养分平衡法在玉米测土推荐施肥中的应用效果

通过小区试验研究,玉米产量和化肥利用率在不同的施肥技术条件下存在差异。其优化次序为:NPK有机肥>NPK>NP>NK>N>PK>ck;深施NPK有机肥>深施NPK>常规施NPK>薅土浅施NPK>撒施NPK>ck。根据养分平衡法建立了目标产量、空白田产量与土壤养分测定值及相应N、P、K化肥施用量的函数关系,在产前提出N、P、K肥的适宜用量和比例以及相应的施肥技术。     

主要环境因子对孔石莼净水作用的影响 (Ⅰ)对氨氮吸收的影响

研究了温度、光照和ｐＨ对孔石莼吸收氨氮的影响。孔石莼对氨氮吸收的最佳温度为２５℃，最适温度范围为２０～３０℃；光照对吸收速率的影响较小，当光强＞５０００ｌｘ时，吸收即达到饱和；养殖水体的ｐＨ（８．０～８．３）有利于孔石莼对氨氮的吸收。     

锌镉交互作用对伴矿景天锌镉吸收性的影响

采用水培试验、不同Zn、Cd污染程度农田土壤结合外加Zn、Cd基础上的土培盆栽法,研究了不同Zn、Cd浓度交互作用对伴矿景天生长及Zn、Cd吸收和分布的影响.水培试验结果表明,增加溶液中Zn和Cd浓度,伴矿景天各组织中Zn和Cd浓度显著增加,但两个高浓度处理间没有显著差异;Zn在伴矿景天体内呈不均匀分布且与水培溶液中Zn和Cd浓度有关,当溶液中Zn浓度＞Cd浓度时,表现为新叶＞成熟叶＞其他部位＞＞根,反之则为成熟叶＞其他部位＞新叶＞＞根;而Cd在伴矿景天不同部位的分布没有一致的规律性;Zn、Cd交互作用主要体现在伴矿景天新叶上:在溶液中外加Cd时,Zn对伴矿景天新叶中Cd浓度具有“低促高抑”效应,而Cd处理对新叶中Zn浓度具有拮抗效应.土培试验也表明,添加Zn显著促进伴矿景天对土壤中Cd的吸收,外加Cd对伴矿景天Zn吸收具有拮抗效应;但无论Zn或Cd,外加量过大均会显著抑制伴矿景天的生长,降低修复效率.     

Phosphorus Dynamics in a Luvic Phaeozem After 50 Years of Different P Fertilization

After 50 years of differentiated P fertilization great differences in plant-available P contents between the treatments were measured. However, yield and P uptake varied marginally and only in few plant species these parameters changed significantly. Investigations of P availability, P release and P sorption in different soil depths should show, which phosphorus fractions are important for P supply of agricultural plants in a Luvic Phaeozem. This information can be used for the improvement of fertilization recommendations. A significant decrease in DL-soluble P content in P0 and P15 treatments down to a soil depth of 60cm was measured. Diffusible P content was substantially higher in the P45 treatment in comparison to P0 and P15. Subsoil seems to be an important additional P source. Plant species have a significant influence on phosphorus dynamic. High P sorption in the investigated Luvic Phaeozem, which could not be reduced by excessive P fertilization, may be one of the reasons for low fertilization efficiency in this trial.     

不同施肥措施对冬小麦灌浆期氮素吸收分配的影响

以黄淮海平原国家潮土土壤肥力与肥料效益长期监测站为平台,研究了长期不施肥(CK)、氮钾配施(NK)、氮磷钾配施(NPK)、氮磷钾配施有机肥(MNPK)或秸秆(SNPK)5种施肥措施对灌浆期冬小麦吸收利用氮素的影响.研究结果表明,在等氮量条件下,施氮量为N 165 kg/hm2时,NPK、MNPK、SNPK处理有利于小麦在灌浆阶段维持田间较高的群体数和干物质的积累量;其中MNPK、SNPK处理较NPK处理有利于小麦灌浆阶段在茎、鞘器官的生长和干物质积累.在氮素吸收方面,NPK、MNPK、SNPK处理有利小麦灌浆期茎、叶、鞘、穗等器官对氮素的吸收、分配和累积.与CK处理相比,施无机氮、有机氮分别为N 49.5、115.5 kg/hm2时,MNPK、SNPK处理可以延长灌浆高峰期7天左右;而施无机氮为165 kg/hm2时,与CK处理相比,NPK、NK处理可以延长14天左右.在花后1 ～ 14天,MNPK、SNPK处理在茎、穗部位氮素吸收累积量要高于NPK处理,其中穗部差异分别达到P≤0.05显著水平、P≤0.01极显著水平;在花后21 ～ 35天,NPK处理在叶、籽粒部位氮素吸收累积量要高于MNPK、SNPK处理,其中叶部差异均达到P≤0.05显著水平或P≤0.01极显著水平.此外,在灌浆期MNPK处理在穗部氮素累积量要高于SNPK处理.总之,在本试验条件下,无机有机肥配施应适当加大无机氮肥的供应量以弥补小麦灌浆中后期起氮肥供应不足的现象.     

Effect of zinc application on the dry matter yield uptake and distribution of zinc and other micronutrients in cocoa (Theobroma cacao. L.)

Abstract

The effects of application of zinc fertilizer on dry matter yield, uptake and distribution of zinc and other nutrients by Amazon and Amelonado cocoa cultivars grown in a soil of low zinc content in the greenhouse were investigated.

There was a differential response to zinc fertilization by the two cocoa cultivars. Maximum dry matter yields of Amazon and Amelonado were attained with 10 ppm Zn and 50 ppm Zn, respectively. Under similar experimental conditions Amelonado seedlings expressed zinc deficiency symptoms whereas Amazon did not.

Zinc concentrations in the leaves, stem and roots of both cuitivars did not give a good index of the zinc status of the crops. This was because of the existence of the “Piper‐Steenbjerg”; effect in that nil zinc rates often gave higher leaf concentration of the zinc than next higher rate. In general, the relative content of zinc followed the pattern; leaves > roots > stem with the Amazon cultivar containing more zinc than the Amelonado.

The distribution of absorbed Cu in the leaves, stem and roots did not differ in both varieties. Whereas Fe uptake was mostly concentrated in the roots, Mn absorbed was largely concentrated in the leaves of both varieties and only Mn uptake in the leaves of Amazon consistently increased with Zn application.

The differences in the uptake and distribution of nutrients between the two cocoa cultivars was attributed to differences in their ability to extract nutrients from the soil and in their requirements for metabolic processes.     

Comparison of Arsenic and Phosphate Uptake and Distribution in Arsenic Hyperaccumulating and Nonhyperaccumulating Fern

Abstract

Uptake of arsenic (As) and its distribution in Chinese Brake fern (Pteris vittata L.), an As hyperaccumulator, and Boston fern (Nephrolepis exaltata L.), a nonhyperaccumulator, in the presence of phosphorus (P), were characterized by employing a hydroponic experiment with a complete three-factorial design. Two levels of As (100 and 1000 µM) and four levels of P (0, 100, 500, and 1000 µM) were used in this study. Arsenic uptake rates on the basis of root fresh weight for the two ferns were similar at low As concentration (100 µM). At high As concentration (1000 µM), however, As uptake rates (373–987 nmol g^?1 f wt h^?1) of P. vittata were significantly greater than those of N. exaltata (164–459 nmol g^?1 f wt h^?1). In both ferns, addition of P reduced their As uptake rate as well as accumulation. Pteris vittata had a greater As TF (Translocation factor = concentration ratio of fronds to roots) than N. exaltata. On the contrary, N. exaltata displayed a greater P TF than P. vittata. As a result, high P/As ratio was observed in the roots of P. vittata, whereas high P/As ratio was observed in the fronds of N. exaltata. The study illustrated that As hyperaccumulation by P. vittata may be facilitated by its high As influx rate and its high molar P/As ratio in the roots resulting from both high As TF and low P TF.     

天丰优101养分吸收特征的研究

通过在高、中、低产田的施肥试验,探讨了水稻品种天丰优101的养分吸收特征。结果表明:天丰优101对氮反应最敏感,对磷反应较敏感;天丰优101籽粒的含氮和含磷量均高于茎秆的,而茎秆的含钾、含锌量则均高于籽粒的;在养分供应平衡条件下籽粒与茎秆各养分含量均较高;天丰优101对N、P2O5、K2O吸收量的比例,低产田为1.00∶0.36∶1.63,中产田为1.00∶0.42∶1.81,高产田为1.00∶0.44∶1.81;在该品种中,氮的运转率为61.5%,磷的运转率为62.0%,钾的运转率为15.6%,锌的运转率为36.6%。     

污泥生物有机肥对大豆产量和氮磷吸收的影响

试验采用随机区组设计,设5个施肥水平(CK为常规化肥;A为化肥+8kg/hm2污泥生物有机肥;B为化肥+11kg/hm2污泥生物有机肥;C为化肥+15kg/hm2污泥生物有机肥;D为化肥+20kg/hm2污泥生物有机肥),2种施肥方式(拌肥和拌种肥),研究了污泥生物有机肥对大豆产量及其营养器官(叶片、主茎和根系)氮、磷养分吸收的影响。结果表明:在施入污泥生物有机肥后,大豆产量及其营养器官中的氮、磷含量均高于对照(C>B>A>D>CK)。且拌种肥处理均高于拌肥处理,其中拌种肥的C处理大豆产量最高,为1 898.5kg/hm2,增产8.18%。说明污泥生物有机肥可提高大豆产量,并对氮、磷吸收有一定的促进作用。     

碳标记甲霜灵在黄瓜植株体内的吸收、分布、传导以及种衣剂缓释作用的研究

本文以~14C-甲霜灵作为示踪剂,运用放射自显影及放射性强度测定技术,研究了甲霜灵在黄瓜植株体内的吸收、分布、传导以及种衣剂的缓释作用机理,结果表明:~14C-甲霜灵在黄瓜体内的传导是迅速的,随药剂作用时间的延长,放射性物质在叶部的积累增加,在根、茎、子叶中却降低;种衣剂中的关键助剂——成膜剂,能将种衣剂中的有效成分固着在种子表面,具有使药剂缓释和延长持效期,提高药剂利用率的作用。