小麦/玉米带田中玉米施氮技术研究

河西走廊小麦/玉米带田中玉米施N技术直接影响其产量。氮肥在玉米生长前期的拔节期或播前作底肥施用平均增产玉米123％～137％,提高带田产量48％～54％,玉米对N素利用率28.9％～31.1％;玉米抽雄期施N玉米增产率减少87～101个百分点,利用率减少21.4～23.6个百分点,带田综合增产率减少32～38个百分点。等量N肥分作底肥和拔节期两次施用是玉米最佳施N时期;带田玉米N肥追施以穴深施和行间单沟深施效果最好,有效地防止了N的挥发损失,比表施增产15％～18.3％。     

稻田15N标记尿素去向的研究

 1987年在中国水稻研究所试验场应用15N示踪技术进行了多处理的田间微区试验。结果表明： 氮肥作基肥使用时，水稻对N素的吸收利用率差异不显著，而随着施用量的增加，在土壤中的N素残留率降低，而氮肥损失率显著提高；基肥配施PK肥对肥料N的去向无显著影响响，但配施适量稻草有助于提高水稻对肥料N的吸收量和土壤残留量，降低氮索损失；氮肥的使用期对肥料15N去向的影响十分显著，追肥的K素利用率比基肥高。稻田采用以水带氮施肥技术能明显地提高水稻的氮素吸收，增加土壤残留率和减少氮素损失，表明此技术是一项合理的稻田氮肥深施技术。     

氮肥运筹方式对油菜产量、氮肥利用率及氮素淋失的影响

通过盆栽模拟试验研究了不同氮肥运筹方式对油菜产量、氮肥利用率、氮素淋失及氮素平衡的影响。试验设5个处理:不施氮肥(CK),氮肥全部基施(TJ),氮肥60%基施、40%做越冬肥追施(TJD),氮肥60%基施、40%做薹肥追施(TJT),氮肥60%基施、20%做越冬肥、20%做薹肥追施(TJDT)。研究结果表明,氮肥分期施用可明显增加油菜产量,提高氮肥利用率,其中以TJDT处理效果最佳,与TJ处理相比,TJDT处理的产量、氮肥农学利用率及表观利用率分别提高了17.6%、2.1kg·kg-1氮和4.9%。同时,TJDT处理的氮素淋失量也最小。氮素平衡计算结果表明,不同时期追施氮肥对氮素平衡影响不大,但是均比氮肥集中做基肥施用(TJ)的表观损失明显减小。尽管油菜收获后,各施氮处理土壤氮素均有盈余,但分期施肥盈余量明显高于TJ。研究表明在油菜生产中,氮肥分期施用既能提高油菜籽的产量和氮肥的利用效率,又可获得较好的环境效应。     

控释氮肥用量对早熟油菜产量及氮素吸收利用的影响?

为控释氮肥在双季稻区早熟油菜生产上大面积应用提供依据,研究控释氮肥用量对早熟油菜产量及氮素吸收利用的影响,以早熟常规油菜“1358”为材料,于2012-2013年在江西省油菜主产县(市)设置6个田间试验,调查控释氮肥用量对早熟油菜产量、产油量及氮素吸收利用的影响。结果表明,控释氮肥施肥效应与普通氮肥施肥效应均有随施氮量的增加而增产的趋势。等量控释氮肥一次性基施比普通尿素分次施用增产,甚至控释氮肥适量降低也能达到普通氮肥合理施用量的产量水平,同时提高了氮肥利用率。在180kg/hm2施氮水平下,控释氮肥一次性基施较普通尿素分底施60%,苗期施20%和抽薹期施20%共3次施用显著增产,油菜籽粒增产7.64％,产油量提高8.30％,氮肥利用率增加2.27个百分点。双季稻区早熟油菜控释氮肥施用量150kg/hm2可以达到普通氮肥180 kg/hm2用量的产量效果。     

灌溉施肥对冬小麦土壤氮素盈亏的影响

通过田间小区试验，研究了灌溉和施肥对冬小麦生育期间0～400cm土壤硝态氮累积、移动特征及小麦产量的影响，并对0～200cm土壤氮素的盈亏、氮肥利用率、残留率及损失率进行了表观估算，旨在为小麦的氮素利用与推荐施肥提供理论依据。结果表明，0-400cm硝态氮累积量随着施氮量的增加而显著增加。施氮量对0～100cm土体硝态氮累积量有显著影响，施氮与灌水对200cm以下土壤中的硝态氮累积都有影响，同时水氮交互作用不容忽视。施氮并结合灌水可以显著提高冬小麦籽粒产量，施氮而不灌水也有一定的增产作用。0～200cm土壤氮素的表现盈余主要出现在小麦拔节～灌策期间，表观亏缺主要在播种～拔节期及灌策～收获期。相同灌水量下，氮肥利用率随施氮量的增加显著降低，而损失率增加。施氮130kg／hm^2、灌水60mm处理的氮肥利用率最大，为25．7％。从硝态氮累积量、产量及氮肥利用率等方面考虑，本试验比较合理的肥水配比应为施氮130kg／hm^2，灌水60mm。     

不同施氮时期对红壤旱地花生生物量和氮素累积的影响

以花生品种粤油256为供试材料,采用田间随机区组试验,设置6个处理:不施氮肥(CK)、氮肥全部基施(N_(10∶0∶0),当地习惯施氮方式)、氮肥70%基施+30%花针期施用(N_(7∶3∶0))、氮肥50%基施+50%花针期施用(N_(5∶5∶0))、氮肥50%基施+30%花针期施用+20%结荚期施用(N_(5∶3∶2))、氮肥30%基施+50%花针期施用+20%结荚期施用(N_(3∶5∶2)),研究不同施氮时期对南方红壤旱地花生生物量累积、氮素累积、氮肥利用率和产量的影响。结果表明:所有处理的花生生物量累积、氮素累积均可用Logistic方程拟合,施氮时期显著影响花生生物量及氮素的累积特征,氮肥分次施用并适当后移可显著提高生物量及氮素的最大累积速率(v_(max))、推迟吸收"峰值"的出现时间(t_(max)),延长生物量及氮素快速累积的持续时间(Δt),从而有利于提高花生产量及氮肥利用率,但氮肥后移比例过大(N_(3∶5∶2))也不利于肥效的充分发挥。本试验条件下,以氮肥50%基施+30%花针期追施+20%结荚期追施(N_(5∶3∶2))的效果最好,其产量达到4 918.5kg·hm~(-2),较CK增产20.0%,较当地传统的一次性施肥也可增产9.8%。合理调控施氮时期是提高我国南方红壤旱地花生产量和氮肥利用率的有效措施,本研究可为该区域花生的科学合理施肥、高产高效栽培提供理论依据。     

氮肥运筹方式对油菜产量、氮肥利用率及氮素淋失的影响（简报）

通过盆栽模拟试验研究了不同氮肥运筹方式对油菜产量、氮肥利用率、氮素淋失及氮素平衡的影响。试验设5个处理：不施氮肥（CK）,氮肥全部基施（TJ）,氮肥60%基施、40%做越冬肥追施（TJD）,氮肥60%基施、40%做薹肥追施（TJT）,氮肥60%基施、20%做越冬肥、20%做薹肥追施（TJDT）。研究结果表明,氮肥分期施用可明显增加油菜产量,提高氮肥利用率,其中以TJDT处理效果最佳,与TJ处理相比,TJDT处理的产量、氮肥农学利用率及表观利用率分别提高了17.6%、2.1 kg&;#8226;kg-1氮和4.9%。同时,TJDT处理的氮素淋失量也最小。氮素平衡计算结果表明,不同时期追施氮肥对氮素平衡影响不大,但是均比氮肥集中做基肥施用(TJ)的表观损失明显减小。尽管油菜收获后,各施氮处理土壤氮素均有盈余,但分期施肥盈余量明显高于TJ。研究表明在油菜生产中,氮肥分期施用既能提高油菜籽的产量和氮肥的利用效率,又可获得较好的环境效应。     

不同地力水平下不同养分管理模式对早稻氮素利用效率及产量的影响

以陆两优996为供试材料,采用田间小区试验,设计了3种养分管理模式,研究了中、低2种地力水平对早稻氮素利用效率及产量的影响。结果表明,施用氮肥在中低肥力地块上增产效果显著,与对照相比,施氮比不施氮能增产14.6%～41.7%,在中肥力地块氮肥利用效率为32.23%,低肥力地块氮肥利用效率为30.70%,分别比相同地力水平的农民习惯施肥处理高出了10.00%和8.36%;在相同的氮素水平下,低肥力地块增产效果要好于中肥力地块。在不同的地力水平下,充足的氮素供应能提高早稻的实粒数和有效穗数,对氮素从源到库的转化也起着积极的促进作用。     

氮水运筹对苏北平原稻茬麦干物质积累、产量和氮肥利用的影响

为明确苏北平原稻茬麦的最优氮水运筹模式,以淮麦30为材料,在大田测土施肥条件下,设置0 kg·hm^-2（N₀）、180 kg·hm^-2（N₁）、270 kg·hm^-2（N₂）3个施氮量和生育期不灌水（W₀）、灌拔节水（W₁）、灌拔节水+孕穗水（W₂）3个灌水处理,研究小麦干物质积累与转运、产量形成和氮素吸收与利用对不同氮水运筹的响应。结果表明,小麦干物质积累量、转运量和转运效率,氮素积累量、转运量和转运效率,花后干物质贡献率及氮素贡献率均随施氮量和灌水次数的增加而增加,各处理均以N₂W₂效果最佳。氮肥和灌水次数的增加对小麦成穗数、穗粒数、千粒重和产量、氮素收获指数与氮素利用效率均有显著促进作用,以N₂W₂效果最佳。氮肥农学效率、氮肥表观利用率和氮肥偏生产力则随施氮量增加而降低,以N₁W₂效果最佳;在相同氮肥水平下,灌水处理的上述三个指标较不灌水处理高。对本试验条件下各测定指标,氮肥在氮水运筹中起主导作用,且氮肥和灌水有显著的互作效应。综上,在苏北平原稻茬麦区,施氮量180 kg·hm^-2结合浇灌拔节水和孕穗水（W₂）的氮水模式可在协调小麦干物质和氮素的积累、转运与分配、促进增产的同时,提高氮肥利用效率,从而实现节氮增产的目标。     

耕作和施肥方式对陇中旱作春小麦氮素利用与硝态氮残留的影响

为解决黄土高原半干旱区土壤贫瘠、氮肥固持率低及化肥不合理施用问题,以陇中春小麦为研究对象,比较分析了不同耕作[传统翻耕(CT)和免耕(NT)]和施肥方式[不施氮肥(CK)、单施化学氮肥(N)、单施有机肥(M)和氮肥有机肥配施(NM)]下春小麦氮素积累量、氮素利用效率和土壤硝态氮残留的差异。结果表明,NT-NM处理对各生育时期春小麦氮素积累具有显著的促进作用,使春小麦氮素偏生产力、氮素回收率、氮肥农学利用效率和氮素收获指数较CT-N处理分别提高了42.93%、20.13%、83.83%和2.55%;土壤硝态氮残留量表现为NM处理低于N和M处理、免耕处理低于翻耕处理,NT-NM处理下的0～100 cm土层土壤硝态氮残留较CT-N处理减少52.56 kg·hm^-2;NT-NM处理优化了春小麦产量构成,提高了产量和生物量,其中产量达到了3 258.26 kg·hm^-2,比CT-N处理显著增加56.21%,有效穗数和千粒重提高是其增产的主要原因。因此,免耕结合氮肥与有机肥配施可实现春小麦增产和氮素高效利用,同时降低氮素残留对农田生态系统的潜在危害,是黄...     

香港市场稻米品质的初步研究

本文研究了来自香港稻米市场上的11个籼米的外观品质和蒸煮食味品质。香港市场要求稻米的外观品质是精白度高、米粒细长、垩白度低及米粒半透明;间接指示食味品质的胶稠度软,糊化温度低及直链淀粉为20%左右。食味品尝试验的结果表明港米饭色泽洁白,饭粒细长,质地柔软而略有黏性,与其外观和食味品质指标相符。品尝小组对港米的评分与香港市场价格成显著正相关,说明港米不但适合香港人民的口味,也可能为广大国内群众所喜爱,可以作为我国优质米的一个重要类型。从对我国供港大米主要基地广东、广西两省的米质分析可以看出;目前两广优质米不论在外观上或是蒸煮食味品质上都与港米存在一定的差距。     

不同施肥制度对红壤地区双季稻田氨挥发的影响

 为系统地了解不同施肥制度下各生育期氨挥发损失的程度及规律,采用密闭室法对南方红壤地区双季稻田的氨挥发进行了监测。不同施肥制度下氨挥发的变化规律基本相同,施肥后1~3 d内达到峰值,随后逐渐下降,1周后无明显排放。氨挥发速率随施N量增加而增加。早季各处理氨挥发累积量基肥时为1.6~3.6 kg/hm2,分蘖肥时为58~18.2 kg/hm2;而晚季基肥、分蘖肥和穗肥时的氨挥发累积量分别为4.5~7.9、12.3~26.8和1.4~2.4 kg/hm2,早、晚季氨挥发总累积量分别占其施N量的4.5%~15.3%和16.9%~32.8%。相对于不施肥处理,尿素的施用促进氨挥发,而在等氮施用量下,缺P处理通过氨挥发损失的N量较多,较高水平的秸秆和绿肥施用也会增加氨挥发量。此外,氨挥发与田面水NH4+ N浓度及水层pH之间存在正相关关系,气候条件也显著影响氨挥发量。     

Traits Related to Chilling-Induced Photoinhibition in Leaves of

Physiological indices related to PSⅡ photochemical efficiency (F_v/F_m) and membrane lipid peroxidation were measured in leaves of indica rice cv Shanyou 63 and japonica rice 9516 at different temperatures and light intensities for four days. No obvious changes in F_v/F_m and MDA were observed in both indica and japonica rice at moderate temperature and medium PFD, implying neither photoinhibition nor photooxidation happened in these cases. In indica rice either at medium temperature with higher PFD or at lower temperature with medium PFD F_v/F_m dropped obviously with no changes in MDA contents, and photoinhibition appeared while photooxidation did not occur. However, D₁ protein, F_v/F_m, (A+Z)/(A+Z+V), and SOD activities dropped, and O₂ production and MDA content increased accordingly, as well as both photoinhibition and photooxidation appeared in two rice varieties at lower temperature and higher PFD. Experiment with inhibitors at lower temperature and higher PFD showed that as compared with japonica rice the decrements appeared in D₁ protein contents, SOD activities, and (A+Z)/(A+Z+V) ratios, the xanthophyll cycle and non-photochemical quench (q_N) were inhibited in a more degree, as well as increments of MDA content were greater, thus exhibiting more distinct photoinhibition and photooxidation in indica rice. It is suggested that F_v/F_m and membrane lipid peroxidation product－MDA were the key indices to predict and diagnose photooxidation.     

双季杂交稻“肥促水调”栽培技术的应用

选用优势强、品质优的杂交组合,早季中熟搭配晚季迟熟组合,培育壮秧,控制分蘖肥用量,增大后期施肥量,超前搁田控制苗峰,在一定穗粒基础上,实现总粒数、实粒数和经济系数的大幅度提高,从而提高产量．     

Crop rotation impacts on potato protein

The impacts of nitrogen (N) fertilization on potato ( Solanum tuberosum L.) protein yield and nutritional quality are well documented but of little benefit to growers with limited access to fertilizer or capital (e.g. in lesser developed countries). This study was conducted 1) to evaluate the extent which crude protein yield in potatoes can be influenced by crop rotation with no N fertilizer and 2) to determine if crop rotation and minimal application of N fertilizer can meet the total protein yield of potatoes achieved with recommended quantities of N fertilizer. A field study was conducted in which potatoes followed previous crops of alfalfa (Medicago sativa L. Nitro), hairy vetch ( Vicia villosa Roth), white lupin ( Lupinus albus L. Ultra), oats ( Avena sativa Astro), and potatoes. Tuber protein yield following alfalfa with no N fertilizer was about 50 kg/ha greater than when following potatoes or oats in one study year. In another year, tuber protein yield was greatest following vetch, achieving 149 kg protein/ha with no N fertilizer. These results were directly linked to the N contributions of rotation crop residues and were reflected in the plant-available N levels measured in soil. Applying one-half the recommended rate of N fertilizer resulted in protein yields comparable to a well-fertilized potato-potato rotation in a relatively dry year, but not in a year with more favorable precipitation. Particular crops grown in rotation with potatoes can make significant contributions to the total protein harvested in tubers.     

Agronomic and economic evaluation of Sesbania rostrata green manure establishment in irrigated rice

Research on crop establishment methods may improve green manure performance, reduce costs, and increase the adaptability of pre-rice green manure technology in lowland rice-based cropping systems. A two-season field experiment was conducted at the International Rice Research Institute (IRRI) in Los Baños, Philippines in 1991–1992 to compare four establishment practices of Sesbania rostrata green manure (zero tillage, with tillage, relay cropping in rice for 2 or 4 weeks) with four mineral N fertilizer levels (0, 30, 60, and 90 kg urea N/ha) in an intensive irrigated lowland system with three rice crops per year. S. rostrata was grown twice a year during the 43-day dry-wet and wet-dry transition periods between the wet and dry season rice crops.

Grain yield potential and fertilizer responsiveness of rice was generally highest in the dry season. On the other hand, S. rostrata growth was more vigorous in the wet season (long-day period) than in the dry season, regardless of establishment method. Green manure N accumulation was lowest with zero tillage (30 and 90 kg N/ha in dry and wet season, respectively) and highest when it was relay-cropped for two weeks (60 and 180 kg N/ha in dry and wet season, respectively). Land preparation for Sesbania ensured best green manure stand (> 100 plants/m² vs 20–40 plants/m² at no-till establishments) but increased costs of green manuring by US$16/ha compared with other establishment methods. A quadratic response function between mineral fertilizer equivalence and green manure N indicated that up to 75 kg N/ha, lowland rice uses green manure N more efficiently than urea. Depending on season and establishment method, S. rostrata substituted for 35 to 90 kg of split-applied urea N. Benefit-cost ratios indicated that pre-rice green manure use in the wet season under the current fertilizer and labor prices in the Philippines was a less attractive economic option than mineral N fertilizer. This was true for all establishment methods. In the dry season, S. rostrata established by relay cropping gave the highest rate of return. The 2-week relay cropping of green manure with irrigated rice gave highest green manure N accumulation and rice grain yield, and may be economically viable where fertilizer prices are higher or labor costs are lower than in the Philippines.     

Effect of N rate,timing and splitting and N type on bread-making quality in hard red spring wheat under rainfed Mediterranean conditions

Three different experiments were designed to study the effects of N fertilizer rate, timing and splitting, and the response to combined application of N and S fertilizer on the bread-making quality of hard red spring wheat (Triticum aestivum L.) over a 3-year period in Vertisols under rainfed Mediterranean conditions. The following parameters were analyzed: grain yield, test weight, grain protein content, gluten index and alveograph parameters (W: alveogram index; P: dough tenacity; L: dough extensibility; P/L: tenacity–extensibility ratio). The N rate experiment included rates of 0, 100, 150 and 200 kg N ha⁻¹ applied on four different sites. The experiment was designed as a randomized complete block with four blocks. For the experiment on N timing and splitting, a single rate of 150 kg N ha⁻¹ was used, different fractions being applied at sowing, tillering and stem elongation, at a single site; again, experimental design was a randomized complete block with four blocks. Finally, for the experiment on the response to combined application of N and S fertilizer, a single fertilizer dose of 150 kg N ha⁻¹ was applied in two forms (urea+ammonium nitrate and urea+ammonium nitrosulfate) with one leaf application at ear emergence (zero, 25 kg S ha⁻¹, 25 kg N ha⁻¹, $\text{25}\text{kg}\text{S}\text{ha}{}^{\mathrm{-1}}\text{+25}$ kg N ha⁻¹ and 50 kg N ha⁻¹), also at a single site, using a split-plot design with four replications. Year-on-year variation in rainfall led to marked variations in wheat yield, grain protein content and bread-making quality indices. A close correlation was observed between rainfall over the September–May period and both grain yield and grain protein content (optimum values for both being recorded in the rainfall range 500–550 mm) as well as the alveogram index. A negative correlation was observed between mean maximum temperatures in May and both test weight and alveogram index (W). N fertilizer rate had a more consistent effect on bread-making quality than on grain yield. The highest values for grain yield were recorded at an N rate of 100 kg ha⁻¹, while maximum grain protein content values were recorded at 150 kg ha⁻¹. Application of half or one-third of total fertilizer N at stem elongation improved grain yield and grain protein content with respect to applications at sowing alone or at both sowing and tillering. Increased N rates led to a considerable increase in W values and to a reduction in the P/L ratio, thus improving dough balance, with a negative effect on the gluten index. Leaf application of N at ear emergence only affected grain protein content and the W index. Soil or leaf application of S had no effect on protein quality indices. The response of grain yield and grain protein content to fertilizer N differed from that reported for temperate climates.     

缓控释肥一次性施用后土壤氮素供应与损失特征研究

采用小区试验,设置常规施肥(U,240 kg/hm²)、包膜控释肥料(CU,180 kg/hm²)、双效抑制剂增效肥料(DU,180 kg/hm²)、添加生物炭保护层的抑制剂增效肥料(BU,180 kg/hm²)一次性施肥、无氮对照(CK)5个处理,研究对夏玉米生长、产量、氨挥发和土壤无机氮残留的影响。结果表明,一次性施肥显著增加了苗期无机氮的供应,在大喇叭口期维持一定的供氮强度,其中BU处理供氮较高。与常规施肥处理相比,一次性减量施肥对营养生长的影响不明显,产量未出现下降,氮肥农学效率显著增加,氨挥发降低54%～63%,硝态氮残留减少6%～20%。3种缓控释肥减量一次性施用均可维持较高的产量并降低环境影响。与聚合物包膜控释肥相比,双效抑制剂增效肥制作简单、成本低,氮素释放快、供应充足,添加生物炭保护层可以进一步促进增产增效。     

平衡施肥对木薯产量及品质的影响初报

采用"3414"完全随机区组设计,开展木薯平衡施肥田间试验,研究施肥对木薯产量及品质的影响.其结果表明:(1)施肥对木薯产量有极显著的增产效应,氮、磷、钾肥增产的主次顺序为K>N>P.(2)木薯最高产量的氮、礴、钾优化施肥组合为N:150.00 kg/hm2,P2O5:36.75 kg/hm2,K2O:150.00 kg/hm2,此时最高产量为36.04t/hm2,其最佳施肥配比为N:P2O5:K2O=4:1:4;木薯最佳施肥利润的氮、磷、钾优化施肥组合为N:150 kg/hm2、P2O5:29.50 kg/hm2、K2O:150 kg/hm2,其最佳施肥利润达10 780.11元/hm2,此时产量为36.00 t/hm2,其最佳施肥利润配比为N:P2O5:K20=5:1:5.(3)施肥对木薯淀粉含量有极显著的影响,氮、磷、钾肥对木薯淀粉含量影响的主次顺序为:N>K>P.     

启动氮加追肥对氮在大豆体内积累分配规律及产量的影响

采用框栽试验方法,在施用等量氮(纯N 50 kg.hm-2)条件下设置基肥一次性施用(对照);R3或R4期一次性追肥;启动氮15 kg加R3或R4期追氮35 kg共5个处理,研究启动氮加追肥对氮在大豆体内积累分配规律及产量的影响。结果表明,在R5期,与对照相比,启动氮15 kg加R4期追氮35 kg处理叶片N积累量减少11.5%,荚果N积累量增加36.6%(P<0.05);而根系N积累量增加21.7%(P<0.05),根瘤N积累量增加64.2%(P<0.05),表明启动氮加追肥处理N运转通畅,可以满足籽粒充实期大豆对氮素的需求。在R4～R8期,启动氮加R3或R4期追氮处理的氮积累量分别比基肥一次性施用处理增加82.6%和105%(P<0.01)。启动氮加R3或R4期追氮35 kg处理单株粒数分别较对照增加14.8%和15.8%(P<0.01),产量分别增加17.6%和19.9%(P<0.01)。大豆植株R4～R8期氮积累量与产量呈极显著正相关(r=0.795**),提高结荚鼓粒期后大豆氮素积累量是增加大豆产量的关键。