Detection of nitrogen and phosphorus nutrient status in winter wheat using spectral radiance

Nitrogen (N) and phosphorus (P) are major limiting nutrient elements for crop production and continued interest lies in improving their use efficiency. Spectral radiance measurements were evaluated to identify optimum wavelengths for dual detection of N and P status in winter wheat (Triticum aestivum L.). A factorial treatment arrangement of N and P (0, 56, 112, and 168 kg N ha^‐1 and 0, 14.5, and 29 kg P ha^‐1) was used to further study N and P uptake and associated spectral properties at Perkins and Tipton, Oklahoma. A wide range of spectral radiance measurements (345–1, 145 nm) were obtained from each plot using a PSD 1000 Ocean Optics fiber optic spectrometer. At each reading date, 78 bands and 44 combination indices were generated to test for correlation with forage biomass and N and P uptake. Additional spectral radiance readings were collected using an integrated sensor which has photodiode detectors and interference filters for red and NIR. For this study, simple numerator/denominator indices were useful in predicting biomass, and N uptake and P uptake. Numerator wavelengths that ranged between 705 and 735 nm and denominator wavelengths between 505 and 545 nm provided reliable prediction of forage biomass, and N and P uptake over locations and Feekes growth stages 4 through 6. Using the photodiode sensor, NDVI [(NIR‐red)/(NIR+red)] and NR [(NIR/red)], were also good indices to predict biomass, and N and P uptake. However, no index was found to be good for detecting solely N and P concentration either using the spectrometer or photodiode sensor.     

Utilization of Existing Technology to Evaluate Spring Wheat Growth and Nitrogen Nutrition in South Dakota

Abstract

Sensor‐based technologies for in‐season application of nitrogen (N) to winter wheat (Triticum aestivum L.) have been developed and are in use in the southern Great Plains. Questions arise about the suitability of this technology for spring wheat production in the northern Great Plains. A field experiment was established in Brookings, SD, to evaluate the GreenSeeker Hand Held optical sensor (NTech Industries, Ukiah, CA) for predicting in‐season N status on three spring wheat cultivars (Ingot, Oxen, and Walworth) across five N treatments. Nitrogen rates were 0, 34, 68, 102, and 136 kg N ha^?1 applied preplant as ammonium nitrate. Sensor readings and plant biomass samples were collected at Feekes 6 and Feekes 10 growth stages. The sensor measures reflectance in the red and near infrared (NIR) regions of the electromagnetic spectrum. A normalized difference vegetation index (NDVI) was calculated. The ability of the sensor readings to predict biomass, plant N concentration, and plant N uptake for each sampling date was determined. In general, biomass, plant N concentration, and N uptake increased with increasing N rate for both sampling dates. Readings collected at Feekes 6 and Feekes 10 showed a significant relationship with plant biomass, N concentration, and N uptake for all varieties. Plant N uptake and NDVI resulted in a higher regression coefficients compared to biomass and plant N concentration for all varieties. Results suggest that existing sensor‐based variable nitrogen technology developed for winter wheat could be utilized in the northern Great Plains for estimating in‐season N need for spring wheat.     

Effect of row spacing,growth stage,and nitrogen rate on spectral irradiance in winter wheat

Soil reflectance affects spectral irradiance measurements taken in winter wheat at early stages of growth when percent cover is low. The objective of this study was to determine the critical percent vegetation coverage needed for forage nitrogen (N) uptake calibration with indirect spectral irradiance measurements. Two field experiments were conducted at Tipton and Perkins, OK in October 1996. The effect of row spacing (15.2, 19.0, 25.4, and 30.5 cm) and growth stage (Feekes 4 and 5) under various N fertilizer rates (0, 56, 112, and 168 kg N ha^‐1) on spectral irradiance measurements from wheat was evaluated. The normalized difference vegetative index (NDVI) was used to characterize wheat canopy irradiance. In general, NDVI decreased with increasing row spacing and increased with N fertilizer rate at Feekes growth stage 4. Row spacing and N rate were independent of each other since no significant interaction was found. High correlation (r=0.81–0.98) was observed between NDVI and vegetation coverage. Percent vegetation coverage was a good predictor of the other dependent variables including forage dry matter, and total N uptake, which could indirectly be determined using NDVI. The coefficients of variation (CV's) from NDVI values decreased with increasing vegetation coverage suggesting that less variable NDVI values (CV less than 10%) might be obtained from plots where vegetation coverage exceeds 50%.     

NITROGEN FERTILIZATION OPTIMIZATION ALGORITHM BASED ON IN-SEASON ESTIMATES OF YIELD AND PLANT NITROGEN UPTAKE

Current methods of determining nitrogen (N) fertilization rates in winter wheat (Triticum aestivum L.) are based on farmer projected yield goals and fixed N removal rates per unit of grain produced. This work reports on an alternative method of determining fertilizer N rates using estimates of early-season plant N uptake and potential yield determined from in-season spectral measurements collected between January and April. Reflectance measurements under daytime lighting in the red and near infrared regions of the spectra were used to compute the normalized difference vegetation index (NDVI). Using a modified daytime lighting reflectance sensor, early-season plant N uptake between Feekes physiological growth stages 4 (leaf sheaths lengthen) through 6 (first node of stem visible) was found to be highly correlated with NDVI. Further analyses showed that dividing the NDVI sensor measurements between Feekes growth stages 4 and 6, by the days from planting to sensing date was highly correlated with final grain yield. This in-season estimate of yield (INSEY) was subsequently used to compute the potential N that could be removed in the grain. In-season N fertilization needs were then considered to be equal to the amount of predicted grain N uptake (potential yield times grain N) minus predicted early-season plant N uptake (at the time of sensing), divided by an efficiency factor of 0.70. This method of determining in-season fertilizer need has been shown to decrease large area N rates while also increasing wheat grain yields when each 1m² area was sensed and treated independently.     

Use of spectral radiance for correcting nitrogen deficiencies and estimating soil test variability in an established bermudagrass pasture

The use of variable rate technology has become increasingly popular for applying plant nutrient elements. The most widely used method for determining variable fertilizer rates is presently based on soil testing and yield mapping. Three field studies (Bumeyville 1995, Burneyville 1996, and Ardmore 1996) were initiated in established Midland bermudagrass [Cynodon dacrylon (L) Pers.] pastures to determine the relationship between spectral radiance at specific wavelengths with forage nitrogen (N) removal and biomass, and to determine field variability of soil test parameters. Variable N (applied to 1.5 × 2.4 m subplots within 2.4 × 45.7 m main plots), fixed N and check treatments were evaluated at each location. Spectral radiance readings were taken in the red (671±6 nm), green (570±6 nm), and near infrared (NIR) (780±6 nm) wavelengths. The normalized difference vegetation index (NDVI) was calculated as NIR‐red/NIR+red. Variable N rates were applied based on NDVI. The highest fixed variable N rate was set at 224, 336, and 672 kg N ha^‐1 for Burneyville, 1995, 1996, and Ardmore, 1996, respectively. At Bumeyville, soil samples were collected in all variable rate plots (1.5 × 2.4 m) and analyzed for various soil test characteristics. NDVI, red, green, and NIR spectral radiance readings were correlated with bermudagrass forage N removal and yield. Correlation of forage yield and N removal with red, NIR, and NDVI were best with maximum forage production, however, when forage production levels were low correlation decreased dramatically for the red wavelength compared with NIR and NDVI. Forage yield and forage N removal in variable rate treatments increased when compared to the check while being equal to the half‐fixed and fixed rates where higher N rates were applied. Also, variability about the mean in variable rate plots was significantly lower than half‐fixed and fixed rates which supports adjusting N rates based on indirect NDVI measurements. Variable N rate plots reduced fertilizer inputs by 60% and produced the same yield as fixed rate plots, while fixed and half‐fixed rates did not increase N content in the forage over that of the variable rate treatment. Soil sample data collected from small consecutive plots (<4 m²) was extremely variable indicating that intense sampling would be needed if variable fertilizer application were to be based on soil test results.     

RED EDGE AS A POTENTIAL INDEX FOR DETECTING DIFFERENCES IN PLANT NITROGEN STATUS IN WINTER WHEAT

Under certain conditions normalized difference vegetative index (NDVI) has low sensitivity; therefore red-edge position (REP) has been tested as an alternative vegetative index. The objective of this study was to determine if REP could be useful for detecting differences in N status for winter wheat compared to NDVI. A spectrometer, and the SPAD meter were used to measure N status. Sensitivity to plant N response and different growth stages was found for NDVI and REP, but NDVI sensitivity tended to decrease as N rate increased and REP sensitivity tended to increase with increased N rate and advancing growth stage. Both NDVI and REP were linearly correlated at all growth stages (r2 = 0.85). REP and SPAD meter readings were highly correlated (r2 = 0.62) as were NDVI and SPAD (r2 = 0.56). Overall, REP and NDVI sensitivity at high plant biomass were similar for winter wheat.     

In-Season Prediction of Nitrogen Use Efficiency and Grain Protein in Winter Wheat (Triticum aestivum L.)

In a 3-year study, grain yield, nitrogen use efficiency (NUE), and grain protein (GP) were evaluated as a function of rate and timing of nitrogen (N) fertilizer application. Linear models that included preplant N, normalized difference vegetation index (NDVI), cumulative rainfall, and average air temperature from planting to sensing (T-avg) were evaluated to predict NUE and GP in winter wheat. GreenSeeker readings were collected at Feekes (F) 3, 4, 5, and 7 growth stages. Combined with rainfall and/or T-avg, NDVI alone was not correlated with NUE. However, NDVI and rainfall explained 45% (r² = 0.45) of the variability in GP at F7 growth stage. Preplant N, NDVI, rainfall and growing degree days (GDD) combined explained 76% (r² = 0.76) of the variability in GP at F3. Mid-season climatic data improved the prediction of GP and should therefore be considered for refining fertilizer recommendations when GP levels are expected to be low.     

Optimum N concentration in winter wheat grown in the coastal plain region of Virginia

Abstract

Limited information is available on optimum N levels in winter wheat (Triticum aestivum L.), particularly at higher yield levels. Three experiments were conducted in the Coastal Plain region of Virginia where N was applied at rates of 0, 67, 90 and 112 kg/ha to Wheeler, Mc Nair 1003 and Coker 747 soft red winter wheat varieties. Yields ranged from 2.33 to 5.83 Mg/ha in the study. Nitrogen fertilization increased yield up to the 67 kg/ha rate and increased N concentration in the plant tissue up to 67 or 112 kg of N/ha, depending on variety. Optimum N concentration, i.e., N concentration at maximum (100%) yield for Wheeler, Mc Nair 1003 and Coker 747, over the three experiments, was 4.54%, 4.52% and 4.81%, respectively, for entire above‐ground plant samples collected at Feekes growth stage 4 and 4.72%, 4.73% and 4.44% for flag leaf samples collected at Feekes growth stage 10. A N sufficiency range of 4.00–5.00% is suggested for use for the plant parts sampled for both growth stages.     

不同生育期冬小麦光谱特征对叶绿素和氮素的响应研究

研究测定了不同施氮水平条件下冬小麦冠层在七个典型生育期叶片叶绿素、地上部分全氮含量以及冠层光谱,分析了单波段反射率、可见光和近红外波段组合而成的归一化植被指数(NDVI)、比值植被指数(RVI)与相应时期叶片叶绿素和地上部分全氮含量的相关性。结果表明,施氮量增加,两个农学参量、冠层近红外波段反射率都随之增加,但当施氮量增加到300kg hm-(2一次性施入)时,上述各项指标均降低;整个生长期中孕穗期在近红外区域反射率最高,与可见光波段反射率相差最大;除分蘖期外,其它时期单波段510nm～1100nm反射率、NDVI、RVI与叶绿素和全氮含量显著相关,植被指数的相关性较单波段高,且从分蘖期到乳熟期,相关性逐渐增强;整体来讲,可见光中560nm、660nm和近红外760nm、1100nm和1200nm组合的NDVI在各生育期与两个农学指标的相关性较好,选择NDVI(560,760)可以准确拟合叶片叶绿素和地上部分全氮含量。     

Influence of sulfur on growth and nutrient composition of soft red winter wheat

Sulfur (S) deficiencies in soft red winter wheat (Triticum aestivum L.) result in reduced yields and inferior grain quality. Diagnosis of S deficiency has been unreliable since soil testing does not accurately measure available soil S, and tissue S concentration varies with plant age. In order to establish more reliable guidelines for determining S deficiency in winter wheat we used nutrient solution culture to provide uniform conditions for determining the effect of tissue S content on dry matter accumulation and nutrient uptake. The critical level of S for 90% of maximum growth in winter wheat seedlings (Feekes scale 1 with 5 leaves) was calculated at 1.4 g kg^‐1 using a modified Mitscherlich model. Root growth was less sensitive to low S levels than top growth which may reduce the effect of S deficiency in the field. Concentrations of N, Mg, Fe, and Cu in the plant tissue increased with increased S concentration. An N/S ratio of greater than 22 was associated with reduced growth. Our results suggest that if care is taken in standardizing the plant age when sampling early diagnosis of S deficiency could be based on total S analysis.     

Winter wheat fertilizer nitrogen use efficiency in grain and forage production systems

Abstract

Nitrogen use efficiency (NUE) is known to be less than fifty percent in winter wheat grain production systems. This study was conducted to determine potential differences in NUE when winter wheat (Triticum aestivum L.) is grown strictly for forage or grain. The effects of different nitrogen rates on plant N concentrations at different growth stages and on grain yield were investigated in two existing long‐term winter wheat experiments near Stillwater (Experiment 222) and Lahoma (Experiment 502), OK. At both locations in all years, total N uptake was greater when wheat forage was harvested twice (Feekes 6 and flowering) compared to total N uptake when wheat was grown only for grain. Percent N content immediately following flowering was much lower compared to percent N in the forage harvested prior to flowering, indicating relatively large losses of N after flowering. Averaged over locations and years, at the 90 kg N ha^?1 rate, wheat produced for forage had much higher NUE (82%) compared with grain production systems (30%). While gaseous N loss was not measured in this trial, the higher NUE values found in the forage production systems were attributed to harvesting prior to anthesis and the time when plant N losses are known to be greater.     

长期定位施肥条件下作物光谱特征及养分吸收量预测

为了明确不同施肥条件下典型生育期冬小麦和夏玉米冠层光谱特征差异,该研究以长期定位施肥试验为研究对象,在确定典型生育期作物冠层光谱反射率与收获期作物地上部分主要养分吸收量相关性的基础上,建立收获期作物主要养分吸收量预测模型。结果表明,可见光波段相似生育期夏玉米冠层光谱反射率与冬小麦相近,但在近红外区域平均高于冬小麦8.42%。生育中期2种作物秸秆、籽粒及地上部分氮(N)、磷(P)、钾(K)吸收量与冠层光谱反射率在可见光波段普遍呈极显著负相关关系,在近红外波段呈极显著正相关关系。全生育期夏玉米冠层光谱反射率与作物吸氮量的相关系数在可见光波段基本持平,但在近红外波段平均高于冬小麦0.4152。全生育期夏玉米冠层反射率与地上部分吸磷量的相关系数在可见光波段和近红外区域较冬小麦平均分别低0.3621和0.2072。全生育期夏玉米冠层光谱反射率与地上部分吸钾量相关系数在可见光波段平均低于冬小麦0.1270,在近红外波段高于冬小麦0.0341。除夏玉米吸磷量外,基于冬小麦和夏玉米典型生育期冠层光谱反射率建立的模型均可准确预测收获期作物主要养分吸收量,且对冬小麦养分吸收量的预测精度略高于夏玉米,该结论可以为黄淮海地区冬小麦和夏玉米的长势监测和肥料管理提供科学依据。     

OPTIMUM FIELD ELEMENT SIZE FOR MAXIMUM YIELDS IN WINTER WHEAT,USING VARIABLE NITROGEN RATES

The resolution at which variability in soil test and yield parameters exist is fundamental to the efficient use of real-time sensor-based variable rate technology. This study was conducted to determine the optimum field element size for maximum yields in winter wheat (Triticum aestivum L.), using variable nitrogen (N) rates based on sensor readings. The effect of applying N at four different resolutions (0.84, 3.34, 13.38, and 53.51 m²) on grain yield, N uptake and efficiency of use was investigated at Haskell, Hennessey, Perkins, and Tipton, Oklahoma. At Feekes growth stage 5 an optical sensor developed at Oklahoma State University measured red (670 ± 6 nm) and near-infrared (NIR, 780 ± 6 nm) reflectance in each subplot. A normalized-difference-vegetative-index (NDVI) was calculated from the sensor measurements. Nitrogen was applied based on a NDVI–N rate calibration. Nitrogen rate, yield, N uptake, and efficiency of use responses to treatment resolution and applied N fertilizer differed in the 3 years of this experiment. In the first year, no significant influence of resolution on N rate, yield, N uptake, or efficiency of use was observed, likely a result of a late freeze that drastically reduced yields. In the second year of the experiment, there was a trend for a lower N rate and a higher efficiency of use for the 0.84 m² resolution. In the third year of this study, there was a trend for a higher yield and a higher efficiency of use for the 53.51 m² resolution at both sites. In general, the finer resolutions tended to have increased efficiency of use in high yielding environments (>2300 kg ha^?1), and decreased yields in low yielding environments. This study indicates that application of prescribed fertilizer rates based on spatial variability at resolutions finer than 53.51 m² could lead to increased yields, decreased grower costs, and decreased environmental impact of excess fertilizers.     

Sap test to determine nitrate‐nitrogen concentrations in aboveground biomass of winter cover crops

Abstract

In the San Luis Valley of south central Colorado, winter cover crops (WCC) are used to reduce soil erosion and scavenge residual soil‐N. Some San Luis Valley farmers are beginning to use WCC as a source of over‐winter or early‐spring grazing. Common WCC used by farmers, wheat (Triticum aestivum L.) and rye (Secale cereale L.) are reported to accumulate high levels of nitrate nitrogen (NO₃ ^‐‐N) in aboveground biomass that can be toxic to animals. Evaluation and calibration of a quick Cardy Meter² Sap Test (CMST) for determination of NO₃ ^‐‐N status in the field will facilitate the management of these WCC. Field and growth chamber studies were conducted to correlate the CMST with laboratory procedures and with plant and soil parameters. In field and growth chamber studies, the CMST was correlated with standard dry tissue NC₃ ^‐‐N laboratory analysis (P<.001) and with soil inorganic N content (P<.05). These field and growth chamber studies show that the CMST can be a tool in helping farmers identify fields where WCC aboveground biomass is accumulating potentially toxic levels of NO₃ ^‐‐N. Additionally, plant parameters such as nitrogen uptake, biomass, and grain yield of WCC grown under growth chamber conditions were correlated with the CMST readings conducted at the growth stage, Feekes five (P<.05). The growth chamber results suggest that if WCC are grown for grain production, the CMST can help identify the needs for additional nitrogen (N) fertilizer application at Feekes five.     

利用新型光谱指数改善冬小麦估产精度

基于冬小麦返青期至乳熟期8次采样的地面光谱数据和收割时的产量数据,首先,利用光谱反射率与产量进行了统计分析,可见光波段的光谱反射率与产量在起身后期才达到稳定的显著负相关水平;近红外波段的光谱反射率与产量在所有生育期都表现出稳定的显著正相关;短波红外波段的光谱反射率与产量在进入灌浆期后才达到稳定的显著负相关水平.其次,根据冬小麦冠层光谱的波形特征,利用近红外波段890 nm反射峰、980 nm和1 200 nm两个弱水汽吸收谷、短波红外1 650 nm和2 200 nm反射峰,设计归一化差值光谱指数,并与冬小麦产量进行相关分析,结果表明:利用上述波段组合定义的归一化差值光谱指数与产量在各个生育期都达到了显著或极显著相关水平,而归一化差值植被指数(NDVI)与产量间的相关在营养生长阶段不显著.最后,以(890 nm,1200 nm)弱水汽吸收光谱指数为例,建立了各个生育期的产量预报模型,为实现冬小麦营养生长期长势监测与更早、更可靠的产量预报提供了依据.     

基于夏玉米光谱特征的叶绿素和氮素水平及氮肥吸收利用研究

本文首先分析不同施 N 水平条件下夏玉米冠层在6个典型生育期的光谱特征曲线,然后计算了可见光和近红外波段光谱反射率组成的归一化植被指数(NDvI)及相应时期叶片叶绿素含量和地上部分全N含量2个重要指标以及孕穗期冠层NDVI和几个N肥吸收利用效率的相关性.结果表明,孕穗期冠层光谱反射率在近红外区域反射率最大,且其可见光和近红外区域反射率差异最大:从苗期到孕穗期,NDVI和叶绿素、全N含量的相关性逐渐增强,到抽雄期减弱,灌浆期又有所增强;整体来讲绿色归一化植被指数 GNDNI(560,760)在各生育期与不同农学参量的相关性比其他波段组合的指数好,其次为NDVI(660,760)波段组合.随着施N量的增加,N肥利用效率、收获指数和N肥收获指数、N素农艺效率以及N肥回收效率均逐渐降低,对各N肥吸收利用指数的预测以NDVI(660,760)、NDVI(660,1100)和GNDVI(560,760)较理想.     

Genetic variability in nitrogen utilization at four growth stages in soft red winter wheat

Studies were conducted to determine relationships among nitrate reductase activity (NRA), dry weight (DW), nitrogen (N) uptake, and N concentration in soft red winter wheat (Triticum aestivwn L.). Data were collected for three growing seasons from field plots grown on a silt loam and one growing season on a sandy loam. Ten cultivars were measured under field conditions with plant samples taken at Feekes Growth Stages 6, 10, 10.5, and 11.1. NRA was measured using an in vivo assay method on fully expanded leaves representing the upper most part of the canopy. Results indicated that N uptake was highest during Stages 10.5 to 11.1, although not significantly different for all cultivars. Few differences were found among cultivars for N concentration. The NRA measured under field conditions was more stable at Growth Stage 6. Path coefficients between NRA and DW, N uptake, and N concentration varied considerably depending on the growth stage, indicating that selection for N utilization using one or more of the measurements evaluated in this study should consider the stage of growth.     

Use of a chlorophyll meter to evaluate the nitrogen status of dryland winter wheat

Abstract

Chlorophyll meter leaf readings were compared to grain yield, leaf N concentration and soil NH₄‐N plus NO₃‐N levels from N rate studies for dryland winter wheat Soil N tests and wheat leaf N concentrations have been taken in the spring at the late tillering stage (Feekes 5) to document a crop N deficiency and to make fertilizer N recommendations. The chlorophyll meter offers another possible technique to estimate crop N status and determine the need for additional N fertilizer. Results with the chlorophyll meter indicate a positive association between chlorophyll meter readings and grain yield, leaf N concentration and soil NH₄‐N plus NO₃‐N. Additional tests are needed to evaluate other factors such as differences among locations, cultivars, soil moisture and profile N status.     

Early season nitrogen accumulation in winter wheat

Cereal rye (Secale cereale L.) is widely used as a winter cover crop to conserve soil residual nitrogen (N) in the mid‐Atlantic region of the United States. Cereal rye, however, has agronomic drawbacks that may make other winter small grain crops more desirable alternatives. Winter wheat (Triticum aestivum L.) is a small grain that could substitute for cereal rye as a cover crop because it would give growers the flexibility of using it as a cover crop or growing it to maturity. There is currently little information on early season N accumulation of winter wheat cultivars, which is critical for the success of a small grain cover crop. To determine the degree of variation in early season N accumulation and early season biomass yield in soft red winter wheat in the mid‐Atlantic region, twenty‐five commercially available cultivars were evaluated at Beltsville, MD in the 1996/1997 and 1997/1998 growing seasons. Acereal rye cultivar ("Wheeler") was included as a cover crop control. Samples of plant tissue were taken at Feekes growth stage 5 and at physiological maturity each year. There were significant differences among cultivars for early season N accumulation and biomass yield. A large group of wheat cultivars had similar early season N accumulation and biomass yield as the cereal rye cover crop control. This suggests that some cultivars of winter wheat may be as effective as cereal rye as a winter cover crop. Early season N accumulation was highly correlated (r=0.90***) with early season biomass yield rather than with plant N content. These results indicate that soft red winter wheat has potential as a dual grain and cover crop and could be considered an alternative to cereal rye as a winter cover crop for conserving residual soil nitrogen in the mid‐Atlantic region of the United States.     

NDVI时序相似性对冬小麦种植面积总量控制的制图精度影响

遥感技术获取的区域作物面积与作物面积统计数据间常常存在不一致的问题,这在一定程度上影响了作物分布遥感制图信息的应用。为获得与作物面积统计数据一致的高精度作物分布遥感制图信息,该研究以河北省衡水市武邑县为研究区,以时序Sentinel-2遥感影像生成的归一化差值植被指数（Normalized Difference Vegetation Index, NDVI）为研究数据,将冬小麦面积目视解译数据作为遥感提取的区域冬小麦面积总量参考,提出基于复合型混合演化算法（Shuffled Complex Evolution-University of Arizona, SCE-UA）和区域作物种植面积总量控制的NDVI时序相似性阈值优化冬小麦分布制图方法,并进行精度验证。在此基础上,进一步开展不同生育阶段NDVI时序相似性及其相似性组合的冬小麦分布提取精度对比研究。结果表明,利用全生育期NDVI时序相似性获得的冬小麦分布制图结果总量精度达99.99%以上,总体精度达98.08%,Kappa系数为0.96,可以保证遥感提取的区域冬小麦面积与冬小麦种植面积总量控制参考间的高度一致性且能获得较高的作物遥感识别精度。从不同生育阶段NDVI时序相似性及其相似性组合的冬小麦分布提取结果可知,利用出苗期-分蘖期、返青期-拔节期的NDVI时序可获得高精度冬小麦分布提取结果,而利用抽穗期-成熟期的NDVI时序数据提取冬小麦结果则精度较低,且综合不同生育阶段NDVI时序数据有利于冬小麦制图精度的提高。该研究可为高精度冬小麦分布提取和制图技术及其方案优化提供一定参考依据,也可为遥感数据和作物面积统计数据融合的大范围农作物分布遥感制图及统计数据空间化提供一定技术方法参考和思路借鉴。