叶面喷施磷酸二氢钾与葡萄糖对番茄光合速率和蔗糖代谢的影响

以辽园多丽和樱桃番茄红玉为试材,采用叶面喷施磷酸二氢钾、葡萄糖及其两者的混合液,研究叶面喷肥对两个品种番茄光合速率及蔗糖代谢的影响。结果表明:叶面喷肥可明显提高番茄叶片中叶绿素的含量及叶片的净光合速率。通过叶面喷肥处理,提高了2个品种番茄果实内果糖和葡萄糖的含量,提高了果实中酸性转化酶和中性转化酶的活力水平,蔗糖合成酶(SS)和蔗糖磷酸合成酶(SPS)活力也得到明显提高。以叶面喷施磷酸二氢钾及其与葡萄糖两者的混合液效果较好,单独喷施葡萄糖效果稍差。表明在叶面喷施葡萄糖、磷酸二氢钾和两者的混合液条件下,果实是通过提高4种酶的活力来提高库强度的。果实库强度增加的同时,相应地促进了同化产物的运转和干物质的积累。     

叶面喷肥对设施番茄产量、品质及干物质分配的影响

在日光温室内以辽园多丽和红玉番茄为试材,进行叶面喷施磷酸二氢钾(K)、葡萄糖(G)、磷酸二氢钾加葡萄糖(K+G)混合液,以喷施清水为对照,以探讨K、G及其相互作用对番茄产量、品质及干物质分配的影响.结果表明,叶面喷施磷酸二氢钾(K)、葡萄糖(G)及磷酸二氢钾加葡萄糖(K+G)处理均能提高番茄果实产量;提高果实成熟期的可溶性糖含量、糖酸比,降低有机酸含量;提高成熟期果实内干物质的分配比率.K+G处理对樱桃番茄品种红玉影响最明显,K处理次之,G处理影响最小,而K处理对大果型番茄品种辽园多丽影响最明显,K+G处理次之,G处理影响最小.     

叶面喷施硫酸锌对马铃薯淀粉合成和积累的影响

"克新13号"马铃薯品种用不同浓度的硫酸锌叶面喷施后,测定叶片与块茎中淀粉、蔗糖和还原糖含量以及相关酶活性。结果表明,适量硫酸锌(2~4 g.L-1)叶面喷施处理后马铃薯叶中蔗糖磷酸合成酶、蔗糖转化酶以及块茎蔗糖转化酶和蔗糖合成酶活性均提高,促进马铃薯叶和块茎中的蔗糖、还原糖的合成,块茎中淀粉合成和积累提高。     

硒肥对猕猴桃果实硒含量及其营养品质的影响

采用叶面喷施、根施及根叶并施方式对猕猴桃植株进行富硒处理。结果表明:3种施肥方式对于提高猕猴桃果实硒含量效果的顺序为叶面喷肥根叶并施根施,以叶面喷施0.5 kg硒肥最优,果实硒含量增加了103.5%;提高果实维生素C(Vc)含量的效果顺序为根施根叶并施叶面喷肥,根施0.5 kg硒肥最为显著,果实Vc含量增加了23.0%,而叶面喷肥后果实Vc含量下降;提高果实可溶性固形物含量的效果顺序为叶面喷肥根叶并施根施,以叶面喷施0.5 kg硒肥最优,果实可溶性固形物含量提高了37.2%。结合猕猴桃果实硒含量、营养品质、果树长势以及果园管理成本等因素,建议选用果树绽叶期根施硒肥0.5 kg·株-1作为富硒猕猴桃果园的施肥技术。     

不同变种甜瓜糖分积累及蔗糖代谢酶活性动态变化

为了解不同类型甜瓜糖分积累及糖代谢特点,选用厚皮甜瓜品种X228、普通甜瓜品种B154及越瓜品种H227为材料,定期取样测定果实成熟过程中的葡萄糖、果糖、蔗糖含量和蔗糖代谢相关酶活性,研究不同变种甜瓜果实发育过程中糖分积累及相关酶动态变化差异。结果表明,授粉15 d至果实成熟期间,3个甜瓜品种的果实葡萄糖与果糖含量的变化均较小,品种间差异不显著。3个甜瓜品种果实蔗糖含量存在显著性差异,其中H227果实几乎无蔗糖积累,葡萄糖和果糖是果实的主要糖组分;B154和X228果实蔗糖含量随着果实发育而快速增加,蔗糖积累存在明显的转折点,蔗糖是B154和X228这2个品种成熟果实中最主要的糖组分,且果实蔗糖含量提高的同时蔗糖磷酸合成酶(SPS)活性上升、酸性转化酶(AI)活性降低,蔗糖合成酶(SS)合成方向的活性与蔗糖含量关系不显著。根据蔗糖含量的差异,可将甜瓜分为蔗糖积累型和低蔗糖积累型两类,前者果实蔗糖含量的上升被认为是SPS活性上升与转化酶(特别是AI)活性下降共同作用的结果,后者果实内极低的蔗糖含量被认为是SPS活性较低导致的。本研究结果为甜瓜种质资源创新利用和甜瓜果实糖分积累调控研究奠定了理论基础。     

外源硒对芒果硒含量及果实营养品质的影响

探讨叶面喷施和土施外源硒对芒果叶片和果实硒含量、果实矿质元素含量及营养品质的影响，以期为富硒芒果的安全生产提供理论依据和技术支持。以“桂热 82号”芒果为试材，叶面喷施以亚硒酸钠为硒源，设置0.0、25.0、50.0、100.0、150.0和 200.0 mg/L 6个浓度水平，于生理落果结束后，每 15 d喷施一次，连喷 2次。土施设置亚硒酸钠处理和硒酸钠处理，施肥量为 10 g/株，于花期沟施。结果表明，芒果叶片和果实中的硒含量随着叶面喷硒浓度的增加而递增。叶面喷施 50 mg/L亚硒酸钠可显著提高果实 Vc含量，200 mg/L亚硒酸钠可显著提高果实K、可滴定酸含量，100～ 200 mg/L亚硒酸钠可显著降低果实Zn、Ca含量。土施相同量的亚硒酸钠和硒酸钠均可显著提高芒果叶片和果实硒含量。土施硒酸钠叶片和果实硒含量显著高于亚硒酸钠。土施 10 g/株亚硒酸钠显著降低果实 Ca、Mg含量，土施 10 g/株硒酸钠显著提高果实 K、Vc含量，降低果实 Ca含量。叶面喷硒和土壤施硒均可显著提高芒果叶片和果实硒含量，其中叶面喷硒提高幅度远大于土壤施硒提高幅度。土施硒酸钠比亚硒酸钠更容易被芒果吸收。富硒芒果生产上推荐叶面喷施 25.0～ 50.0 mg/L亚硒酸钠，或者土施 10 g/株硒酸钠。     

外源铁对不同品种番茄光合特性、品质及镉积累的影响

【目的】在人工模拟镉污染土壤条件下,讨论了叶面喷施Fe对番茄Cd积累及化学形态的影响,旨在为镉污染土壤上番茄的安全生产提供理论依据。【方法】采用土培试验研究了在重金属Cd(10 mg/kg)污染条件下,叶面喷施不同浓度Fe(0、200和400μmol/L,Fe SO4·7H2O)对2个番茄品种(‘4641’和‘渝粉109’)生长、光合特性、品质及果实Cd形态和Cd积累量的影响。【结果】叶面喷施Fe提高了番茄的根、茎、叶、果实干重及植株总干重,增幅分别为20.4%~48.6%、13.3%~56.0%、16.0%~63.1%、9.8%~16.5%和21.6%~40.3%,随着喷施Fe浓度的增加,番茄各部位干质量及总干质量呈先增加后降低的趋势,比较两个番茄品种,‘4641’耐Cd性更强,而‘渝粉109’对Fe的反应更为敏感;随着喷施Fe浓度的增加,2个番茄品种的叶片净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)呈先增加后降低趋势,在Fe 200μmol/L时最大,品种‘4641’的Pn、Gs和Tr较对照分别增加了8%、11%和2.9%,而‘渝粉109’较对照分别增加了28.7%、15.5%和18.8%。而喷Fe处理却降低了番茄叶片胞间CO2浓度(Ci),比较2个供试番茄品种,‘4641’光合作用和蒸腾作用强度均高于‘渝粉109’;喷Fe提高了2种番茄果实的硝酸盐含量以及渝粉‘109’还原糖含量,降低了‘渝粉109’果实氨基酸含量,喷施高浓度Fe(400μmol/L)能提高2种番茄果实Vc含量,与对照相比,‘4641’和‘渝粉109’果实硝酸盐增加的幅度分别为18.1%~22.2%、2.3%~22.0%,Vc较对照分别增加了8.2%和13.2%;番茄果实中Cd的主要存在形态为残渣态,其次为盐酸提取态,去离子水提取态和乙醇提取态所占比例较小,残渣态Cd(FR)和盐酸提取态Cd(FHCl)为活性偏低形态Cd,占Cd提取总量的70.8%,去离子水提取态(FW)和乙醇提取态(FE)为活性较高形态Cd,仅占Cd提取总量的11.8%,有效地抑制了Cd的毒害作用。叶面喷施Fe降低了番茄果实各形态镉含量;番茄中Cd主要积累在叶和茎中,而果实和根的积累量较少;喷Fe降低了番茄叶、根、茎、果实的Cd含量,降低幅度分别为7.1%~21.9%、35.6%~50.4%、13.0%~37.0%和2.8%~8.2%,但喷施高浓度Fe(400μmol/L)相比低Fe(200μmol/L)时的番茄各部位Cd含量有所增加,无论是非否喷施Fe,叶、茎、果实中的Cd积累量以及总Cd积累量总是以‘4641’‘渝粉109’,表明在Cd污染土壤上种植‘4641’较‘渝粉109’风险更大。【结论】叶面喷施适量Fe能够促进番茄的光合作用和蒸腾作用,提高了番茄各部位的干重,降低了Cd对番茄的毒害效应,同时减少了番茄各部位Cd含量。     

铜基叶面肥及控释肥对辣椒生长发育和叶片保护酶等生理特性的影响

【目的】针对辣椒喜肥、耐肥、对水分要求严格的特点,采用铜基叶面肥、控释肥两种新技术,研究了叶面喷施铜基叶面肥和土施控释肥对辣椒产量、矿质养分在植株体内的分布、保护性酶活性以及果实品质的影响,为提高果蔬产量和改善品质提供理论依据。【方法】分别于2011年4~11月和2012年3~9月,在山东农业大学南校区土肥资源高效利用国家工程实验室新型肥料中试基地, 以赤峰牛角王为供试辣椒品种设置肥料盆栽试验,试验设8个处理: 1）喷清水土壤不施肥对照（CKW- NF）;2）喷清水+土施普通肥（CKW+CCF）; 3）喷清水+土施控释肥（CKW+CRF）; 4）喷清水+土施控释肥+保水剂（CKW+CRF+W）; 5）喷铜基叶面肥土壤不施肥（CBFF-NF）; 6）喷铜基叶面肥+土施普通肥（CBFF+CCF）; 7）喷铜基叶面肥+土施控释肥（CBFF+CRF）;8）喷铜基叶面肥+土施控释肥+保水剂（CBFF+CRF+W）。采用称重法测定辣椒产量,于收获期取果实及叶片鲜样用于果实品质和生理生化指标测定,植株各部位干样用于微量元素测定。【结果】1）两年内喷施铜基叶面肥和土施控释肥均能提高辣椒产量,其中叶面喷施铜基叶面肥+土施控释肥+保水剂（CBFF+CRF+W）组合对辣椒产量的提高幅度最大,与CKW+CRF+W相比2011年增产24.1%,2012年增产29.0%。2）相同的土壤施肥条件下,与喷清水相比,喷施铜基叶面肥能够显著提高辣椒植株体内的铜浓度。其中,土施控释肥加保水剂基础上喷施铜基叶面肥处理的辣椒果实中铜浓度比叶面喷清水显著提高了103.9%;土施控释肥条件下,叶面喷施铜基叶面肥较喷清水处理下的果实铜浓度增加了41.5%。3）喷施铜基叶面肥后,辣椒叶片的超氧化物歧化酶（SOD）和过氧化物酶（POD）活性升高,而过氧化氢酶（CAT）活性下降。CBFF+CRF+W处理下的辣椒叶片SOD活性较CKW+CRF+W处理显著提高了26.6%,CBFF+CRF+W组合的叶片的POD活性和CAT活性与CKW+CRF差异显著。4）与喷清水处理相比,无论在土壤施用控释肥还是土壤施用控释肥+保水剂的条件下,叶面喷施铜基叶面肥均使辣椒果实可溶性蛋白和维生素C的含量显著提高,其增加幅度在12.8%~178.4%。【结论】综合考虑几种肥料组合,叶面喷施铜基叶面肥和土施控释肥可在一定程度上调控植株微量元素的积累,改善辣椒营养品质,提高辣椒产量。     

牛蒡根酶解物对番茄生长、品质及土壤生物特性的影响

为明确将牛蒡根酶解物用作水溶性有机肥的可行性及其肥效,采用叶面喷施和灌根施肥两种方式,研究了其对番茄生长、品质及土壤生物特性的影响。结果表明,与空白对照相比,叶面喷施和灌施牛蒡根酶解物均可显著提高番茄的株高和茎粗,叶片抗坏血酸过氧化物酶(APX)、过氧化氢酶(CAT)、过氧化物酶(POD)和超氧化物歧化酶(SOD)等抗氧化酶的活力提高,丙二醛(MDA)含量降低;番茄中可溶性糖、维生素C和番茄红素含量提高,有机酸含量降低;根际土壤中细菌和放线菌数量增加,过氧化氢酶、磷酸酶、脲酶和蔗糖酶等酶活力显著提高。牛蒡根酶解物的肥效与其施用浓度有关,与低浓度牛蒡根酶解物叶面喷施和灌根施肥相比,高浓度牛蒡根酶解物叶面喷施和灌根施肥处理的株高增长量分别提高了17.06%和6.20%,茎粗增长量分别提高了12.20%和7.91%,叶片MDA含量分别降低了17.75%和17.79%,APX、CAT、POD、SOD等叶片抗氧化酶活力和过氧化氢酶、磷酸酶、脲酶和蔗糖酶等土壤酶活力提高,根际土壤中细菌和放线菌数量增加,番茄品质提高。牛蒡根酶解物水溶性好,且具有普通有机肥的肥效特征,是一种优质的水溶性有机肥料。综合利用牛蒡根废弃物制备水溶性有机肥对解决因其废弃堆积而造成的环境污染问题具有重要意义。     

水稻专用叶面营养液对水稻生长及其主要生理特性的影响

通过田间小区试验及大田示范的对比,研究了专用叶面营养液的适宜喷期及其对水稻的生理特性;根系活力,养分吸收,叶片叶绿素含量,光合速率等和产量的影响。研究结果表明：适宜喷期在植后７－１０天,并喷施１次,效果最好,专用叶面营养液使水稻根系活力在分蘖盛期,灌浆期明显提高;显著提高分蘖盛期叶片及灌浆期剑叶的叶绿素含量,促进剑叶提高光合速度及水稻对Ｎ,Ｐ,Ｋ营养的吸收;     

Ameliorative Effects of Potassium Phosphate on Salt‐Stressed Pepper and Cucumber

Abstract

Bell pepper (Capsicum annuum cv. Urfa Isoto) and cucumber (Cucumis sativus cv. Beith Alpha F1) were grown in pots containing field soil to investigate the effects of supplementary potassium phosphate applied to the root zone of salt‐stressed plants. Treatments were (1) control: soil alone (C); (2) salt treatment: C plus 3.5 g NaCl kg^?1 soil (C + S); and (3) supplementary potassium phosphate: C + S plus supplementary 136 or 272 mg KH₂PO₄ kg^?1 soil (C + S + KP). Plants grown in saline treatment produced less dry matter, fruit yield, and chlorophyll than those in the control. Supplementary 136 or 272 mg KH₂PO₄ kg^?1 soil resulted in increases in dry matter, fruit yield, and chlorophyll concentrations compared to salt‐stressed (C + S) treatment. Membrane permeability in leaf cells (as assessed by electrolyte leakage from leaves) was impaired by NaCl application. Supplementary KH₂PO₄ reduced electrolyte leakage especially at the higher rate. Sodium (Na) concentration in plant tissues increased in leaves and roots in the NaCl treatment. Concentrations of potassium (K) and Phosphorus (P) in leaves were lowered in salt treatment and almost fully restored by supplementary KH₂PO₄ at 272 mg kg^?1 soil. These results clearly show that supplementary KH₂PO₄ can partly mitigate the adverse effects of high salinity on both fruit yield and whole plant biomass in pepper and cucumber plants.     

EXOGENOUS APPLICATION OF POTASSIUM DIHYDROGEN PHOSPHATE CAN ALLEVIATE THE ADVERSE EFFECTS OF SALT STRESS ON SUNFLOWER

A greenhouse experiment was conducted to examine whether foliarly applied potassium + phosphorus (K + P) in the form of monopotassium phosphate (KH₂PO₄) could mitigate the adverse effects of salt stress on sunflower plants. There were two levels of root-applied salt [0 and 150 mM of sodium chloride (NaCl)], and varying levels of KH₂PO₄ [(NS (no spray), WS (spray of water), 5 + 4, 10 + 8, 15 + 12, and 20 + 16 mg g^?1 K + P, pH 6.5] applied foliarly to 18-day old non-stressed and salt stressed sunflower plants. Salt stress adversely affected the growth, yield, photosynthetic capacity, and accumulation of mineral nutrients in the sunflower plants. However, varying levels of foliar applied KH₂PO₄ proved to be effective in improving growth and yield of sunflower under salt stress. The KH₂PO₄ induced growth in sunflower was found to be associated with enhanced photosynthetic capacity, water use efficiency and relative water contents.     

Response of wheat to foliar phosphorus treatments under field and high temperature regimes

Potassium phosphate (KH₂PO₄) is applied commonly in dilute foliar sprays to wheat (Triticum aestivum L.) in China. Yield responses to foliar P sources have also been reported for several crop species in other countries. Experiments were conducted to determine efficacy of four P sources and four rates of KH₂PO₄ as foliar treatments on wheat under field conditions and KH₂PO₄ under two controlled temperature regimes. Grain yields were increased most by KH₂PO₄ followed by β‐glycerophosphate and tripolyphosphate; only phytic acid was ineffective. All rates of 1 to 4 kg ha^‐1 KH₂PO₄ increased grain yields. Foliar KH₂PO₄ applications increased grain weight early under low controlled temperatures, but did not affect final grain weight under either temperature regime. Beneficial effects of foliar P treatments were associated with increased plant P content, which may have increased cell sugar content and protected membranes. Although preliminary results are favorable, additional research is needed to determine optimum methods and conditions for treating wheat with foliar P sources.     

Salinity tolerance in tomato: Implications of potassium,calcium, and phosphorus

Abstract

The effect of salinity on the growth and yield of tomato plants and mineral composition of tomato leaves was studied. Five tomato (Lycopersicon esculentum Mill) cultivars, Pearson, Strain B, Montecarlo, Tropic, and Marikit, were grown in sand nutrient culture. The nutrient solutions applied consisted of a modified half‐strength Hoagland solution with 50 mM sodium chloride (NaCl), 3 mM potassium sulphate (K₂SO₄), 1.5 mM orthophosphoric acid (H₃PO₄), and 10 mM calcium sulphate (CaSO₄). Stem height and number of leaves of tomato plants were not found to be significantly different but leaf and stem dry weight were reduced significantly in plants irrigated with saline nutrient solution in contrast with control plants. The total yield was reduced in plants that received saline treatments, but there was no significant difference in fruit number and fruit set percentage. The fruit electrical conductivity and total soluble solids were increased in plants irrigated with saline nutrient solution. Fruit pH was not found to be significantly different among salinity treatments. Mineral composition of tomato leaves were increased by addition of potassium (K), phosphorus (P), and calcium (Ca) to the saline nutrient solution. The addition of K to the solution resulted in an increase in sodium (Na) leaf content. The amounts of K and magnesium (Mg) were not significantly different among salinity treatments. Calcium content was increased when CaSO₄ was added. Application of H₃PO₄ resulted in the highest amount of P in tomato leaves under saline conditions. The present study revealed that application of K, P, and Ca under saline conditions improved fruit electrical conductivity and total soluble solids. Sufficiency levels of the mineral nutrients K and P were obtained in tomato leaves when the appropriate nutrient was used in the saline solution.     

Comparison of potential potassium leaching associated with organic and inorganic potassium sources in different arable soils in China

Potassium (K) leaching is detrimental to the maintenance of sustainable arable soil K fertility,especially in low-K fixation soils.It is not known whether the application of inorganic fertilizers with lower K mobility or crop straw can reduce potential K leaching in low-K fixation arable soils.The potential K leaching of 14 representative arable soils with different K fixation capacities in China was evaluated with or without the addition of K under two rainfall intensities (90 and 225 mm),and then potential K leaching was assessed in relation to five K sources (KCl,K₂SO₄,KH₂PO₄,maize (Zea mays L.) straw,and rice (Oryza sativa L.) straw).Without K addition,K leaching mainly occurred in sandy soils at 90 mm of rainfall and in soils with greater organic matter at225 mm of rainfall.With K addition,the leaching percentage of exogenous K ranged from 0.6%to 11.6%at 90 mm of rainfall and 1.2%to 21.2%at 225 mm of rainfall.The greatest K leaching occurred in soils with fewer K-bearing minerals and lower pH at both rainfall intensities.In most cases,KH₂PO₄,which has lower K mobility,markedly reduced K leaching in both high-and low-K leaching soils at the two rainfall intensities.Maize and rice straw reduced K leaching only in soils with high K leaching,regardless of rainfall amount,whereas more K was leached in soils with lower K leaching at high rainfall intensity.In conclusion,KH₂PO₄ and straw should be preferred for reducing K leaching in low-K fixation arable soils.     

叶面营养对黄瓜生物效应的影响

采用盆栽和田间大棚小区试验，研究了施用不同叶面营养组分对黄瓜的养分吸收分配和叶片光合生理及果实产量与品质的影响。结果表明:（1）P、N、K三要素可被黄瓜（苗期）叶片快速吸收并显著提高其在体内的含量，天然植物生长活性物质具有促进黄瓜N、P、K养分，尤其是N、K的吸收功效。特别是当它与营养元素配合施用时，这种促进作用最为明显。（2）叶面施用适当浓度的该活性物质或硫酸铵或KH2PO4均有显著提高黄瓜处理叶绿素及其光合速率的作用。从总体上讲，三者的作用效果相当，其中活性物质的作用速度较快，但持续时间稍短。叶面施肥后48小时与72小时，不同处理间的叶片光合速率与叶绿素含量差异分别达到最大，一直到108小时，仍维持较稳定的显著差异。说明叶面营养对作物的光合作用的影响主要发生在施肥三天（72小时）以后。（3）叶面肥不同组分配施均能增加黄瓜的生物量与果实产量，提高果实蛋白质、Vc、可溶性糖的含量，降低脂合纤维的含量，而果实酸度则基本不受叶面施肥的影响。（4）在不同叶面营养处理中，无论是促进叶片光合作用还是提高果实产量与改善品质，均是营养元素与该种物质的合理团合达到最理想的效果，两者呈现极其显著的正交互作用。     

Nutrient Removal in a Three-Step Sequencing Batch Reactor with Different Carbon Sources

A three-step sequencing batch reactor was used for nutrient (COD, NH₄-PO₄-P) removal from synthetic wastewater by using different carbon sources. The operation consisted of anaerobic, anoxic and oxic (An/Ax/Ox) phases with durations of 2/1/4.5 h. Different carbohydrates, glucose, lactose, sucrose, maltose and a mixture of glucose/maltose (50/50), were used as the sole carbon source in the first phase of experiments. Sludge age was kept constant at 10 days. Glucose was found to be the most suitable carbohydrate source with percent COD, NH₄-N and PO₄-P removals of 96%, 99% and 94%, respectively. Nutrient removals obtained with sucrose as the sole carbon source were close to those obtained with glucose. A mixture of glucose and organic acids (50/50) such as acetic, citric, propionic and butyric acid were used as carbon source in the second phase of the experiments. Maximum percent COD, NH₄-N and PO₄-P removals were 93%, 97% and 96%, respectively when a mixture of glucose and acetic acid (50/50) was used. Glucose-citric acid (50/50) combination also resulted in comparable nutrient removals.     

Comparison of Foliar and Root Application of Potassium Dihydrogen Phosphate in Regulating Cadmium Translocation and Accumulation in Tall Fescue (<Emphasis Type="Italic">Festuca arundinacea</Emphasis>)

The efficiency of phytoremediation is mainly dependent on the capacity of plants in absorption, translocation, and accumulation of Cd. This study was designed to investigate whether Cd translocation and accumulation in tall fescue plants was regulated by foliar application of KH₂PO₄. The results showed that the foliar application of KH₂PO₄ significantly increased Cd concentration and total Cd accumulated in leaves and the capacity of Cd extraction, compared to the root application. The water-soluble organic acid complexes and the pectate- and protein-integrated Cd were the two major Cd chemical forms deposited in leaves. The foliar application increased Cd in the pectate- and protein-integrated forms and decreased the water-soluble forms in leaves. Cd phosphates were not the major chemical forms deposited in leaves in both foliar and root applications. The results indicated that the foliar application of KH₂PO₄ enhanced Cd accumulation in leaves of tall fescue, which might be associated with the leaf deposit of the pectate- and protein-integrated Cd forms.     

沼液对地膜小麦根系及产量影响研究

沼液浸种的地膜小麦具有合理的产量结构，比地膜小麦增产9.88%，比露地小麦增产67.65%，苗期着重促进了根系的发育，中后期更快地促进了地上部的生长发育，使植株的抗逆性增强。喷施叶面肥均表现为增产，其中KH₂PO₄效果最好，增产幅度11.94%～13.92%，其余依次为麦丰乐、沼液、红苹果2号，增产幅度不足6%，同时提高了株高、成穗数、穗粒数和粒重。