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1.
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   

2.
Gram sorghum [ Sorghum bicolor (L.) Moench] is grown on marginal land and johnsongrass [Sorghum haiepense (L.) Pers] is the most common and hard to control weed in this crop. The agronomic performance of gram sorghum at different nitrogen (N) and johnsongrass infestation levels in the field has not been adequately investigated. Therefore, research was conducted on a Decatur silty clay loam soil (Rhodic Paleudult) to determine the influence of N rates (0, 40, 80 and 120 kg ha-1) and johnsongrass infestation levels (0, 2, 4, 6 and 8 plants per 5 m crop row) on the growth and yield of grain sorghum (cv. GK522G) and johnsongrass. Increase in N rates increased seed weight, seed yield and percent protein in grain sorghum as well as dry matter and percent protein of johnsongrass. The increase in johnsongrass infestation (from 0 to 8 plants per 5 m crop row) significantly decreased the performance of grain sorghum and johnsongrass at all the N rates. The results suggest that 40 kg N ha-1 with up to 2 johnsongrass plants per 5 m crop row or 80 kg N ha-1 with up to 4 johnsongrass plants per 5 m crop row produced grain sorghum yields equivalent to absence of johnsongrass in the crop.  相似文献   

3.
Experiments were conducted in two consecutive years to investigate the response of two corn (Zea mays, L.) cultivars, Eperon and Challenger, to timing of N fertilizer in a desert climate. Fertilizer was applied three times (at planting, 6 weeks after sowing (6WAS) and at 9WAS) to give a seasonal total of 180 kg N ha-1 The N treatments were Nooo (control), NLOH (60 kg N ha-1 at planting, none at 6WAS and 120 kg N ha-1 at 9WAS), NLLL (60 kg N ha-1 at sowing, 6WAS and at 9WAS) and NLOH, (60 kgN ha-1 at planting, 120 kg N ha-1 at 6WAS and none at 9WAS). Generally, N ha-1 was associated with the highest grain and dry matter yields. Plants in N treated plots had significantly larger number of leaves and ear leaf N contents than the control at mid-silk. High ear leaf N was associated with high leaf area index and dry matter yield. Based on these results, it would appear that the application of 60 kg N ha-1 at planting, followed by 120 kg N ha at 6WAS (NLHO) is the most suitable for enhancing corn yields in the desert climate.  相似文献   

4.
The effects of increased yield and grain number per unit area in barley in response to nitrogen application are well known. However, the influence of applied nitrogen on the rates and durations of developmental phases in barley are less well understood. Our objective was to investigate the effect of applied nitrogen on the duration of pre-anthesis development in barley and the number of spikelets per spike in two barley cultivars, Franklin and Schooner, in two studies. We found no effect of nitrogen on the duration of the pre-anthesis period in Schooner, when applied to pots at a rate of 0 or 55 kg N ha-1, or when applied in the held at 0, 40 or 160 kg N ha-1. However, this duration was extended in Franklin in the first study by an application of 55 kg N ha-1. Both plant biomass and grain yield at maturity were increased between 0 and 55 kg N ha-1, and 0 and 160 kg N ha-1. Meld increase was largely associated with an increase in the number of tillers per plant.  相似文献   

5.
Field experiments were conducted during the wet seasons of 1991,1992 and 1993 at the Abubakar Tafawa Balewa University Farm, Bauchi (10 ° 22'N, 09 ° 47'E) to study the response of sunflower ( Helianthus annaus L.) to N rates and plant population under rainfed conditions. Four N rates (0, 50, 100 and 150 kg N ha -1) and four plant populations (40000,80000,120000 and 160000 plants ha-1) were factorially combined in a randomized complete block design with three replications. Leaf area index, shoot dry weight and seed yield (kg ha-1) increased significantly with increasing N rates from 0 to 100 kg N ha-1. The growth and yield parameters per plant decreased significantly with increasing plant populations from 40000 to 160000 plants ha-1, but the seed yield (kg ha-1) obtained at 80000 plants ha-1 was significantly higher than all the other plant populations. The interactions of N x plant population confounded the main effect of each factor on the growth and yield of sunflower. The seed yield (3425 kg ha-1) obtained from the use of 100 kg N ha-1 at 80000 plants ha-1 was significantly higher than those obtained from all other combinations of N x population and out-yielded the main effects of 100 kg N ha-1 and 80000 plants ha-1 by 18 % and 25 %, respectively. The use of 100 kg N ha-1 at 80000 plants ha-1 is therefore recommended for maximum yield of sunflower in Bauchi.  相似文献   

6.
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   

7.
A field experiment was carried out at four location-years in Southwestern Quebec, Canada in 1990 and 1991, to evaluate the effects of nitrogen (N) application on protein, lipid, non-structural carbohydrate (NSC), and remaining grain components concentrations of maize ( Zea mays L.) grain during kernel development. Three N fertilizers (ammonium nitrate, urea, and calcium ammonium nitrate) were compared for plants receiving pre-plant incorporated N fertilizer at 180 kg ha-1 as well as a control which received no N fertilizer. The results indicated that between 20 and 30 days after pollination (DAP) protein concentration of maize kernels declined sharply, thereafter only slightly, irrespective of the treatment. At most stages and in all four location-years protein concentration was raised significantly by N-application without clear difference between N-fertilizer sources. At 20 DAP seeds of N-fertilized plants contain 25.5 mg g-1 more than those without N-application (control); later on, this difference was lower (12.8 mg g-1) but remained constant over time if averaged over N-sources and location-years. At most growth stages and in most location-years the lipid concentration did not respond to N fertilizer application. Lipid concentration followed an "N" shaped curve over the course of grain development. Non-structural carbohydrate (NSC) concentration increased significantly during grain filling and showed little effect due to N application. However, at most growth stages in the four location-years, the concentration of remaining grain components tended to decline with N application. A significant negative correlation existed between the changes in protein concentration and NSC concentration during kernel development.  相似文献   

8.
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   

9.
A 2-year (1989, 1990) experiment was conducted in the Carpathian Basin near Keszthely, Hungary to evaluate the course of nitrogen (N), phosphorus (P) and potassium (K) concentrations in the developing grain. Two maize hybrids were grown at four rates of N application (0, 50, 150 and 250 kg N ha-1). Plots had been fertilized at these levels since 1983. As a result of the long-term N treatments, stocks of P and K in the soil decreased as the rate of N application increased. As expected, concentrations of N in the mature grains were higher at high doses of N, whereas the rate of N application had little impact on the P and K concentrations in the ripe grains. Only in 1989, when grain yield showed a relatively stronger response to applications of N than in 1990, were the concentrations of P and, to a lesser extent, K reduced by additions of N. These results illustrate that P and K concentrations in the grain are well-buffered against increments in grain yield resulting from the application of N and are also relatively insensitive to low supplies of P and K in the soil. In both hybrids, concentrations of N, P and especially K declined considerably with ongoing grain filling, irrespective of N treatment. Differences in concentrations of P and K for hybrids existed but were not consistent across years.  相似文献   

10.
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   

11.
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   

12.
Aspects of intensive management practices such as high N fertilization inputs and plant growth regulator use could potentially increase cereal yields in regions with a short crop-growing season and occasionally dry and hot weather. A field experiment was carried out for four years (1987 to 1990) at Agronomy Research Centre of McGill University, Canada to evaluate the response of spring barley ( Hordeum vulgare L.) cv. Cadette, Laurier and Leger to N rates (0, 70 and 140 kg N ha−1) and ethephon (2-chloroethyl phosphonic acid) growth regulator treatment. The application of higher than conventional N level (70 kg N ha−1) did not increase barley yields under dry weather conditions and when the soil N resources were high. The high levels of N did increase the grain crude protein concentration by 2 to 10 g kg−1, as did ethephon treatment. The feed quality of spring barley was improved. Ethephon treatment reduced grain yield due to a severe reduction in the number of grains spike−1, and/or 1000-grain weight, although the number of spikes m−2 was increased. Thus, the overall effect of ethephon treatment on yield was inconsistent and was influenced to a large extent by the prevailing weather conditions.  相似文献   

13.
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   

14.
Nitrogen (N) fertilizer is an important and expensive input in small-grain cereal production, and growers therefore should aim to optimize its use. Possibilities for using grain protein concentration for post-harvesr evaluation of N sufficiency were determined in this study. Field experiments including spring wheat ( Triticum aestivum L.), spong barley ( Hordeum vulgare L) and spring oats ( Avena sativa L.), and various rates of N fertilizer application were conducted in southern and western-Finland over 2 years. Grain yield and grain protein were positively correlated and firred quadratic regression models. Both critical and optimum levels for grain protein concentration were determined by Cate-Nelson analysis Critical values were 12.2 for wheat, 10.2 for barley and 10.9 for oats, and corresponding optimum values were 13.3, 11.1 and 12.7, respectively. The accuracy of the method was tested using results from on-farm spring wheat trials. The results indicated that N fertilizer uptake and grain yield were best in held where gram protein concentration exceeded the critical values but not the optimum. Growers should use more intensive N fertilization management if grain protein concentration does not exceed critical values. Grain protein concentrations above optimum values indicate over-fertilization for maximum grain yield. Analysing previous research data to identify the "critical level" of grain protein concentration is not difficult, and will provide powers, extension personnel, and fertilizer dealers with a cost effective means of evaluating the efficiency of N use by the crop and for developing N fertilization recommendations.  相似文献   

15.
Three chemicals, viz., thiourea, thiamine and ascorbic acid capable of potentiating-SH turnover, were tested with the objective to improve growth and productivity of maize. Thiourea was tested as seed-soaking and foliar-applied treatments as also in combination. Thiamine and ascorbic acid were tested as foliar sprays alone. Foliar treatments were applied at vegetative stage (30 and 45 days after sowing).
The results of the field experiment showed that seed soaking with thiourea (500 ppm) tended to improve grain yield (13.4 per cent over control), but improvement in biological yield was significant. However, seed soaking plus foliar treatment of thiourea significantly increased both biological and grain yields, besides causing significant improvement in leaf area index and number of green leaves plant-1. The increase in grain yield ha-1 was of the order of 34.6 per cent over control.
It was further noted that foliar sprays of thiourea (1000 ppm), thiamine (100 ppm) and ascorbic acid (100 ppm) significantly increased leaf area index, number of green leaves plant-1 and biological yield ha-1. These treatments also significantly increased grain yield ha-1 by 40.6, 20.2 and 26.3 per cent, respectively over control. Improvement in maize yield with thiourea, thiamine and ascorbic acid treatments appeared to have resulted from increased photosynthetic efficiency and canopy photosynthesis on account of the biological activity of -SH group. It was also apparent that leaf senescence was delayed under the influence of these chemicals. It is therefore suggested that thiourea, thiamine and ascorbic acid are the potential bioregulators for improving photosynthetic efficiency and grain yield of maize and possibly other cereals, and that thiourea, a sulphydryl compound, holds considerable promise in this context.  相似文献   

16.
Most farmers in the rainfed parts of Jordan who use fertilizers use less than optimum rates of N and P because of the uncertainties associated with rainfall. Research results obtained by the national program indicated that the use of improved barley cultivars and fertilizers would result in substantial yield increases. The objective of the present investigation was to determine the optimum combination level of N and P for newly promising cultivars. The effect of 0–0, 5–10, 10–20 and 15–30 kg.ha−1 of nitrogen (N) and phosphorus (P) levels on barley cultivas Rum, Giza, Fun, Harmel and Arta under rainfed conditions in the Mediterranean climate was studied during two cropping seasons, 1994-95 and 1995–96. Increased grain and straw yields, total N and P uptake and RUE were recorded with increasing N and P levels for almost all cultivars. Rum was significantly (P = 0.05) the highest grain and straw producer and highest RUE at the 10 N- and 20 P kg.ha−1 level. The cultivar × fertility level (N–P) interactions were not significant for both grain and straw yields and for total N and P uptake.  相似文献   

17.
氮肥和密度对高粱产量及氮肥利用率的影响   总被引：5，自引：1，他引：4  
为了研究氮肥施用量和密度对高粱产量的影响,在大田试验条件下,采用裂区设计,以密度为主区,以氮肥施用量为副区,分别设置3个密度水平（7.5万、10.5万和13.5万株/hm 2）和5个氮肥水平（0、75、150、225和300kg/hm 2）,对不同密度和氮肥处理的产量构成因素和农艺性状进行分析,结果表明：高粱的产量先随密度的增加和氮肥施用量的增加呈增加趋势,在密度为10.5万株/hm 2,施氮量为225kg/hm 2时,高粱的产量达到最高。在不同密度和氮肥处理,高粱的单位面积穗数和穗粒数变异较大,千粒重变异较小。密度主要是通过单位面积穗数,氮肥主要是通过穗粒数来影响产量的构成。施氮量与高粱产量是非线性关系,氮肥在高密度条件下对产量的调控更加明显。氮肥的农学利用率在高密度处理比低密度处理要高,并随着氮肥施用量的增加呈先增加后减少的变化趋势,在密度为13.5万株/hm 2,施氮量为150kg/hm 2时,氮肥的农学利用率达到最大。本研究表明,增加密度、控制氮肥用量是增加高粱产量和提高氮肥利用率的有效措施,建议晋杂23号在汾阳种植时宜采用密度为10.5万株/hm 2,施氮量为225kg/hm 2的种植模式。  相似文献   

18.
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   

19.
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   

20.
为探索中高海拔山区有机肥不同用量与配比对食粒豌豆常见病害的防控效果,采用多水平随机区组试验,分别研究播种时施用有机肥、苗期浇施氮钾全水溶性有机肥或(和)磷酸二氢铵对食粒豌豆枯萎病、白粉病和褐斑病的田间防效。结果表明,施用4500 kg/hm2有机肥作底肥与氮钾全水溶性有机肥组配在中、高海拔点对食粒豌豆枯萎病、褐斑病有很好的防控效果,枯萎病最高防效为100%,褐斑病最高防效为48.23%,但有机肥不同用量与配比对白粉病没有防控效果;施用4500～9000 kg/hm2有机肥作底肥与苗期追施2次氮钾全水溶性有机肥组配对食粒豌豆有增产效果,高海拔点最高增幅为25.55%,中海拔点最高增幅为19.71%。综合两地试验结果,施用4500 kg/hm2有机肥作底肥+2次全水溶性有机肥作追肥处理具有控病增产效果。  相似文献   

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