氮肥用量对吉林省玉米产量和氮肥利用效率的影响

选取2005~2013年吉林省"3414"田间试验中的氮肥用量处理,研究施氮水平对玉米产量和氮肥利用效率的影响,明确不同生态区之间的差异。结果表明,不施氮条件下吉林省玉米的平均产量为7 596 kg/hm~2。氮肥施用显著提高玉米产量,以适宜施氮量(N3)处理表现最好,产量最高达9 967 kg/hm~2,较不施氮(N1)处理平均增产2 371 kg/hm~2。玉米的氮肥农学利用率和偏生产力均以适宜施氮量的1/2(N2)处理最高,随施氮量增加氮肥利用效率均逐渐降低。不同生态区显著影响玉米的增产效果和氮肥利用效率,吉林省中部半湿润平原区的产量水平最高,东部湿润山区次之,西部半干旱平原区最低。施氮增产量和农学利用率以东部地区显著高于中、西部地区,偏生产力以东部地区最高而西部地区最低。     

施钾对春玉米产量、养分吸收及分配的影响

通过连续两年田间试验,研究吉林省中部玉米主产区施钾对春玉米产量、养分吸收、转运、分配及钾肥利用率的影响。结果表明,施用钾肥可显著提高春玉米产量,在一定施钾范围内,春玉米产量随施钾量的增加而增加,当施钾量超过90 kg/hm2后产量不再增加,根据玉米产量(y)和施钾量(x)拟合,得出最佳施钾量为82.9~86.6 kg/hm2。施钾肥可提高干物质最大积累速率和积累总量、养分最大吸收速率和吸收总量,提前干物质最大积累速率和养分最大吸收速率出现的时间。施钾可提高春玉米氮、磷、钾养分向子粒的转运量及转运率,施钾量30~90 kg/hm2范围内抽雄期养分积累量与子粒转运量和转运率呈正比,当施钾量超过90 kg/hm2后,氮、磷、钾养分转运出现负效应。钾素农学利用率和偏生产力随着施钾量的增加而下降,钾肥当季回收率以施钾量90 kg/hm2处理最高。在吉林省中部玉米主产区,适宜施钾量为82.9~86.6 kg/hm2。     

优质玉米喜肥特性与施肥效益研究

试验研究结果表明:高油玉米、高淀粉玉米和高蛋白玉米对氮磷钾的敏感顺序均为氮>钾>磷。在目前的肥料施用量及玉米和肥料价格情况下,高油玉米氮磷钾配施获得的经济效益为341元/hm2,磷钾配施的经济效益为120元/hm2,氮钾配施和氮磷配施的效益均为负值;高淀粉玉米施肥效益为负值;高蛋白玉米氮磷钾配施可获得609元/hm2的效益。氮磷配施、氮钾配施及磷钾配施的效益均为负值。氮磷钾配施对高蛋白玉米的增产效益最大,对高淀粉玉米的增产效益最小。     

氮肥运筹对春玉米产量、养分吸收和转运的影响

研究氮肥不同运筹方式对玉米产量、养分吸收利用、转运及分配的影响。结果表明,基肥:拔节期:抽雄期施氮比例为3∶4∶3处理玉米产量和氮肥利用效率最高,较其他基追比例处理增产3.2%~20.5%,氮收获指数、当季回收率、农学利用率和偏生产力分别提高2.0~5.3个百分点、2.0~21.3个百分点、2.3~10.0 kg/kg和2.3~10.0 kg/kg。施氮可显著增加玉米主要生育期氮、磷、钾吸收量,并可提高玉米抽雄期氮、磷、钾养分向子粒转运和子粒养分增加量,其中基肥∶拔节期∶抽雄期施氮比例为3∶4∶3处理玉米灌浆期氮、磷、钾吸收量最高,成熟期子粒氮、磷、钾积累总量高于其他基追比例处理。相关分析结果表明,玉米各生育期氮、磷、钾吸收间存在显著或极显著的正向相关,且除苗期外,其他生育期氮、磷、钾吸收量与产量均存在极显著正相关,灌浆期氮、磷、钾吸收状况与产量相关系数最大。     

吉林省春玉米土壤中、微量元素“潜缺乏”初探

在吉林省中、西部玉米主产区进行高产条件下硫、镁、锌、锰、硼施用效果试验。结果表明,增施中、微量元素可以有效促进植株对营养元素的吸收、子粒的形成以及干物质的累积,不同中、微量元素响应程度区域性差异较大。中部地区以硫效果最好,产量增幅10.4%～12.0%,氮、磷、钾养分累积量分别增幅12.0%～12.8%、12.9%～21.7%、0～11.5%,其次是硼、镁;西部地区以锌效果最好,产量增幅18.7%～35.0%,氮、磷、钾养分累积量分别增幅40.8%～62.4%、39.4%～59.5%、9.4%～70.5%,其次是硼、锰、硫。依据区域特点,有针对性地补充中、微量元素可有效提高作物生产力,增产增收。     

不同施氮水平对春玉米氮素吸收、转运及产量的影响

采用田间试验研究吉林省中部玉米主产区不同氮水平对玉米产量、氮素吸收、转运及氮肥利用率的影响。结果表明,施用氮肥可以提高干物质最大积累速率和氮素最大吸收速率,并能提前干物质最大积累速率和氮素最大吸收速率出现的天数。在施N 60~180 kg/hm2之间,玉米产量、干物质最大积累速率、氮素最大吸收速率、转运量、转运率及子粒中养分比例等指标均有显著提高;超过N180 kg/hm2,干物质最大积累速率、氮素最大吸收速率、转运量、转运率及子粒中养分比例等指标开始下降。根据玉米产量(y)和施氮量(x)拟合得出,最高产量氮肥用量为184.2 kg/hm2,最佳经济产量氮肥用量为172.9 kg/hm2。氮素农学利用率、氮肥当季回收率及偏生产力随着氮肥用量的提高而显著降低。综合考虑提高玉米产量、效益和氮肥利用效率等方面的要求,在吉林省中部玉米主产区,适宜施氮量为172.9 kg/hm2。     

吉林省中部黑土区玉米氮肥效应研究

在吉林省中部地区黑土条件下,通过田间试验研究氮肥对玉米的增产效应和氮肥的利用效率。结果表明,施用氮肥处理产量极显著高于不施氮肥处理,但并不随施N量的增加而持续增加,当施N量增加至145 kg/hm2时,玉米产量最高,再增加施N量,其产量下降,符合二次曲线方程Y=ax2+bx+c。从施肥效益考虑,最大效益施N量为152.3～173.9 kg/hm2,获得玉米产量8 800～12 127 kg/hm2。玉米对氮肥的利用率随施N量的增加而降低。范家屯镇、陶家屯镇、万发镇3个试验点的施N量由90 kg/hm2增加至255 kg/hm2,其氮肥利用率分别由32.71%、58.95%和30.81%降低至14.52%、21.74%和11.16%。     

膜下滴灌水肥耦合对半干旱区玉米生长发育及产量的影响

在田间条件下,采用水肥一体化的施肥模式对覆膜玉米水氮耦合效应进行研究,明确水氮耦合对吉林省西部玉米生长的影响,提出最佳灌水量和施氮量。研究结果表明,水、氮在一定范围内配合表现出明显的正交互作用,促进玉米的生长发育;施氮量超过一定范围将产生负效应,对玉米的生长发育及产量起到一定的抑制作用。在吉林省西部施氮量280 kg/hm~2、灌水量500 mm为最佳水氮组合,玉米株高、叶面积指数、生物量与其他处理间存在显著性差异;产量最高,比不施氮处理增产36.1%。     

仙草“3414”肥料效应田间试验初报

通过对仙草不同施肥水平的田间试验,研究了武平县岩前镇仙草对氮、磷、钾的肥料效应,结果表明,合理施用氮、磷、钾肥对仙草的增产效应是钾肥氮肥磷肥。钾肥的增产量最大,每667m2增产179.3 kg,增产率32.7%;氮肥的增产次之,为163.2 kg,增产率28.9%;磷肥的增产最小,为147.8 kg,增产率25.5%。仙草每667m~2最佳施氮(N)、磷(P_2O_5)、钾(K_2O)量分别为12.59 kg、6.05 kg、15.68 kg,三要素比例为1∶0.48∶1.25;最佳经济产量每667m~2为723.92 kg。     

溶磷生物肥料在玉米上的施用效果及其对土壤、植株磷素效率的影响

通过田间试验、示范研究溶磷生物肥料在玉米上的施用效果及其对土壤、植株磷素效率的影响。结果表明,施入溶磷菌液玉米整个生育期磷肥利用率达21.75%～37.98%,植株从土壤吸收磷素养分的效率达10.94%。从植株磷素吸收效率分析,磷肥减量1/3处理与全量磷肥处理吸磷量无明显差异,随着磷肥施用量的增加植株吸收效率明显降低。溶磷生物肥在吉林省不同生态区域示范应用,可使化学磷肥用量减少1/3而产量均有所增加,在吉林省中部半湿润半干旱地区增产幅度为8.2%～11.7%,在西部干旱地区幅度为4.1%～8.3%,在东部湿润冷凉区增产幅度为5.6%～13.0%。溶磷生物肥料对不同生态区域的不同土壤类型有一定的环境适应性。     

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。     

Advances in Variable Rate Technology Application in Potato in The Netherlands

Precision agriculture is a farming management concept based on observing, measuring and responding to inter- and intra-field variability in crops. In this paper, we focus on responding to intra-field variability in potato crops and analyse variable rate applications (VRAs). We made an overview of potential VRAs in potato crop management in The Netherlands. We identified 13 potential VRAs in potato, ranging from soil tillage to planting to crop care to selective harvest. We ranked them on availability of ‘proof of concept’ and on-farm test results. For five VRAs, we found test results allowing to make a cost-benefit assessment. These five VRAs were as follows: planting, soil herbicide weed control, N side dress, late blight control and haulm killing. They use one of two types of spatial data: soil maps or biomass index maps. Data on costs and savings of the VRAs showed that the investments in VRAs will pay off under practical conditions in The Netherlands. Savings on pesticide use and N-fertilizer use with the VRAs were on average about 25%, which benefits the environment too. We foresee a slow but gradual adoption of VRAs in potato production. More VRAs will become available given ongoing R&D. The perspectives of VRAs in potatoes are discussed.     

我国高粱育种研究进展

对我国高粱育种的主要途径和研究方向进行了概述,针对目前高粱产量徘徊现象,提出了高粱超高产育种设想,并对其技术路线进行了探讨。     

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.     

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。     

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.