长期定位监测钾肥施用效果研究

缺钾是水稻土的主要障碍因子之一,合理增施钾肥,既能促进水稻的营养代谢,又能大幅度提高水稻产量。为此本文利用5 a施肥定位监测资料,研究了钾肥在水稻土上的施用效果。结果表明:施用有机肥增施钾肥一般可增产6%左右,不施有机肥增施钾肥一般可增产4.9%左右。增施农肥及氮、磷、钾肥配合使用,才能保证水稻高产稳产。     

杂交早稻金优706优化施肥技术研究

为了探讨不同施肥水平对杂交早稻金优706产量形成的影响,2006年在桃源双溪口乡进行了氮、磷、钾3因素4水平14个处理田间试验(即3414)。结果表明,施用适量肥料与不施肥料相比,增产效应居首位的是氮肥(平均增55.4%),其次是钾肥(平均增12.7%),磷肥效果最差(平均增3.0%)。在不同施氮处理中,以施氮165.0 kg/hm2处理产量最高,效益最好;磷、钾肥的增产效果与土壤有效磷或速效钾含量有关。采用二次多项式逐步回归的方法对产量结果进行肥料效应回归模型模拟,得到3丘试验田的三元或二元二次多项式回归模型。据此提出了中等肥力河沙泥土壤上金优706的最佳施肥量。     

漳州香蕉氮钾肥适宜用量及其对品质的影响

针对漳州香蕉氮肥用量普遍超量和钾肥用量超量与不足并存的施肥现状,通过4个田间试验研究氮钾肥适宜施用量及其对果实品质的影响。结果表明,在高产蕉园或中低产蕉园增施适量氮肥、高产蕉园增施适量钾肥等措施都具有显著增产效果,但在中低产蕉园,在施用中量至高量氮肥时增施钾肥才有显著增产作用。氮钾肥适宜施用量和比例,有利于改善果实农艺性状,并提高香蕉果实固形物、可溶糖和维生素C含量。高产蕉园氮钾肥经济施肥量分别为N 691 kg/hm2和K2O 1 154 kg/hm2,氮钾比例为1∶1.67;中低产蕉园则分别为N 631 kg/hm2,K2O 877 kg/hm2,氮钾比例为1∶1.39。高产蕉园的钾肥需求比例明显高于中低产蕉园。     

马铃薯施肥肥效及养分利用率的研究

对6年14项次的马铃薯氮磷钾肥肥效试验,研究了施用氮磷钾化肥对马铃薯的增产效果、肥料利用率和施肥对淀粉含量的影响。结果表明,增施氮肥(N)平均增产21.3%,每千克N增产马铃薯37.9kg;增施磷肥(P2O5)增产18.4%,每千克P2O5增产马铃薯51.8kg;增施钾肥(K2O)平均增产15.3%,每千克K2O增产马铃薯35.9kg。总的增产效果:氮肥>磷肥>钾肥。14项次试验中增施氮肥的肥料利用率(N)为24.3%～45.2%,平均32.9%;增施磷肥的肥料利用率(P2O5)为7.5%～20.9%,平均14.8%。增施钾肥的肥料利用率(K2O)为38.3%～92.6%,平均49.8%。平均生产1t马铃薯吸收N为6.15kg,吸收P2O5为1.36kg,吸收K2O为6.17kg。马铃薯淀粉含量旱地明显大于水浇地。减N处理马铃薯淀粉含量最高,其次是NPK配合处理。     

施氮次数对无刺卡因菠萝产量和品质的影响研究

选用无刺卡因菠萝,采用大田试验,固定N肥施用水平(400 kg/hm2),从0至4依序增加施肥次数,分析施氮次数对菠萝产量和品质的影响.结果表明:2次平均分施对增加无刺卡因的产量最适宜,在此基础上,增加或减少施氮次数都会造成单果重和产量的下降;就品质而言,增加N的施肥次数将导致可滴定酸、含糖量和Vc含量下降,不利于保持卡因的品质.本研究为果农从事无刺卡因菠萝的优质栽培提供施肥参考.     

施用硼肥对油菜产量的影响

为探索硼肥在油菜种植上的增产效应,2008-2009年在浏阳进行了不同施肥方式对油菜产量影响的研究,结果表明,施用油莱专用肥、增施爱棵硼或者在抽墓期喷施流体硼肥均能促进油菜生长,增高增枝增荚,提高油菜产量。以每公顷施油菜专用肥600kg为基肥,尿素150kg为追肥的增产效果最显著;抽墓期每公顷喷施硼肥900g增产效果较好。与对照相比,施硼各处理增产幅度为63～696kg／hm^2。     

优质油菜中油杂8号施用氮磷硼肥的产量和品质效应

双低油菜新品种中油杂8号施用氮磷硼肥的田间试验结果显示,苗期、抽薹期、成熟期的干物重都有增加,以抽薹期至成熟期的干物重增加最为显著,表明施用氮磷硼肥的作用主要是促进油菜后期的生长发育,显著增加分枝数、角果数和单株粒重;以氮磷和氮磷硼处理增加幅度最大.不同施肥处理均显著增加籽粒产量,增产幅度为12.1%～30.5%,增产效果顺序为:N＞P＞B,以配合施用的增产效果最佳,NP、NB、NPB处理分别增产30.5%、29.3%、28.5%.增施B可提高菜籽油分含量,而N、P及NP配合施用则可提高蛋白质含量,降低油分含量.增施B还可提高油酸、亚油酸含量,降低芥酸和硫甙含量.同时对中油杂8号施肥增产和提高品质成分的原因进行了分析讨论,提出了增施硼肥和氮磷硼配合施用是保证中油杂8号高产高油优质特性充分发挥的技术关键.     

钾肥运筹对砂质潮土冬小麦产量、品质及土壤钾素平衡的影响

为给黄淮海地区冬小麦合理施用钾肥提供依据,在砂质潮土上设置田间试验,研究了施钾量与钾肥运筹方式对冬小麦产量、品质及土壤钾素平衡的影响.结果表明,在作基肥一次施用情况下,钾肥不同用量的增产、增收效应以施钾(K2O)150 kg·ha-1时最佳;随着钾肥用量的增加,籽粒蛋白质含量、支链淀粉含量呈增加的趋势,直/支比呈降低的趋势;随着钾肥用量的增加,土壤速效钾含量和植株钾素积累量均升高,要保持土壤速效钾平衡,钾肥用量应达150 kg·ha-1以上.在相同施钾水平下,分次施钾的增产、增收效应、钾肥利用率均显著高于一次基施肥处理;分次施钾处理的籽粒蛋白质含量、直/支比低于钾肥一次基施的处理,籽粒支链淀粉含量则相反,但两处理之间上述指标的差异均未达显著水平.从钾肥的增产、增收效应,以及冬小麦对钾肥利用率、土壤钾素平衡的影响等方面综合分析,以施钾量150 kg·ha-1分次施用(5∶5)时效果最好,与不施钾处理相比可增产1 225.23 kg·ha-1,每公斤K2O增产8.17 kg,增收930.24 元·ha-1,钾肥利用率为53.4%,并能够实现土壤速效钾的收支平衡.     

不同土壤马铃薯施钾的增产效果试验

马铃薯是需钾量大的作物之一 ,施用钾施有显著的增产效果。本试验进一步明确不同土壤施用钾肥对马铃薯的增产效果 ,以及合理用量。试验结果表明 ,不同土壤类型的不同钾肥用量均能起到有效增产作用 ,在 6 6 7m2 施钾低于 2 2 5kg时 ,随施钾量的增加而增产幅度提高 ,施钾量超过2 2 5kg时 ,则马铃薯产量随钾增加而下降     

渭北旱塬小麦高效施肥的产量及水分效应

为给旱地小麦资源高效利用提供依据,通过不同养分配置及相应集成栽培技术处理,研究了旱作条件下小麦高效施肥的产量和水分利用效应。结果表明,在高量施肥水平基础上氮肥减少75 kg.hm-2的情况下,小麦产量增加569.85 kg.hm-2,增产幅度达8.1%;高量减氮施肥处理比农民习惯施肥处理（CK）增产11.3%,其增产幅度比高量施肥处理高8.4个百分点;高量减氮处理养分效益为4.25元.kg-1,比CK提高250.3%;肥料对产量的贡献率为12.3%,比CK高9.9个百分点;水分利用效率达到19.8 kg.mm-1.hm-2,比CK提高16.5%。旱地在目前氮磷肥投入水平基础上增施钾肥,单位有效养分经济产量、生物产量和收益分别增加10.0%、30.6%和8.2%,说明增施钾肥是促进旱地小麦肥料有效利用和增产的有效途径之一。     

Characterization of starches of proso,foxtail, barnyard,kodo, and little millets

Scanning electron microscope (SEM) pictures of small millet starch granules showed more large polygonal and few small spherical or polygonal granules. The granules of small millets resembled those of rice starch granules. The size of the starch granules ranged from 0.8–10 m. The size of the granules was larger in barnyard millet and smaller in proso millet. Several granules showed deep indentation caused by protein bodies. SEM of starch isolated from 24 hour-germinated kodo millet showed pitting or pinholes at some points due to the attack of amylases (preferentially on bigger granules). Brabender viscoamylograph studies on small millet starches revealed that the gelatinization temperatures ranged from 75.8 to 84.9 ^° C. Barnyard millet possessed lower amylograph viscosity, minimum breakdown, and relative breakdown values when compared to the other small millets.     

Effects of application of nitrogen fertilizer on concentrations of P, K, S, Ca, Mg, Na, Cl, Mn, Fe, Cu and Zn in perennial ryegrass/white clover pastures in south-western Victoria, Australia

Effects of timing and rate of N fertilizer application on concentrations of P, K, S, Ca, Mg, Na, Cl, Mn, Fe, Cu and Zn in herbage from perennial ryegrass/white clover pastures were studied at two sites in south-western Victoria, Australia. Nitrogen fertilizer (0, 15, 25, 30, 45 and 60 kg ha^–1) was applied as urea in mid-April, early May, mid-May, early June and mid-June 1996 to pastures grazed by dairy cows. At Site 1, N fertilizer resulted in a linear increase in P, K, S, Mg and Cl concentrations in herbage and a linear decrease in Ca concentration. For all times of application, concentrations of P, K, Ca, Mg and Cl in herbage increased by 0·0048, 0·08, −0·010, 0·0013 and 0·053 g kg^–1 dry matter (DM) per kg N applied respectively. For S concentration, maximum responses occurred in mid-May (0·012 g kg^–1 DM per kg N applied). At Site 2, N fertilizer resulted in a linear increase in P, S and Na concentrations in herbage, a linear decrease in Ca concentration and a curvilinear increase in K and Cl concentration. The maximum responses for P, S and K concentrations in herbage occurred for the N application in mid-June and were 0·015, 0·008 and 0·47 g kg^–1 DM per kg N applied respectively. For Cl concentration, the maximum response occurred for the N application in early June and was 0·225 g kg^–1 DM per kg N applied. Overall, applications of N fertilizer up to 60 kg ha^–1 did not alter herbage mineral concentration to levels that might affect pasture growth or animal health.     

Evaluation of the enzyme-amplified ELISA for the detection of potato viruses A,M, S,X, Y,and leafroll

Various parameters,e.g. types of microtiter plate for DAS-ELISA (double antibody sandwich-enzyme-linked immunosorbent assay), use of fresh or frozen amplifier solutions for enzyme-amplified-ELISA, and use of sodium diethyldithiocarbamate (NaDIECA) in sample buffer in cocktail-ELISA were evaluated for the detection of potato viruses A, M, S, X, Y and leafroll from potato foliage. Dynatech Immulon immunoplates provided higher readings for all viruses. Fresh amplifier solution in amplifed-ELISA was superior to frozen solutions. Amplified ELISA gave only marginal improvement in the sensitivity over the standard DAS-ELISA. Addition of NaDIECA in sample buffer did not improve the detection of viruses in DAS-, amplified-, or cocktail-ELISA. Cocktail-ELISA can reduce antigen incubation time to as short as 15 min for PVA, PVM and PVX; 1 hr for PVY and PLRV; and 2–4 hr for PVS using pre-coated plates. Although amplified-ELISA is slightly more sensitive than DAS-ELISA for certain potato viruses, it is not suitable for large-scale indexing of potato viruses in Seed Certification Laboratories, in view of the additional steps needed in carrying out this procedure.     

Milling,functional and thermo-mechanical properties of wheat,rye, triticale,barley and oat

The milling potential of hulled barley, hulled oat, triticale, rye and wheat was studied using a long tempering process and a laboratory four-roller mill. Regardless of the investigated cereal, the results indicated a significant influence (p < 0.05) of volume per surface area ratio on the milling yield and ash contents of the flour. The lowest milling yield was obtained in case of hulled oat. Solvent retention capacity profiles were determined for all investigated whole cereals and flours for predicting the contribution of different polymers to the functionality of samples. For all solvents higher values were obtained for the whole cereals compared to the corresponding flour. Thermo-mechanical properties of the whole cereals and refined flours were also investigated. If in case of wheat the gluten proteins play an essential role on dough behaviour during kneading at 30 °C, in case of triticale, rye, hulled barley and hulled oat, the fibers play a major role as well. Thermo-mechanical properties of starch registered a large variation between cereals and/or flours. The lowest torque value corresponding to starch gelatinization (C3) was registered in case of the hulled oat flour, 1.92 Nm, while the highest value in case of rye flour, 2.65 Nm.     

Study of antimicrobial activity of aloevera, chitosan, and curcumin on cotton, wool, and rabbit hair

Aloevera, chitosan, and curcumin were applied in alone and in combination with each others on cotton, wool and rabbit hair by exhaustion method for the assessment of their antimicrobial activity. The antimicrobial activity of these natural ingredients was better in peroxide treated cotton, formic acid treated wool/rabbit hair fibrous substrates than their corresponding intact ones. Aloevera shown better antimicrobial activity than chitosan and curcumin when applied alone and its antimicrobial activity was enhanced by addition of both chitosan and curcumin. The application of aloevera+chitosan+curcumin combination on peroxide treated cotton and formic acid treated wool/rabbit hair fibrous substrate was fast up to twenty five washing cycles.     

Response of permanent and reseeded grassland to fertilizer nitrogen. 2. Effects on concentrations of Ca, Mg, K, Na, S, P, Mn, Zn, Cu, Co and Mo in herbage at a range of sites

The concentration of mineral elements in herbage from permanent swards of mixed species composition (predominantly Agrostis spp., Holcus lanatus, Festuca rubra, Lolium perenne, Poa spp., etc.) was compared with that from sown perennial ryegrass ( Lolium perenne ) at two fertilizer rates (0 and 300kg N ha⁻¹ year⁻¹, both with P and K) and with L. perennel Trifolium repens (at 0 N with P and K). The investigation was conducted over four years at sixteen contrasting sites in England and Wales. Herbage samples for mineral analysis were taken at first and fourth harvests (May and August) each year from plots under 4-weekly cutting. There was a wide degree of variation between sites, particularly for concentrations of Ca, Mg, Na and all trace elements analysed. Herbage from L. perenne reseeds had significantly higher concentrations of Ca, Mg, Na, Co and S, but K, Mo, Zn, Cu and P were generally lower than in the permanent swards. L. perennel T. repens swards had the highest concentration of major cations, but trace element levels were generally intermediate between those for 0 N permanent and L. perenne swards. Fertilizer N reduced concentrations of Ca, Mn, Mo and S, and increased Mg, Na and Zn, with no consistent effects on K, Co and Cu. Herbage at harvest 4, compared with harvest 1, had higher Ca, Mg, Na, Mn, Zn and S. Permanent and L. perenne swards responded similarly to fertilizer N and between harvest dates. Results are discussed in relation to previous reports of botanical and fertilizer effects on mineral concentrations, and the mineral requirements of livestock. Changes in mineral concentration resulting from reseeding permanent swards are considered unlikely to increase mineral-related livestock disorders, and in many cases could be beneficial, though problems might arise on sites where some elements, e.g. Cu and Mg, are low.