基于星载SAR的冬小麦估产模型比较分析

旨在让农业部门等提前预知小麦产量,从而准确判断粮食生产形式,制订相关政策。应用2014年4月中旬和5月初星载合成孔径雷达(SAR)——RADARSAT-2各一幅,选择安徽省寿县和怀远县冬小麦产区,通过试验田产量和反演的雷达影像后向散射系数,建立冬小麦线性估产模型,在此基础上对2013和2014年估产模型精度进行比较。结果表明：通过星载SAR的同极化HH和交叉极化HV方式建立的估产模型对寿县涧沟镇冬小麦估产精度分别为68.37%和74.01%,对怀远县龙亢镇冬小麦估产精度分别为63.10%和69.10%。特别是针对倒伏区域冬小麦估产模型精度差异进行理论详细分析,指出冬小麦大面积倒伏区域,基于交叉极化(HV)估产模型精度高于同极化(HH)估产模型精度。最后指出将来可选择四极化SAR影像,针对不同的生长方式有针对性的选择不同极化方式进行估产。模型结果分析结论为将来冬小麦估产模型参数纠正及推广奠定基础和积累经验。     

Relevance of Osmotic and Frost Protecting Compounds for the Winter Hardiness of Autumn Sown Sugar Beet

The cultivation of autumn sown sugar beet (winter beet) is supposed to result in a marked yield increase compared with spring sown sugar beet. Although the importance of the growth stage reached before winter for the survival of autumn sown sugar beet has already been shown, it is not clear to which extent osmotic and potentially frost protecting compounds may contribute to winter hardiness. The study thus aimed to analyse the acclimatization process of sugar beet to low temperatures and to identify compounds which are important for survival of frost. Field trials with autumn sown sugar beet were conducted at eleven environments in Germany from 2009/10 to 2012/13, which were accompanied by greenhouse experiments with controlled temperature regimes. In the field trials, the survival rates after winter varied from 0 % to 99 %, but only in four environments differences between the five genotypes occurred. During acclimatization, betaine, glutamine, proline and raffinose were markedly accumulated and osmolality was enhanced. In particular betaine, amino acids and osmolality showed a positive correlation to the survival rate and were thus identified as potentially frost protecting substances for sugar beet. In contrast, raffinose and proline seem to act rather as stress indicators as they were negatively related to survival. Possible frost protecting substances were identified which can be used in breeding to improve the winter hardiness of sugar beet.     

旱地冬小麦缩行覆盖对土壤温、湿度的调控影响

为了确定在缩小行距的情况下,不同时间秸秆覆盖和不同覆盖量对土壤温度、湿度以及产量的影响,通过缩小种植行距、利用玉米秸秆整秆覆盖,采用裂区设计,主区为2个处理A1（冬后覆盖）、A2（冬前覆盖）,副区为不同覆盖量的4个的处理以及不覆盖对照进行试验。结果表明：在0~15 cm的土壤温度敏感层,冬前覆盖比冬后覆盖的增温明显,在整个生育期中不同覆盖量各层地温的变化曲线基本相同;0~40 cm的土壤含水量在生育期的变化趋势基本一致,冬前覆盖比冬后覆盖的土壤含水量平均高0.54%;冬后不同覆盖量处理的干物质的积累量在抽穗期—灌浆期明显高于冬前覆盖的各处理,而成熟期干物质的积累量冬前各处理要高于冬后覆盖;在产量表现最大的分别是A2B3(3669.12 kg/hm2)、A1B2(3654.79 kg/hm2)说明冬前覆盖量为6000 kg/hm2的增产效果明显。因此,利用玉米整秆覆盖,缩行增密,形成不同播幅和覆盖区宽度的种植模式,增温保墒,节水增产,提高水分利用率,是小麦增产稳产的一条有效途径。     

黄淮平原冬小麦霜冻害时空分布特点的研究

黄淮平原是中国小麦的主产区,而该区又是中国遭受霜冻害最严重的地区之一。霜冻害造成该区小麦产量减少,影响着中国的粮食安全问题,通过研究霜冻害在黄淮平原的时空分布特点,为小麦的种植提供科学的决策依据。选取小麦拔节期后日最低温度及距拔节期天数为指标,构造霜冻害灾度函数,利用该函数得到各个地区的冬小麦霜冻害灾度值,根据灾度值进行霜冻害的等级划分,计算各级霜冻害的发生频率,运用GIS得到霜冻害的时空分布特征。研究结果表明：在时间上,各级霜冻害的发生频率随年代呈减少趋势,轻霜冻害发生最为频繁,在各个年代频率值都在15%左右,重霜冻害次之发生频率约为6%左右,中霜冻害最轻;在空间上,该区的霜冻害多发地区以河南省和山东省霜冻害发生最为频繁且受灾较严重,其发生频率可达30%以上,最高可达70%。总体上北部地区霜冻害的发生频率高于南部地区。通过对冬小麦霜冻害时空分布特点的分析,为该区冬小麦霜冻害的防灾减灾以及冬小麦品种的选择提供一定的理论依据。     

Effect of Rht Alleles on the Tolerance of Wheat Grain Set to High Temperature and Drought Stress During Booting and Anthesis

Factorial pot experiments were conducted to compare the responses of GA‐sensitive and GA‐insensitive reduced height (Rht) alleles in wheat for susceptibility to heat and drought stress during booting and anthesis. Grain set (grains/spikelet) of near‐isogenic lines (NILs) was assessed following three day transfers to controlled environments imposing day temperatures (t) from 20 to 40 °C. Transfers were during booting and/or anthesis and pots maintained at field capacity (FC) or had water withheld. Logistic responses (y = c/1+e^{‐b(t ‐m)}) described declining grain set with increasing t, and t₅ was that fitted to give a 5 % reduction in grain set. Averaged over NIL, t₅ for anthesis at FC was 31.7 ± 0.47 °C (S.E.M., 26 d.f.). Drought at anthesis reduced t₅ by <2 °C. Maintaining FC at booting conferred considerable resistance to high temperatures (t₅ = 33.9 °C) but booting was particularly heat susceptible without water (t₅ = 26.5 °C). In one background (cv. Mercia), for NILs varying at the Rht‐D1 locus, there was progressive reduction in t₅ with dwarfing and reduced gibberellic acid (GA) sensitivity (Rht‐D1a, tall, 32.7 ± 0.72; Rht‐D1b, semi‐dwarf, 29.5 ± 0.85; Rht‐D1c, severe dwarf, 24.2 ± 0.72). This trend was not evident for the Rht‐B1 locus or for Rht‐D1b in an alternative background (Maris Widgeon). The GA‐sensitive severe dwarf Rht12 was more heat tolerant (t₅ = 29.4 ± 0.72) than the similarly statured GA‐insensitive Rht‐D1c. The GA‐sensitive, semidwarfing Rht8 conferred greater drought tolerance in one experiment. Despite the effects of Rht‐D1 alleles in Mercia on stress tolerance, the inconsistency of the effects over background and locus led to the conclusion that semidwarfing with GA‐insensitivity did not necessarily increase sensitivity to stress at booting and flowering. In comparison with effects of semidwarfing alleles, responses to heat stress are much more dramatically affected by water availability and the precise growth stage at which the stress is experienced by the plants.     

陇东半干旱地区冬季积温变化特征及对冬小麦的响应

为了解陇东半干旱地区环县冬季积温变化特征及其对冬小麦的影响,通过Mann-Kendell统计检验法、Pearson相关分析法等手段对冬季积温以及冬小麦发育期资料进行分析研究。结果表明：（1）冬季积温在近36年的变化过程中呈现出逐年上升趋势;Mann-Kendall突变检验发现,1990年为冬季积温突变的年份;Morlet小波变换分析得到在30~35年上冬季积温呈现出最为显著的周期变化规律;（2）通过对冬小麦发育期特征分析,发现冬小麦除了在分蘖期表现为推迟的状况,其他播种、出苗、三叶、越冬等发育期均表现为提前的变化特征;对冬小麦发育期与积温进行相关分析,相关系数均为负相关,表明大多数发育期提前1~5天;在冬季积温偏高的年份,冬小麦各发育期普遍提前4~14天;（3）对冬小麦物候间隔期的特征进行分析发现：冬小麦在播种—出苗、播种—分蘖、播种—越冬、播种—返青以及播种—抽穗期,间隔时间呈现出延长的变化特征;在播种—三叶、播种—起身、播种—拔节、播种—开花、播种—成熟期,间隔时间呈现出缩短的变化特征。     

Relationship between Prehardening, Photosynthetic Activity at Cold Acclimation Temperatures and Frost Tolerance in Winter Rape (Brassica napus var. oleifera). The Consequences for the Reliability of Frost Resistance Estimation under Controlled Conditions

The effect of prehardening (early stage of growth at moderate low temperatures (+12°C) during the day) on the reliability of frost resistance estimation in a controlled environment has been studied on three winter oilseed rape cultivars differing markedly in their field survival rate (Leo, Górczański and Idol). It has been also examined the relationship between the photosynthetic activity during the first stage of cold acclimation and the level of frost resistance observed in investigated cultivars. Presented results demonstrated that prehardening, which increases to a significant degree the effectiveness of the cold acclimation process, also increases the differences in cold hardiness between cultivars, and limits the magnitude of experimental errors made during frost resistance estimation under controlled conditions. In all studied cultivars, prehardening increases significantly the photosynthetic activity during cold acclimation. On the other hand, both in the prehardened and in the non-prehardened plants, no relation has been found between either gas exchange rates or chlorophyll 'a' fluorescence characteristics at low temperatures and cultivar ability for acclimation. Neither the existing differences in photosynthetic activity, nor the degree of photosynthetic apparatus acclimation to cold, which occurs during prehardening, are the factors responsible for the frost resistance variation observed between studied cultivars.     

Effect of Simulating Drought in Various Phenophases on the Water Use Efficiency of Winter Wheat

In Central Europe, drought is the most important limiting factor for autumn‐sown cereals. Due to the decline in groundwater, it is a priority to use less water‐demanding forms of crop production. Water use efficiency (WUE) can only be increased if cultivars with satisfactory water management traits are grown, so that they can exploit the water reserves of the soil even if drought occurs during the vegetation. Water consumption and water use efficiency of winter wheat genotypes were investigated in a model experiment carried out in a climate‐controlled glasshouse. The plants were grown either with optimum water supplies or with simulated drought in three phenophases, and measurements were made on the yield parameters, phenological traits and water use parameters of the plants. Substantial differences were observed between the water demands of the cultivars, and it was found that the later the phenophase in which drought was simulated, the greater the decline in water uptake. The analysis of WUE led to the conclusion that the WUE values of cultivars with short vegetation periods dropped to the greatest extent when water deficit was suffered at first node appearance, while cultivars with longer vegetation periods were more sensitive to drought during the heading and grain‐filling stages.     

Winter Hardiness, Frost Resistance and Vernalization Requirement of European Winter Oilseed Rape (Brassica napus var. oleifera) Cultivars within the Last 20 Years

Cultivars of European winter oilseed rape cultivated in the second half of the 1970s and in the mid-1990s were screened for their winter hardiness, frost resistance and vernalization requirement. A strong correlation between winter hardiness and frost resistance in both groups of rape has been noticed. Among oilseed rapes cultivated in the late 1970s, low erucic acid and particularly double zero cultivars were less winter hard than high erucic acid cultivars. Double zero cultivars were characterized by lower frost resistance and lower vernalization requirement. A significant correlation between vernalization requirement and both frost resistance and field survival has also been shown. Frost resistance of the 1990s (double zero) cultivars was higher than that of double low cultivars from the late 1970s. Their vernalization requirement was still small and did not correlate with either frost resistance or winter hardiness. It was concluded that reduction in the content of glucosinolates in the 1970s involved decrease in winter hardiness and vernalization requirement of cultivars. During the following 20 years winter hardiness of double low cultivars has been improved, but vernalization requirements have not changed. As a result no correlation between winter hardiness and vernalization requirement in contemporary canola cultivars has been observed.     

晋南冬麦区春霜冻发生特点及其对产量影响分析

为了明确晋南冬麦区春霜冻发生特点及对小麦的冻害影响,利用临汾市气象局1990—2015 年3 月下旬和4 月上、中旬日最低气温及日最低气温旬平均值资料以及2012—2015 年小麦区域试验产量资料,分析了晋南冬麦区春霜冻发生的特点及其对小麦产量的影响。结果表明：晋南冬麦区春霜冻发生频繁且严重,80%以上的年份都会受到春霜冻危害。3 月下旬的最低温度对当地小麦后期产量的影响不大,但平均日最低气温与后期产量成正相关。春霜冻冻害主要集中在4 月上、中旬。在春霜冻警戒期内4 月上旬的最低气温与后期产量显著或极显著正相关,平均日最低气温与后期产量正相关或显著正相关。4月中旬最低温度和平均日最低气温与后期产量均呈正相关或显著正相关。     

Effects of Temperature and Frost on Genotypes of Medicago truncatuh L. and Medicago aculeata L. from Contrasting Climatic Origins

The growth of M. truncatula and M. aculeata genotypes collected from sites of contrasting altitudes and winter temperatures was compared under different temperature regimes. Genotypes collected from mild winter environments produced more shoot dry matter, had higher leaf area and lower specific leaf weight than those from cold environments; however these effects were largely related to seed size for M. aculeata. Only genotypes from mild environments were responsive to temperature.
Frost tolerance of the genotypes was tested using a laboratory freezing test based on seedling survival. There was a relationship between frost tolerance and winter temperature at site of collection for M. aculeata , with the most frost tolerant genotypes coming from high altitudes. All genotypes of M. truncatula demonstrated low survival rates following frost damage. Genotypes from high altitudes represent a promising source for breeding for first tolerance with greater variation m M. aculeata than M. truncatula.     

土壤扩蓄增容肥对小麦产量及品质的影响

2012—2013年在陕西三原县（水地）和永寿县（旱地）进行土壤扩蓄增容肥应用效果试验,研究了土壤扩蓄增容肥对小麦产量、产量构成因素和品质的影响。结果表明,土壤扩蓄增容肥对冬小麦有极显著的增产作用。水地较对照净增产1304.06 kg/hm²,增产幅度为16.8%;旱地较对照增产224.70 kg/hm²,增产幅度为8.6%。同时,土壤扩蓄增容肥处理的水地小麦多个品质指标较对照显著降低,其中蛋白质含量降低4.2%,硬度降低2.2%,湿面筋含量降低4.6%,沉降值降低11.6%,面团流变学特性中除吸水率外均显著减少;但土壤扩蓄增容肥对旱地小麦品质指标无显著影响。     

猪场沼液灌溉冬小麦对土壤质量的影响

为了研究猪场沼液灌溉冬小麦后,对土壤有机质、全氮、全磷以及铜、锌等金属元素含量变化的影响程度,笔者通过田间试验的方法对规模化猪场沼液灌溉冬小麦进行研究,重点研究沼液利用对土壤质量和生态安全的影响。结果表明,沼液处理使表层土壤有机质增加达3.0 kg/hm2,全氮含量提高65%,土壤pH值下降0.4个单位,土壤铜、锌、铅、镉含量符合《小麦产地环境技术条件》NY/T 851-2004的要求。本研究结果仅说明沼液以大田灌溉方式利用在短期内不会造成土壤质量下降和土壤环境污染,长期灌溉的影响需进一步研究确定。     

江苏省冬油菜生育期内低温事件的年际变化及对产量的影响

为探讨气候变化对我国油菜生产带来的可能影响,选取江苏省地区52个气象站1961—2012年日气温资料及冬油菜产量逐年数据,采用M-K趋势检验探求冬春季节8种低温指数的变化趋势,并依托一阶差分法探讨低温指数与产量的数量关系。结果表明：（1）1961-2012年间省内大部分地区冬春季节低温事件的总天数、连续低温事件的场次、强度及持续性呈现出显著的减弱趋势;（2）不同类型低温指数中,FI1（越冬期日最低气温<-5℃的总天数）与CI4（蕾薹期连续日最低气温<0℃天气的最长持续时间）对冬油菜产量的负效应最为显著;（3）各站点产量对FI1及CI4敏感性分析表明江苏省北部地区冬油菜种植对低温灾害事件更为敏感;（4）1961-2012年间江苏大部分地区FI1及CI4的减少趋势给研究区冬油菜产量带来了一定幅度的增产。     

滨海盐渍麦田施用微生物菌肥的降盐效果及冬小麦长势响应

本文旨在探究滨海盐渍麦田施用微生物菌肥的降盐效果及冬小麦长势响应.选择黄河三角洲滨海盐渍麦田,布设不同种类生物产品、不同用量微生物菌肥的小麦田间试验,采集土壤盐分、小麦株高、SPAD值、冠层NDVI和小麦产量数据,以各处理间的对比分析及方差分析方法,系统分析微生物菌肥对盐渍麦田的降盐效果及其冬小麦长势响应.结果表明:不...     

Spring Freeze Effect on Wheat Yield is Modulated by Winter Temperature Fluctuations: Evidence from Meta‐Analysis and Simulating Experiment

Increasing climatic variability is projected to affect large‐scale atmospheric circulation, triggers and exacerbates more extreme weather events, including winter warming and more frequent extreme low temperatures in spring. Historical data from 1961–2000 indicate these temperature fluctuations may seriously affect grain yield of winter wheat crops. In this study, a field air temperature control system (FATC) was used to simulate the winter warming, spring cold and freezing events in the field experiment in 2010–2011 to explore their impacts on growth and yield of winter wheat. Eight elite wheat varieties released during 1961–2000 were included and four temperature scenarios were applied, including late spring freeze alone, winter warming + late spring freeze, early spring cold + late spring freeze and the normal temperature condition as control. Winter warming combined with late spring freeze significantly decreased tiller survival rate, leaf photosynthetic rate and leaf growth in wheat plants, and reduced the spike number and kernel number per spike, and the final grain yield. In contrast, the wheat plants experienced early spring cold had higher tiller survival rate, leaf photosynthetic capacity and sugar accumulation and improved tolerance to the late spring freeze, resulting in less yield loss, as compared with those without experiencing early spring cold. Both the meta‐analyses and the field experimental data demonstrated that the effects of later spring freeze stress on wheat yield were exacerbated by winter warming but were extenuated by early spring cold events. Therefore, it is important to consider the characteristics of temperature fluctuations during winter to spring for precise evaluation of climate change effects on wheat production.     

基于ETM植被指数和冠层温度差异遥感监测棉花冷害

 大范围地、及时地遥感监测棉花的冻害状况及损失对安排救灾、灾后评估有着现实的意义。利用2001年6月7日、8月10日和2000年8月7日ETM影像,结合农业灾害和农作物生长发育统计数据,通过植被指数变化和冠层温度差异对新疆沙湾2001年8月初棉花结桃时发生的冷害进行遥感监测。结果表明:与往年未遭受冷害的同期棉花植被指数相比,棉花植被指数NDVI绝对差值降低区域占67.8％,其中下降0～0.2占51％,下降大于0.2占17％,降低百分比处于0～20％。植被指数和温度图像散点图呈现显著负相关,相关系数－0.63。其中未受冷害影响,植被指数增加,长势较好的棉花冠层温度平均为26.4℃,植被指数未变化区域为27.6℃,植被指数降低较多,冷害程度较重区域冠层温度约为29.3℃,冠层温度差异显著。基于ETM遥感影像植被指数变化幅度和冠层温度差异可用于冷害程度区域划分。     

有机质包膜尿素对冬小麦产量和氮肥利用率的影响

此文利用盆栽试验研究了3类有机质包膜尿素对冬小麦的产量、氮肥利用率与农学效率、氮素生理效率与收获指数的影响。结果表明：在等氮量条件下,有机质包膜尿素可显著提高冬小麦产量和氮肥利用率。在含N 0.10 g/kg土和含N 0.20 g/kg土水平下,YU2（有机质包膜尿素2）处理较普通尿素分别增产12.7%和19.4%,氮肥的利用率分别提高14.8%和10.8%,效果最为显著。在含N 0.20 g/kg土水平下,与普通尿素相比,3类有机质包膜尿素不同程度的提高了氮肥的农学效率、氮素生理效率和收获指数,YU3（有机质包膜尿素3）对氮素生理效率和收获指数的影响最大,分别提高了0.83 kg/kg和2.56%;YU2处理对提高氮肥农学效率的效果最显著,在含N 0.10 g/kg土和含N 0.20 g/kg土水平下,每千克氮分别增产4.04 kg和3.64 kg小麦籽粒。     

气候变化对郑州市冬小麦适宜播种期的影响

为了探明气候变暖对郑州市冬小麦适宜播种期的影响,对郑州市1981-2010年间冬小麦冬前生长期内的正积温及其生长状况进行统计分析。结果表明：郑州市10-12月的正积温呈上升趋势,且与冬小麦冬前株高和分蘖数呈显著正相关,相关系数分别为0.720和0.495;同时1981-2010年间,稳定通过冬小麦适宜播种温度的日期呈推后趋势,2001-2010年以来稳定通过17℃的日期分别较1981-1990和1991-2000推后5天和6天,而稳定通过15℃的日期分别推后5天和4天。因此,初步认为郑州市冬小麦适宜播种期在10月中下旬。     

播种方式对旱区冬小麦产量及土壤水分、土壤温度的影响

针对甘肃省旱作农业区年降水量少、季节分布不均匀、冬小麦生产中春旱严重的问题,采用田间试验的方法,研究了5种不同播种方式对旱区冬小麦土壤温度、土壤水分、产量及水分利用效率的影响。结果表明:全膜覆土穴播方式能有效调控耕层的昼夜温差,减少冬、春季土壤水分的无效蒸发,增加土壤水分含量和孕穗期之前的土壤温度,提高了农田降水利用率和作物水分利用效率;全膜覆土穴播处理的产量可达4268.23kg/hm²,比露地高32.88%;水分利用效率为13.23kg/(hm².mm),比露地高21.97%。