稻田春玉米氮、磷、钾配方施肥数学模型的初步研究

采用氮、磷、钾三因素旋转组合设计,通过计算机模拟寻优,建立了稻田春玉米--杂交晚稻种植制度中玉米产量--施肥量,玉米生产利润--施肥量数学模型:分析了氮(X₁)、磷(X₂)、钾(X₃)的主效应及交互效应与产量的关系,它们对产量的影响为氮＞钾＞磷.筛选出玉米产量≥8250kg/hm²的最优方案为:N394.96～401.25kg/hm²、P₂O₅116.99～121.8kg/hm²、K₂O 232.29～237.06kg/hm²,其比例为N∶P₂O₅K₂O=3.4∶1∶2.并筛选出玉米利润≥6800元/hm²的最优方案为:N380.60～385.55kg/hm²,P₂O₅104.73～108.03kg/hm²、K₂O222.20～225.12kg/hm².其比例为N∶P₂O₅K₂O=3.6∶1∶2.1。     

吉林省不同类型土壤玉米施肥效应研究

吉林省东、中、西不同类型土壤田间试验结果表明:不同类型土壤的氮、磷、钾肥施用模式符合二次曲线Y=ax²+bx+c。利用该模式,结合肥料和玉米价格进行综合分析,明确了不同类型土壤上的氮、磷、钾施用效益,即东部冲积土玉米最佳施肥量为N192kg/hm²、P2O556kg/hm²、K₂O33kg/hm²;中部黑土玉米最佳施肥量为N133kg/hm²、P₂O₅38kg/hm²、K₂O47kg/hm²;西部淡黑钙土玉米最佳施肥量为N59kg/hm²、P₂O₅65kg/hm²、K₂O51kg/hm²。     

氮、磷、钾和密度等因素对玉米产量形成的作用

采用回归正交旋转组合设计的方法,研究影响玉米产量的N、P₂O₅、K₂O三要素施肥量及种植密度,并对各因素的单独反应规律及其互作效应进行探讨。结果表明种植密度和施N量是制约玉米产量的主导因素,单产6000kg/hm²以上农艺措施为:公顷施纯N 240.6～266.4kg、P₂O₅106.75～121.4kg、K₂O 206.6～238.2 kg及公顷留苗52560～55440株。     

套种玉米高产施肥指标的研究与生产实践

通过研究确立了套种玉米施肥与产量的二元二次回归模型，模型经方差分析F值达极显著水平。进一步分析，该研究的三个主放因子对量的影响大小程度是氮＞磷＞钾，其相关程度为0.93。经过模拟寻优，玉米单产9000－9750kg/hm²的N、P、K施量的优化组合是：玉米施氮360kg／hm²，施P₂O₅69.8kg/hm²，施K₂062.7kg/hm²。该施肥指标通过大面积生产示范验证，玉米平均产量在940－9600kg/hm²，比常规栽培田玉米产量7411.5kg/hm²，增产1993.5－2188.5kg/hm²，增产历26.9%－29.5%。增产效果显著。生产示范产量接近目标产量，说明该方程可以为大田预测，研究所得的施肥指标可以作为小麦套种玉米高产施肥的依据。     

吉林中部玉米高产施肥与提高化肥利用率研究

通过两年的试验研究结果表明:应用现代高产施肥技术比当地大田玉米增产40%～115%,抗灾能力较强,年际间的产量变异较小;高产与经济效益协调统一的化肥施用量,N素为255kg/hm²较合理,而配施P₂O₅90kg/hm²,K₂O 135kg/hm²产量较高,同时N肥利用率可以从目前的30%左右提高到40%以上,土壤残留N较少,环境负荷小。     

栽培措施对玉米根系生长状况影响

本文通过用ABT生根粉4#、肥宝对玉米种子的不同处理及不同施肥水平试验观察结果为:ABT生根粉及肥宝对玉米有明显的促进生根作用,其根长、根重、根体积均比对照在同一生育期有显著增加,尤以生根粉+肥宝处理的效果最佳,表现明显互作正效应;不同施肥水平比较观察,在N、P₂O₅及K₂O为2∶1∶1情况下施用中肥处理即:N∶P₂O₅:K₂O为250kg∶125kg∶125kg/hm²为最佳,表现出根系强壮的特点.根重对维持叶绿素含量水平有一定作用.表现为根重大者,其叶绿素含量相对为高.     

锦科杂1号高产优质施肥模型的研究

 利用“3414”回归设计方案对锦科杂1号高产优质栽培施肥用量进行试验,对试验结果进行统计建模,建立了以子棉产量为目标函数的氮、磷、钾三因素肥料效应模型.经模拟仿真因素取值和统计分析,得出子棉产量3982.11～4015.17 kg·hm^-2的施肥量的95%置信区间分别为纯氮311.91～328.73 kg·hm^-2,P₂O₅ 151.87～162.33 kg·hm^-2,K₂O 238.88～255.86 kg·hm^-2。并对两因素互作效应及单因素效应进行了剖析。通过对氮磷钾、氮磷、氮钾、磷钾及氮、磷、钾三类7种模型提供的施肥量和期望产量进行经济效益分析,据此提出锦科杂1号高产优质高效栽培的推荐施肥措施：每公顷施纯氮300 kg,P₂O₅ 145.53 kg,K₂O 232.85 kg,产量期望为4029.42 kg·hm^-2,产投比12.57。     

氮磷钾用量对小麦冠层不同层次光截获和干物质分配的影响

为明确不同氮、磷、钾用量对小麦冠层不同层次光截获和干物质分配的影响，以济麦22为供试材料，设置F0（不施肥）、F1（N 180 kg·hm^-2，P₂O₅ 75 kg·hm^-2，K₂O 60 kg·hm^-2）、F2（N 225 kg·hm^-2，P₂O₅ 120 kg·hm^-2，K₂O 105 kg·hm^-2）和F3（N 270 kg·hm^-2，P₂O₅ 165 kg·hm^-2，K₂O 105 kg·hm^-2）4个施肥量处理，比较分析开花后不同氮、磷、钾用量对小麦叶面积指数、冠层不同层次光截获特性和成熟期干物质分配的影响。结果表明，F1处理下叶面积指数显著高于F0处理，而与F2和F3处理间无显著差异；开花后15 d，F1处理下小麦冠层不同层次及总PAR截获率和截获量均显著高于F0处理，而与F2和F3处理间无显著差异。F1处理下成熟期干物质在小麦冠层不同层次营养器官中的分配量、籽粒中的分配量及总干物质积累量显著高于F0处理，而与F2和F3处理间无显著差异。成熟期干物质在小麦冠层不同层次营养器官和籽粒中的分配量以及总干物质积累量与冠层上层（顶部至株高2/3）、中层（株高2/3至株高1/3）和总PAR截获率均呈显著正相关。F1处理（N 180 kg·hm^-2，P₂O₅ 75 kg·hm^-2，K₂O 60 kg·hm^-2）为本试验条件下的最优处理。     

氮磷钾配比对高产夏玉米产量、养分吸收积累的影响

通过大田试验研究了高产夏玉米土壤养分限制因素及植株养分吸收积累规律。结果表明：各施肥处理均比不施肥显著增产,增产7.3%～15.9%,氮磷钾推荐施肥(OPT)处理产量最高,达到12 051.2 kg/hm²,增产1 651.2 kg/hm²;施用氮肥、钾肥能显著提高夏玉米的产量,N、K是高产夏玉米主要养分限制因素。高产夏玉米植株体内氮、磷、钾的积累量均随生育期的延长而增加,养分积累量的大小顺序为N>K>P,从拔节期至大喇叭口期是氮素、磷素和钾素吸收量和吸收速率最大的时期,整个生育期,高产夏玉米能持续吸收N、P、K养分。N当季回收率为18.05%,P₂O₅为14.55%,K₂O为18.34%,每生产100 kg经济产量需吸收的N、P₂O₅、K₂O的量分别为1.62、0.69、1.83 kg。     

不同配方专用肥对冬小麦产量和养分吸收的影响

为给关中地区小麦生产筛选适宜的专用肥,2008-2009年以小偃22为材料,通过田间试验研究了不同配方的小麦专用肥对冬小麦产量、养分吸收及其经济效益的影响。结果表明,在总施氮量基本一致的条件下,不同专用肥和追肥配施处理对小麦产量、氮磷钾养分吸收和利用以及经济效益有显著的影响。在8个处理中,基施复合肥（N∶P₂O₅∶K₂O=18%∶18%∶18%）500 kg·hm^-2、返青期追施纯氮50 kg·hm^-2处理的籽粒产量、氮磷钾养分吸收量、氮钾肥利用效率、氮肥偏生产力和农学利用效率以及经济效益最高,相比农民习惯施肥处理分别增产和增收38.4%和38.9%。因此,18%∶18%∶18%的N∶P₂O₅∶K₂O比例可作为关中地区小麦专用肥配方。     

Factors in the Reduction in Grain Number in Winter Wheat by Early-Sowing in Yamaguchi

Abstract

Grain number per spike of wheat is lower in early sowing than in the conventional standard cultivation in Yamaguchi, Prefecture, Japan. Components of the grain number per spike in five cultivars were analyzed with respect to temperature during the spike development period throughout three growing seasons 2001/2002, 2002/2003 and 2003/2004 to find the cause of the problem of early sowing cultivation. The plants sown in early-October and late-November were called the early sown group and the standard group, respectively, in the following. Three of the five cultivars, Hokushin, Akitakko and Nanbukomugi, showed a strong winter habit, which requires very cold temperatures for spike differentiation. The other two cultivars, Iwainodaichi and Airakomugi, had a moderate winter habit. Grain number per spike and grain yield were decreased by early-sowing (compare with the standard group) in almost all cultivars throughout the three growing seasons. The three cultivars which had a strong winter habit had fewer spikelets per spike in the early-sown group than in the standard group. The other two cultivars which had a moderate winter habit had fewer grains per spikelet in the early-sown group. The higher the temperature during the spikelet formation phase, which is from flag leaf initiation to terminal spikelet initiation, the higher the number of spikelets per spike in the standard group. The spikelet number per spike in the early-sown group increased with the increase in productive tillers under fertile conditions. Such conditions also increased the grain number per spike.     

Allelopathy in Agroecosystems in Spain

Summary

This paper reviews the effects of allelopathic interactions in agroecosystems in Spain on plant physiological activity and their ecological advantages. The phenological stage of growth of donor plants and the effective allelochemicals in the soil solution while studying the role of phenolic compounds were highlighting. Finally possible future prospects and conclusions regarding weed control by allelochemi-cals under integrated crop management strategies are discussed.     

2009年中国稻米市场分析及2010年展望

以翔实的资料对2009年中国稻米生产、消费、进出口、供求平衡、库存、价格走势、购销政策和国际稻米供求等情况进行了全面地分析,对影响2010年稻米市场价格走势的各种因素进行了深入研究,并在此基础上对2010年我国稻米市场价格走势进行了预测,结论是我国稻米价格仍呈上行趋势。     

我国干热区甘蔗抗旱植蔗主要问题研讨

我国干热蔗区是我国甘蔗糖业的重要生产基地,蔗区光热资源丰富,唯降水分布不均成为植蔗生产的主要限制因子;根据蔗区植蔗特点和甘蔗需水规律,苗期抗旱是干热蔗区抗旱植蔗的关键,保证较多的总苗数和足够的生长量是苗期抗旱植蔗需解决的关键技术难题,制定相应的苗期抗旱植蔗栽培技术措施是解决该难题的重要保障;该观点为我国干热蔗区植蔗生产、甘蔗引育种提供理论和技术支持。     

Diurnal changes in net photosynthetic rate in potato in two environments

Summary Diurnal changes in net photosynthetic rate were measured in a furrow-irrigated potato crop and in a riverbed crop where the water table was always maintained at 20–28 cm from the soil surface. In the irrigated crop, the photosynthetic rate during mid-afternoon was about half the peak rate observed at noon. This reduction was accompanied by a near tripling of stomatal resistance, a 45% reduction in transpiration, and a 5-fold increase in the difference between leaf and air temperatures. No such changes were observed in the riverbed crop where the photosynthetic rate remained nearly constant at about 0.9 mg m⁻² s⁻¹ between 9 a.m. and 4 p.m. Tuber yield in the riverbed crop was about 30% higher than in the irrigated crop.     

棉花体细胞无性系变异的研究进展

体细胞无性系变异是一种重要的细胞工程育种技术,其应用于棉花育种的前提是建立高效的组织培养诱导再生植株体系.本文简要综述了棉花离体诱导植株再生研究的现状,重点讨论了棉花体细胞无性系变异的表现、利用方法及机理,提出了当前研究存在的问题并对今后的研究进行了展望.     

Sugar and dry matter changes in potatoes overwintered in soil in Greece

Summary Potatoes were left in the soil from December, when the vines died, until February (cvs Claustar and Sebago) or April (cv. Spunta) in a location of central Greece with light, well drained soils and a mild climate. Tubers were analysed every two months for dry matter and sugar content and usually the dry matter content did not change significantly from December to February or April. The reducing sugars increased from December to February in tubers of all cultivars and significantly decreased in cv. Spunta from February to April.     

Changes in daily rainfall characteristics in major rice producing provinces in Laos

In order to find the changes in rainfall characteristics and to examine the flood damage to lowland rice, a statistical analysis was carried out on the 40-year daily rainfall record at four rainfall stations (Thangon, Paksane, Seno, and Pakse) in Laos. The rainfall record was divided into two periods of 20 years each. The results of this analysis revealed the trends in changes regarding the frequency and the timing of the heavy daily rainfall events at the four stations. In Paksane in particular, heavy daily rainfall events tended to occur in the latter half of the rainy season.     

兜兰离体快繁技术研究进展

由于生境破坏和人工过度采挖及繁殖的障碍,兜兰已是世界上最濒危的植物物种之一,所有野生种均被列入《濒危野生动植物种国际贸易公约》附录I而被禁止交易。突破其种苗繁殖技术瓶颈有利于兜兰种质资源的保护和可持续利用。本文对兜兰属植物无菌播种、共生萌发和组织培养技术等离体快繁技术的进展进行综述,并提出了目前存在的问题和解决方法,以期为兜兰属植物离体繁殖技术的深入研究和优质种苗的规模化生产提供参考。     

中国马铃薯单倍体诱导进展

马铃薯产量、品质、加工等方面都较其他作物有更大的提升空间,但由于四倍体马铃薯存在遗传基础狭窄且复杂、难以创新等诸多问题阻碍了相关研究的深入开展。利用马铃薯单倍体或双单倍体植株有望解决上述诸多难题。马铃薯单倍体具有加速育种过程、提高选择效率等优点。马铃薯单倍体的获得包括花药培养、花粉培养、孤雌生殖、子房培养。其中,花药培养因更易取材,并且得到胚性细胞团、愈伤组织或胚状体的几率更大等优点而研究最为广泛。获得单倍体植株的成功率与试验材料的基因型、培养条件、培养基添加物等诸多因素相关。根据不同的诱导方法简要阐述了中国马铃薯单倍体研究的历史及进展。