Effects of intercropping sugarcane and soybean on growth, rhizosphere soil microbes, nitrogen and phosphorus availability

The effects of sugarcane plantation intercropped with soybean on plant growth, yield, enzyme activity, nitrogen and phosphorus contents, the microbe quantity of rhizosphere soil were investigated. Results showed that dry weight of biomass and yield under sugarcane/soybean intercropping were increased by 35.44 and 30.57 % for sugarcane, and decreased by 16.12 and 9.53 % (100-grain weight) for soybean, respectively. The nitrogenase activity of intercropping soybean nodule was significantly increased by 57.4 % as compared with that in monoculture models. The urease activities of intercrops sugarcane and soybean were promoted by 89 and 81 % as compared to that of the monoculture models, respectively. The effective nitrogen and phosphorus contents of rhizospheric soil of intercrops sugarcane and soybean were increased by 66 and 311.7 %, respectively, as compared to those in the monoculture system. Microbe number of rhizosphere soil in the intercropping pattern increased significantly as compared to those in the monoculture models. The quantities of bacteria, fungi, and actinomyces increased by 42.62, 14.5 and 78.5 % in the intercropping sugarcane, while the intercropping soybean increased by 188, 183 and 73 %, respectively. Therefore, growing sugarcanes in combination with soybean can be considered a good agriculture management practice, helping to promote plant growth, yield and increase soil nutrients.     

The effect of gamma BHC on response of sugarcane to nitrogen,in relation to inherent soil fertility

Summary The sugarcane plants were grown on two non-calcareous sandy loam soils of different fertility with three levels of nitrogen (0-150 kg N/ha) both in the presence and the absence of gamma BHC.On the soil of higher fertility with respect to total mineralizable N the response to gamma BHC was higher and there was practically no response to nitrogen even up to 125 kg/ha. On the soil of low fertility, however, the response to gamma BHC was comparatively smaller and there was an increase in cane yield with the increase in the level of nitrogen. On the latter soil, nitrogen proved much more efficient in the presence of gamma BHC than in its absence. The results show that in the presence of gamma BHC response of sugarcane to nitrogen varies to a great extent in relation to potential mineralizable N in soil.     

保护地蔗田对土壤优先流与根系生物量及产量品质的影响

为探明保护性耕作对蔗田土壤及甘蔗生长的影响,该研究设置2种耕作方式(常规耕作、粉垄耕作)与2种施肥水平(减量施肥20%、常规施肥),并于甘蔗苗期后在甘蔗行间近根部覆盖豆科秸秆,以第二年宿根蔗为研究对象,采用染色示踪法测定秸秆覆盖下蔗田土壤优先流特征,同时测定分析甘蔗株高、茎围、地下根系生物量、产量及品质等重要农艺性状。结果表明:(1)粉垄耕作方式下蔗田土壤优先流发生速度快且活跃,添加秸秆覆盖降低了土壤优先流发生程度,增加了土壤水分在10～25 cm土层的横向运移能力,在一定程度上提高了土壤蓄水能力。(2)粉垄保护性耕作在秸秆覆盖下提高了甘蔗根系生物量和产量,秸秆覆盖下粉垄免耕宿根蔗根系生物量提高了8.97%～25.54%,并且减量施肥处理中秸秆覆盖宿根蔗伸长期地下根系生物量显著高于无秸秆覆盖,秸秆覆盖下甘蔗株高提高了4.2%～13.1%; 在减量施肥处理中,粉垄耕作添加秸秆覆盖甘蔗产量提高了16.27%,并且添加秸秆覆盖较常规施肥中无秸秆覆盖,产量提高了5.95%。(3)粉垄保护性耕作利于提高甘蔗品质,对比无秸秆覆盖处理,粉垄耕作下秸秆覆盖后显著提高了甘蔗蔗汁视纯度,并且宿根蔗纤维分、蔗汁锤度、转光度和蔗糖分均有提升。综上认为,免耕秸秆覆盖可作为粉垄红壤坡耕地蔗田保护性生产调控方式。     

耕作深度对蔗地土壤物理性状及甘蔗产量的影响

探讨蔗地机械化耕作深度对耕层土壤物理性状及甘蔗产量构成因子的影响,阐明深松作业的针对性土壤区位和障碍因子,可为甘蔗良好耕层的构建和土壤改良策略的制定提供科学依据.本研究设置3种深松作业深度(35、40和45 cm),以不深松为对照,对蔗地土壤物理性状(紧实度、容重、含水率、孔隙度、三相容积率)和甘蔗产量构成因素及蔗茎产量等指标进行研究.结果表明: 耕作作业深度与蔗地土壤结构特性及甘蔗产量的改善提升效应呈显著正相关.深松能够打破犁底层,显著降低土壤紧实度和容重,减小机械作业相应的贯入阻力和抗剪强度,尤其对20～30 cm土层的上述因子具有显著改善效应,对甘蔗高产意义重大.深松显著提高了30 cm以内土层的液相容积率,增大了土壤水分库容,使10～30 cm土层的水分指标显著改善.10～30 cm土层是深松对耕层土壤固相容积率改善效应最显著的区位.耕作深度的增加对甘蔗有效茎数、株高、蔗茎产量及蔗糖含量具有显著的促进效应.鉴于蔗区当前较普遍的机具装备水平,我国适宜蔗区实施机械化深松的作业深度标准应不小于40 cm.     

有机肥对粉垄蔗地土壤养分及甘蔗产量品质的影响

为了研究施用有机肥对粉垄条件下甘蔗产量和品质的影响,该研究以蚯蚓粪、猪粪分别与复合肥配施于粉垄蔗地中,并以单施复合肥作为对照,研究有机肥与复合肥配施对粉垄土壤理化性状及甘蔗养分、产量、蔗茎品质的影响。结果表明:(1)与对照相比,有机肥与复合肥混施可在不同时期分别提高粉垄土壤有机质、全氮、全磷、碱解氮、速效磷、速效钾含量,且对于土壤中速效养分含量的提升主要集中于甘蔗生长前期(6—8月),但在土壤pH值和容重方面影响不显著。(2)蚯蚓粪、猪粪与复合肥混施均能不同程度提高甘蔗生长前期的+1叶和根系中的全氮、全磷、全钾含量,使产量分别比对照提高了28.09%、32.81%。砍收时甘蔗的茎长、茎径、单茎重、有效茎数、蔗汁糖分、甘蔗糖分高于对照但不显著,出苗率、分蘖率、锤度影响不显著。粉垄耕作条件下,选择合适的有机肥与复合肥配施可增加土壤速效养分和有机质、全氮、全磷含量,也能提高甘蔗根叶全氮、全磷、全钾含量,提高甘蔗产量。     

间作大豆对甘蔗根际土壤细菌及固氮菌多样性的影响

为探讨间作大豆(Glycine max)对甘蔗(Saccharum officinarum)根际土壤细菌及固氮细菌多样性的影响, 收集和开发固氮菌资源, 筛选高效甘蔗联合固氮体系, 选用3个甘蔗栽培品种‘ROC22’、‘GT21’、‘B8’与大豆品种‘Guizao 2’进行间种栽培, 采用巢式PCR特异扩增细菌16S rRNA基因片段和固氮细菌nifH基因片段, 并结合变性梯度凝胶电泳(DGGE)技术, 对间作大豆的甘蔗根际土壤细菌及固氮细菌进行系统演化和多样性分析。聚类分析结果显示, 间作大豆改变了甘蔗根际土壤细菌及固氮细菌原来的群落组成结构, 尤其对固氮菌群落组成的改变更大, 但对群落物种的优势度影响较小。Shannon-Wiener多样性指数和Simpson多样性指数分析结果表明, 甘蔗-大豆间作显著影响甘蔗根际土壤中细菌和固氮菌的多样性, 其中对固氮细菌多样性的影响较大。不同甘蔗品种的根际土壤细菌和固氮菌在间作大豆条件下表现出不同的多样性, ‘ROC22’和‘GT21’间作处理甘蔗根际土壤固氮细菌的Shannon-Wiener多样性指数显著高于单作处理, 而‘ROC22’与大豆间作处理的甘蔗根际土壤固氮菌多样性最为丰富。在大豆生长盛期, 间作处理的甘蔗根际土壤细菌多样性最为丰富, 不同处理间的差异也最大, 随后下降。总体来看, 甘蔗-大豆间作显著地影响根际土壤细菌和固氮菌的群落结构和群落多样性, 有助于对甘蔗合理间作栽培模式的认识和筛选高效甘蔗联合固氮体系。     

赤红壤植蔗坡地坡面径流及溶解态氮磷流失特征

为探究南方高强度、高频次降雨下赤红壤区坡耕地土壤侵蚀及氮磷养分流失的特征,基于野外径流小区原位观测试验,通过测定自然降雨下赤红壤植蔗坡地坡面径流和溶解态氮磷流失量,探讨自然降雨下甘蔗种植对赤红壤坡面径流及溶解态氮磷流失的影响。结果表明：(1)2019年和2020年,径流量分别为1111.3 m~3/hm~2和3269.4 m~3/hm~2,硝态氮(NO~-₃-N)流失量分别为1.39 kg/hm~2和15.60 kg/hm~2,铵态氮(NH~+₄-N)流失量分别为0.37 kg/hm~2和1.02 kg/hm~2,可溶性磷流失量分别为0.20 kg/hm~2和0.27 kg/hm~2。2019年和2020年植蔗坡地径流及溶解态氮磷流失量均集中在6月份,占流失总量的45%以上,硝态氮(NO~-₃-N)是径流氮素流失的主要形式,占79%以上。此外,2019年和2020年5月至8月,侵蚀性降雨场次分别为18次和23次,侵蚀性降雨量分别为407.8 mm和668.0 mm。(2)不同侵蚀性降雨条件下,植蔗坡地溶解态氮磷流失量及其...     

不同施肥制度甘蔗地土壤养分对微生物群落结构的影响

以广西红壤长期定位施肥甘蔗地为研究对象,探讨了不同施肥措施甘蔗地土壤微生物群落特征以及土壤养分对微生物群落结构的影响。结果表明,长期优化施肥可以提高土壤微生物多样性,不施肥土壤微生物生长得到显著抑制。土壤全氮、全钾、速效钾含量与微生物群落结构密切相关,可采取适当增加钾肥用量以增加微生物多样性,提高土壤肥力。土壤中磷素含量与微生物群落结构无显著相关,红壤甘蔗地中磷肥用量应适当,不宜过量施用。     

Yield of micropropagated sugarcane varieties in different soil types following inoculation with diazotrophic bacteria

It is well described that the beneficial interactions between plants and bacteria are genotype and site specific. Brazilian sugarcane varieties can obtain up to 70% of their nitrogen requirement from biological nitrogen fixation (BNF), and this contribution is related to the Brazilian breeding and selection processes, by example of the variety SP70-1143. In this study the effect of two inoculation mixtures containing diazotrophic bacteria in our earlier pot experiment was evaluated with two sugarcane varieties, a known responder, SP70-1143, and a newly selected variety, SP81-3250, to investigate the sugarcane genotype effect and the role of the mixtures. The sugarcane varieties SP70-1143 and SP81-3250 were grown under commercial field conditions at three sites with contrasting soil types: an Alfisol, an Oxisol and an Ultisol that means a low, medium and high natural fertility respectively. The stem yield and BNF contribution in response to bacterial inoculation were influenced by the strain combinations in the inoculum, the plant genotype, and the soil type and nitrogen fertilization, confirming the genetic and environmental influence in PGP-bacteria interactions. Inoculation effects on the BNF contribution and stem yield increased in the variety SP70-1143 grown in the Alfisol without nitrogen fertilization for three consecutive crops, and it was equivalent to the annual nitrogen fertilization. The plants grown in the Oxisol showed small increases in the productivity of the variety SP70-1143, and in the Ultisol the sugarcane plants presented even decreases in the stem productivity due to inoculation with diazotrophic bacteria mixtures. The results demonstrate the feasibility of the inoculation technology using diazotrophic bacteria in micropropagated sugarcane varieties grown in soils with low to medium levels of fertility. In addition, the results also indicated that specific plant – bacteria – environment combinations are needed to harness the full benefits of BNF. Section Editor: C. P. Vance     

有机无机肥配施对双季稻轮作系统产量、温室气体排放和土壤养分的综合效应

本研究开展了连续3年(2017-2019年)的田间试验,通过设置不施肥(CK)、单施化肥(F)、等氮条件下有机肥配施化肥(FM)(有机肥全部于早稻季施用)3个处理,对双季稻轮作系统作物产量、土壤肥力进行分析,并连续2年(2018-2019年)对单施化肥和有机肥配施化肥处理的CH4和N20排放进行监测.结果表明:施肥可以...     

甘蔗/大豆间作减量施氮对甘蔗产量、品质及经济效益的影响

在大田栽培条件下,研究了减量施氮对广州地区不同甘蔗/大豆间作模式下甘蔗产量、品质、生物量动态变化及甘蔗群体经济效益的影响.结果表明:氮肥和种植模式对甘蔗产量、品质均无显著影响,各处理甘蔗产量、品质均无显著差异.不同施氮水平的甘蔗/大豆间作系统较单作甘蔗提高了土地利用率,其土地当量比(LER)为1.36～2.12.各处理甘蔗总生物量的动态积累随生育期的推进均符合"S"型生长曲线,低氮水平下问作甘蔗的生物量动态积累特征参数最协调,高氮水平下,甘蔗生长高峰期提前,快速生长最大持续期缩短,甘蔗产量下降,因此,可以通过调整氮素的投入量来改善生物量的增长参数,从而获得高产.低氮处理甘蔗/大豆间作系统经济效益比高氮处理高3.2%～26.3%,说明减量施氮可有效提高群体经济效益.甘蔗/大豆1∶2间作模式的经济效益最好.     

灌溉方法与施氮对土壤水分、硝态氮和小麦生长发育的调控效应

为探明玉米秸秆还田下小麦的合理灌溉与施肥方法,于田间研究了漫灌(FI)、微喷灌(SI)、滴灌(DI)和灌水施氮模式(N₁, 基施纯N 157.5 kg·hm^-2+拔节期施纯N 67.5 kg·hm^-2; N₂, 基施纯N 157.5 kg·hm^-2+拔节期施纯N 45.0 kg·hm^-2+灌浆期施N 22.5 kg·hm^-2)对土壤水分、硝态氮(NO₃^--N)含量和小麦生长发育的影响.结果表明: 灌溉方法和灌水施氮模式共同影响土壤含水量和贮水量的变化.其中,灌溉方法对越冬期和返青期0～60 cm、孕穗期和灌浆期0～160 cm、成熟期100～160 cm土层含水量影响相对较小,对越冬期和返青期80～160 cm、成熟期0～80 cm土层含水量影响大;FI对含水量和贮水量影响最大,DI次之,SI最小;SI和DI的灌水施氮模式中灌水量多,则土层含水量高、贮水量多,变化大.NO₃^--N含量受灌溉方法和施氮的影响,施氮对0～20 cm土层影响大,SI生育期NO₃^--N含量变化大,DI越冬期至孕穗期NO₃^--N含量变化小,此后变化大,FI与DI相反;生育前中期灌水量对NO₃^--N含量影响大,后期施氮对NO₃^--N含量影响大;SI和DI的2种灌水施氮模式中冬前灌水量多的NO₃^--N含量变化大.灌溉方法中SI越冬期总茎数和单株分蘖高,成穗率高,成穗数多,产量、水分利用效率(WUE)和氮素利用效率最高,滴灌次之,漫灌最低;SI和DI中N₁生育期总茎数、成穗数多,但穗粒数和千粒重低,产量、WUE和氮素利用效率低于N₂.因此,玉米秸秆还田后播种小麦,微喷灌代替漫灌生育期灌4水,施足基肥,拔节期和灌浆期分次追氮,是山西南部小麦-玉米一年两熟区小麦节水高产高效栽培模式.     

九个甘蔗新品种在桂林地区的适应性观察和评价

为探讨甘蔗新品种在桂林地区的适应性表现,该研究以ROC22为对照,采用大区互比法,对国家甘蔗产业技术体系的9个甘蔗品种进行1年新植2年宿根的区域试验,观察记录出苗率、分蘖率、株高、产量和糖分等14个性状表现,并利用DTOPSIS法进行综合评价。结果表明:桂糖29号、桂糖31号、云蔗03-194、粤糖60号、福农38号和粤糖55号的综合性状表现优于对照ROC22,其中桂糖29号宿根性好、蔗茎产量和产糖量较高,但病虫害有不同程度的发生,田间栽培需加强病虫害防控;桂糖31号有效茎多、蔗糖分高,建议加强肥水管理,提高产量;云蔗03-194出苗率较高,出苗整齐,有效茎数较多,宿根性好,但枯心苗和黑穗病发病程度较其他品种严重,建议加强苗期病虫管理,保障成茎率;粤糖60号蔗糖产量较高、抗倒伏能力强,但新植出苗率较低,建议加大下种量;福农38号蔗糖分较高、抗病性较好,是优异的抗病材料;粤糖55号宿根性较好。上述筛选出的6个甘蔗品种宿根性好、抗逆性强、高产高糖,适宜在桂林地区进行扩大种植,用于指导当地的甘蔗示范推广。     

Influence of the application of sugarcane bagasse on lindane (gamma-HCH) mobility through soil column: implication for biotreatment

In the present study we employed sugarcane bagasse for biotreatment of soil containing 50mgkg(-1) of lindane. Garden soil were treated with lindane and amended with varying concentrations of sugarcane bagasse (10%, 20%, 30%, 40% and 50%; w/w). Data on dissipation and degradation of lindane in soil columns (0-15, 15-30cm) were studied at six consecutive samplings (0, 3, 7, 45 and 60 days). Treatment with 50% sugarcane bagasse resulted in >53% degradation of lindane in upper soil column with minimal leaching to lower soil column (0.002%) while highest leaching of lindane from upper soil column to lower soil column was occurred in garden soil (35.8%). Similarly, a substantial microbial biomass input has detected in amended soil than garden soil. Our results provide evidence that sugarcane bagasse can accelerate lindane degradation by enhanced microbial activity and prevent pesticide mobility through soil column by adsorption. Sugarcane bagasse could be useful as cheaper, easy available alternative for the biotreatment of lindane impacted soil.     

Effect of some nitrification suppressants on nitrification of urea and its implication on growth and nitrogen nutrition of sugarcane

Summary In laboratory incubation studies 2-amino-4-chloro-6-methyl pyrimidine (AM) and 2-sulfanilamidothiazole (ST) gave partial control of nitrification in soil. In a pot experiment, millable cane yield, dry matter synthesis, and nitrogen uptake were significantly increased by these chemicals. The results are discussed with respect to suppression of nitrification as related to concentration of inorganic nitrogen in soil and growth of sugarcane.     

The effect of biomass moisture content on bioethanol yields from steam pretreated switchgrass and sugarcane bagasse

This study aimed to determine the effect of moisture content of three different feedstocks on overall ethanol yield. Switchgrass and sugarcane bagasse from two sources were either soaked in water (∼80% moisture) or left dry (∼12% moisture), and half each of these were impregnated with 3% w/w SO₂ and all were steam pretreated. The twelve resulting substrates were compared based on overall sugar recovery after pretreatment, cellulose conversion following enzymatic hydrolysis, and ethanol yield following simultaneous saccharification and fermentation. The overall ethanol yield after simultaneous saccharification and fermentation of hexoses was 18-28% higher in samples that were soaked prior to SO₂ addition than in SO₂-catalyzed samples that were not soaked. In samples that were uncatalyzed, soaking made little difference, indicating that the positive effect of increased moisture content may be related to increased permeability of the biomass to SO₂.     

Shifting abundances of communities associated with nitrogen cycling in soils promoted by sugarcane harvest systems

Sugarcane cultivation supports Brazil as one of the largest world sugar and ethanol producer. In order to understand the impact of changing sugarcane harvest from manual to mechanized harvest, we studied the effect of machinery traffic on soil and consequently soil compaction upon soil microbial communities involved in nitrogen cycling. The impact of sugarcane harvest was dependent on soil depth and texture. At deeper soil layers, mechanized harvesting increases the abundance of nitrogen fixers and denitrifying communities (specifically nosZ clade I and II) while manual harvesting increases the abundance of ammonia oxidizers (specifically AOA) and increases denitrifying communities (nosZ clade I and II) on top and at intermediate depth. The effect of change on the harvest system is more evident on sandy soil than on clay soil, where soil indicators of compaction (bulk density and penetration resistance) were negatively correlated with soil microorganisms associated with the nitrogen cycle. Our results point to connections between soil compaction and N transformations in sugarcane fields, besides naming biological variables to be used as proxies for alterations in soil structure.     

Production and characterization of a glycolipid biosurfactant, mannosylerythritol lipid B, from sugarcane juice by Ustilago scitaminea NBRC 32730

Mannosylerythritol lipids (MELs) are glycolipid biosurfactants excreted by fungal strains. They show not only excellent surface-active properties but also versatile biochemical actions. Ustilago scitaminea NBRC 32730 has been reported mainly to produce a mono-acetylated and di-acylated MEL, MEL-B, from sucrose as sole carbon source. In order to make biosurfactant production more efficient, we focused our attention on the use of sugarcane juice, one of the most economical resources. The fungal strain produced MEL-B at the yield of 12.7 g/L from only sugarcane juice containing 22.4% w/w sugars. Supplementation with organic (yeast extract, peptone, and urea) and inorganic (sodium nitrate and ammonium nitrate) nitrogen sources markedly enhanced the production yield. Of the nitrogen sources, urea gave the best yield. Under optimum conditions, the strain produced 25.1 g/L of MEL-B from the juice (19.3% sugars) supplemented with 1 g/L of urea in a jar fermenter at 25 °C over 7 d. The critical micelle concentration (CMC) and the surface-tension at the CMC for the present MEL-B were 3.7×10(-6) M and 25.2 mN/m respectively. On water-penetration scan, the biosurfactant efficiently formed the lamella phase (L(α)) and myelins over a wide range of concentrations, indicating excellent surface-active and self-assembling properties. More significantly, the biosurfactant showed a ceramide-like skin-care property in a three-dimensional cultured human skin model. Thus, sugarcane juice is likely to be effective in glycolipid production by U. scitaminea NBRC 32730, and should facilitate the application of MELs.     

The effect of some pesticides in conjunction with nitrogen sources on growth and carbohydrate and nitrogen constituents of sugarcane during formative phase

Summary The effect of gamma isomer of benzene hexachloride and Telodrin both in absence and presence of ammonium and nitrate nitrogen carriers on shoot and root growth and carboydrate and nitrogen constituents of sugarcane was studied. The pesticides induced shoot emergence and development of tillers and roots. Shoot growth, nitrogen intake and insoluble nitrogen content invariably increased by pesticide application while soluble carbohydrate and soluble nitrogen content of the shoot decreased. Pesticides also increased the water-soluble nitrate content of the soil.The effect of pesticides was not confined to ammonical source of nitrogen rather the pesticides proved equally effective under nitrate source of nitrogen and also in absence of additional nitrogen. Beneficial effect of pesticides on growth and development of sugarcane appears largely on account of more efficient utilisation of soil and fertilizer nitrogen. The results raise an interesting possibility of using these pesticides as growth stimulators to increase the efficiency of sugarcane plants growing under sub-optimal conditions of nitrogen     

Long-term culture of embryogenic sugarcane callus

Embryogenic calluses of sugarcane capable of regenerating green plants after long-term culture were sought. The largest quantities of embryogenic calluses were produced on Murashige & Skoog medium, but cultures maintained on Chu N6 medium remained embryogenic and totipotent longer. Both media contained 4.5 M 2,4-dichlorophenoxyacetic acid (2,4-d). The effect of supplements on somatic embryogenesis was examined. Kinetin (0.5 M) and 10% (v/v) coconut water in callus initiation medium were inhibitory to subsequent embryogenesis. Embryogenic calluses on N6 medium increased in fresh weight with proline concentration up to 90 mM. Maximum fresh weight was achieved with 5% sucrose. Although genotypic differences were observed, embryogenesis occurred in all 17 sugarcane clones tested. Embryogenic calluses of one cultivar regenerated green plants after 16 months, but suspensions were totipotent for only 8 months. Total number of regenerated plants decreased with time in culture, while the number of pale green plants increased starting after 5 months in culture.Published as Paper No. 785 in the journal series of the Experiment Station, HSPA