共查询到17条相似文献，搜索用时 562 毫秒
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冬油菜叶片SPAD的时空分布和氮素诊断的叶位选择 总被引：5，自引：0，他引：5
在大田试验条件下测定分析不同施氮水平冬油菜关键生育期SPAD值的时空分布特征,并对不同叶位及叶片不同部位SPAD值与叶绿素含量、叶片含氮量、植株全氮含量及籽粒产量之间的相关性进行分析,探求应用SPAD仪诊断油菜氮素营养状况的最佳测试叶位及位点。结果表明,油菜主茎顶部4片完全展开叶SPAD值存在显著空间差异,增加施氮量能显著提高各叶位叶SPAD值,同时减少叶位间的差异;六叶期、蕾薹期以顶4叶（TL4）SPAD值对氮素的敏感性最大,初花期和盛花期则最低。不同部位间,六叶期和初花期以中部SPAD值对施氮量增加的响应最敏感,盛花期则最迟钝,蕾薹期介于顶部和基部之间。综合分析认为,应用SPAD仪监测油菜氮素营养状况的最佳测试叶位和位点为主茎顶4片完全展开叶中部,该部位SPAD值与叶绿素含量、叶片含氮量和植株全氮含量之间的相关性均达到显著或极显著水平,满足氮素营养快速诊断的要求。 相似文献
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为探究适宜滴灌春小麦的氮素诊断方法,比较了硝酸盐反射仪、GreenSeeker手持光谱仪和SPAD-502叶绿素计三种氮素营养诊断施肥方法,分析不同生育时期测定指标与施氮量和产量之间的关系。结果表明,小麦茎基部NO-3含量、归一化植被指数(NDVI)和叶绿素含量相对值(SPAD)三种诊断指标与施氮量的拟合度均较高,与产量呈显著或极显著正相关,均可用于滴灌春小麦氮素营养诊断施肥。三种诊断指标与施氮量、产量的决定系数均表现为NDVISPAD茎基部NO-3含量。硝酸盐指标与施氮量的拟合精度较差,试验操作也相对繁琐;GreekSeeker手持光谱仪法表现最优,拟合精度高,操作方便,较适合用于滴灌春小麦的诊断施肥;SPAD值与施氮量的拟合度也较高,也可以作为一种氮素诊断参考方法。 相似文献
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无人机载多光谱遥感监测冬油菜氮素营养研究 总被引：1，自引：0，他引：1
为探索无人机搭载的多光谱相机对冬油菜冠层氮素营养状况监测的可行性,设置9种施氮水平的油菜试验小区,获取八叶期、十叶期、十二叶期和蕾臺期的多光谱影像,同步采样分析获取地上部生物量、叶片氮浓度和氮素积累量等氮营养指标。以宽波段植被指数和氮营养指标的相关性为基础,通过敏感性分析确定最佳指数,建立预测模型并进行精度验证。结果显示,宽波段植被指数与氮营养指标有极显著的相关性,不同生育期差异明显。其中,红光标准值和蓝光标准值在蕾臺期均与各氮营养指标相关关系最好,且敏感性因子的值小而稳定。进一步研究表明,三种指标均可用红光标准值和蓝光标准值建立的二次模型进行估计,决定系数R2均大于0.85,模型精度较高,说明无人机多光谱遥感能有效辅助冬油菜氮素营养监测。 相似文献
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春玉米叶片SPAD值与氮含量及产量的相关性研究 总被引：8，自引：1，他引：7
通过田间小区试验,研究不同时期玉米叶片SPAD值与叶绿素、氮含量及产量的相关性,确定SPAD值测定的最佳叶位及时期。结果表明,上位叶SPAD值对氮素的敏感时期顺序为12叶期>10叶期>8叶期;穗位叶SPAD值对氮素的敏感时期顺序为抽雄期>灌浆期>蜡熟期。叶片SPAD值可以很好的反映植株叶绿素和氮含量及产量水平,以某一特定叶片的SPAD值来诊断春玉米氮素营养状况和推荐追肥时期时,10叶期是较为理想的测定时期;作为早期预测玉米产量的指标,12叶期为最佳时期。测定SPAD值方法简便、快捷,不破坏叶片生长,可作为早期预测玉米产量的指标。 相似文献
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叶绿素仪(SPAD)在茶树氮素营养诊断中的适用性研究 总被引：6，自引：0，他引：6
测定叶片氮素含量是诊断茶树氮素状况的一项重要方法。本文利用盆栽试验,通过不同的供氮水平,研究了利用叶绿素仪(SPAD-502)进行茶树氮素营养快速诊断的适用性。结果表明,茶树新梢产量与氮素用量、成熟叶氮素含量之间呈线性加平台的反应关系,成熟叶的SPAD值与其全氮含量呈显著线性正相关,并与茶树产量存在着比较明显的关系拐点,初步显示SPAD可以较好地表征茶树的氮素营养状况,有可能作为快速诊断方法用于指导茶树施肥,但是还需要通过大田试验进行进一步验证。本文还探讨了测定位点、叶位、天气状况、田间原位或离体测定方式、表面清洗以及样本量等因素对SPAD测试精度的影响。 相似文献
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油菜氮素吸收效率的基因型差异及其与农艺性状的关系 总被引：6，自引：0，他引：6
采用土培试验,在不同供氮水平下,对50份甘蓝型油菜材料进行氮素吸收效率筛选。结果表明,不同油菜基因型的氮素吸收效率具有显著差异,氮素供应水平较高时不同基因型氮素吸收效率的变异更大;在油菜各器官生物量、各生育期地上部生物量、各器官生物量占总生物量的比例和各种农艺性状等指标中,根系生物量差异最大,表明根系生物量可能是评价油菜氮素吸收效率的重要指标。氮素供应水平较高时,氮高效基因型与氮低效基因型地上部生物量的差异从五叶期到成熟期呈增高的趋势,有效角果数、株高和第一个有效分枝高度差异显著;而施氮水平较低时,地上部生物量差异不显著,千粒重和每角粒数差异也不显著。供氮水平改变时,氮高效基因型的油菜生物量、籽粒产量和茎叶生物量占总生物量的比例及多个农艺性状指标都有显著变化,而氮低效基因型的相应指标变化则较小,表明氮高效基因型对氮素供应水平更敏感。 相似文献
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《中国油料作物学报(英文)》2020,5(3):114-120
To establish identification and evaluation methods of N (nitrogen) absorption and utilization of rapeseed (Brassica napus L.), difference of N nutrition efficiency (NNE) among rapeseed germplasms and relationship between NNE and plant traits under various N application rates were analyzed in this research. Pot cultivating experiments were conducted to investigate NNE with 3 N application rates in soil (0.05, 0.2 and 0.3 g/kg). A total of 12 rapeseed germplasms were planted, nitrogen absorption efficiency (NAE) and nitrogen utilization efficiency (NUE) in seedling stage, bolting stage, initial flowering stage, final flowering stage, and maturity stage were obtained. Results showed that bolting stage was the best period for NAE identification and evaluation. Low N application rate in soil (0.05 g/kg) was the best for NAE, and the indirect indexes were basal stem diameter, plant root dry weight and above ground plant dry weight. Maturity stage was the best period for NUE identification and evaluation. High N application rate in soil (0.3 g/kg) was the best for NUE, and indirect indexes were above ground plant dry weight and basal stem diameter. N application rates of 0.05 g/kg in soil was the best for nitrogen harvest index at maturity stage, and indirect indexes was number of pods per plant. Plant traits of rapeseed germplasms affected NNE. Higher basal stem diameter, plant root dry weight and above ground plant dry weight at bolting stage under low N application rate were important characteristics of N absorption in rapeseed. Higher above ground plant dry weight and basal stem diameter at maturity stage under high N application rate were important characteristics of N utilization. Higher number of pods per plant at maturity stage under lowe N application rate was an important characteristic of N harvest index. These results provided a reliable index for N management and provided theoretical basis for guiding rapeseed breeding. 相似文献
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《Plant Production Science》2013,16(4):317-322
AbstractHand-held SPAD meter can be used to evaluate the leaf nitrogen status of potato. For practical use, it is necessary to select a proper compound leaf, a proper leaflet within compound leaf and position of leaflet suitable for measurement. Therefore, field experiments were conducted in northern China in 2009 and 2010. The SPAD values, plant growth, N uptake of potato plants at tuber initiation and tuber bulking stages under different N supply levels, and final tuber yields were examined. The criteria for determining the most suitable leaf, leaflet and position within a leaflet are that the SPAD values show less variation at a given N supply level, and show a more sensitive response to different nitrogen levels. Our results showed that the coefficients of variance of SPAD values ranged from 8.7 to 25.9% with a leaf N concentration range of 2.1 to 3.8 gN 100 g-1 at tuber initiation stage, and 7.2 to 21.6% with leaf N concentration range of 0.96 to 1.26gN 100 g-1 at the tuber bulking stage. The SPAD values of the 4th compound leaf from apex were more stable and more sensitive to the nitrogen level than those of other leaves, suggesting that the 4th compound leaf is suitable for estimating the leaf N status using a SPAD meter. Within a compound leaf, the SPAD value of the top leaflet was more sensitivethan the other leaflets to nitrogen supply, whereas it was less stable, making it difficult to chose the leaflet for measurement. However, the top leaflet emerges and expands much earlier than the side leaflets, and should be better for SPAD value measurement. The SPAD measurements at the top point of the top leaflet of the 4th leaf demonstrated both less variation and higher sensitivity to nitrogen supply. Therefore, we conclude that the top point of the top leaflet of the 4th compound leaf is the best position for potato N status diagnosis using a SPAD meter. 相似文献
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《Plant Production Science》2013,16(1):81-92
AbstractPlant-based diagnosis is one of the most important methods to determine nitrogen (N) content of crops. Our objective was to establish the relationship between soil-plant analysis development (SPAD) values and N nutrition index (NNI) during the three developmental stages of rice and apply the SPAD meter as diagnostic tools for predicting grain yield response to N fertilization. We determined the SPAD values of four uppermost fully expanded leaves of two rice cultivars at six N fertilization levels at three growth stages and examined the relationship between SPAD values and NNI. The critical N concentration (Nc) was 5.31 W–0.5 in Xiushui63, and 5.38 W–0.49 in Hang43, where W is the total shoot biomass. The correlation between SPAD value and NNI varied with the leaf position, developmental stage, and variety. The lower leaf appeared to be more sensitive to the N level than the upper leaf in the response of biomass, and could be more suitable as a test sample for N status diagnosis, especially in the booting and heading stage. The dependence of grain yield on SPAD values of the fourth fully expanded leaf (L4) was significant at booting stage (R2L4 = 0.82** in 2011, R2L4 = 0.72** in 2012). Ratio of SPAD values of L4 to that in the N-saturated plot (RSPAD) (R2L4 = 0.92** in 2011, R2L4 = 0.77** in 2012) and NNI (R2 = 0.96** in 2011, R2 = 0.86** in 2012) at booting stage demonstrated a closer relationship with grain yield. 相似文献
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《Field Crops Research》1998,56(3):309-314
A two-location experiment was carried out at five to six nitrogen levels to study the relationship between chlorophyll-meter readings (SPAD values) and physiological or yield traits in short-season cotton. The results showed that there were highly significant (P<0.01) linear relationships between SPAD values and contents of both nitrogen and chlorophyll at each growth stage, and as well as with the daily increase in plant height during early flowering. The relationship between nitrogen concentration and SPAD was stronger when nitrogen was expressed on a leaf area (Na) rather than on a dry weight (Ndw) basis. Significant curvilinear relationships were found between SPAD values at various stages and photosynthetic intensity, lint yield, and total boll number per hectare, respectively. Furthermore, the linear regressions between SPAD values and N fertilizer levels were highly significant (P< 0.01), and before the boll opening stage, the slopes of these regressions were similar (0.040–0.041) at the two locations. These data provided evidence that the chlorophyll meter could be used to determine sidedress N requirements of short-season cotton before boll opening stage. Critical SPAD levels for maximum lint yield were established as 32.4, 33.1, 35.0, 43.55, and 39.7 at early flowering, flowering peak, boll forming, the beginning of boll opening and boll opening stages, respectively. It was also established that 24.2–25.0 kg ha−1 increase in N application should be necessary for each unit decrease in SPAD value below the critical level. 相似文献
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马铃薯氮素营养状况的SPAD仪诊断 总被引：6，自引：2，他引：4
以马铃薯品种克新1号为材料,研究了叶片SPAD值、叶片全氮含量、叶绿素含量以及块茎产量随供氮水平的变化规律及相互关系,旨在为使用叶绿素仪进行马铃薯无损伤氮素诊断和推荐施肥奠定基础。研究结果表明,从马铃薯苗期到块茎淀粉积累各个生育阶段叶片的SPAD测定值均与马铃薯叶片含氮量呈显著正相关关系。除苗期外,块茎形成期、块茎膨大期、淀粉积累期的马铃薯叶片含氮量和叶片SPAD值随土壤施氮量的变化均表现为线形加平台的模式。因此马铃薯块茎形成期后叶片的SPAD读数可揭示马铃薯的氮素营养状况。统计分析结果还表明,叶片SPAD值与块茎相对产量呈线形加平台的数量关系模式,据此确定了应用叶绿素仪SPAD-502进行马铃薯推荐施肥的SPAD临界值为块茎形成期47.3、块茎膨大期45.1、淀粉积累期40.2。 相似文献
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施氮水平及方式对玉米冠层NDVI、氮含量、叶绿素和产量的影响 总被引：4，自引：0，他引：4
在不同施氮水平和方式（不追肥和拔节期追肥）的田间试验条件下,采集并测定玉米不同生育期的冠层归一化植被指数（NDVI）、叶片SPAD值、叶绿素含量、叶片全氮含量和产量,研究不同氮素水平下各指标间的相互关系。结果表明,在不同生育期玉米叶片叶绿素含量和冠层NDVI值均随施氮量的增加而增大,追肥能显著提高叶片叶绿素含量和冠层NDVI值,灌浆期玉米叶片叶绿素含量增加幅度最大。冠层NDVI值与叶片氮含量、叶绿素含量的相关系数在各生育期均达到显著或极显著水平,叶片SPAD值与叶绿素含量的关系同冠层NDVI值一致,两者均可以对玉米进行氮素营养的诊断,但NDVI比SPAD更具有快速可靠的优点。追肥较不追肥处理有明显增产效果,平均增产幅度为29.23%,最大增幅为44.13%。 相似文献
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不同地力和施氮水平下水稻叶片SPAD值及产量的分析 总被引：3，自引：0，他引：3
以Q优6号为材料,分析了不同地力条件下不同施氮水平对水稻叶片SPAD值和产量的影响。结果表明,水稻产量与表观供氮量存在极显著的曲线相关,且当表观供氮量在575.27 kg/hm~2时,Q优6号产量较高;不同处理下各生育时期SPAD值大小顺序为抽穗期拔节期成熟期,且差异主要表现在抽穗期和成熟期;拔节期和抽穗期不同地力和施氮水平下水稻冠层4张叶片各自的差异主要表现在顶3叶和顶4叶上,可以利用两者的SPAD值作为参数进行氮素营养诊断;SPAD值与表观供氮量之间存在显著线性相关,且采用SPAD_(L3×L4/mean)进行拟合时效果更好,均达到极显著水平。获取水稻叶片SPAD值次级指标可以实现对田块速效氮含量的估计。 相似文献