Key Points of Simple Cultivation Technique for Whole-plant Silage Maize in Guangxi

With the vigorous development of animal husbandry in Guangxi,feed problems have become increasingly prominent.Silage maize has the characteristics of rapid growth,high nutritional value,easy digestion and absorption,and a large amount of biological output being obtained in a short time.It is one of the ideal basic feeds for cattle and sheep and other breeding industries.Based on this,the simple cultivation technique of whole-plant silage maize was summarized from the aspects of land preparation,selection of maize variety,sowing,field management,pest control and timely harvesting,so as to provide technical reference for scientific planting of silage maize in Guangxi.

Surveying the genomic landscape of silage-quality traits in maize(Zea mays L.)

Despite the longstanding importance of silage as a critical feed source for ruminants,its quality improvement has been largely overlooked.Although numerous quantitative trait loci(QTL)and genes affecting silage quality in maize have been reported,only a few have been effectively incorporated into breeding programs.Addressing this gap,the present study undertook a comprehensive meta-QTL(MQTL)analysis involving 523 QTL associated with silage-quality traits collected from 14 published studies.Of the 523 QTL,405 were projected onto a consensus map comprising 62,424 genetic markers,resulting in the identification of 60 MQTL and eight singletons.The average confidence interval(CI)of the MQTL was 3.9-fold smaller than that of the source QTL.Nine of the 60 identified MQTL were classified as breeder’s MQTL owing to their small CIs,involvement of more QTL,and large contribution to phenotypic variation.One-third of the MQTL co-localized with DNA marker-trait associations identified in previous genomewide association mapping studies.A set of 78 high-confidence candidate genes influencing silage quality were identified in the MQTL regions.These genes and associated markers may advance marker-assisted breeding for maize silage quality.

Effects of Whole-plant Corn Silage and Whole-plant Wheat Silage on Growth Performance and Economic Benefits of Beef Cattle

[Objectives]This study was conducted to study the effects of whole-plant corn silage and whole-plant wheat silage on growth performance and economic benefits of beef cattle.[Methods]Thirty Simmental crossbred cattle were selected and randomly divided based on their weight into two groups,15 cows in each group,with an average weight of 398 kg.Each group was fed the same concentrated feed,and the whole-plant corn silage and wheat silage were fed as roughage feed,respectively.The experimental period was 90 d.[Results](1)There was no significant difference in the initial weight of beef cattle between test group 1 and test group 2(P>0.05).Compared with group 2,group 1 had a higher final weight,average daily gain,and dry matter intake of beef cattle,without significant differences(P>0.05).Group 1 was 0.58%,1.99%,and 1.43%higher than group 2,respectively.The feed-to-gain ratio of test group 1 decreased by 0.54%compared with test group 2(P>0.05),with no significant difference therebetween.(2)The economic benefit of group 1 was 11.45 yuan/(day·capita),while the economic benefit of group 2 was 2.41 yuan/(day·capita),and group 1 was 9.04 yuan/(day·capita)higher than group 2.[Conclusions]Whole-plant corn silage for feeding beef cattle has the advantages of good weight gain and low breeding cost,and can be popularized in beef cattle fattening.

Effects of Maize Silage Harvest Stage on Growth Performance and Economic Benefits of Beef Cattle

[Objectives]This study aimed to investigate the effects of whole-crop maize silage harvested at different stages on growth and economic benefits of beef cattle.[Methods]A total of 30 Simmental crossbred cattle weighing about 378 kg were randomly divided into three groups,respectively fed for 70 days with whole-crop maize silage harvested at milk stage(GroupⅠ),dough stage(GroupⅡ)and physiological maturity stage(GroupⅢ).Moreover,the cattle in all groups were given the same concentrate diet.[Results]There were significant differences in dry matter,crude protein and neutral detergent fiber between whole-crop maize silages harvested at different stages(P<0.05).The dry matter in GroupⅡandⅢwas significantly higher than that in GroupⅠ(P<0.05).The crude protein content peaked in GroupⅡ,up to 6.37%,which was significantly higher than that in GroupⅠ(by 12.74%,P<0.05)and GroupⅢ(by 9.26%,P<0.05).Starch content significantly increased with the postponing of maize harvest(P<0.05).The content of neutral detergent fiber in Group I was significantly higher than that in GroupⅡ(P<0.05)and GroupⅢ(P<0.05).The average daily weight gain in GroupⅡwas 8.53%higher than that in GroupⅠ(P<0.05)and 3.70%higher than that in GroupⅢ(P>0.05).The dry matter intake in GroupⅡwas significantly higher than that in GroupⅠ(P<0.05)and GroupⅢ(P<0.05).There was no significant difference in feed/gain ratio between the groups(P>0.05).The economic benefit in GroupⅡwas the highest,up to 9.99 yuan/day per capita.,followed by that in GroupⅢ,9.79 yuan/day per capita,and that in GroupⅠwas the lowest,only 8.03 yuan/day per capita.[Conclusions]The whole-crop maize silage harvested at dough stage has the best quality and produces the highest economic returns for beef cattle.

Chemical composition and in vitro fermentation characteristics of high sugar forage sorghum as an alternative to forage maize for silage making in Tarim Basin, China

The chemical composition, mineral profile and in vitro fermentation characteristics of maize （MZ）, high sugar forage sorghum （HS） and forage sorghum （FS）, and silages made from each forage type were measured. The MZ and MZ silage （MZS） had higher crude protein, starch and ether extract contents than both sorghum forages and sorghum silages. HS had higher ash and water-soluble carbohydrate concentrations than FS and MZ. MZ, MZS, HS and HS silage （HSS） had lower neutral detergent fibre, acid detergent fibre and acid detergent lignin than FS and FS silage （FSS）. FSS had higher dry matter （DM） and pH than MZS and HSS. HSS contained higher concentrations of P and K than FSS and MZS. MZS and HSS had higher in vitro dry matter and organic matter digestibility, CH4 production, total volatile fatty acids, acetate and propionate than FSS. pH was higher for FSS than for HSS, and ammonia was lower for HSS than for MZS and FSS. HSS had higher gas production than MZS and FSS after 2, 4, 6 and 8 h incubation. MZS had higher gas production than HSS and FSS after 26 and 28 h of incubation. The results indicate that HS may substitute for MZ to make good quality silage. However, animal studies are needed to assess the acceptability and feeding values of HSS vs. MZS for ruminant production.

The Effect of Organo-Mineral Fertilizer Applications on the Yield of Winter Wheat, Spring Barley, Forage Maize and Grass Cut for Silage

Biosolids were applied with urea to produce a granulated organo-mineral fertiliser (OMF) for application by farm fertiliser equipment to a range of agricultural crops. The recommended rates of nitrogen, phosphate and potash were calculated for the test crops using “The Fertiliser Manual”, which assesses the nutrient requirement based on previous cropping, rainfall and soil index. The OMF produced similar crop yields compared to ammonium nitrate fertiliser when applied as a top-dressing to winter wheat, forage maize and grass cut for silage in the cropping years 2010 to 2014. In 2012 the grain yield of spring barley top-dressed with OMF was significantly lower than the conventional fertiliser treatment, due to dry conditions following application. For this reason it is recommended that OMF is incorporated into the seedbed for spring sown crops and The Safe Sludge Matrix guidelines followed. The experimental work presented shows that OMF can be used in sustainable crop production systems as a source of nitrogen and phosphorus for a range of agricultural crops.

Effects of Replacing Maize Silage with Silage Sweet Sorghum on Milk Production and Blood Biochemical Indexes of Dairy Cows

In order to study the effects of replacing different proportions of silage maize with silage sweet sorghum treated by different fermentation methods on the production performance and blood biochemical indexes of dairy cows,25 Chinese Holstein lactating cows were randomly divided into 5 groups,5 in each group.The control check (CK) was fed the basal diet;for the experimental group 1 and the experimental group 2,50% of the silage maize in the basal diet was replaced with the additive silage sweet sorghum and the conventional silage sweet sorghum,respectively;and as to the experimental group 3 and the experimental group 4,all the silage maize in the basal diet was replaced with additive silage sweet sorghum and conventional silage sweet sorghum,respectively.The preliminary trial period was 7 d,and the trial period was 35 d.The results showed that the experimental group 1 and the experimental group 3 had the dry matter intake significantly higher than that of the experimental group 2,the experimental group 4 and the CK ( P <0.05).The daily milk yields of the experimental group 1 and the experimental group 2 were significantly lower than that of the CK ( P <0.05),and the experimental group 3 and the experimental group 4 were significantly lower than the experimental group 1 and the experimental group 2 ( P <0.05).The milk protein percentage of the experimental group 2 was extremely significantly higher than that of the experimental group 4 ( P <0.01).The experimental group 1,the experimental group 2 and the experimental group 3 showed the blood glucose levels extremely significantly higher than that in the CK ( P <0.01).The blood urea nitrogen contents in the experimental group 2 and the experimental group 4 were significantly higher than those in the experimental group 1 and the CK ( P <0.01).There were no significant differences in other blood biochemical indexes between various groups ( P >0.05).It is feasible to use silage sweet sorghum to feed dairy cows,but the proportion should not be too large,and attention should be paid to the energy and nitrogen balance of the diet.

Effects of Different Planting Pattern of Maize (<i>Zea mays</i>L.) and Soybean (<i>Glycine max</i>(L.) Merrill) Intercropping in Resource Consumption on Fodder Yield, and Silage Quality

An experiment was carried out at the field units of the north campus experimental areas in Northwest Agriculture and Forestry University, Yangling, Shaanxi Province, P. R. China. The experiment was conducted on summer season (June to September) to determine the effects of different planting patterns of maize and soybean intercropping in resource consumption on fodder yield and silage quality. The main treatments were one sole crop of maize (SM) and four maize-soybean intercropping patterns (1 row maize to 1 row soybean (1M1S), 1 row maize to 2 rows soybean (1M2S), 1 rows maize to 3 rows soybean (1M3S) and 2 rows maize to 1 row soybean (2M1S), respectively. The experiment was a randomized complete block design with three replications, and plot size of 12 m by 5 m. The crops were harvested when the maize reached at milk stage and soybean at R7 stage. The result indicated significant increase in fresh biomass and dry matter production of maize fodder alone as compared to maize intercropped with soybean fodder. It was correlated with a higher consumption of environmental resources, such as photosynthetically active radiation (PAR) and soil moisture by intercropping. After 45 days of ensiling period, silage samples were analyzed for pH, organic acids (Lactic, acetic, and butyric), dry matter (DM), crude protein (CP), ether extract (EE), neutral detergent fibre (NDF), acid detergent fibre (ADF), calcium (Ca), sodium (Na), phosphorus (P), magnesium (Mg), and potassium (K). It was concluded that in all intercropped silages, crude protein (CP) values were higher (1M1S, 12.1%;1M2S, 12.2%;1M3S, 12.4%;2M1S, 12.1%) than the monocrop maize (SM, 8.7%) silage. Higher organic acids (p < 0.05) were produced in the 1M3S silages as compared to others silages. The study indicated that among all intercropped silages, the 1M3S (1 row maize to 3 rows soybean) was preferable according to nutrient composition than other intercropped silages.

Effects of Biogas Slurry Recirculation on Anaerobic Digestion Performance of Maize Straw Silage

In order to investigate the effects of slurry recirculation technology on anaerobic digestion performance of maize straw silage,maize straw silage was fermented with recirculated biogas slurry,and the gas production,p H value,methane content,volatile organic acids( VFAs)contents,chemical oxygen demand( COD) removal rate and other indicators were studied. The results showed that the fermentation time was positively correlated with daily gas production,methane content,cumulative gas production,VFAs and COD removal rate. Although the p H value fluctuated,it was still in the normal reaction range. The daily gas production was about 1. 26 L. The acetic acid content increased first,then decreased,then increased,and finally stabilized. The biogas slurry recirculation technology saves water resources by 40 m L/d without affecting the normal gas production of anaerobic fermentation,and reduces the consumption of environmental resources. It has important development significance for the sustainable use of biomass resources.

Effect of Lactate and Starter Inoculum on Biogas Production from Fresh Maize and Maize Silage

Lactate is a key intermediate during anaerobic digestion of carbohydrates;however, it fails to receive significant consideration in biogas plants. We examined the influence of lactic acid on biogas production. Two commonly used feeds, fresh maize and maize silage, were selected as substrates due to their difference in lactic acid contents. Additionally, inocula from an agriculture-based biogas plant, a waste water treatment plant and a standardised laboratory reactor were selected to investigate the impact of starter culture on the process. Experiments demonstrated increased total biogas yield of up to 45% in the lactate-rich maize silage over the lactate-devoid fresh maize, but only in cases where the starting inocula had been previously exposed to lactic acid. Our findings suggest lactic acid is a significant intermediate in biogas production and merits consideration. Additionally, the ability of the starter inoculum to utilize lactic acid is an important factor in process optimization and enhanced biogas production.

Optimizing the utilization of maize silage in forage blends-based rations to improve production performance and reduce methane emissions from fattening calves

This research investigated the effect of various mixtures of maize silage and ryegrass fodder on nutrient digestibility,production performance,and methane(CH4)emission of fattening calves.Twenty-four fattening calves((228±10)kg body weight(BW),(280±5)d of age)were allocated to 8 diets for 84 d,according to a randomized complete block design,and the blocks were balanced for BW,age,and sex.The diets consisted of 4 levels of maize silages,i.e.,40%(MS40),50%(MS50),60%(MS60),and 70%(MS70)in the maize silage and ryegrass fodder mixture on a dry matter(DM)basis,and each of the mixture was supplemented with either low(LC,1.0%BW)or high(HC,1.5%BW)levels of fattening concentrate.The results revealed greater(p<0.05)intakes of DM(8.35 kg/d),organic matter(OM,7.85 kg/d),and metabolizable energy(ME,12.00 Mcal/d)in calves fed with MS70-LC diet.The highest(p<0.05)digestibility(g/100 g)of DM(65.2),OM(67.3),crude protein(69.1),and neutral detergent fibre(56.3)was recorded for MS40-HC diet.The maximum(p<0.05)average daily gain(ADG,571 g/d)was recorded for diet MS70-LC.The lowest value(p<0.05)of CH4 emission was recorded in MS70-LC,MS70-HC,and MS60-HC as compared to other diets.Including 70%maize silage in the ryegrass-maize silage based diet improved ADG by 174 g/d with LC feeding.It is concluded that the optimum inclusion level of maize silage and ryegrass in the fattening ration can improve animal production performance and reduces CH4 production and concentrate requirements of fattening calves.

Optimization design and experiment on feeding and chopping device of silage maize harvester

Horizontal feeding devices and plate hob chopping devices are the key component of silage maize harvester.To solve the problem of feeding blockage,reduce energy consumption,and improve the chopping quality of the chopping device a horizontal different diameter five-rollers device(HDDFD)was designed and the plate hob chopping device was simultaneously optimized and analyzed.Through the dynamic analysis,the feeding conveying speed was determined to be 2.0-4.5 m/s.The distance equation of the actual and theoretical cutting-edge curve and the position of the fixed blade were finally obtained.Single factor and response surface orthogonal tests in the bench site were carried out with feeding speed,rotating speed of chopping cylinder,feeding amount,and feeding direction as influencing factors,standard grass length rate(SGLR),and energy consumption per unit mass(ECPUM)as evaluation indexes.The optimal working parameters for chopping performance could be concluded as a feeding speed of 3.39 m/s,rotating speed of the chopping cylinder of 1016.17 r/min,feeding amount of 8.04 kg/s,and feeding direction of 52.2°.In addition,the SGLR and ECPUM were obtained as 95.35%and 37.63 kJ/kg,respectively.The relative error between the experimental results with round parameter combination and the predicted value was verified to be less than 5%.Field tests verified the reliability of the optimized feeding and chopping device.It can be seen that the HDDFD and optimized plate hob chopping device can meet the requirements of mechanized silage harvesting which obviously improves the working quality and reduce the energy consumption of chopping.

基于环境型鉴定技术划分生态区综合评价黄淮海青贮玉米品种

气候因子对农作物区域试验丰产性和适应性的影响较大。为准确评价青贮玉米品种在黄淮海夏播区的适应性、丰产性和稳定性,采用2002-2021年20 a的气象数据资料,依据环境型鉴定技术(ET)对2022年青贮玉米区域试验中12个试点进行生态区(ME)划分,依据品种-性状(GT)双标图和品种-产量×性状(GYT)双标图对15个参试品种的生物干重、干物质含量、倒伏率、倒折率、空秆率、小斑病、弯孢叶斑病、南方锈病、茎腐病、瘤黑粉病、生育期、株高和穗位高13个农艺性状以及全株淀粉含量、中性洗涤纤维含量、酸性洗涤纤维含量和粗蛋白质含量4个品质指标进行综合评价。结果表明,加性主效应和积性互作效应(AMMI)方差分析被测的13个农艺性状中基因型效应和环境效应均达到了极显著水平(P<0.01),除穗位高外其余性状基因型与环境互作效应也达到了极显著水平。6个省份的12个试点被划分为4个生态区,不同生态区间气象因子呈较大的变化趋势。生物干重与株高、穗位高呈极显著正相关,而与倒伏率、倒折率呈极显著负相关。GYT双标图与生态区结合,可以鉴别出不同生态区的优势品种。参试品种中渝单805在划定的4个生态区中均表现出丰产性突出、稳定性较好的特征,属于丰产稳产型品种。皖农科青贮8号、成单3601、正大511和衡玉1996等品种在ME2、ME3和ME4中丰产性和稳定性较好。安科青2号和KNX2202等品种在ME1和ME4中丰产性较差,金诚6在ME2和ME3中丰产性和稳定性均较差。基于环境型鉴定技术划分生态区和GYT双标图相结合评价青贮玉米品种的丰产性、稳定性和适应性,可以实现品种推广的精细定位。

滇中地区不同种植密度青贮玉米的主要农艺性状、产量和质量变化

为了探讨不同种植密度对青贮玉米的农艺性状、产量和质量的影响,在滇中地区以推广较多的曲晨9号为供试材料,开展6株/m^(2)(低密度)、9株/m^(2)(中等密度)和12株/m^(2)(高密度)三个种植密度的试验研究。结果表明:高密度种植青贮玉米的群体干物质产量比低密度的提高12.3%,并且高密度种植模式中的单株节数、叶片数和枯叶数也比低密度处理的单株分别增加9.98%(P<0.05)、2.78%(P>0.05)和126.92%(P<0.01),但是高密度种植模式中单株的株高、基部茎宽、穗叶面积和不同位叶的干重比低密度的处理分别降低15.12%(P>0.05)、38.80%(P<0.01)、16.38%(P<0.05)和26.88%~38.79%(P<0.05)。在营养成分方面:高密度种植青贮玉米的粗蛋白、中性洗涤纤维、酸性洗涤纤维和酸性木质素分别比低密度种植的青贮玉米低了1.7%、21.51%、22.14%和56.79%。表明增加种植密度可有效地增加单位面积青贮玉米群体的干物质产量,增加单株的叶片数和节数,但是降低单株的株高、穗叶面积、不同位叶干重和基部茎宽,并有效地降低中性洗涤纤维、酸性洗涤纤维和酸性木质素的含量。建议在种植青贮玉米时一定在关注单株农艺性状的变化和群体养分含量变化同时,通过合理密植获得单位面积的高产和优质的青贮玉米,同时避免植株倒伏等因素引起的减产。

玉米品种和发酵剂对全株玉米青贮营养品质的影响

本试验旨在探究不同玉米品种和发酵剂对全株玉米青贮营养品质的影响,筛选出最优发酵剂和最适合甘肃中东部地区的青贮玉米品种。以“京科627”(H1)、“金穗1915”(H2)、“铁研53”(H3)、“登海3721”(H4)、“大京九26”(H5)、“陇青贮1号”(H6)6个玉米品种为试验材料,在蜡熟期收获,分别添加以植物乳杆菌、乳酸片球菌等为主的饲草青贮剂1(A1)、以布氏乳杆菌9-2和戊糖片球菌为主的饲草青贮剂2(A2)和以植物乳杆菌A1和植物乳杆菌LP-21为主的饲草青贮剂3(A3)3种发酵剂并设置空白对照组(CK),共24个处理,每个处理3个重复。发酵90 d后测定其品质。结果表明:玉米品种对干物质(DM)、粗蛋白质(CP)、中性洗涤纤维(NDF)、乳酸(LA)、乙酸(AA)、丙酸(PA)、氨态氮(NH 3-N)含量以及中性洗涤纤维消化率有极显著影响(P<0.01);与空白对照组相比,3种发酵剂显著提高了DM、CP、LA、AA含量(P<0.05),极显著降低了NH 3-N含量(P<0.01)。综上所述,3种发酵剂对不同品种全株玉米青贮的品质有不同程度的提升,灰色关联度分析结果表明以“饲草青贮剂3”处理的“登海3721”为最优组合,最适合在临夏地区种植和推广应用。

全株大豆和玉米混贮采收时期和混合比例研究

为了确定全株大豆进行青贮的最佳采收时期,制定全株大豆、玉米混合青贮的最佳比例,本研究把不同品种大豆在不同生育期进行采收,检测饲草价值,通过对比确定最佳采收时期。将玉米和濮豆5110按照鲜重比1∶0、3∶1、2∶1、1∶1、1∶2、1∶3、0∶1进行混合青贮,并对混合青贮的饲用品质进行测定,采用成分分析和模糊隶属函数对不同比例混合青贮品质进行评定,以筛选出最适宜混合比例。结果显示:比例为1∶1混合青贮的饲用品质、发酵品质和能量值最高,且相对饲用价值在此处理下达到最佳。同时,通过隶属函数得知1∶1混合综合得分为0.78,综合性能最好。结果说明在结荚期后期或者鼓粒期前期采收的全株大豆和1/2~1/3乳线区的全株玉米以1∶1的比例混合青贮效果最佳。

冀西北青贮玉米耐寒抗旱种植及果穗青贮技术研究

为使冀西北农牧交错区青贮玉米增产提质,优化青贮技术,试验以德美亚1号、郑单958和先玉335为试验材料,设置不同药剂浸种和不同果穗青贮比例,测定青贮玉米出苗率、根系指标、干物质积累规律、产量和青贮品质等指标。结果表明:不同种子处理下青贮玉米的根系长势不一致,表现为大葱液处理和纳米胶处理根系长势旺盛,根长和根干重增加显著;3个品种中大葱液处理郑单958的产量最高,鲜产量为148.2 t/hm2,生物产量为27.9 t/hm2;青贮饲料中的粗灰分、中性洗涤纤维和酸性洗涤纤维含量与茎含量呈正相关,淀粉、粗脂肪、泌乳净能以及干物质含量与茎含量呈负相关;全果穗青贮饲料营养品质高于其他青贮方式,粗蛋白含量为10.3%,较全株青贮增加了21.18%。研究表明,大葱液浸种处理可加速青贮玉米出苗,提高出苗率,对玉米植株干物质积累量及产量的影响优于其他处理,增产效果显著。德美亚1号的产量和青贮品质在冀西北坝上地区表现优于先玉335和郑单958。果穗青贮的粗蛋白含量更高。

湖南东西部地区青贮玉米生产性能比较研究

为筛选出适合在湖南东西部地区推广应用的青贮玉米(Zea mays L.)品种,本试验利用灰色关联度法对湘东试验站和湘西试验站8个青贮玉米品种的6个农艺性状指标进行综合评价。结果表明:不同品种间‘先玉30T60’的株高、叶片数、穗位高、鲜草和干草产量(217.49 cm、10.49片·株-1、113.71 cm、56.10和18.59 t·hm^(-2))均最高,而倒伏率(0.37%)最低,‘屯玉7969’的茎粗(20.12 mm)最高,‘屯玉899’的空杆率(0.67%)最低;试点×品种互作间湘西试验站的‘先玉30T60’株高、叶片数、穗位高、鲜草和干草产量均最高,而倒伏率最低,湘西试验站的‘屯玉7969’茎粗最高,湘东试验站的‘屯玉899’空杆率最低;不同试验点间湘西试验站的株高、茎粗、叶片数、穗位高、鲜草和干草产量均较高,而倒伏率和空杆率均较低。综合评价结果显示,‘先玉30T60’表现最优,生产性能最好,‘屯玉168’表现较优,生产性能较好,适宜在湖南东西部地区推广应用。

黄淮海地区苜蓿田夏季套作青贮玉米研究初探

研究旨在探究黄淮海地区苜蓿田夏季套作青贮玉米的可行性,以期提高苜蓿田牧草生产力,为牧草高效种植发掘新的种植模式。在黄淮海地区播种第三年的苜蓿田刈割两茬后套作青贮玉米,探究在黄淮海地区苜蓿套作青贮玉米的牧草生产力、对苜蓿田杂草的影响及套作前后的经济效益。与单作苜蓿相比,苜蓿套作青贮玉米显著提高了苜蓿田的总产草量、土地当量比和总经济效益;苜蓿套作青贮玉米可有效减少夏季高温高湿季苜蓿田杂草的种类,抑制杂草的生长。为黄淮海地区苜蓿田夏季套作青贮玉米提供理论依据,提出了一种苜蓿高效种植推广应用模式。

12个青贮玉米苗期抗旱性综合评价

本研究以12个青贮玉米品种为供试材料,通过盆栽试验,在苗期采用限制灌溉方式进行干旱处理,测定干旱胁迫下不同玉米品种叶片相对含水量、株高、地上部分干重、根冠比、抗氧化酶活性等与抗旱性相关的表型性状和生理生化指标。首先计算各品种10个指标的抗旱系数,随后结合隶属函数法和主成分分析,对不同品种青贮玉米苗期抗旱性进行综合评价,筛选抗旱性强的青贮玉米品种,为旱区青贮玉米生产提供材料和理论依据。研究结果表明,干旱胁迫下,12个不同青贮玉米品种叶片相对含水量、株高、茎粗、地上部分干重、地下部分干重等指标均有所下降,过氧化物酶、超氧化物歧化酶、过氧化氢酶、丙二醛和根冠比则不同程度升高,且不同品种间各指标下降或增加的幅度有很大差异;隶属函数分析结果显示抗旱性强的品种为正饲玉2号、宁玉688和禾玉36,D值分别为0.498、0.478和0.464;主成分结合聚类分析结果显示抗旱性强的品种为正饲玉2号、禾玉36和大唐8号,Y值分别为1.06、1.04和0.88。综合2种评价方法,正饲玉2号和禾玉36属于抗旱性强的品种。