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1.
A field experiment was conducted at the Indian Agricultural Research Institute, New Delhi to study the growth and yield of wheat as influenced by the concentrations of ammonium-N and nitrate-N in soil. A series of ammonium and nitrate nitrogen concentrations in soil on a time frame was developed by treating prilled urea with nitrification inhibitors DCD or neem cake as well as by changing the dose and time of N application. The study revealed that number of tillers m-1 as well as ears m-1 row length were significantly positively correlated with ammonium-N concentration at 15 and 30 DAS and nitrate-N concentration at 30 and 45 DAS. Number of grains ear-1 was significantly positively correlated with ammonium-N at 30, 45 and 60 DAS and nitrate-N at 45 and 60 DAS. Ultimately grain yield in wheat was significantly positively correlated with ammonium-N concentration at 15 and 30 DAS and nitrate-N concentration at 30, 45 and 60 DAS. The response between grain yield and concentrations of both ammonium and nitrate forms of N was quadratic. The optimum concentration of ammonium-N in soil for maximum grain yield gradually decreased with the age of the crop from 54.6 to 63.6 μg g-1 at 15 DAS to 22.7 to 26 μg g-1 at 30 DAS. In the case of nitrate-N its optimum concentration for maximum grain yield increased with age of the crop from 25.1 to 30 μg g-1 at 15 DAS to 31.6 to 34 at 45 DAS and it decreased thereafter.  相似文献   

2.
Field experiments were conducted at Tamil Nadu Rice Research Institute, Aduthurai, India, during the wet seasons of 1992 and 1993 to study the effect of full and partial substitution of fertiliser N with green manure N (Sesbania rostrata) on nitrogen uptake, yield attributes and yield of rice. The experiment consisted of eight treatments with two levels of N (100 and 200 kg ha−1) and three sources of N application viz., fertilizer, integrated (1:1 fertilizer and green manure N) and green manure N compared to the recommended practice (150 kg fertilizer plus 6.25 t ha−1 (72 kg N) green manure) and a no N control. Nitrogen application markedly increased the N uptake. Combined use of the two N sources at 200 and 222 kg N ha−1 and of single fertilizer N at 200 kg N ha−1 recorded the maximum N uptake, increased the yield attributes such as number of panicles per unit area, weight per panicle, number of total and filled grains per panicle and test weight. At 200 kg N ha−1 full substitution of N by green manure reduced the grain yield but only partial substitution of N by green manure resulted in almost similar yield as single fertilizer N. Thus 200 kg N ha−1 applied in equal proportions of fertilizer and green manure N can be recommended for medium duration rice cultivars.  相似文献   

3.
To determine a suitable nitrogen fertilizer application rate, an experiment was conducted using Jinza 34, Liaoza 27, Jinsi 2, Jinnuo 3, and Fenjiuliang 1 with six nitrogen (N) fertilization levels, including 0 (N0), 75 (N75), 150 (N150), 225 (N225), 300 (N300), and 450 kg hm-2 (N450). The effects of long-term nitrogen fertilization with different levels on sorghum grain yield, nitrogen use characteristics and soil nitrate nitrogen distribution were investigated. The grain yield, grain number and N accumulation of sorghum increased initially and then tended to be stabile with the increase of nitrogen fertilizer application. Among them, the maximum increase of sorghum under N75 treatment compared with that under N0 treatment was 23.68%, 48.05%, and 51.86%, respectively. With the increase of nitrogen fertilizer application, the grain starch content decreased, while the grain starch yield increased firstly and then decreased. Nitrogen apparent recovery rate, nitrogen fertilizer agronomic efficiency and nitrogen use efficiency which were accumulated for five years were reduced significantly with the increase of nitrogen fertilizer application. Compared with the N150 treatment, nitrogen use efficiency accumulated for five years under N75 treatment, which was 63.01%, was increased by 76.91%. When nitrogen fertilizer application was beyond 225 kg hm-2, after four to five years later, nitrate nitrogen residue was increased rapidly in the 60-200 cm soil layer year by year, NO3--N accumulation peaks distributed in the 0-200 cm soil layer and the risk of nitrate nitrogen leaching was increased. In view of the yield, starch yield, nitrogen utilization and environmental benefit, the reasonable nitrogen fertilizer application for sorghum was between 75 kg hm-2 and 150 kg hm-2.  相似文献   

4.
不同降水状况下旱地玉米生长与产量对施氮量的响应   总被引：2，自引：0，他引：2  
水分不足是旱地玉米生长主要限制因素,渭北旱塬雨养玉米种植区降水季节波动大,干旱频繁发生,已严重影响春玉米正常生长发育及产量稳定性。于2016—2018年在渭北旱塬合阳县进行旱地玉米施氮量定位试验,设置5个施氮量处理, 2016—2017年包括0、75、150、270、360 kg hm~(–2) (分别以N0、N75、N150、N270、N360表示), 2018年施氮量处理为0、90、180、270、360kgNhm~(–2) (分别以N0、N90、N180、N270、N360表示),供试品种为郑单958(ZD958)和陕单8806(SD8806)。分析了不同降水分布年份施氮量对春玉米生育期土壤水分变化动态、干物质积累动态、产量构成、经济效益及水分利用效率(WUE)的影响。结果表明,试验年份降水分布可分为穗期多雨、粒期干旱型(2016年和2018年)和穗期干旱、粒期多雨型(2017年)。生长季降水量及其分布显著影响土壤蓄水量和玉米地上部干物质积累,从而影响玉米产量及其构成因素,穗期干旱显著降低地上部干物质积累量和穗粒数,粒期干旱会明显降低粒重。不同降水分布年份施氮处理较N0增产6.72%～91.23%不等,施氮量对玉米产量、水分利用效率(WUE)影响呈现二次曲线关系,穗期多雨、粒期干旱型以N270处理籽粒产量和WUE最高,而穗期干旱、粒期多雨型以N150处理产量和WUE最好。籽粒产量与"休闲至抽雄期降水(FP2)"、"播前土壤蓄水量+播种至抽雄期降水(SP2)"相关性较强(FP2:R2=0.839**; SP2:R2=0.837**)。根据产量、水分利用和经济收益综合评价,渭北旱地玉米最适施氮方案为基施氮肥150kghm~(–2),再根据休闲至抽雄期降水量或播前土壤蓄水量与播种至抽雄期降水量之和预测产量,估算并及时追施适宜施氮量。  相似文献   

5.
小麦产量对中后期氮素胁迫的响应及品种间差异   总被引：2，自引：0，他引：2  
生育中后期土壤供氮不足是导致小麦减产的重要原因之一。2015—2017年连续2个生长季,选择人工合成六倍体小麦衍生品种(synthetic hexaploid wheat-derived cultivar, SDC)和非人工合成小麦衍生品种(Non-synthetic hexaploid wheat-derived cultivar, NSC)各3个,设置2个施氮水平,研究其产量及相关生理参数对中后期氮素胁迫的响应。SDC包括川麦42、川麦104和绵麦367, NSC包括绵麦37、川农16和川麦30。2个施氮水平为正常施氮处理(Nn, 150kg N hm~(–2),底肥40%、拔节肥60%)和中后期氮胁迫处理(Ns, 60 kg N hm~(–2),全部作底肥)。结果表明,氮胁迫下,两类品种产量均值降幅接近(SDC 19.6%, NSC 20.4%),但正常供氮下SDC产量高于NSC (高14.4%),其氮胁迫下的产量也较高(高15.9%)。氮胁迫下, SDC的生物产量、单位面积粒数均高于NSC。开花期,两类品种在2个氮素水平下的叶面积指数(LAI)接近,但在灌浆中后期的降幅SDC小于NSC,花后22d,SDC在高、低施氮水平下的LAI较NSC分别高25.1%和16.0%。开花灌浆阶段, 2个施氮水平下SDC旗叶和倒二叶SPAD始终高于NSC,氮胁迫下二者的差距增大。两类品种的净光合速率(NPR)和群体光合速率(CAP)的差异也主要出现在灌浆中后期,氮胁迫下SDC以上2个参数较NSC均有优势。氮胁迫下,花后功能叶片的硝态氮、铵态氮、可溶性糖含量SDC也高于NSC。SDC较NSC有更高的氮素利用效率(NUtE),氮胁迫下,二者NUtE的差距增加。以上结果表明,低氮胁迫下SDC的生产力高于NSC,这与其较高的库容、较长叶片功能期有关。  相似文献   

6.
氮磷钾肥对青贮玉米产量和品质的影响   总被引：1，自引：0，他引：1  
为了探讨施肥对青贮玉米原料及青贮饲料的影响,在撒施羊粪的田间,青贮玉米栽培管理时,分别单独施用氮肥（N-150kg/hm 2）、磷肥（P2O5-120kg/hm 2）、钾肥（K2O-150kg/hm 2）,以不施用化肥为对照,经田间测产和取样,并对其青贮发酵后进行分析。结果表明,增施氮肥能极显著提高青贮玉米产量（P<0.01）,Milk2006奶亩指数显著高于单施磷钾肥和对照处理（P<0.05）;增施钾肥显著提高了青贮玉米的产量（P<0.05）。增施氮肥除了提高玉米青贮饲料氨态氮含量外（P<0.05）,玉米青贮饲料的其他发酵品质参数差异不显著。青贮不仅保存了原料的养分,同时降低了硝酸盐含量。  相似文献   

7.
When one of the crops is a legume, intercropping has potential to reduce fertilizer nitrogen (N) needs and increase food quality. Total dry matter (DM) and grain yields of different plant populations of intercropped maize ( Zea mays L.) and climbing beans ( Phaseolus vulgaris L.), cowpeas ( Vigna unguiculata [L.] Walp.), or velvet beans ( Mucuna pruriens [L.] DC. var utilis [Wight] Bruck.) were compared in two experiments. Maize populations were 40,400 and 50,500 plants ha−1 in combination with climbing bean populations of 0, 20,200, 40,400 and 80,800 plants ha−1 in Experiment 1. In the second experiment, climbing beans, cowpeas and velvet beans at 215,200 plants ha−1 were intercropped with maize at 64,600 plants ha−1. Climbing beans contributed up to 5% to total DM yields in the first experiment. In the second experiment legume contributions to total DM were 20% for climbing beans, 12% for cowpeas and 8% for velvet beans. Increasing populations of maize and climbing beans increased grain and DM yields. Dry matter yield of maize was lowered by intercropping. However, DM yields of the intercrop were not different to maize sole cropped. Maize/cowpeas produced more total DM than maize/climbing beans. Cowpeas increased the total yield of crude protein by over 15% without lowering total DM yield of the intercrop compared to maize alone and are promising as a legume for intercropping with maize. Climbing beans show little promise as a possible legume for intercropping with maize.  相似文献   

8.
Results reported in the literature with regard to productivity of intercropping systems in comparison to sole cropping are very inconsistent. A field experiment was therefore conducted in the northern part of the Guinea Savanna in Ghana to compare the productivity of maize/cowpea mixed cropping, maize/cowpea relay intercropping with maize/cowpea rotation and maize monocropping over a 4-year period. The treatments included two levels of nitrogen (0 and 80 kg of N ha−1 y −1 as urea) and two levels of phosphorus application (0 and 60 kg of P ha−1 y−1 as Volta phosphate rock). At all levels of N and P application, maize yields of the intercropping systems, especially of maize/cowpea mixed cropping, were significantly lower than in sole cropping. Highest maize yields were obtained in maize/cowpea rotation, which in contrast to the other cropping systems did not show any reductions in yields over years. Cowpea yields were generally less affected by the cropping system, but were notably depressed when cowpea was relay-intercropped with maize. In treatments without fertilizer application (N and P) Land Equivalent Ratios (LER) and Area x Time Equivalency Ratios (ATER) generally indicated lower productivity of the intercropping systems as compared to sole cropping, with the maize/cowpea rotation showing the highest productivity. Conversely, fertilizer application resulted in higher productivity of the intercropping systems over the 4-year period. Productivity on the basis of ATER was generally lowest in maize/cowpea relay-intercropping as a consequence of the long time of land occupation. All of the parameters indicate low productivity of maize monocropping, clearly demonstrating that crop sequence as well as fertilizer application must be considered as important for maintaining high production levels at this site.  相似文献   

9.
Knowledge of optimum fertilization for com production is required to increase crop yields while minimizing fertilizer costs. Field experiments were carried out from 1988 to 1993 to study the effects of fertilizer N rates on yield and N concentration of corn ( Zea mays L.) grain on a clay soil in Quebec. Grain yields and grain N concentrations generally followed a exponential relationship with increasing N fertilizer rates. The critical grain N concentration, defined as that associated with the highest grain yield, occurred at 285 kg N ha-1 for all years except 1969 when it occurred at 170 kg N ha-1. The critical grain N concentrations and grain yields over the years were found to be linearly related. The relationship between the critical grain N concentration and grain yield could serve as a diagnostic tool for N applications.  相似文献   

10.
A field experiment was conducted with different nitrogen regimes to assess the growth and yield performance of wheat genotypes which differ in nitrate assimilation potential. Genotypic differences in biomass accumulation were observed at different growth stages. The nitrogen treatment had little effect on biomass accumulation at early stages of growth, while at later stages of growth there was enhanced biomass accumulation when N was applied in more than two splits. On an average, genotypes with high nitrate reductase activity (the 'HNR' genotypes) accumulated 14.2 % more biomass than the genotypes with low nitrate reductase activity ('LNR' genotypes) when an extra dose (40 kg N ha−1) of nitrogen was given at the time of anthesis. The application of nitrogen in more than two splits increased grain yield of both 'HNR' and 'LNR' genotypes mainly by increasing grain weight per ear. The application of an extra dose of nitrogen (40 kg N ha−1) at the time of anthesis increased grain yield of 'HNR' genotypes by 38.5 % as compared to 'LNR' genotypes.  相似文献   

11.
为给冬小麦提供“更合理、更节约、更高效”的水肥运筹技术方案,以‘豫教5号’为试验材料,采用三因素裂区方法研究了不同灌水次数和施氮处理对小麦叶面积指数和产量的影响。结果表明,灌水次数、施氮量以及基追比例分别对小麦叶面积指数、产量及构成因素有显著影响。在W1（底墒水）处理下叶面积指数与施氮量均呈线性正相关关系;在W2（底墒水+拔节水）、W3（底墒水+拔节水+灌浆水）处理条件下,拔节期、孕穗期、抽穗期的叶面积指数与施氮量呈线性正相关关系,抽穗后20天与施氮量则呈二次曲线关系,且以N3R2为最大值。在不同灌水次数条件下,产量、穗数、穗粒数与施氮量呈二次曲线关系,千粒重随施氮量的增加呈线性下降趋势。在灌溉底墒水+拔节水+灌浆水、施氮量为240 kg/hm2及基追肥5:5处理组合下实现了水肥的高效配合,产量、穗数、穗粒数分别为8609.60 kg/hm2、688.2×104株/hm2、37.9粒,其中产量比对照W1N0 (3517.5 kg/hm2) 增产144.8%。由此可知,在小麦生长后期降雨量偏少的黄淮豫东地区,小麦生产中灌溉水的节约空间相对较小,氮肥的节约空间则相对较大。  相似文献   

12.
In a 3-year field experiment conducted on a Gleyic Luvisol in Stuttgart-Hohenheim, ten maize cultivars (nine commercial and one experimental hybrid) were compared in their ability to utilize a high soil nitrogen (N) supply. Total N content of the shoots at about silage maturity ranged from 213 to 328 kg N ha−1 (1986), from 177 to 223 kg N ha−1 (1987) and from 185 to 226 kg N ha−1 (1988). In all three experimental years, total shoot N uptake was significantly positively correlated to stover yield, and also to N concentrations in the ears and in the total plant dry matter. In contrast, a negative correlation between ear yields of the cultivars and total N uptake was indicated. Differences between the cultivars in N uptake were reflected in a corresponding soil nitrate depletion. At harvest, residual nitrate-N in the 0–90 cm soil layer ranged from 34–63 kg N ha−1 m 1987 and 32–71 kg N ha−1 in 1988. The results indicate, that growing of cultivars selected for high N uptake-capactiy of the shoots may contribute to an increased utilization of a high soil N supply and thus to a reduction of nitrate leaching.  相似文献   

13.
Soil and climatic conditions in Newfoundland are on the margins of agricultural capability, and almost all feed grain is imported. The overall objective of this work was to develop guidelines for the production of barley in Newfoundland, with the goal of establishing modern cropping recommendations. We conducted a 4-year study near St. John's to examine the effect of seeding rate and topdress ammonium nitrate (N) fertilization rate on Chapais six-row barley ( Hordeum vulgare L.) yield components and grain yield. Increasing seeding rate from 200 to 380 seeds m–2 did not alter grain yield in any year. Increasing topdress fertilization from 0 to 60 kg N ha–1 increased spike density m–2 at harvest, resulting in linear increases in grain yield in all years. Highest N rates had greatest lodging in two years. Based on our results, agronomic recommendations for eastern Newfoundland now include barley seeding rates of 250 ± 50 seeds m–2, with topdress applications up to at least 30 kg N ha–1.  相似文献   

14.
The effect of varying seed rates (100–1000 seeds m−2) and nitrogen fertilizer (0–60 kg N ha-1) applied either in a single basal dose or in splits was investigated on a tall elongating, photosensitive rice variety, Nalini, under semi-deepwater conditions (0–100cm) during 1993 and 1994 at Cuttack, India. Seedling emergence was higher in 1993 (53.9 %) than in 1994 (44.1 %) and it increased proportionately with increasing seed rate, Increase in the number of tillers and panicles m−2 at higher seed rates was associated with a corresponding decrease in panicle weight. Regression analysis indicated a decrease of 0.91–1.28g in panicle weight for an increase of 100 panicles m−2. The grain yield of rice was significantly higher at 400 seeds m−2 in 1993 and at 600 seeds m−2 in 1994 than at low seed rates but further increase in seed rate did not increase the yield. Application of N fertilizer increased the panicle number and thereby grain yield significantly. The effect of basal and split applied N at active or maximum tillering stages as well as between 30 and 60 kg N ha−1 was not significant on the grain yield. The results suggest that a basal dose of 30kg N ha−1 and seeding density of 400–600 seeds m−2, resulting in 40–50 % seedling emergence and 150–200 panicles m−2, each with 2.0–2.5 g weight, may be adequate for optimum productivity of rice under semideepwater conditions.  相似文献   

15.
More detailed information on the causes of yield variability among wheat cultivars is needed to further increase wheat yield. Field studies were conducted in Northern Greece over the two cropping seasons of 1985—1986 and 1986—1987 to assess the effects of nitrogen fertilizer and application timing of the various component traits that determine grain yield, grain nitrogen yield and nitrogen utilization efficiency of two bread ( Triticum aestivum L.) and two durum ( Triticum durum Desf.) wheat cultivars, using yield and yield component analysis. Nitrogen at a rate of 150 kg ha-1 was applied before planting or 100 N kg ha-1 before planting and then 50 N kg ha-1 top dressed at early boot stage. Nitrogen and cultivars affected all traits examined, while split nitrogen application affected only some of the traits. Grain yields in the most cases were correlated with number of grains per unit area and grain weight and grain nitrogen yields in all cases with grain number per unit area. The contribution of the number of grains per spike to total variation in grain yield among cultivars was almost consistent (37 to 55 %), while the contribution of grain weight was more significant (up to 55 %) in high yields (>6.500kg ha-1) and number of spikes per unit area (>500). The number of grains per spike contributed from 60 to 83 % to the total variation in grain nitrogen per spike. Increased grain nitrogen concentration resulted in a reduction of its contribution in grain nitrogen yield variation. Nitrogen utilization efficiency was higher during grain filling than during vegetative biomass accumulation. The contribution of nitrogen harvest index to the variation of utilization efficiency for grain yield was higher in plants receiving nitrogen application.  相似文献   

16.
Determination of optimal N-fertilization rates, NOR , for crop production that minimize risk of environmental degradation require accurate application of a response model. Several models are available to describe crop yield response to N fertilization. The objective of this work was to compare the relative accuracy of a quadratic, f(N Q), a modified Mitscherlich, and tanh( N ) models on 48 data sets. Data were collected from a Tara silt loam (fine-silty, mixed, frigid Pachic Udic Haploboroll) over a 6-year period using two maize ( Zea mays L.) hybrids and four tillage treatments, mouldboard plough, chisel plough, ridge tillage and no-tillage. In about one-third of the cases, all models performed about equally well. Generally, the tanh( N ) and modified Mitscherlich models gave better fit between N rate and grain yield data. The NOR, ranged from about 140 to 170 kg ha−1 for the modified Mitscherlich model, 136 to 184 kg ha−1 for the tanh( N) function, and 124 to 173 kg ha−1 using the f(N Q) model. Estimated grain yields at these rates ranged between 6.58 ± 1.30 to 7.59 ± 1.69 Mg ha−1 for the 90-day Minnesota maturity rated (MR) hybrid and between 7.52 ± 2.40 to 8.72 ± 1.70 Mg ha−1 for the 95-day MR hybrid.  相似文献   

17.
黄淮海区域现代夏玉米品种产量与养分吸收规律   总被引：6，自引：0，他引：6  
为玉米合理施肥,实现高产高效提供理论依据,2016年在济南商河国家农作物新品种展示示范中心和山东农业大学作物生物学国家重点实验室进行试验,于玉米完熟期进行植株取样,测定产量、产量构成因素和植株矿质元素含量,探究黄淮海区域现代夏玉米品种的产量与养分吸收规律。探测分析和正态分布检测结果表明单株生产力、单株生物产量、千粒重和籽粒产量分别符合正态分布N (167.0, 22.722)、N (285.0, 33.472)、N (318.0, 35.752)和N (10.9,1.502),其变化范围为141.55～246.99 g株–1、197.68～389.92 g株–1、226.58～413.76 g和5.84～13.41 t hm~(–2)。每生产100kg籽粒氮素需求量平均为1.95 kg,单位籽粒氮素需求量随籽粒产量提高呈降低趋势。当产量水平由7.0 t hm~(–2)增加到8.0～9.0 t hm~(–2)时,每生产100 kg籽粒氮素需求量从2.15 kg降低到1.96 kg,主要是收获指数升高和籽粒氮浓度降低造成的;当产量水平由8.0～9.0 t hm~(–2)增加到10.0～11.0 t hm~(–2)时,每生产100 kg籽粒氮素需求量从1.96 kg降低到1.84 kg,主要是籽粒氮浓度降低造成的;当产量水平由10.0～11.0 t hm~(–2)增加到11.0 t hm~(–2)时,单位籽粒氮素需求量基本不再变化。生产100kg玉米籽粒的磷素需求量平均为0.97kg,其与籽粒产量呈显著负相关,从产量水平7.0t hm~(–2)的1.07 kg下降到产量水平11.0 t hm~(–2)的0.92 kg,这是由收获指数升高和籽粒磷浓度降低造成的。生产100 kg玉米籽粒钾素需求量平均为1.89 kg,其与籽粒产量呈显著负相关,从产量水平7.0 t hm~(–2)的2.14 kg下降到产量水平11.0 t hm~(–2)的1.74 kg,这是由收获指数升高、茎秆钾浓度增加和叶片钾浓度降低造成的。当前黄淮海区域现代玉米品种籽粒产量为(8.91±1.23)thm~(–2),生产100kg籽粒的氮素、磷素和钾素需求量的变化范围分别为(1.95±0.24)、(0.97±0.11)和(1.89±0.28)kg。氮磷钾需求量随产量的提高而增加,但每生产100kg籽粒产量的氮素、磷素和钾素需求量随着产量升高而下降。  相似文献   

18.
In a soil lacking indigenous Bradyrhizobium japonicum , soybean ( Glycine max [L.] Merr.) nodulation depends upon the number of rhizobia applied with the inoculum. This field study reports the effect of different rates of applied rhizobia on nodulation, dry matter and nitrogen content in soybean in a Mediterranean soil lacking B. japonicum.
Treatments included six rates of B. japonicum , ranging from 2.5 × 104 to 6.075 × 106 rhizobia cells per seed applied to the seed as peat inoculant at planting, 100 kg N ha−1 and an uninoculated control. The experiment was conducted in an Entisol soil. Regression analysis showed linear relationship between the rate of applied rhizobia and the number of the nodules per plant or the dry weight per nodule. In early stages of development (32 and 68 days after planting) plant dry weight was not affected by inoculation rate. At harvest a rate of 7.5 × 104 rhizobia cells per seed was necessary for maximum total and stover dry weight. A higher rate, 6.75 × 105 rhizobia cells per seed, was required to obtain maximum grain yield, total N content in plant tops and grain N content. Grain percentage N was increased up to 2.025 × 106 rhizobia cells per seed. Nitrogen application increased grain yield, total N content and grain N content at the same level as the lower inoculation rate.  相似文献   

19.
Nitrogen management for production of bread quality wheat ( Triticum aestivum L.) in eastern Canada has received little research attention. An experiment was conducted for 2 years at each of two sites in Québec to study the effect of level and timing of nitrogen (N) fertilizer application on grain protein concentration, protein content per seed, non-protein seed dry matter, grain protein yield and nitrogen harvest index (portion of plant N in the grain) of four hard red spring wheat cultivars known to have potential as bread wheats in eastern Canada. The soil types were Bearbroock clay (fine, mixed, non-acid, frigid, Humaquept) and Ste-Rosalie clay (typic, non-acid, frigid, Humaquept). The experiment was a 4 × 4 × 2 factorial. Four cultivars were used: Columbus, Katepwa, Max and Hege 155–85. In both years 0, 60, 120 and 180 kg Nha−1 were applied either all at seeding or 60 % at seeding and 40 % at heading. Grain protein concentration and grain protein yield increased consistently with increasing N fertilizer and with split N application. Nitrogen harvest index was not increased by increasing applications of N fertilizer. Protein content per seed was more critical in determining grain protein concentration than non-protein seed dry matter content. The western Canadian cultivars Columbus and Katepwa generally had greater grain protein concentration than the European cultivars Max and Hege 155–85, With reasonable N fertility the grain protein concentration of spring wheats grown in eastern Canada are sufficient for bread production.  相似文献   

20.
From all plant nutrients N fertilizer rates deserve highest attention as too high rates may result in nitrate leaching, volatilisation of N2O (greenhouse gas) and affect the farmers’ profit. Too low rates will also depress the profit. The problem is accentuated by the fact that crops not only feed from soil inorganic but also from organic soil N. Most soil N tests do not consider the available organic soil N. The Electro-Ultra-Filtration (EUF) method applied by us takes into account the EUF extractable inorganic and organic soil N for calculating the N fertilizer rate. This method developed at the Liebig University Giessen is called Giessen model (sampling in autumn out of the upper soil layer, 0–30 cm). We compared it with the standard soil N test the “Nmin method” recommended by German officials which method does not consider the available organic soil N (sampling in spring out of three or two soil layers, depending on soil depth). The investigation was carried out on farmers’ fields on five different sites with winter cereals (wheat, barley) in 1989/1990, 1990/1991 and 1991/1992. Recommended fertilizer application rates differed somewhat for both methods. Of the 23 cases, significantly higher grain yields were obtained five times by Nmin and four times by EUF; otherwise grain yields did not differ significantly between both methods. Grain yield and crude protein concentration were increased by fertilizer N compared with the plots without N fertilizer. On the site Giessen, however, there were some cases in which the N fertilizer did not increase grain yield. The soil of the Giessen site was rich in interlayer NH4+ which is not recovered by the EUF and Nmin method, but which obviously contributed to the N supply of the crop, and therefore the N rates were too high. Grain crude protein concentration were higher with Nmin for Wernborn and Bruchkobel sites because of higher N fertilizer rates. For the Giessen site in 1989/1990 the reverse was true. Nitrogen agronomic efficiency (AE) ranged from 0 to 35.6. Apparent N recovery (ANR) ranged from 0 to 111. The gross profit differed from −88 to 489 Euro/ha. Negative values (three cases out of 23) were found on the Giessen site where no yield increase was obtained by the N fertilizer because of interlayer NH4+. This interpretation is supported by the finding that interlayer NH4+ significantly decreased from autumn to spring. Apart from the results found in 1 year on the Giessen site, the gross profit calculation showed that a precise N fertilizer application based on soil analysis yields a high profitability of cereal production.  相似文献   

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