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1.
The permanent bed planting system for wheat (Triticum aestivum L.) production has recently received additional attention. Studies using hard red spring wheat (cultivar Nahuatl F2000) were conducted at two locations in central Mexico. The studies included the installation of three furrow diking treatments, two granular N timing treatments and three foliar N rates applied at the end of anthesis. The objective was to evaluate the effect of these factors on wheat grain yield, yield components and grain N in a wheat–maize (Zea maize L.) rotation with residues of both crops left as stubble. Results indicated that diking in alternate furrows increased both grain yield and the final number of spikes per m2. The split application of N fertilizer enhanced the number of spikes per m2 and grain N uptake, but the effect on grain yield was inconsistent. Similarly, grain protein increased with the foliar application of 6 kg N ha?1, depending upon the maximum temperature within the 10 days following anthesis. The normalized difference vegetative index (NDVI) readings collected at four growth stages were generally higher for the split N application than for the basal N application at planting. Grain N uptake was associated to NDVI readings collected after anthesis.  相似文献   

2.
The effects of planting wheat in permanent beds with fertilization on grain yield and quality need to be better understood. An experiment was conducted at five sites during 2008 and 2009. The objective was to estimate the effects on wheat (Triticum aestivum L.) grain yield and quality of two granular forms of nitrogen (N) (urea and ammonium sulfate, AS) split applied at planting and tillering, and three sprays (urea, AS, and a fungicide) at anthesis. The granular N source affected yield, spike number, and rheological parameters depending upon the soil reaction. Dough resistance/extensibility ratio (P/L) was associated with the normalized difference vegetative index (NDVI) readings collected during tillering before the granular N application. Fungicide spray at anthesis improved yield and grain physical quality evaluated as thousand-grain weight (TGW), test weight, and hardness. Grain protein concentration (GPC) appeared to be mainly affected by environmental factors rather than fertilization practices.  相似文献   

3.
Gaseous nitrogen (N) loss from winter wheat (Triticum aestivum L.) plants has been identified, but has not been simultaneously evaluated for several genotypes grown under different N fertility. Two field experiments were initiated in 1993 and 1994 at the Agronomy Research Station in Stillwater and Perkins to estimate plant N loss from several cultivars as a function of N applied and to characterize nitrogen use efficiency (NUE). A total of five cultivars were evaluated at preplant N rates ranging from 30 to 180 kg·ha‐1. Nitrogen loss was estimated as the difference between total forage N accumulated at anthesis and the total (grain + straw) N at harvest. Forage, grain, straw yield, N uptake, and N loss increased with increasing N applied at both Stillwater and Perkins. Significant differences were observed among varieties for yield, N uptake, N loss, and components of NUE in forage, grain, straw, and grain + straw. Estimates of N loss over this two‐year period ranged from 4.0 to 27.9 kg·ha‐1 (7.7 to 59.4% of total forage N at anthesis). Most N losses occurred between anthesis and 14 days post‐anthesis. Avoiding excess N application would reduce N loss and increase NUE in winter wheat varieties. Varieties with high harvest index (grain yield/total biomass) and low forage yield had low plant N loss. Estimates of plant loss suggest N balance studies should consider this variable before assuming that unaccounted N was lost to leaching and denitrification.  相似文献   

4.
中、高产型小麦干物质和氮素累积转运对水氮的响应   总被引:2,自引:2,他引:0  
  【目的】  研究产量高低差异明显的小麦品种干物质和氮素积累转运对水氮响应的差异,为以产量为目标的小麦优化水氮运筹提供参考。  【方法】  于2016—2018年,以中产型品种‘泰科麦33’和高产型品种‘济麦22’为供试材料进行了两因素三水平完全方案田间试验。两因素为灌水量和氮肥用量,3个灌溉水平为300、450和600 m3/hm2,依次表示为W1、W2、W3;3个施氮量为135、180和225 kg/hm2,依次表示为N1、N2、N3。测定小麦关键生育期氮素和干物质积累量,在成熟期调查了产量和产量构成因素。  【结果】  两个品种小麦水氮互作效应对穗数、穗粒数、千粒重、籽粒产量和氮肥偏生产力影响显著,中产型品种的产量对水氮的响应顺序表现为W2 > W3 > W1、N2 > N3 > N1;高产型品种的产量对水氮的响应顺序表现为W3 > W2 > W1、N2 > N3 > N1。高产和中产品种产量对氮素的反应一致,高产品种比中产品种对水分的要求更高。品种特性及其水氮互作效应显著影响小麦开花期和成熟期干物质积累量。籽粒产量与花前干物质对籽粒的贡献率呈线性负相关,与开花后干物质对籽粒贡献率呈线性正相关,表明开花后干物质是籽粒干物质的主要来源。品种及其水氮互作效应均显著影响小麦开花期和成熟期氮素的积累量。籽粒产量与花前氮素积累量对籽粒的贡献率呈线性正相关,与开花后氮素积累对籽粒贡献率呈线性负相关,表明花前氮素积累是籽粒氮素的主要来源。在显著相关的性状中,生物量、开花后干物质输入籽粒量、开花后干物质对籽粒的贡献率之间呈显著正相关;花前氮素积累量、总氮素积累量、花前氮素转运量、开花后氮素输入籽粒量、花前氮素积累量对籽粒的贡献率以及氮素收获指数之间显著正相关。  【结论】  水、氮及其互作效应显著影响小麦穗数、穗粒数、千粒重、籽粒产量、氮素偏生产力、花前干物质积累量、成熟期干物质积累量、开花后干物质输入籽粒量、花前氮素积累量、成熟期氮素积累量、花前氮素转运量等性状。不适宜的灌水量和氮肥施用量会促进花前干物质向籽粒的过度运转,不利于形成高产。中、高产型小麦籽粒产量对氮素的响应均表现为为N2 > N3 > N1,但对灌溉量的响应不同,中产型品种适宜的灌水量为450 m3/hm2,高产型品种适宜的灌水量以600 m3/hm2较为理想。  相似文献   

5.
为明确微喷水肥一体化条件下灌溉次数和氮肥用量对冬小麦产量形成和水分利用的影响,该试验在灌水定额1 500 m3/hm2下设置微喷2次(拔节期750 m3/hm2+开花期750 m3/hm2)、3次(拔节期450 m3/hm2+开花期750 m3/hm2+灌浆期300 m3/hm2)、4次(拔节期450 m3/hm2+孕穗期300 m3/hm2+开花期450 m3/hm2+灌浆期300 m3/hm2)和氮肥追施45、90、135 kg/hm2处理,N肥随灌水等量分次施入,考察群体光合特性、物质生产和水分利用特征。结果表明:微喷3次和4次相比于微喷2次,产量提高了5.3%~18.9%,水分利用效率提高了5.3%~27.8%,但微喷3次与4次之间差异不显著。适当增加微喷次数提高了开花期和灌浆期群体绿色叶面积指数,延缓了叶片衰老,提高了生育后期干物质积累,增加了千粒质量,进而提高了籽粒产量;多次微喷(3次或4次)降低了总耗水量和开花前耗水比例,提高了开花后耗水比例;适当增施氮肥能进一步提高花后物质积累和花后耗水比例。综合来看,1 500 m3/hm2灌溉定额下微喷4次,追施氮肥90 kg/hm2产量和水分利用效率较高。  相似文献   

6.
氮硫互作对冬小麦旗叶衰老、产量和氮素利用效率的影响   总被引:2,自引:0,他引:2  
王丽  王东  周杰  韩坤 《土壤学报》2016,53(6):1476-1488
试验采用裂裂区设计,小麦品种(烟农19和汶农6号)为主区,施氮(N)量为裂区,设0(N0)、120(N120)、240(N240)kg hm-2三个施N水平,施硫(S)量为裂裂区,设0(S0)、20(S20)、40(S40)、60(S60)kg hm-2四个施S水平。结果表明,汶农6号开花后旗叶超氧化物歧化酶(SOD)活性、旗叶净光合速率、产量和氮素利用效率均高于烟农19。在一定施氮水平下适量施硫显著提高烟农19和汶农6号小麦开花后旗叶SOD活性和可溶性蛋白质含量,提高旗叶净光合速率和开花后干物质积累量,增加植株地上部氮素积累量和籽粒产量;当施氮水平为120 kg hm-2施硫量超过40 kg hm-2和施氮240 kg hm-2施硫量超过20 kg hm-2时,汶农6号植株地上部氮素积累量仍继续增加,但旗叶抗氧化能力和光合同化能力均无明显提高,籽粒产量不再增加,烟农19号旗叶SOD活性、可溶性蛋白质含量和光合速率均降低,植株地上部氮素积累量和籽粒产量均减少。在同一施氮水平下,两小麦品种氮素利用效率总体表现为随施硫量增加而降低的趋势。在土壤有效硫为38.9~42.1 mg kg-1的条件下,适量施用氮肥和硫肥有利于延缓小麦花后旗叶衰老,提高光合同化能力,增加籽粒产量,但不同品种小麦对氮肥和硫肥施用量的响应不同,氮素利用效率较高的品种在较高的氮硫供给水平下仍有较好的光合同化和产量表现,而氮素利用效率相对低的品种对高氮高硫的适应性较差,后期易早衰,影响产量和氮素利用效率。  相似文献   

7.
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.  相似文献   

8.
An experiment was carried out to determine how the late application of nitrogen (N) fertilizer affects the use of pre‐anthesis carbon reserves during the grain‐filling period of pot‐grown wheat with no water shortage. Increasing doses (equivalent to 0, 140, and 180 kg N ha–1) of N fertilizer were applied, either in two amendments (stages GS20 and GS30) or in three amendments (stages GS20, GS30, and GS37, according to Zadoks scale). The management of fertilizer by combining an increased N rate with late N application was able to stimulate canopy development, to raise photosynthetic capacity and carbohydrate accumulation during the vegetative stages, and to increase grain yield. Based on the dynamics of carbohydrate accumulation in the ear, three phases were differentiated during the grain‐filling period, whose temporary pattern remained stable regardless of the fertilizer management. The net remobilization of carbohydrates started 12 d after anthesis from the leaves and 28 d after anthesis from roots and stems. The increase of the N dose with late N application allowed on one hand a lower use of the pre‐anthesis carbon reserves in favor of greater de novo photosynthesis during the grain‐filling period, and on the other hand greater relative contribution of the leaf and ear C reserves to remobilization towards the grain. Further splitting the dose increased only the relative contribution of ear C reserves. The stem contribution seemed to be independent of N applied whereas the root contribution tended to diminish with late N application.  相似文献   

9.
Late application of nitrogen (N) fertilizers at heading or anthesis is usually performed to produce wheat (Triticum aestivum L.) with high bread‐making quality. However, increasing energy costs and ecological problems due to N losses call for efficient and simplified N fertilization strategies. This study aimed to investigate the effect of late N fertilization on grain protein quality and thus baking quality and to evaluate if similar wheat quality can be maintained without late N application. Field experiments with two winter wheat cultivars differing in quality groups were conducted. The fertilization treatments comprised a rate of 220 kg N ha?1 applied in two or three doses (referred to as split N application), and 260 kg N ha?1 applied in four doses (additional late N fertilization) with different N fertilizer types. The results show that although split N application had no effect on grain protein concentration (GPC), it affected N partitioning in the grain, increasing mainly the concentration and proportion of the glutenin fraction. As a result, baking quality was improved by split N application. Late N fertilization enhanced GPC and the relative abundance of certain high molecular weight glutenin subunits (HMW‐GS). However, it had no effect on N partitioning in the grain and did not further improve baking quality. No obvious differences were found between N fertilizer types on grain yield and quality. The N fertilization effect was more pronounced on the wheat cultivar whose baking quality was more dependent on protein concentration. In evaluating baking quality of wheat flour, gliadin and glutenin proportions were better correlated with loaf volume than the overall protein concentration.  相似文献   

10.
不同施氮量及种植密度对小麦开花期氮素积累转运的影响   总被引:9,自引:3,他引:6  
本文以小麦品种‘周麦22’为材料,研究了不同施氮量[0 kg(N)?hm~(-2)、120 kg(N)?hm~(-2)、240 kg(N)?hm~(-2)和360 kg(N)·hm~(-2),以N0、N1、N2和N3表示]和种植密度(225×104基本苗?hm~(-2)、375×10~4基本苗?hm~(-2)和525×104基本苗?hm~(-2),以M_1、M_2和M_3表示)处理下小麦植株地上部不同空间分布各器官的氮素含量及其转运特性。结果表明:施氮量、种植密度及二者互作对开花期、成熟期植株地上部各器官氮素含量的影响均达显著水平。不同施氮量及种植密度处理小麦开花期至成熟期各营养器官氮含量和积累量下降。开花期和成熟期,植株单茎氮积累量为7.27~59.65 mg?茎-1和8.48~60.83 mg?茎-1,以N_0M_3处理最低,以N_3M_2最高。从空间位置看,植株地上部各营养器官开花期氮含量、氮积累量及花后氮转运量和对籽粒氮的贡献率均随空间位置下移而降低。营养器官氮含量、积累量及转运量随施氮量增加而呈递增趋势,上部和中部营养器官氮转运率高于50%。营养器官对籽粒氮的总贡献率高于67%。增施氮肥配套合理的种植密度,可以促进植株地上各营养器官氮的积累和转运,对植株下部器官氮积累转运的作用尤为明显,高肥及中密度处理(N3M2)下倒四叶、倒四节及余叶和余节氮含量和积累量增加,缩小了与上部各器官的差异。植株地上部群体氮素转运量为28.56~549.49 kg·hm~(-2),亦随施氮量增加而增加,以穗部和茎节氮转运量较高。施氮量对籽粒产量、蛋白质含量及蛋白质产量影响显著。施氮量与种植密度互作对籽粒蛋白质含量及产量影响显著,种植密度对籽粒蛋白质产量的影响亦达显著水平。从氮素转运和产量性状来看,施用氮肥240 kg·hm~(-2)配套225×10~4基本苗?hm-2的种植密度是黄淮小麦玉米两熟区小麦生产较为适宜的栽培模式。  相似文献   

11.
Field experiments were conducted in 2006–2007 and 2007–2008 to evaluate the effects of three calcium carbide (CaC2) based formulations (slow release sources of acetylene and ethylene) - matrix-1 [(M-1)(21% CaC2, 58% polyethylene and 21% plaster of paris)], matrix-2 [(M-2)(42% CaC2, 48% polyethylene and 10% plaster of paris)] and paint coated [(PC)(35% CaC2, 44% paint and 21% plaster of paris)] - on nitrification inhibition; growth, yield and nitrogen (N)-uptake of wheat. All the three CaC2 formulations (CCF,s) inhibited nitrification, reduced plant height, and improved N-uptake, spike bearing tillers, 1000-grains weight and yield of Inqulab-91 and Bhakhar-02 wheat cultivars. Increase in grain yield was found maximum (22% over the control) with M-1 applied at 30 kg CaC2 ha?1; followed by M-2 and PC. Furthermore, CaC2 significantly reduced lodging in Bhakhar-02 plots. It is concluded that grain yield of wheat can be enhanced by the application of CaC2 formulations particularly M-1 along with NPK fertilizers.  相似文献   

12.
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.  相似文献   

13.
ABSTRACT

Nutrient uptake and grain and straw yield of Egyptian winter wheat (Triticum aestivum L. Merr.) were evaluated for two site-years after the seed inoculation with two biofertilizer products, Phosphorien, containing the phosphorus (P)-solubilizing bacteria Bacillus megatherium, and Nitrobien, containing a combination of nitrogen (N)-fixing bacteria Azotobacter chroococcum and Azospirillum liposerum. Ammonium nitrate and polymer-coated urea fertilizers were applied to plots alone and together with the biofertilizers at rates of either 83 kg N ha?1 or 186 kg N ha?1 for comparison. The highest grain yield (5.76–6.74 Mg ha?1) and straw yield (11.49–13.32 Mg ha?1) occurred at the highest fertilizer rates with N fertilizer. There was a slight additional increase in grain and straw yields when a biofertilizer was applied along with N fertilizer. A slightly higher grain and straw yield was measured with the polymer-coated urea treatment than with the ammonium nitrate treatment. The biofertilizer materials were not as effective as N fertilizers in producing grain (4.02–4.09 Mg ha?1) or straw (7.71–8.11 Mg ha?1) for either year, although the Nitrobien + Phosphorien combination increased these parameters over the N-fertilizer control. The effect of the Nitrobien biofertilizer in increasing grain yields was equivalent to a urea application rate of about 13 kg N ha?1. Biofertilizer inoculations increased iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) concentrations in wheat tissue (at boot stage), but these higher levels did not influence grain or straw yield.  相似文献   

14.
ABSTRACT

Grain yield increases (responses) of canola (oilseed rape, Brassica napus L.) and spring wheat (Triticum aestivum L.) to application of nitrogen (N) and potassium (K) fertilizers were compared in the same experiment at eight field sites over three years (2000–2002) in southwestern Australia. Four rates of N (0–138 kg N/ha as urea) and four rates of K (0–60 kg K ha?1 as potassium chloride) were applied. Significant grain yield responses to applied N and K occurred for both crop species at all sites of the experiment, and the NxK interaction was significant. Canola required an average of 26% more applied N and 32% more applied K than wheat to produce 90% of the maximum grain yield. Applying increasing rates of K increased the rate of N required for 90% of maximum grain yield. Likewise, applying increasing rates of N increased the rate of K required for 90% of the maximum grain yield. Fertilizer K had no significant affect on the concentration of oil in canola grain or concentration of protein in both canola and wheat grain. Application of increasing rates of N decreased the concentration of oil while increasing the concentration of protein in canola grain, and increased concentration of protein in wheat grain. The NxK interaction was not significant for concentration of oil or protein in grain.  相似文献   

15.
Abstract

Stem bases from wheat plants in a glasshouse pot experiment conducted under varying nitrogen and two water regimes, were analysed for nitrate (NO3) concentration. The concentration of NO3 at three stages of growth i.e. tillering, jointing and anthesis were related both to rates of applied nitrogen and to shoot dry matter yield at time of sampling. Plotted against rate of increasing nitrogen application, the response curve of NO3 concentration in wheat stem bases was sigmoidal. The level of nitrogen application at which NO3 began to accumulate in the plants was the supply at which plants reached maximum dry matter yield. The concentration of NO3 at which plant yield was 90% of maximum dry matter was taken as the critical level. This concentration was around 1000 ppm NO3‐N at all stages. Compared with plants supplied with unlimited water, plants under moderate water stress accumulated relatively more NO3 but had a similar critical NO3 concentration.

Maximum grain yield was obtained from plants which stayed above the critical level throughout the growing season.  相似文献   

16.
Yield and nitrogen (N)-content in wheat was studied under applied treatments of crop residues (legume vs. cereal), tillage depths (deep vs. shallow) and N-fertilizer rates (0, 40, 80, 120 and 160 kg ha?1) at wheat-maize cropping systems. Experiments were conducted at Agronomy Research farm, the University of Agriculture, Peshawar Pakistan, during winter season 2009–2010 and 2010–2011 crop growth seasons. Well-chopped crop residues (5 t ha?1) on dry matter basis of legume (Vigna unguicuata) and cereal (Zea mays) were applied to soil and subsequently plowed with mold-board plow as deep tillage (DT) and cultivator as shallow tillage (ST) treatment (main plot treatments). A month after residue and tillage application, seedbed was prepared and wheat was planted with drill in rows 25 cm apart in middle of November each year. Phosphorus and potassium were applied uniformly 80 and 40 kg ha?1, respectively during seedbed preparation. N-fertilizer rates were applied in two splits: half 15 days after sowing (DAS) and other half 45 DAS (sub-plot treatment). Uniform cultural practices were applied during crop growth and development. Legumes residues amendments showed better responses than cereal but lower than no-residue treatment for N-content in leaf blade before anthesis (LBA), after anthesis (LAA), straw N-content (SNC), grain N-content (GNC), grain N-uptake (GNU), crop N-removal (CNR), recovery efficiency of added nitrogen (REAN), N-use efficiency (NUE), grain N-uptake (GNU) and grain yield. Likewise, shallow tillage proved better than deep tillage system for LBA, LAA, SNC, GNC, GNU, CNR, REAN, NUE, GNU and grain yield. Increased N-fertilizer from control onwards showed significant (p > 0.05) increments in LBA, LAA, SNC, GNC, GNU, CNR, N-uptake and grain yield. Treatments interaction was also found significant (p > 0.05). Study suggested, regardless of the given treatments, GNU and grain yield were in strong positive linear relationship. Legume residue incorporated shallow out yielded GNU and NUE of spring wheat in wheat-maize cropping system. It is concluded that LR and ST with 120 kg N ha?1 ensures production of good wheat quantity and quality.  相似文献   

17.
Nitrogen and phosphorus fertilizers were applied at different levels to three hard winter wheat cultivars ranging in grain protein potential to elucidate their interaction and relationship to yield components. Plant N content was higher in the high‐protein cultivar than in the normal‐protein cultivars at jointing two years and at anthesis one year. Plant P content was higher in the semidwarf cultivars than in the tall cultivar and was unrelated to protein potential. All cultivars contained similar plant N and P levels at maturity. Nitrogen fertilization increased plant N content and decreased plant P content at all stages, whereas P fertilization usually increased plant P content but did not affect plant N content. Grain protein was correlated positively with plant N content at all stages and with plant P content at maturity. Grain yield was correlated positively with plant N content at anthesis but correlated negatively with plant P content at maturity. We concluded that high plant N content at anthesis is necessary for high grain yield and protein content regardless of the cultivars1 inherent protein potential and that plant P nutrition is more critical when N nutrition is altered by fertilization or by genetics.  相似文献   

18.
[目的]研究秋闲期秸秆覆盖对旱地小麦播前土壤墒情和小麦生产特性的影响以及减少氮肥用量的可行性,为四川旱地小麦高产高效管理提供理论依据.[方法]于2016―2018年在四川省仁寿县四川农业大学试验基地开展冬小麦–夏玉米轮作田间定位试验,供试作物为冬小麦.试验采用裂区设计,主区为夏玉米秸秆粉碎覆盖(SM)和不覆盖(NM);...  相似文献   

19.
通过田间试验研究了西北旱地4个主要冬小麦品种在不同供氮水平下对氮素的吸收、累积和转移特性。结果表明,增施氮肥显著地促进了小麦地上部分氮素累积总量,子粒氮素累积量在施氮量180.kg/hm2时最高,再增加氮肥用量子粒氮素累积量降低;施氮明显增加了收获时茎秆氮素的残留量。不同品种间氮素累积量差异显著,其中小偃22最高,其后依次为陕253、小偃503和陕229;小偃22的氮肥利用率、氮肥农学效率和氮肥生理效率均高于其它几个小麦品种。不同器官相比,开花前氮素主要累积在叶片中,茎秆的累积量在开花期达到最大。不同部位氮素转移效率为叶片穗茎秆;叶、茎、穗氮素转移效率存在基因型差异。  相似文献   

20.
Abstract

Nitrogen (N) or growth regulator application to small grain cereals near anthesis has been demonstrated to alter grain fill and grain yield, the protein yield and nutritional quality may also be modified by these management factors. The objective of this study was to determine whether delivery of N, growth regulator, or sucrose solutions into greenhouse‐grown barley (Hordeurn vulgare L. cv. Leger) or wheat (Triticum aestivum L. cv. Katepwa), plants through peduncle perfusion altered the amino acid composition of the grain. The following treatments were tested: N (25 and 50 mM), chlormequat (30 μM), ethephon (15 μM), N + chlormequat, N + ethephon, detillering + N, sucrose (250 mM), distilled water check, and non‐perfused check. Perfusion lasted 30 d beginning 5 to 8 d after spike emergence. Addition of N via peduncle perfusion increased protein concentrations and concentrations of all amino acids in both barley and wheat when expressed in terms of grain dry matter. Protein yield and lysine content were also increased. However, the increase in essential amino acids such as lysine, methionine, threonine, isoleucine, arginine, and leucine was relatively small, and the proportions of these amino acids in the grain protein were actually reduced. The sucrose treatment only affected wheat, increasing lysine concentration and decreasing the total protein concentration. Growth regulators used in this study did not alter protein yield or amino acid composition in either crop.  相似文献   

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