Evaluating SHOOTGRO 4.0 as a potential winter wheat management tool in the Czech Republic

Improving current cultural practices often involves more precise timing of the management activity based on crop development. Using crop simulation models to predict crop development and phenology has several problems. First, most existing models do not simulate sufficient developmental and phenological detail required to optimize selected management practices. Second, crop models normally emphasize the cultivars and conditions for the region in which they were developed, and may not generate satisfactory results when applied in new regions. Lastly, when users apply these models to new regions they often lack the specific data and knowledge of the model to adequately determine the crop parameters. Our objective was to assess whether the simulation model SHOOTGRO 4.0, which had the necessary level of developmental and phenological detail required for use as a management decision aid, could be easily and adequately parameterized to simulate winter wheat phenology and grain yield in the Czech Republic. We found that only a few parameters from the generic winter wheat cultivar used for the Central Great Plains in the USA needed to be changed, and the information needed to determine these few parameters were readily obtainable. The result was that the dates of anthesis and physiological maturity and final grain yield were predicted well at sites within the three major crop production regions of the Czech Republic. Sensitivity analysis also showed that the most sensitive management practices and initial conditions in SHOOTGRO are relatively easy to determine (e.g. sowing date, N fertilizer rate and timing, daily temperature), while it is not overly sensitive to those variables more difficult to determine (e.g. initial soil water in the profile). Based on this study, farmers and scientists needing wheat development information to increase the efficacy of their management practices can use SHOOTGRO 4.0 as a tool.     

限水条件下氮肥用量及施氮时期对冬小麦产量、土壤硝态氮含量的影响

在节水栽培条件下,研究了不同施氮量及氮肥施用时期对冬小麦产量、生育期间土壤硝态氮含量的影响。结果表明,冬小麦施氮处理产量均高于N0,N88.5 69处理产量最高,氮肥生理效率则随施氮量增加而显著降低。开花期以及成熟期各施氮处理0~100 cm土体硝态氮含量均明显高于N0,各生育期0~60 cm土层硝态氮含量均随施氮量增加而增加,开花期各处理2 m土体硝态氮含量达到最高值,成熟期20~60 cm土层相同施氮量(157.5,226.5kg/hm2)均表现为氮肥分次施用处理硝态氮含量高于一次性底施处理(N88.5 69>N157.5,N123 103.5>N226.5)。成熟期土壤硝态氮2 m土体累积量随施氮量增加显著增加,且等量氮肥分次施用显著高于一次性底施。     

The impact of variation in grain number and individual grain weight on winter wheat yield in the high yield potential environment of Ireland

Previous studies from regions that produce high proportions of global winter wheat have highlighted that difference in sink size influences the majority of variations in winter wheat yield. However, the potential for source limitation due to environmental differences in regions that consistently produce a large sink capacity (i.e. >20,000 grains/m²), such as Ireland, have not been widely studied. The aim of this study was to characterise the variation in growth pattern and yield components that contribute to variations in grain yield in regions of high yield potential, and to identify the periods of development that are most likely to influence yield in these regions. Monitor crops of winter wheat were grown at three sites with contrasting latitudes on the island of Ireland, during three growing seasons (2013–2015). Crops were assessed regularly for measurements of crop growth and development, including biomass accumulation, canopy development and light interception. Grain yield ranged between 10.7–15.8 t/ha at 15% moisture content, with a grand mean of 12.7 t/ha. Results indicated that variations in grains/m² had a larger effect on winter wheat yield than variations in individual grain weight. Variability in grains/m² was influenced by changes in spikes/m² more than the number of grains/spike. While spikes/m² at harvest was significantly related to the number of shoots/m² at GS59, no significant relationship was observed between the shoots/m² at the time of maximum tillers/plant and spikes/m² at harvest. Furthermore, a significantly negative linear relationship was observed between shoots/m² at the time of maximum tillers/plant and grains/spike. Therefore, high rates of tillering were not beneficial to yield formation in the majority of crops monitored. A strong effect of individual grain weight was observed at one site of the nine evaluated in the study, indicating that a partial source limitation of yield is possible in certain Irish environmental conditions. However, variations in grain yield of crops of winter wheat grown at different locations in Ireland in different seasons were primarily driven by variations in grain number, and therefore were generally sink-limited.     

冬小麦—夏玉米轮作体系优化施氮对土壤硝态氮的影响

为了建立小麦/玉米轮作体系下的作物营养诊断推荐施肥技术体系,确定最佳施肥方案,对不同施肥方式下每一季作物进行硝态氮、产量、施肥量进行观测。结果表明,不同的施肥处理对作物产量影响显著,优化施肥产量提高2.73%~6.39%。不施肥处理条件下,二、三季作物产量显著降低,四季作物减产幅度趋于平衡;长期优化施肥使0~60 cm土壤硝态氮含量维持在同一个水平,而长期习惯施肥则使土壤硝态氮含量有增高的趋势;长期不施肥使土壤硝态氮含量稳定在较低水平;优化施肥节约化肥36.84%~52.97%。上述三种施肥方式以优化施肥最佳。     

黄淮麦区高产小麦品种的产量结构及其生理基础的研究

研究了黄淮麦区具有不同产量潜力水平的小麦品种的产量结构及其相关生理基础。结果表明,随着小麦品种由低产型向高产型转变,每穗粒重,每穗粒数,千粒重,收获指数,生物产量均有所增加,其中以收获指数和每穗粒重所起的作用最大;在生理特征上,干物重呈现出拔节期递增、开花期递减、成熟期又表现递增的“Ｎ”型变化曲线,相对生长率的变化也呈同一趋势。旗叶净光合强度及叶绿素含量均呈递增趋势。开花期叶面积指数（ＬＡＩ）则呈     

北方冬麦区高肥区域试验品种产量性状分析与探讨

对北方冬麦区1983～1988年高肥区域试验的80个参试品种的产量性状进行相关与通径分析。结果表明,北部冬麦区和黄淮麦区北片参试品种的增产因素主要是穗粒重,其次是亩穗数;黄淮南片参试品种的穗粒重与亩穗数对产量的贡献几乎相等,亩穗数稍大于穗粒重。鉴于直线相关是有一定范围的,结合各片的生态条件及育种实践,认为培育400公     

种子大小对冬小麦繁殖体及产量的影响

采用大、小粒种子分别单种和大、小粒种子混合种植进行盆栽试验。研究表明：大粒种子形成的繁殖体较大,等级差异较小,产量较高;小粒种子形成的繁殖体较小,等级差异较大,产量较低;大小粒混值群的繁殖体其大小和差异变化不一,产量居中。     

Long term effects of tillage practices and N fertilization in rainfed Mediterranean cropping systems: durum wheat,sunflower and maize grain yield

Long term investigations on the combined effects of tillage systems and other agronomic practices such as mineral N fertilization under Mediterranean conditions on durum wheat are very scanty and findings are often contradictory. Moreover, no studies are available on the long term effect of the adoption of conservation tillage on grain yield of maize and sunflower grown in rotation with durum wheat under rainfed Mediterranean conditions. This paper reports the results of a 20-years experiment on a durum wheat-sunflower (7 years) and durum wheat–maize (13 years) two-year rotation, whose main objective was to quantify the long term effects of different tillage practices (CT = conventional tillage; MT = minimum tillage; NT = no tillage) combined with different nitrogen fertilizer rates (N0, N1, N2 corresponding to 0, 45 and 90 kg N ha⁻¹ for sunflower, and 0, 90 and 180 kg N ha⁻¹ for wheat and maize) on grain yield, yield components and yield stability for the three crops. In addition, the influence of meteorological factors on the interannual variability of studied variables was also assessed. For durum wheat, NT did not allow substantial yield benefits leading to comparable yields with respect to CT in ten out of twenty years. For both sunflower and maize, NT under rainfed conditions was not a viable options, because of the unsuitable (i.e., too wet) soil conditions of the clayish soil at sowing. Both spring crops performed well with MT. No significant N × tillage interaction was found for the three crops. As expected, the response of durum wheat and maize grain yield to N was remarkable, while sunflower grain yield was not significantly influenced by N rate. Wheat yield was constrained by high temperatures in January during tillering and drought in April during heading. The interannual yield variability of sunflower was mainly associated to soil water deficit at flowering and air temperature during seed filling. Heavy rains during this latter phase strongly constrained sunflower grain yield. Maize grain yield was negatively affected by high temperatures in June and drought in July, this latter factor was particularly important in the fertilized maize. Considering both yield and yield stability, durum wheat and sunflower performed better under MT and N1 while maize performed better under both CT and MT and with N2 rates. The results of this long term study are suitable for supporting policies on sustainable Mediterranean rainfed cropping systems and also for cropping system modelling.     

气候变化对北京地区小麦玉米两熟种植制度的影响

研究了北京地区小麦和玉米生产与气象条件的关系，并根据未来气候变化 的研究设计了气候情景，在此基础上讨论了未来气候化对小麦玉米一年二熟种植制度的影响。结果表明，温度升高对小麦和玉米生产有利，玉米产量的提高大于小麦；降水减少首先对小麦生产不利，当降水进一步减少时，对玉米生产也不利。     

雨养条件下植物生长调节剂对冬小麦根系生长和产量形成的调控研究

为了探讨雨养模式下植物生长调节剂协同调控冬小麦根系生长和产量形成的机理,在华北平原雨养条件下,研究烯效唑和矮壮素复配剂以及清水对照对冬小麦产量形成、群体数量和根系生长的影响。结果表明:植物生长调节剂处理显著提高冬小麦穗数和籽粒产量,但是对小穗数和穗粒数没有显著影响。植物生长调节剂可以促进冬小麦冬前分蘖,明显提高生育前期群体数量。植物生长调节剂处理下,冬小麦分蘖期单株根系根长和根表面积显著降低,但是冬小麦单株根直径、根条数、根重和根冠比显著增加。植物生长调节剂处理主要影响冬小麦分蘖期0~30 cm土层的根长密度和0~50 cm土层的根重密度,而对深层土壤中的根长密度和根重密度影响较小。植物生长调节剂可以协同调控冬小麦根系生长和分蘖形成,从而有利于塑造合理群体结构和提高产量。     

氮肥调控对小麦/玉米产量、氮素利用及农田氮素平衡的影响

为了实现小麦/玉米高产高效生产,采用田间小区试验方法,研究了不同氮肥管理措施对小麦/玉米产量、氮素利用及农田氮素平衡的影响。结果表明,小麦季在农民常规施肥的基础上适当减少追氮量不会对小麦产量产生明显影响,在施氮总量195 kg/hm2基础上配施调控剂处理小麦增产8.3%~24.6%,氮肥偏生产力、表观利用率和农学效率及氮肥贡献率均得到相应提高。在玉米季,以一次性基施适量氮肥同时配施抑制剂的氮肥管理方案为最佳,在施氮240 kg/hm2水平上与不添加抑制剂等氮量一次性基施和基追结合处理相比,增产幅度分别为7.4%~9.6%和13.9%~16.2%,氮肥贡献率、肥料偏生产力和农学效率亦得到显著提高;经过一个轮作周期后,农田土壤氮素盈余量为63.94~126.83 kg/hm2。在总施氮量435 kg/hm2的情况下,与单施尿素相比较,配施氮素调控剂的氮素盈余量降低了27.4%~44.2%,其中脲酶与硝化抑制剂配施效果最佳。但在总施氮量480 kg/hm2的情况下,即使施用了氮素调控剂,氮素平衡盈余率仍在20%以上,存在较大的环境风险。     

Low yield gap of winter wheat in the North China Plain

The yield gap (YG) between the potential yields (Yp) and the average on-farm yields (Ya) is an indicator of the potential improvement for crop production. Understanding how large the current gap is and how this gap has changed over the past few decades is essential for increasing wheat production to meet increased food demand in China. This paper describes a study conducted using an APSIM-Wheat model and farm-level crop yield to analyze the spatio-temporal distribution of the yield gap of winter wheat from 1981 to 2010 in the North China Plain. Nine varieties were calibrated and evaluated based on the data from 16 agro-meteorological experimental sites and then potential yields were estimated considering cultivar replacement. In addition, a trend pattern analysis of on-farm yields for the period 1981–2010 was conducted. Results revealed an estimated yield gap across the entire North China Plain region of 1140–6810 kg ha⁻¹, with a weight average of 3630 kg ha⁻¹ in 1981–2010. Expressed as a relative yield (yield gap % of potential yields), the range was 15–80%, and the weight average was 45%. Despite the negative effects of increasing temperature and decreasing radiation, the potential yields significantly increased by 45 kg ha⁻¹ per year due to cultivar improvement. On-farm yields increased even more notably because of new cultivar selection, increased fertilizer application and other management improvements, but were stagnating in 32.3% of wheat areas, located mainly in Hebei province, Shandong province, Beijing and Tianjin. The improvement of on-farm yields have substantially contributed to yield gap spatio-temporal variation. As a result, the yield gap decreased from 4200 kg ha⁻¹ (56%) in 1981–1990 to 3000 kg ha⁻¹ (35%) in 2001–2010 at a rate of −69 kg ha⁻¹ per year. However, yields stagnation will expand to the northern Henan province without cultivar potential productivity improving, where yield gap was close to or less than 20% of the potential yields and proved difficult to reduce. To further improve the total production of winter wheat in the coming decades, efforts should be paid to break the potential ceiling and reduce the yield gap by breeding higher yield variety and introduction of new agricultural technology.     

播期播量对不同穗型冬小麦群体及子粒产量的影响

为明确不同播期播量处理对两种穗型小麦群体结构和产量构成要素的影响,以大穗型品种山农23号和多穗型品种济麦22为材料,研究了小麦群体动态、花后叶面积指数、子粒灌浆进程及产量构成要素的变化规律。结果表明,10月10日播期处理有利于两个品种小麦群体的构建,延迟播期后,即使增大播量也不能获得高产。山农23号在延迟播期后,有效叶面积减少,子粒灌浆速率减慢,单位面积穗数和穗粒数降低,差异显著,加大播量后,穗粒数减少,千粒重降低;济麦22延迟播期后单位面积穗数和千粒重下降,加大播量后,单位面积穗数不升反降,花后叶片衰老加剧。本试验条件下,两个品种的最适播期均为10月10日,山农23号的适宜播量为180kg/hm ²,济麦22的适宜播量为105kg/hm ²。     

播种方式及追肥时期对寒地冬麦旗叶叶绿素荧光参数及产量的影响

在大田条件下,进行了播种方式和追肥时期的运筹对黑龙江冬小麦旗叶叶绿体荧光参数及产量影响的研究。结果表明,适量追肥有利于提高旗叶PSⅡ的潜在活性(Fv/Fo)、光化学的最大效率(Fv/Fm)、实际量子产量和光化学猝灭系数(qP),减小非光化学猝灭系数(qN),从而提高产量。其中,以在垄播条件下返青期追施75kg/hm2尿素+拔节期追施75kg/hm2尿素效果最好。     

不同施肥结构的增产效应和对小麦籽粒品质的影响

１３年的定位监测研究结果表明，不同施肥结构对小麦、玉米两熟制轮作的年产量影响明显，各处理总的产量趋势是：ＭＮＰＫ＞ＭＮＰ＞ＭＮ＞ＮＰＫ＞ＮＰ＞Ｍ＞Ｎ＞ｃｋ。基础地力的产量效应为３７．９％，肥料的增产效应为６２．１％；肥料增产效应中，化肥占７５．８％，有机肥占２４．２％，显示出化肥为主要增产途径；在化肥的增产效应中，Ｎ的增产效应为７０．６％，Ｐ为２３．５％，Ｋ为５．９％；以ＭＮＰＫ处理的产量和小麦籽粒蛋白质含量最高，这说明有机肥与无机肥配合施用，可使作物高产优质，土壤有机质含量得到提高。     

黄淮海地区冬小麦关键生育期不同灌溉水平对产量影响的模拟

研究黄淮海地区不同灌溉水平下冬小麦产量的变化规律,对于识别干旱对冬小麦产量的影响和制定合理的节水灌溉措施具有指导意义。基于DSSAT作物模型,参考各生育阶段的水分亏缺量以及当地的灌溉习惯,制定模型输入的不同处理的灌溉量,模拟分析近30年黄淮海灌溉冬麦区4个典型站点冬小麦关键生育期不同灌溉水平下,产量及产量构成的相对变化规律,并且以典型处理为例,探讨2个关键生育阶段减产的累积概率。结果表明,拔节至抽穗期的水分胁迫对冬小麦的产量影响最大,产量相对变化主要由水分胁迫引起单位面积粒数的相对变化引起。在重度干旱条件下,拔节至抽穗期胁迫造成中等程度减产概率约为灌浆期胁迫的2倍(山东兖州点除外);在河北石家庄和天津点,轻度和重度减产主要由拔节至抽穗期胁迫引起,而在山东兖州和河南新乡点,拔节至抽穗期及灌浆期胁迫造成轻度减产概率差别不大,但灌浆期重度干旱导致一定概率的重度减产。因此,在黄淮海冬小麦灌区偏南部,不但要加强拔节至抽穗期的灌溉措施,还应该注重灌浆期的干旱风险。     

应用15N研究小麦各部位氮素分配利用及施肥效应

应用同位素示踪技术通过对盆栽小麦的不同施肥处理,研究小麦不同部位对氮素肥料的分配利用规律,结果表明,小麦主茎穗籽粒的ＮＤＦＦ为２８．５９％,分穗籽粒的ＮＤＦＦ为２９．３０％,茎秆的ＮＤＦＦ为２６．０２％,根系的ＮＤＦＦ为３２．１６％,而土壤的ＮＤＦＦ仅为１．８８％。从氮肥的利用率分析,籽粒的氮肥利用率为１９．５５２％。茎秆的利用率为３．４９０％,根系的利用率为０．６７４％,氮肥的回收率平均为４１．     

夏玉米施氮量对后茬冬小麦土壤氮素供应与利用的影响

在冬小麦施氮144 kg/hm2的基础上,研究了夏玉米4个施氮量(0,90,180,270和360 kg/hm2)对后茬冬小麦生长期间土壤硝态氮含量变化、无机氮供应以及小麦氮素吸收与利用的影响。结果表明:与玉米不施氮(简称不施氮)相比,玉米施氮(简称施氮)0~200 cm土壤硝态氮含量在冬小麦生长期间显著增加,自冬小麦拔节起,0~40,0~130和0~200 cm 3层深的土壤硝态氮含量均随着玉米施氮量(简称施氮量)的增加而明显递增;与冬小麦播种时相比,不施氮0~130 cm土壤无机氮减少156 kg/hm2,施氮90 kg/hm2该层土壤无机氮富积41 kg/hm2,且富积量随着施氮量继续增加而递增;随着施氮量增加,冬小麦收获时的植株吸氮量和子粒氮素积累量均增加;当施氮量低于180 kg/hm2时,植物氮素积累量在不同施氮量之间无显著差异;当施氮量低于270 kg/hm2时,不同施氮量的子粒氮素积累量差异不明显。在本试验条件下,冬小麦子粒氮肥利用率随着施氮量增加而递增,但差异不显著。     

宽幅条播冬小麦水分利用与干物质积累、品质的关系及播种密度的调控研究

为明确冬小麦采用宽幅条播技术的增产及优质机理,于2017-2018年在黄淮海流域西部开展不同播种密度对宽幅条播冬小麦植株干物质积累量、水分利用效率及品质影响的研究。结果表明,播种密度为480万株/hm²时,提高了植株各阶段干物质积累量,增加了花前作物耗水量及生育期总耗水,显著提高了小麦产量,增幅达3.5%~16.2%,提高水分利用效率1.3%~11.8%;显著提高了籽粒蛋白质及其组分含量,总蛋白提高2.5%~11.8%,提高了谷/醇值;显著提高了淀粉、湿面筋和干面筋含量;提高了淀粉糊化特性,其中峰值黏度、保持黏度、最终黏度和糊化温度均达显著水平。较其他播种密度处理,小麦吸水率和面团形成时间以播种密度为240万株/hm²时最高;240万和480万株/hm²处理的面团稳定时间和粉质质量数高于其他处理;弱化度以360万株/hm²处理最高。宽幅条播冬小麦不同播种密度条件下,拔节―开花阶段耗水量与产量、籽粒蛋白质含量、谷/醇值、淀粉含量、湿面筋含量、干面筋含量和面筋指数均呈显著正相关。总之,宽幅条播冬小麦采用480万株/hm²播种密度有利于提高植株干物质积累量,增加花前作物耗水,提高产量、水分利用效率、籽粒营养品质和面粉加工品质,实现了冬小麦优质增产增效。     

精量播种条件下冬小麦的高产优质初探

为了研究冬小麦在小播量条件下的产量和品质表现，2001～2003年在北京安排了两个年度的秋播试验。参试品种有DS1号、临抗1号、冀麦30、鲁麦21和京411，京411是对照品种，播种量是22．5kg／hm^2。2001-2002年度，参试品种中临抗1号的最高产量达到6652．5kg／hm^2；2002-2003年度中，京411、鲁麦21、临抗1号、DS1号、冀麦30的平均产量分别达到8537．6，7403．7，7353．75，6836．25，6169．8kg／hm^2，品种的品质也较好。试验中，这些品种有正常的生育表现，较强的分蘖能力，旺盛的生理活动。在产量结构中，这些品种的单株穗数较多。