物量和总生物量最大值出现在D10P4处理,地下生物量最大值出现在D5P1处理,最大值分别为524.98、817.54、374.46 g/m^(2);紫花苜蓿根系长度、根体积以及根尖数最大值均出现在D15P3处理,分别为7288.48 cm、371.51 cm3、3698个/株,且均显著高于对照(P<0.05);根冠比和茎叶比最大值出现在D20P0和D20P1处理,分别为2.00和1.19,且均显著高于对照(P<0.05);施磷深度与施磷水平组合对紫花苜蓿叶片C、N、P含量以及C∶N、C∶P、N∶P的影响各不相同。综上,施磷深度15 cm、施磷水平208 kg/hm^(2)组合较适宜紫花苜蓿的生长和发育。

基于产量及越冬特性对40个紫花苜蓿品种在科尔沁地区综合评价

科尔沁沙地紫花苜蓿(Medicago sativa)品种选择一直是制约该地紫花苜蓿产业发展的核心问题,2021-2022年连续两年通过田间试验对40个紫花苜蓿品种越年产量、越冬率和越冬芽、根颈可溶性糖、淀粉及可溶性蛋白等生理指标进行测定,利用方差分析、灰色关联度分析完成40个紫花苜蓿品种的综合评价,为科尔沁沙地紫花苜蓿科学选种提供依据。结果表明:紫花苜蓿越年干草产量最高的品种为‘4030’,为17082 kg·hm^(−2);不同品种紫花苜蓿越冬率、越冬芽数量不同,其中‘巨能601’和‘肇东苜蓿’越冬率最高,分别为93.48%和89.41%,显著高于其他品种(P<0.05);‘3010’越冬芽数量最多,为16.20,其与‘4030’和‘巨能耐盐’越冬芽数量差异不显著(P>0.05),但显著高于其他品种(P<0.05);越冬前‘阿迪娜’品种根颈可溶性糖(SS)含量最高,‘巨能801’根颈淀粉(S)含量最高,‘WL168HQ’可溶性蛋白(SP)含量最高;利用灰色关联度法综合评价得出,‘阿迪娜’‘4030’‘康赛’‘3010’‘中苜一号’‘WL168HQ’6个品种关联度最高,适宜在科尔沁沙地推广种植。

不同氮肥对南疆地区苜蓿饲草产量与品质的影响

试验旨在探究不同氮肥种类对南疆地区苜蓿生长性状及品质性状的影响。试验以2个紫花苜蓿品种(WL366和佰苜401)为材料,设置不同氮肥处理组,即对照组(CK)、尿素组(UR)、尿素硝铵溶液组(UAN)及40多态氮肥组(40)。试验测定不同氮肥施用后的紫花苜蓿生产性能和品质性状,运用隶属函数分析,对不同氮肥种类施用效果进行综合评价。结果显示,施肥对紫花苜蓿产量和株高有一定影响,并且能够提高紫花苜蓿的相对饲喂价值。苜蓿品质综合表现为UAN>40>UR>CK,40多态氮施肥能够明显增加紫花苜蓿的产量和株高。研究表明,40多态氮肥对南疆地区苜蓿产量与品质综合提升效果最佳。