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1.
Advances in precision agriculture technology have led to the development of ground-based active remote sensors that can determine
normalized difference vegetation index (NDVI). Studies have shown that NDVI is highly related to leaf nitrogen (N) content
in maize (Zea mays L.). Remotely sensed NDVI can provide valuable information regarding in-field N variability and significant relationships between
sensor NDVI and maize grain yield have been reported. While numerous studies have been conducted using active sensors, none
have focused on the comparative effectiveness of these sensors in maize under semi-arid irrigated field conditions. Therefore,
the objectives of this study were (1) to determine the performance of two active remote sensors by determining each sensor’s
NDVI relationship with maize N status and grain yield as driven by different N rates in a semi-arid irrigated environment
and, (2) to determine if inclusion of ancillary soil or plant data (soil NO3 concentration, leaf N concentration, SPAD chlorophyll and plant height) would affect these relationships. Results indicated
that NDVI readings from both sensors had high r
2 values with applied N rate and grain yield at the V12 and V14 maize growth stages. However, no single or multiple regression
using soil or plant variables substantially increased the r
2 over using NDVI alone. Overall, both sensors performed well in the determination of N variability in irrigated maize at the
V12 and V14 growth stages and either sensor could be an important tool to aid precision N management. 相似文献
2.
Due to the nature of waterlogged fields used for rice production, we hypothesized that micro-elevation (micro-relief, micro-topography, or differences in elevation) is an important factor for site-specific management within rice fields. A 0.5-ha transplanted and weed-free paddy field was selected as the observation site, where there was micro-elevation in a range of 100 mm within the field. Combine-monitored grain yield and the surveyed micro-elevation were compared at 96 locations in the field, and 60 hand-taken grain samples were analysed for protein content. Grain yield and protein content showed significant negative correlations with micro-elevation (r=-0.50*** and -0.67***, respectively), indicating that at lower elevations, grain yield increased gradually with protein content. Spatial variation in yield and protein content was attributed to availability of water and nutrient uptake at locations with different micro-elevation. Therefore, micro-elevation is expected to be one of the important factors for managing spatial variation in a small paddy field. 相似文献
3.
《农业科学学报》2019,18(8):1701-1713
North China Plain(NCP) is the primary winter wheat production region in China, characterized by smallholder farming systems. Whereas the winter wheat average yield of smallholder farmers is currently low, the yield potential and limiting factors driving the current yield gap remain unclear. Therefore, increasing the wheat yield in NCP is essential for the national food security. This study monitored wheat yield, management practices and soil nutrient data in 132 farmers' fields of Xushui County, Baoding City, Hebei Province during 2014–2016. These data were analyzed using variance and path analysis to determine the yield gap and the contribution of yield components(i.e., spikes per hectare, grain number per spike and 1 000-grain weight) to wheat yield. Then, the limiting factors of yield components and the optimizing strategies were identified by a boundary line approach. The results showed that the attainable potential yield for winter wheat was 10 514 kg ha~(–1). The yield gaps varied strongly between three yield groups(i.e., high, middle and low), which were divided by yield level and contained 44 farmers in each group, and amounted to 2 493, 1 636 and 814 kg ha~(–1), respectively. For the three yield components, only spikes per hectare was significantly different(P0.01) among the three yield groups. For all 132 farmers' fields, correlation between yield and spikes per hectare(r=0.51, P0.01), was significantly positive, while correlations with grain number per spike(r=–0.16) and 1 000-grain weight(r=–0.10) were not significant. The path analysis also showed that the spikes per hectare of winter wheat were the most important component to the wheat yield. Boundary line analysis showed that seeding date was the most limiting factor of spikes per hectare with the highest contribution rate(26.7%), followed by basal N input(22.1%) and seeding rate(14.5%), which indicated that management factors in the seeding step were the most important for affecting spikes per hectare. For desired spikes per hectare(6.598×10~6 ha~(–1)),the seeding rate should range from 210–300 kg ha~(–1), seeding date should range from 3th to 8th October, and basal N input should range from 90~(–1)80 kg ha~(–1). Compared to these reasonable ranges of management measures, most of the farmers' practices were not suitable, and both lower and higher levels of management existed. It is concluded that the strategies for optimizing yield components could be achieved by improving wheat seeding quality and optimizing farmers' nutrient management practices in the NCP. 相似文献
4.
Effects of nitrogen fertilizer rates and ratios of base and topdressing on wheat yield, soil nitrate content and nitrogen balance 总被引：1，自引：0，他引：1
Application of nitrogen (N) fertilizer is one of the most important measures that increases grain yield and improves grain
quality in winter wheat (Triticum aestivum L.) production. Presently, there is a large number of investigations (experiments) in the field on different nitrogen fertilizer
application regimes. However, there still exists a serious problem of low nitrogen use efficiency, especially in winter wheat
high yield conditions: unsuitable nitrogen fertilizer, which often leads to lower yield and large accumulation of nitrate
in the soil, bringing a potential risk to the environment. In order to explore the optimal regime of nitrogen fertilizer application
suitable for environment and economy, a field experiment on the different rate and ratio of base and topdressing of nitrogen
fertilizer at the different growth periods of winter wheat was conducted. The field experiment was undertaken from the fall
of 2003 to the summer of 2004 in the village of Zhongcun in Longkou city, in the Shandong Province of China. The field experiment
with three repeats for each treatment was designed in a split-plot. The major plot was applied with urea at a nitrogen fertilizer
rate of three levels, namely, 0 kg·hm−2 (CK), 168 kg·hm−2 (A), and 240 kg·hm−2 (B). In the sub-plot, the ratios of base and topdressing nitrogen fertilizer at the different development periods of wheat
were 1/2:1/2 (A1 and B1), 1/3:2/3 (A2 and B2) and 0:1 (A3 and B3). Treatment B1 was under a regime used now in the local region.
It was found that the amount of N accumulation in plants had no significant difference between treatments applied with nitrogen
fertilizer. The grain yield and grain protein content were all elevated remarkably by applying nitrogen fertilizer compared
with those of treatment CK. There was no significant difference in the grain yield and grain protein content between A2 and
B2 and B3. However, when compared with those of B2 and B3, in A2 there was an increase in nitrogen use efficiency and residual
soil NO3
−-N and N losses were reduced. Under the condition of the same rate of nitrogen fertilizer, increasing topdressing nitrogen
rate clearly elevated the grain yield, grain protein content and nitrogen use efficiency. The results indicated that the residual
soil NO3
−-N in A1 and B1 accumulated higher than that of CK in 80–160 cm soil layers at the jointing stage, but that of A2 had no significant
difference compared with that of CK in 0–200 cm soil layers. At the maturity stage, more residual soil NO3
−-N was detected in B2, B3 and A3 than that in CK in 120–180 cm soil layers, which could not be absorbed by the roots of wheat,
but led to be eluviated easily. The amount of soil NO3
−-N accumulation in treatment A2 had no significant difference compared with that of treatment CK in the 100–200 cm soil layer.
In conclusion, A2, whose nitrogen fertilizer rate was 168 kg·hm−2 and the ratio of base and topdressing was 1/3:2/3, had a higher grain yield and grain protein content, and heightened N use
efficiency and minimized the risk of NO3
−-N leaching. This should be one of the most appropriate nitrogen fertilizer application regimes in wheat production in local
regions in China.
__________
Translated from Acta Ecologica Sinica, 2006, 26(11): 3661–3669 [译自: 生态学报] 相似文献
5.
明确不同种植密度对施氮条件下玉米灌浆期叶片光合特征的影响，对通过种植密度调控玉米个体光合作用与群体产量关系，实现玉米稳产丰产具有理论和实践指导意义。在甘肃河西走廊，通过3 a田间试验，以施氮360 kg/hm2(N360)和不施氮(N0)为主区，玉米种植密度75 000株/hm2(D1)、87 000株/hm2(D2)和99 000株/hm2(D3)为副区，研究施氮条件下玉米灌浆期叶片光合特征对不同种植密度的响应。结果表明，试区玉米灌浆期光合有效辐射和大气温度最大值出现在14:00，最小值出现在6:00，而空气相对湿度最大值出现在6:00，最小值出现在14:00。施氮能够显著增加玉米灌浆期叶片净光合速率(Pn)、叶片蒸腾速率(Tr)和气孔导度(Gs)，N360较N0在8:00-18:00的Pn平均增加19.5%~41.7%、Tr平均增加27.4%~44.1%、Gs平均增加27.4%~44.1%，但叶片胞间CO2浓度（Ci）显著降低；随着种植密度的增大，玉米灌浆期8:00―18:00的Pn、Tr、Gs呈降低趋势；N360D2与N360D1玉米灌浆期Pn差异不显著，显著大于其他处理。施氮水平和种植密度对玉米灌浆期8:00―16:00的叶片水分利用效率均无显著影响。N360较N0同时增加玉米籽粒产量和生物产量，但使玉米收获指数降低3.5%~5.3%；在N0中D2玉米籽粒产量大于D1和D3，而在N360中D2玉米籽粒产量与D3无显著差异，均显著大于D1；N360D2与N360D1的玉米籽粒产量无显著差异，均大于其他处理。总之，在施氮360 kg/hm2条件下，种植密度从75 000株/hm2增加到87 000株/hm2，能够使玉米灌浆期叶片光合速率保持在较高水平，提高收获指数，促进生物产量向籽粒产量的转化效率，获得最大籽粒产量。 相似文献
6.
Active remote sensing and grain yield in irrigated maize 总被引：2，自引：0，他引：2
Advances in agricultural technology have led to the development of active remote sensing equipment that can potentially optimize N fertilizer inputs. The objective of this study was to evaluate a hand-held active remote sensing instrument to estimate yield potential in irrigated maize. This study was done over two consecutive years on two irrigated maize fields in eastern Colorado. At the six- to eight-leaf crop growth stage, the GreenSeeker? active remote sensing unit was used to measure red and NIR reflectance of the crop canopy. Soil samples were taken before side-dressing from the plots at the time of sensing to determine nitrate concentration. Normalized difference vegetation index (NDVI) was calculated from the reflectance data and then divided by the number of days from planting to sensing, where growing degrees were greater than zero. An NDVI-ratio was calculated as the ratio of the reflectance of an area of interest to that of an N-rich portion of the field. Regression analysis was used to model grain yield. Grain yields ranged from 5 to 24 Mg ha?1. The coefficient of determination ranged from 0.10 to 0.76. The data for both fields in year 1 were modeled and cross-validated using data from both fields for year 2. The coefficient of determination of the best fitting model for year 1 was 0.54. The NDVI-ratio had a significant relationship with observed grain yield (r 2 = 0.65). This study shows that the GreenSeeker? active sensor has the potential to estimate grain yield in irrigated maize; however, improvements need to be made. 相似文献
7.
小麦组织氮的积累与分配及其相关性研究 总被引：1，自引：0，他引：1
对１７ 个澳大利亚小麦品种的组织氮研究表明：品种间组织氮含量存在不同程度差异。叶片、茎秆和植株氮积累峰值分别出现在抽穗初期、灌浆初期和灌浆末期;花期前氮素主要积累在叶片中,花期后籽粒成为氮素最主要的贮藏器官。植株氮积累（ｇ／ｍ ２）与干物质积累呈极显著正相关,而与其果糖积累、籽粒产量、籽粒蛋白质产量及含量无显著相关关系;植株氮含量（ｇ·ｋｇ－ １）与其干物质积累、果糖含量和籽粒产量均呈显著负相关,与籽粒蛋白质含量显著正相关。 相似文献
8.
Farmers account for yield and soil variability to optimize their production under mainly economic considerations using the
technology of precision farming. Therefore, understanding of the spatial variation of crop yield and crop yield development
within arable fields is important for spatially variable management. Our aim was to classify landform units based on a digital
elevation model, and to identify their impact on biomass development. Yield components were measured by harvesting spring
barley (Hordeum vulgare, L.) in 1999, and winter rye (Secale cereale, L.) in 2000 and 2001, respectively, at 192 sampling points in a field in Saxony, Germany. The field was stratified into
four landform units, i.e., shoulder, backslope, footslope and level. At each landform unit, a characteristic yield development
could be observed. Spring barley grain yields were highest at the level positions with 6.7 t ha−1 and approximately 0.15 t ha−1 below that at shoulder and footslope positions in 1999. In 2000, winter rye harvest exhibited a reduction at backslope positions
of around 0.2 t ha−1 as compared to the highest yield obtained again at level positions with 11.1 t ha−1. The distribution of winter rye grain yield across the different landforms was completely different in 2001 from that observed
in 2000. Winter rye showed the highest yields at shoulder positions with 11.1 t ha−1, followed by the level position with 0.5 t ha−1 less grain yield. Different developments throughout the years were assumed to be due to soil water and meteorological conditions,
as well as management history. Generally, crop yield differences of up to 0.7 t ha−1 were found between landform elements with appropriate consideration of the respective seasonal weather conditions. Landform
analysis proved to be helpful in explaining variation in grain yield within the field between different years. 相似文献
9.
太湖稻麦轮作区减施磷肥对土壤供磷和小麦吸收磷的影响 总被引：2，自引：1，他引：2
为了探究太湖稻麦轮作区土壤供磷能力,寻找适宜的减磷措施,通过田间减施磷肥试验,以稻麦季均施磷(PR+W)为对照,设置稻季施磷麦季不施磷(PR)、麦季施磷稻季不施磷(PW)、稻麦季均不施磷(Pzero)3种处理,于第7年测定土壤速效磷含量、梯度扩散薄膜技术(Diffusive Gradients in Thin films,DGT)提取态磷含量、小麦产量以及小麦磷吸收量,分析太湖稻麦轮作区减施磷肥对土壤供磷和小麦吸收磷的影响。结果表明:与PR+W处理相比,PW处理的土壤速效磷含量、小麦籽粒产量以及植株全磷含量均无显著降低;但PR处理显著(P0.05)降低了44.8%的土壤速效磷含量、32.8%的小麦籽粒产量以及27.9%的地上部植株吸收磷量。线性回归分析发现,利用DGT技术提取的磷与土壤速效磷有显著的正相关关系(P0.05,R2=0.42),且两者皆与小麦籽粒产量、地上部植株全磷含量及地下部植株全磷含量呈显著的正相关关系。可见,麦季施磷稻季不施磷的减磷措施能够保证土壤速效磷供应和小麦吸磷量,并维持小麦籽粒产量,但麦季不施磷的减磷措施会显著降低土壤速效磷含量、小麦吸磷量以及小麦籽粒产量,同时DGT提取磷可作为稻麦轮作系统土壤供磷与作物需磷动态关系研究的评价指标。 相似文献
10.
为优化玉米覆盖和灌溉制度并为其提供必要的理论依据,在河西绿洲灌区,通过田间试验研究玉米各生育时期内光合速率(P_n)、蒸腾速率(T_r)、气孔导度(G_s)、叶水势(W_p)等水分生理指标对覆膜比例(70%覆盖和100%覆盖)与灌水水平(低、中、高)的响应特征及其与籽粒产量的相互关系。结果表明,2种覆盖比例对玉米水分生理指标和籽粒产量的影响不显著,但灌水水平影响显著,两者的互作效应显著。70%覆盖条件下,中灌水水平处理玉米生育期平均P_n、G_s、叶片水分利用效率(WUE)较低灌水处理分别提高22.5%、21.1%和56.1%,较高灌水分处理别提高44.5%、4.5%和18.5%;生育期内平均T_r为高灌水水平最大,比中、低灌水水平分别增大21.1%和43.2%;生育期平均Wp则为中灌水水平最高,在大喇叭口期比低灌水提高19.6%,在灌浆期比高灌水提高12.1%。此外,70%覆盖结合中灌水处理的玉米籽粒产量最高,比相同覆膜比例下低、高灌水处理分别提高13.1%和9.1%,但收获指数较100%覆盖中灌水处理显著降低。玉米P_n、WUE及G_s与玉米籽粒产量呈极显著正相关(P0.01)。因而,70%覆盖结合中灌水水平能优化玉米生育期内各项水分生理指标,可作为该区玉米生产的推荐模式,从而实现节水与增产。 相似文献
11.
对宁夏黄灌区大豆农艺及产量性状的相关分析表明,株高与茎粗、底荚高度和主茎节数,生育时间与株高、主茎节数和百粒质量呈显著正相关;单株有效荚数与单株粒数、单株粒质量,单株粒数与单株粒质量、单位面积产量呈极显著正相关;单株粒数、单株荚数与百粒质量呈显著负相关。主成分分析确定4个主成分因子为产量、粒质量、茎粗和百粒质量。在所设计密度范围内有效荚数、单株粒数、粒质量和经济系数随密度的增大而减少。模拟产量回归方程表示为y=-1.962 6x2+6.639 2x+5.339 3(r2=0.846 5),解得密度在1.69×104/666.7m2时,可获得最高产量405.73kg/666.7m2。 相似文献
12.
为青海草地早熟禾(Poa pratensis L.cv.Qinghai)高产优质栽培和大面积栽培推广提供科学依据,在青海省祁连山试验田中采用正交设计,研究不同行距(A)、播种量(B)及施肥量(C)对青海草地早熟禾产量和光合特性的影响。结果表明:不同处理对青海草地早熟禾的地上植物量和光合特性均有一定影响。对地上植物量、种子产量、净光合速率影响的主次因素大小分别为:施肥量行距播种量,行距施肥量播种量,行距施肥量播种量;行距对地上植物量、种子产量、Pn影响极显著,对种子千粒质量、Tr影响显著;播种量对地上植物量影响极显著,对Tr影响显著;施肥量对地上植物量、种子产量、Ci影响极显著,对Pn、Tr影响显著。经分析得出青海草地早熟禾地上植物量丰产栽培最佳方案为30cm行距+4.5kg·hm~(-2)播种量+750kg·hm~(-2)施肥量;种子最佳方案为30cm行距+3kg·hm~(-2)播种量+450kg·hm~(-2)施肥量;施肥对青海草地早熟禾光合特性有改善作用。 相似文献
13.
Chanseok Ryu Masahiko Suguri Michihisa Iida Mikio Umeda Chungkeun Lee 《Precision Agriculture》2011,12(3):378-394
In this study, protein content (PC) of brown rice before harvest was established by remote sensing (RS) and analyzed to select
the key management factors that cause variation of PC using a GIS database. The possibility of finding out the key management
factors using GreenNDVI was tested by combining RS and a GIS database. The study site was located at Yagi basin (Japan) and
PC for seven districts (85 fields) in 2006 and nine districts (73 fields) in 2007 was investigated by a rice grain taste analyzer.
There was spatial variability between districts and temporal variability within the same fields. PC was predicted by the average
of GreenNDVI at sampling points (Point GreenNDVI) and in the field (Field GreenNDVI). The accuracy of the Point GreenNDVI
model (r
2 > 0.424, RMSE < 0.256%) was better than for the Field GreenNDVI model (r
2 > 0.250, RMSE < 0.298%). A general-purpose model (r
2 = 0.392, RMSE = 0.255%) was established using 2 years data. In the GIS database, PC was separated into two parts to compare
the difference in PC between the upper (mean + 0.5SD) and lower (mean − 0.5SD) parts. Differences in PC were significant depending
on the effective cumulative temperature (ECT) from transplanting to harvest (Factor 4) in 2007 but not in 2006. Because of
the difference in ECT depending on vegetation term (from transplanting to sampling), PC was separated into two groups based
on the mean value of ECT as the upper (UMECT) and lower (LMECT) groups. In 2007, there were significant differences in PC
at LMECT group between upper and lower parts depending on the ECT from transplanting to last top-dressing (Factor 2), the
amount of nitrogen fertilizer at top-dressing (Factor 3) and Factor 4. When the farmers would have changed their field management,
it would have been possible to decrease protein contents. Using the combination of RS and GIS in 2006, it was possible to
select the key management factor by the difference in the Field GreenNDVI. 相似文献
14.
以耐密植大豆品种铁豆119号和普通大豆品种辽豆11号为材料,设置8.0、14.0、20.0、26.0、32.0、38.0万株/hm2共6个种植密度,研究了不同种植密度对两个耐密性不同的大豆品种的产量性状及产量的影响。结果表明：耐密植品种铁豆119号的单株荚数、单株粒数和粒茎比均多于普通品种辽豆11号。随种植密度的增加,单株荚数、单株粒数减少,百粒重与种植密度关系不显著。耐密植品种铁豆119号的籽粒产量高于普通品种辽豆11号,随种植密度的增加,铁豆119号和辽豆11号的籽粒产量随种植密度增加而先增后减。在一定种植密度范围内是如此,超过了一定种植密度,会因倒伏带来减产,特别是普通品种。铁豆119号的适宜种植密度为32.0万株/hm2,辽豆11号为14.0万株/hm2,铁豆119号在种植密度变化时籽粒产量水平较辽豆11号稳定,说明适宜的增加种植密度可以提高大豆的籽粒产量,铁豆119号更适于密植栽培。 相似文献
15.
Proximal sensing, or obtaining information from close range, is a potentially useful tool for measuring the crop nitrogen status in real-time The objective of this study was to use proximal sensing of crop canopy spectral reflectance to evaluate variable-rate application of nitrogen in terms of its effect on yield and grain quality of winter wheat (Triticum aestivum L.). The sensor used was the Hydro-Precise N-Sensor System. Yield and grain quality maps were used as a basis for full-scale field trials with winter wheat growing under four nitrogen application treatments: a large (274 kg ha?1), recommended (167 kg ha?1) and two sensor-assisted (167 kg ha?1) rates. The recommended rate of 167 kg N ha?1 was given in a three-split application that meets the present Danish regulations to reduce nitrogen leaching. These require arable farmers to decrease nitrogen fertilizer application to 90% of the economically optimal level. Each farm’s baseline is calculated to take into account land quality, land allocated to each crop, and crop rotation. In the two sensor-assisted applications the Hydro-Precise N-Sensor System directs the last two of the three-split N application. Grain samples were collected directly from the grain flow of a combine harvester and analysed for protein, water and starch content. Grain data were related to and compared with combine yield meter registrations. Within the field, the variances of protein yield (698–1208 kg ha?1) and grain protein (9.5–13.4%) were large. The nitrogen application treatments affected the average protein content (10.5–12.3%) and grain yield (9.87–10.42 t ha?1) strongly. The grain starch content was largest in the uniform and sensor applied systems and smallest in the high nitrogen application treatment. Applying nitrogen according to the Hydro-Precise N-Sensor System did not increase grain yield or the protein and starch contents. Minor differences only were observed in both protein content and yield between uniform-rate N application and sensor-based variable-rate N application. 相似文献
16.
Effect of delayed sowing on grain number,grain weight,and protein concentration of wheat grains at specific positions within spikes 
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下载免费PDF全文 《农业科学学报》2023,22(8):2359-2369
Delays in sowing have significant effects on the grain yield, yield components, and grain protein concentrations of winter wheat. However, little is known about how delayed sowing affects these characteristics at different positions in the wheat spikes. In this study, the effects of sowing date were investigated in a winter wheat cultivar, Shannong 30, which was sown in 2019 and 2020 on October 8 (normal sowing) and October 22 (late sowing) under field conditions. Delayed sowing increased the partitioning of 13C-assimilates to spikes, particularly to florets at the apical section of a spike and those occupying distal positions on the same spikelet. Consequently, the increase in grain number was the greatest for the apical sections, followed by the basal and central sections. No significant differences were observed between sowing dates in the superior grain number in the basal and central sections, while the number in apical sections was significantly different. The number of inferior grains in each section also increased substantially in response to delayed sowing. The average grain weights in all sections remained unchanged under delayed sowing because there were parallel increases in grain number and 13C-assimilate partitioning to grains at specific positions in the spikes. Increases in grain number m–2 resulted in reduced grain protein concentrations as the limited nitrogen supply was diluted into more grains. Delayed sowing caused the greatest reduction in grain protein concentration in the basal sections, followed by the central and apical sections. No significant differences in the reduction of the grain protein concentration were observed between the inferior and superior grains under delayed sowing. In conclusion, a 2-week delay in sowing improved grain yield through increased grain number per spike, which originated principally from an increased grain number in the apical sections of spikes and in distal positions on the same spikelet. However, grain protein concentrations declined in each section because of the increased grain number and reduced N uptake. 相似文献
17.
施用生物炭对华北平原冬小麦土壤水分和籽粒产量的影响 总被引：1，自引：0，他引：1
为探究施用生物炭对华北平原农田土壤水分和冬小麦籽粒产量的影响,于2014—2017年在中国农业大学吴桥实验站设置施用生物炭7 200(BH)、3 600(BM)、1 800(BL)和0kg/hm~2(CK)4个处理。结果表明:与CK处理相比,BH、BM和BL处理3年平均增产分别为1.84%、7.28%和5.03%,并且降低了耗水量,水分利用效率分别提高5.96%～14.86%、9.42%～19.18%和5.96%～13.50%。同时施用生物炭增加了土壤含水量,与CK处理相比,土壤上层0～60cm BM处理增幅最大;中层60～120cm和下层120～200cm均为BL处理增幅最大(P0.05)。综上所述,施用生物炭可以增加土壤含水量和籽粒产量。统计分析表明,当施炭量分别为3 389～3 882和3 500～4 357kg/hm~2,0～60cm土层土壤含水量和籽粒产量均最高,且0～60cm土层土壤含水量与籽粒产量间存在显著的正相关关系(P0.05)。因此,施用生物炭可以增加土壤含水量,降低水分消耗,提高冬小麦籽粒产量和水分利用效率,在本试验条件下以施用3 000～4 500kg/hm~2为宜。 相似文献
18.
This study was conducted to determine whether, and if so how, the grain yield and nitrogen (N) requirements of hybrid rice transplanted as single seedlings are affected by no-tillage (NT) practices. A fixed field experiment was done at the Experimental Farm of Hunan Agricultural University in Changsha, Hunan Province, China, from 2004 to 2014. Grain yield and yield attributes (panicle number per m2, spikelet number per panicle, spikelet filling percentage, grain weight, total biomass, and harvest index) were evaluated as well as the N-use characteristics (total N uptake, internal N-use efficiency, and N requirements) of hybrid rice transplanted as single seedlings comparing NT with conventional tillage (CT). A significant finding was that there were no significant differences in grain yield, yield attributes, and N-use characteristics between CT and NT. Averaged across the 11 years, grain yield and N requirements were 9.51 t ha–1 and 20.2 kg t–1 under CT and 9.33 t ha–1 and 20.0 kg t–1 under NT, respectively. There were significant yearly variations in grain yield, yield attributes, and N-use characteristics observed under both CT and NT. The yearly variation in grain yield was related to simultaneous changes in spikelet number per panicle, grain weight, total biomass, and harvest index. Also, it was found that grain yield was positively correlated with internal N-use efficiency but negatively correlated with N requirements. It is concluded that grain yield and N requirements in hybrid rice when transplanted as single seedlings are not affected adversely by NT. The results of this study suggest that (1) compatible relationships among yield attributes can be established in hybrid rice that is transplanted as single seedlings, and (2) higher grain yield and higher N-use efficiency can be concurrently achieved in hybrid rice transplanted as single seedlings. 相似文献
19.
氮锌配施对冬小麦氮利用、产量及籽粒蛋白质含量的影响 总被引：2，自引：0，他引：2
以豫农202为材料,在大田条件下,研究氮锌配施对冬小麦不同生育时期氮吸收的影响,并探讨氮锌配施对冬小麦氮素利用率、产量以及籽粒蛋白质含量的影响.结果显示:氮锌配施能够促进冬小麦对氮素的吸收,与单施氮肥相比,氮锌配施的冬小麦在开花期、灌浆期吸收的氮素较高,成熟期小麦茎杆氮素含量较低而籽粒含氮量较高.氮锌配施能显著提高冬小麦氮素利用效率,施氮90、180和270 kg/hm2分别配施锌肥15和30 kg/hm2,与单施等量氮肥相比,氮肥表观利用率、氮肥生理利用率和氮素农学利用率分别提高4.8％～14.4％、1.4～9.8 kg/kg和0.6～6.4 kg/kg.氮锌配施比单施同量氮肥增产8.6％、10.5％ (N90),5.9％、14.6％ (N180)和5.9％、5.3％(N270),其中施氮180 kg/hm2配施锌肥30 kg/hm2的产量最高,显著高于其他处理.氮锌配施比单施同量氮肥提高小麦籽粒蛋白质含量,分别提高了8.3％、9.8％ (N90),11.4％、2.3％(N180)和6.9％、5.7％ (N270),其中N180Zn15的籽粒蛋白质含量最高,显著高于其他处理.N180Zn30在实现高产的同时可以显著提高氮肥利用率、氮肥生理利用率和氮素农学利用率,是比较好的氮锌配施组合. 相似文献
20.
PENG Yuan-ying PENG Zheng-song SONG Hui-xing XU Jia-shao 《中国农业科学(英文版)》2006,5(8):579-586
Researches on the relationship between photosynthesis and wheat yield have equally attracted the attention of both domestic and overseas scholars. No report has existed so far on the study of the effects of exogenous chromosomes on photosynthesis using the substitution series as materials. In this research, Triticum aestivum cv. Chinese Spring-Lophopyrum elongatum （Host） A.Loeve disomic substitution series were used as materials and flag leaves as the measuring position. And the CI-310 Portable Photosynthesis System made by CID Co. in USA was used to measure the net rate of photosynthesis of flag leaves in different developing stages and also to correlate photosynthesis with yield. Results showed that, out of the whole developing stages, at the anthesis stage the line of DS2Ee （2A） had the highest photosynthetic rate, therefore it could be used in improving process of the character of kernel number. The flag leaves of DS4Ee （4A, 4B, 4D） lines demonstrated certain high net photosynthetic rate from heading to grain filling stage, so it is valuable in the researh of promoting the yield index like 1 000-grain weight through improvement of the photosynthetic rate at grain filling stage. 相似文献