烤烟根系分泌物对烤烟幼苗生长和养分吸收的影响

连作是烟草栽培中的普遍现象,已引起生长抑制、产量下降和品质恶化等问题。本试验采用溶液培养的方法,在培养液中分别加入未分组和分组后的烤烟根系分泌物,研究根系分泌物对烤烟幼苗生长和养分吸收的影响。结果表明,加入未分组的烤烟根系分泌物显著抑制幼苗的生长,降低根系活力,并随加入量的增加抑制作用增强;加入酸溶性、碱溶性、中性组分的根系分泌物,均降低幼苗根系活力,以中性组分的抑制作用较强。三种不同组分的根系分泌物均显著降低根系对NO3-、PO43-、K+离子的吸收,其中中性组分对NO3-吸收的影响最大,而酸溶性组分对K+的吸收抑制作用较强。推测在烤烟根系分泌物中,可能存在多种抑制烤烟生长和养分吸收的化学物质。     

二氧化碳施肥对番茄幼苗生长与养分吸收利用的影响

Exposing tomato seedlings to elevated CO2 concentrations may have potentially profound impacts on the tomato yield and quality. A growth chamber experiment was designed to estimate how different nutrient concentrations influenced the effect of elevated CO2 on the growth and nutrient uptake of tomato seedlings. Tomato (Hezuo 906) was grown in pots placed in controlled growth chambers and was subjected to ambient or elevated CO2 (360 or 720 μL L-1), and four nutrient solutions of different strengths (1/2-, 1/4-, 1/8-, and 1/16-strength Japan Yamazaki nutrient solutions) in a completely randomized design. The results indicated that some agricultural characteristics of the tomato seedlings such as the plant height, stem thickness, total dry and fresh weights of the leaves, stems and roots, the G value (G value = total plant dry weight/seedling age),and the seedling vigor index (seedling vigor index = stem thickness/(plant height × total plant dry weight) increased with the elevated CO2, and the increases were strongly dependent on the nutrient solution concentrations, being greater with higher nutrient solution concentrations. The elevated CO2 did not alter the ratio of root to shoot. The total N, P, K, and C absorbed from all the solutions except P in the 1/8- and 1/16-strength nutrient solutions increased in the elevated CO2 treatment. These results demonstrate that the nutrient demands of the tomato seedlings increased at elevated CO2 concentrations.     

腐植酸水溶肥对枇杷幼苗养分吸收的影响

目的探究喷施腐植酸水溶肥对枇杷幼苗生长及养分吸收的影响,筛选出能够促进枇杷幼苗生长和养分吸收的浓度。方法采用盆栽试验,以‘大五星’枇杷幼苗为材料,以喷施清水为对照,比较喷施不同稀释倍数（1600、1300、1000和700倍液）腐植酸水溶肥后枇杷幼苗生物量和养分吸收数量。结果喷施适宜浓度腐植酸水溶肥有助于提高枇杷幼苗根系、地上部分的生物量、全氮、全磷和全钾含量,促进对氮、磷、钾的吸收和转运,提高其转运效率和转运贡献率。所有浓度处理对枇杷幼苗根系和地上部分的氮、磷、钾收获指数均无显著影响。灰色关联度分析表明枇杷幼苗生物量与全氮、全磷、全钾含量密切相关。结论枇杷幼苗期推荐施用996 ~ 1154倍液腐植酸水溶肥（腐植酸 ≥ 40 g L⁻¹,N + P₂O₅ + K₂O ≥ 350 g L⁻¹）。     

不同氮肥对油菜生长和养分吸收的影响

利用盆栽试验研究了潮土中不同氮肥对油菜生长和N、P、K、Ca、Mg等养分吸收的影响,结果表明:不同氮肥对油菜生长和养分吸收的影响以生长初期(5周时)差异最显著。生长初期,除硝酸钙外,不同氮肥均显著抑制油菜的生长,氯化铵>硫酸铵、尿素>硝酸铵;对N、K、Ca、Mg的吸收,氯化铵、硫酸铵和尿素表现显著的抑制作用,且氯化铵和尿素有大于硫酸铵的趋势,而硝酸钙表现显著的促进作用,硝酸铵大多情况下作用不明显;对P的吸收,各氮肥均表现显著的抑制作用,且氯化铵>尿素>硫酸铵、硝酸铵和硝酸钙。但随着时间推移,各氮肥最终均显著促进油菜生长和养分吸收,且不同氮肥的差异也逐渐减小。     

酸胁迫对不同基因型玉米生长和养分吸收的影响

采用盆栽试验研究了4个不同耐酸特性的玉米自交系在几个关键生育期的氮、磷、钾营养特性和生长状况。结果表明,耐酸自交系在苗期、拔节期和开花期对氮、磷、钾的吸收和累积均高于酸敏感自交系;不同生育期耐酸自交系的营养利用率和再分配特征存在差异,苗期表现为氮的利用率较高,开花期表现为磷、钾营养的再分配能力强。不同耐酸材料对酸胁迫土壤反应不同,耐酸自交系在不同生育阶段始终能较好生长,尤其是Z01,即使在pH4.6的酸性土壤上干物质累积几乎不受酸胁迫影响;中等耐酸自交系则受酸的危害,且随着发育进程而加剧,而酸敏感自交系表现出与中等耐酸材料相同的趋势,但各生育阶段受到的危害更大。     

不同养分配比对高粱根系生长及养分吸收的影响

为探明高粱养分吸收和根系生长对氮、磷、钾胁迫的响应,通过长期定位试验,在高粱/玉米轮作条件下研究了不同养分配比NPK、PK、NK、NP、CK对高粱根系生长及养分吸收的影响。结果表明:与NPK相比,长期不施氮肥(PK)条件下高粱总根长增加18.29%,总根体积降低26.52%,且根系主要分布在0~10 cm土层,直径小于0.5 mm细根所占比例显著增加。不施磷肥(NK)显著抑制了高粱根系生长,总根长、总根表面积和总根体积分别降低24.03%、27.48%和41.29%。不施钾肥(NP)对细根生长有明显抑制作用。不施氮、磷、钾均降低高粱对相应养分的吸收和累积,不施氮促进了营养器官中氮和钾素向籽粒转运,不施磷或钾肥抑制了氮、磷及钾的转运。高粱对养分的吸收、积累和转运与根系形态有关,不同养分积累与运转与根系形态关系表现不尽相同:氮素、钾素积累和转运与根系形态具有较好的相关性,氮素的积累和转运与植株生物量和产量的相关性大于磷素和钾素。综上,高粱根系形态及养分吸收对氮、磷及钾胁迫响应不同,该研究可为不同养分瘠薄地高粱高效栽培提供理论依据。     

供镁水平对烤烟生长及养分吸收的影响

采用盆栽土培试验研究了不同供镁水平对烤烟生长和养分吸收的影响。结果表明,施MgSO4量为0.06～1.08 g/kg时,各处理烤烟的生长状况和干物质积累量明显优于对照和施MgSO4 1.88 g/kg。烤烟各器官对钾的吸收最多,氮次之,磷最少,各处理表现一致。施MgSO4量为0.18～0.72 g/kg的3个处理烤烟各器官对氮磷钾的吸收量明显高于其他处理,且在施MgSO4量为0.36 g/kg时达到峰值。当施MgSO4量较低（≤0.06 g/kg）或较高（MgSO4≥1.08 g/kg）时都会抑制烤烟的生长发育、干物质和养分的积累。而烤烟各器官对镁的吸收量则均表现出随施镁量增加而增加的趋势,且各器官镁吸收量表现为:叶＞茎＞根;镁肥的施用能够在一定程度上促进烤烟对镁素的吸收。     

控释氮肥不同用量对移栽玉米幼苗生长及养分吸收的影响

通过盆栽试验,研究了控释氮肥不同用量对移栽玉米幼苗生长及养分吸收的影响。结果表明,玉米育苗期内适宜的控释氮素用量可形成健壮幼苗; 其最大安全控释氮素用量为N 200400 mg/plant,该用量下,移栽时单株可携带N 137290 mg。随控释氮肥用量的增加,植株地上部氮素浓度及氮素累积量增加; 磷素的浓度及累积量与控释氮肥的用量没有显著相关性; 控释氮肥的供应抑制了植株对钾的吸收。     

不同基因型小麦铁营养效率差异及其可能机制

采用营养液培养试验对苗期6个不同小麦基因型旱选10,鲁麦14,小偃54,京411,洛夫林和中国春的铁营养效率进行了研究,并对其可能机制进行了探讨。试验设低铁(2μmol/L)和正常铁(100μmol/L)2个处理。结果表明,小麦的铁营养效率存在基因型差异,其范围从58%到92%。供试基因型中铁营养效率最高的基因型为中国春,最低的为旱选10。本试验条件下,小麦种子中铁浓度与其苗期铁营养效率间未发现相关性。多重回归分析表明,小麦铁营养效率差异主要由铁吸收决定,而铁吸收主要由根表面积差异决定。说明具有较大根表面积的小麦基因型在苗期具有更高的铁营养效率与抵抗铁缺乏的能力。     

Assessment of ZN Interaction with Nutrient Cations in Alkaline Soil and its Effect on Plant Growth

An experiment was conducted to assess the zinc (Zn) availability to wheat in alkaline soils during Rabi 2009–2010. Wheat seedlings in pots having 2 kg alkaline sandy soil per pot were treated with 5, 10 and 15 kg Zn ha^?1 as soil and with 0.5 and 1.0% zinc sulfate (ZnSO₄) as foliar application. Results showed that Zn increasing levels in soil helped in phosphorus uptake up to boot stage but its conversion to grain portion lacked in Zn treated plants. Potassium (K) uptake also increased up to 6.24% in boot stage with treatment of 10 kg Zn ha^?1 + 1.0% ZnSO₄ foliar spray. Zinc (Zn) concentration increased in plant tissues with the increasing level of Zn application but this disturbed the phosphorus (P)-Zn interaction and, thus, both of the nutrients were found in lesser quantities in grains compared to the control. Despite of the apparent sufficient Zn level in soil (1.95 mg kg^?1), improvement in growth and yield parameters with Zn application indicate that the soil was Zn deplete in terms of plant available Zn. The above findings suggest that the figure Zn sufficiency in alkaline soil (1.0 mg kg^?1) should be revised in accordance to the nature and type of soils. Furthermore, foliar application of Zn up to 1.0% progressively increased yield but not significantly; and it was recommended that higher concentrations might be used to confirm foliar application of Zn as a successful strategy for increasing plant zinc levels.     

Effect of soil solution phosphorus on seedling growth of the pejibaye palm in an oxisol 1

Two experiments were undertaken to determine the effect of mycorrhizal inoculation and soil solution phosphorus (P) concentration on the growth of pejibaye (Bactris gasipaes, Palmae) seedling progenies from two Amazonian populations in a Hawaiian Oxisol. Mycorrhizal colonization and effectiveness were insignificant, perhaps because of residual fumigant toxicity and apparent water stress. Soil solution P concentration had highly significant effects on seedling leaf number, leaf area, plant biomass, anthracnose damage to leaves, and growth and physiological parameters in both experiments. Genotype effects were significant in the experiment involving progenies from two different populations, but not in the experiment involving two progenies from the same population. Native soil solution P concentration in this Oxisol was insufficient for acceptable pejibaye growth, while 0.2 mg/L soil P gave very good growth.     

钾营养对不同基因型小麦幼苗NaCl胁迫的缓解作用

在温室砂培条件下,研究了钾营养对NaCl胁迫下不同基因型小麦幼苗生长、植株可溶性糖、丙二醛(MDA)含量及几种抗氧化酶活性的影响。结果表明,100.mmol/L.NaCl胁迫下,施入5～10.mmol/L.K+可提高小麦幼苗茎叶及根的生长及含水量;耐盐品种DK961可溶性糖含量随外界K+浓度的提高出现先升高后降低的趋势,而盐敏感品种JN17则随溶液K+浓度的提高一直降低;两品种电解质外渗量及MDA含量都比对照增加,但随外界K+浓度的升高呈现先降低后升高的趋势,以10.mmol/L.K+时最接近对照;两品种超氧物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性随外界K+浓度升高都是先升高后降低,以Na+/K+比值为10∶1最好,并且对POD活性的影响更显著。表明根据NaCl胁迫程度不同,按Na+/K+比值为10∶1的比例施用钾肥可最大限度地降低NaCl胁迫对小麦幼苗造成的伤害,促进小麦生长。     

氮素运筹对淮北地区超高产小麦养分吸收利用的影响

2006～2008年,以强筋小麦烟农19和中筋小麦皖麦50为材料,研究了氮素不同基追肥比例对小麦植株养分含量、肥料吸收及其利用效率的影响。结果表明,小麦产量达9000 kg/hm2以上的超高产水平,每公顷吸收氮、磷、钾量分别为259.25～315.00 kg、82.86～89.70 kg、224.67～305.28 kg; 形成100 kg子粒消耗的氮、磷、钾量分别为2.933.19 kg、0.871.04 kg、2.473.27 kg。两品种氮肥当季利用率随拔节肥比例增加显著提高,当基追比例为6∶44∶6时,烟农19的氮肥当季利用率高于皖麦50,说明适宜的氮肥运筹比例有利于提高氮肥当季利用率; 氮肥农学效率、氮收获指数与产量间呈显著正相关。随拔节肥比例增加,氮素利用效率有下降的趋势,说明植株随吸氮量的增加,子粒形成产量增幅减弱。淮北地区小麦实现超高产栽培的拔节期追肥的适宜的氮素基追比例为5∶5～4∶6。