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1.
V. Borkovec S. Procházka M. El.-D. Ibrahim 《Journal of Agronomy and Crop Science》1990,165(4):217-223
A lysimeter trial is described in which the fate of 15 N was monitored in a sand, loam and clay soil by using it over a period of 6 years. The following results were obtained.
1. The uptake of fertilizer nitrogen by plants, determined by using15 N, is lower than by using the conventional method ("difference method"). Nitrate 15 N is better utilized by the plants than is ammonium 15 N. The total nitrogen uptake only gives hints of these differences.
2. The extent to which plants utilize fertilizer15 N is between 38 and 58%; in the case of the method of differences this figure is between 48 and 68%.
3. Plants remove more nitrogen from the soil when fertilizer N is applied than when without fertilization. The influence of these two nutrient forms is of subordinate significance.
4. After a trial period of six years between 26 and 54 % of the fertilizer15 N remains in the soil. The resulting sequences are clay > loam > sand > and ammonium > nitrate.
5. The immobilization of the fertilizer15 N is most pronounced in the first four years but then decreased considerably; in the case of the sandy soil it is then even slightly regressive.
6. The biggest part of the15 N is deposited in the uppermost layer of the soil. The amount of 15 N in the deeper layers is diminished appreciably. The type of soil has a greater influence than the form of nitrogen.
7. If the amount of fertilizer N left in the soil is compared with the N losses from the soil's reservoir (plants' uptake, leaching) there is a negative balance for the soil nitrogen which mainly is determined by the type of soil. 相似文献
1. The uptake of fertilizer nitrogen by plants, determined by using
2. The extent to which plants utilize fertilizer
3. Plants remove more nitrogen from the soil when fertilizer N is applied than when without fertilization. The influence of these two nutrient forms is of subordinate significance.
4. After a trial period of six years between 26 and 54 % of the fertilizer
5. The immobilization of the fertilizer
6. The biggest part of the
7. If the amount of fertilizer N left in the soil is compared with the N losses from the soil's reservoir (plants' uptake, leaching) there is a negative balance for the soil nitrogen which mainly is determined by the type of soil. 相似文献
2.
H. Bergmann H. Eckert C. Weber und D. Roth 《Journal of Agronomy and Crop Science》1991,166(2):117-126
Effect of monoethanolamine on yield of crops
I. Studies on the effect of monoethanolamine on the grain yield and the nitrogen household in cereal plants (pot experiments)
The effect of monoethanolamine (EA, applied as foliar spray, 10 mg per pot) on grain yield and yield components was investigated in pot experiments with spring barley, winter wheat, and winter rye. Under conditions of a moderate drought stress the applied EA increased the grain yield of spring barley from 5 % to 7 % (significance only at α= 0.05). A stimulating effect of EA on the grain yield of winter wheat and winter rye was also obtained.
The positive influence of EA on the grain yield of spring barley was reproducible under the conditions of a limited water supply in small-scale plot experiments (increase of yield about 9 %).
In case of spring barley and winter rye the increase of the grain yield by EA, applied at growth stage 31 (= DC 31) was connected with a greater number of ear-bearing tillers. The increase of the winter wheat yield resulted from more grains per ear of the tillers.
The enhanced formation of tiller grain mass and total tiller biomass by EA was in correlation with a higher nitrogen import into tillers (r = 0.8+ ). Since an export of N from the main shoots into the tillers was not observed a higher N uptake (≥ 6 %) was calculated from N balances. After a fertilization with 15 N-labelled fertilizers the additional 15 N uptake was 13 % to 20 %.
Possible stress reducing activities caused by EA are discussed. 相似文献
I. Studies on the effect of monoethanolamine on the grain yield and the nitrogen household in cereal plants (pot experiments)
The effect of monoethanolamine (EA, applied as foliar spray, 10 mg per pot) on grain yield and yield components was investigated in pot experiments with spring barley, winter wheat, and winter rye. Under conditions of a moderate drought stress the applied EA increased the grain yield of spring barley from 5 % to 7 % (significance only at α= 0.05). A stimulating effect of EA on the grain yield of winter wheat and winter rye was also obtained.
The positive influence of EA on the grain yield of spring barley was reproducible under the conditions of a limited water supply in small-scale plot experiments (increase of yield about 9 %).
In case of spring barley and winter rye the increase of the grain yield by EA, applied at growth stage 31 (= DC 31) was connected with a greater number of ear-bearing tillers. The increase of the winter wheat yield resulted from more grains per ear of the tillers.
The enhanced formation of tiller grain mass and total tiller biomass by EA was in correlation with a higher nitrogen import into tillers (r = 0.8
Possible stress reducing activities caused by EA are discussed. 相似文献
3.
Strategies to Improve the Use Efficiency of Mineral Fertilizer Nitrogen Applied to Winter Wheat 总被引:4,自引:0,他引:4
Recovery of fertilizer nitrogen (N) applied to winter wheat crops at tillering in spring is lower than that of N applied at later growth stages because of higher losses and immobilization of N. Two strategies to reduce early N losses and N immobilization and to increase N availability for winter wheat, which should result in an improved N use efficiency (= higher N uptake and/or increased yield per unit fertilizer N), were evaluated. First, 16 winter wheat trials (eight sites in each of 1996 and 1997) were conducted to investigate the effects of reduced and increased N application rates at tillering and stem elongation, respectively, on yield and N uptake of grain. In treatment 90‐70‐60 (90 kg N ha?1 at tillering, 70 kg N ha?1 at stem elongation and 60 kg N ha?1 at ear emergence), the average values for grain yield and grain N removal were up to 3.1 and 5.0 % higher than in treatment 120‐40‐60, reflecting conventional fertilizer practice. Higher grain N removal for the treatment with reduced N rates at tillering, 90‐70‐60, was attributed to lower N immobilization (and N losses), which increased fertilizer N availability. Secondly, as microorganisms prefer NH4+ to NO3? for N immobilization, higher net N immobilization would be expected after application of the ammonium‐N form. In a pot experiment, net N immobilization was higher and dry matter yields and crop N contents at harvest were lower with ammonium (ammonium sulphate + nitrification inhibitor Dicyandiamide) than with nitrate (calcium nitrate) nutrition. Five field trials were then conducted to compare calcium nitrate (CN) and calcium ammonium nitrate (CAN) nutrition at tillering, followed by two CAN applications for both treatments. At harvest, crop N and grain yield were higher in the CN than in the CAN treatment at each N supply level. In conclusion, fertilizer N use efficiency in winter wheat can be improved if N availability to the crops is increased as a result of reduced N immobilization (and N losses) early in the growth period. N application systems could be modified towards strategies with lower N applications at tillering compensated by higher N dressing applications later. An additional advantage is expected to result from use of nitrate‐N fertilizers at tillering. 相似文献
4.
Ten charges of 15 N-labelled straw with different C/N ratios were incubated with lightly loamed sand at 25 °C and 50 % of the maximum water capacity. At the start of the 18-week incubation, mineral nitrogen was added and the 15 Nmin (NH4 and NO3 -N) content was determined six times during the course of the experiment. A slow release of 15 N was observed. After 111 days, between 2.5 and 13.0% of the total applied 15 N was mineralized. The addition of ammonium sulphate caused an increasing degradation of organic N compounds of the straw material even during the first weeks. Finally, between 6.4 and 33.3 %15 N was released. The 15 N release only partially shows the straw degradation. 相似文献
5.
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
6.
Nitrogen Balance of Legume-Wheat Cropping Sequences 总被引:1,自引:0,他引:1
In a lysimeter trial the legumes faba bean ( Vicia faba ), red clover ( Trifolium repens ), and alfalfa ( Medicago sativa ) were grown for two years, followed by winter wheat on all plots in the third year. Plots fertilized with mineral nitrogen and a rye/maize – wheat cropping sequence were included for comparisons. These four cropping sequences were replicated twice in 1982–1984 and 1985–1987, respectively. Two soils, a loamy sand and a sandy loam were used.
On average of both soils:
– N fixation during two years was 461 kg N/ha, 803 kg N/ha, and 790 kg N/ha for faba bean, red clover, and alfalfa, respectively.
– Leaching of nitrogen occurred mainly during the periods of winter fallow or, in case of the perennial legumes, after incorporation of residues into the soil and planting of wheat. Average leaching for all 6 years was 49, 28, and 29 kg ha−1 year−1 for faba bean, red clover, and alfalfa, respectively.
– In the period of wheat growth and before planting the new crop (1.5 years) in 1984/85 51–64 kg N/ha and 1986/87 68–94 kg N/ha were leached after growing legumes. Leaching was less for rye/maize fertilized with mineral N, 41 kg N/ha in 1984/85, and 51 kg N/ha in 1986/87, respectively.
– Winter wheat grown after legumes took up 18 kg N/ha < 47 kg N/ha < 65 kg N/ha on average of both soils and 2 years (1984, 1987) after faba bean, red clover, and alfalfa, respectively. This indicates a nitrogen recovery of 24–44% of the legume N potentially available, and consequently a loss by leaching from 56 to 76 %.
On the sandy loam amount of drainage water and N leaching were lower, and faba bean and wheat yields higher than on the loamy sandy soil. 相似文献
On average of both soils:
– N fixation during two years was 461 kg N/ha, 803 kg N/ha, and 790 kg N/ha for faba bean, red clover, and alfalfa, respectively.
– Leaching of nitrogen occurred mainly during the periods of winter fallow or, in case of the perennial legumes, after incorporation of residues into the soil and planting of wheat. Average leaching for all 6 years was 49, 28, and 29 kg ha
– In the period of wheat growth and before planting the new crop (1.5 years) in 1984/85 51–64 kg N/ha and 1986/87 68–94 kg N/ha were leached after growing legumes. Leaching was less for rye/maize fertilized with mineral N, 41 kg N/ha in 1984/85, and 51 kg N/ha in 1986/87, respectively.
– Winter wheat grown after legumes took up 18 kg N/ha < 47 kg N/ha < 65 kg N/ha on average of both soils and 2 years (1984, 1987) after faba bean, red clover, and alfalfa, respectively. This indicates a nitrogen recovery of 24–44% of the legume N potentially available, and consequently a loss by leaching from 56 to 76 %.
On the sandy loam amount of drainage water and N leaching were lower, and faba bean and wheat yields higher than on the loamy sandy soil. 相似文献
7.
A pot experiment was conducted to investigate the translocation of N in pods during siliqua developing of oilseed rape using 15 N-urea. The 15 N was applied on the surface of pods at lower stem in three periods after flowering. At maturity the hulls and seeds of pods at different parts of plants were subjected to analyse N content and 15 N abundance and calculate recoveries of N applied.
79.1–84.3 % of labelled N applied were recovered from the total pods including 75.3–80.4 % in labelled pods. A great part of the N was translocated in seeds, the later the labelled N application, the more proportion of N in seeds was. Application of MgSO4 combined with urea promoted the uptake and translocation of N, but not at a significant level. 相似文献
79.1–84.3 % of labelled N applied were recovered from the total pods including 75.3–80.4 % in labelled pods. A great part of the N was translocated in seeds, the later the labelled N application, the more proportion of N in seeds was. Application of MgSO
8.
K. Waloszczyk 《Journal of Agronomy and Crop Science》1991,166(4):238-248
Results of yield formation at ecological oriented winter wheat cultivation on Calcic Chernozem soil in arid areas
The influence were examined in field experiments of wheater elements (air temperature, precipitation), nitrogen fertilization, sowing rate and irrigation on the yield and yield formation of winter wheat stands. The average level of yields amounts to 81.3 dt/ha (76…93.8 dt/ha). Limiting factor for yields is the availability of water in the soil. In humide seasons 9…12 % higher yields were obtained then in dry seasons. Without nitrogen fertilization yields of winter wheat are lower by 18 % than with nitrogen fertilization. At very high level of N fertilization only vegetative biomass increases, and the water use efficiency decreases.
Increase in plants/m2 caused a rise of vegetative biomass and of ears/m2 , kernels per ear strongly decreased in the same time. At winter wheat cultivation in low input farming systems without nitrogen fertilization high yields will be obtained with 320…370 plants/m2 and 15,000 kernels/m2 . Nitrogen uptake from the soil amounts to 180 kgN/ha. Because of great amounts of inorganic in the soil (70…200 kgN/ha) sufficient nitrogen is available until heading of the wheat plants. The nitrogen supply of wheat plants in later stages of development is influenced by wheater conditions. 相似文献
The influence were examined in field experiments of wheater elements (air temperature, precipitation), nitrogen fertilization, sowing rate and irrigation on the yield and yield formation of winter wheat stands. The average level of yields amounts to 81.3 dt/ha (76…93.8 dt/ha). Limiting factor for yields is the availability of water in the soil. In humide seasons 9…12 % higher yields were obtained then in dry seasons. Without nitrogen fertilization yields of winter wheat are lower by 18 % than with nitrogen fertilization. At very high level of N fertilization only vegetative biomass increases, and the water use efficiency decreases.
Increase in plants/m
9.
10.
Differences between Maize Cultivars in Yield Formation, Nitrogen Uptake and associated Depletion of Soil Nitrate 总被引:6,自引:0,他引:6
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
11.
Evaluation of N Fertilizer Rate and Timing and Wheat Cultivars on Soil Residual Nitrates 总被引:3,自引:0,他引:3
Nitrogen (N) fertilizer management for production of bread quality wheat may increase nitrate residues in the soil. To assess soil nitrate levels associated with bread quality wheat ( Triticum aestivum L.) production in Eastern Canada, an experiment was conducted for 2 years at each of two sites in Québec. Four cultivars (Columbus, Katepwa, Max and Hege 155-85), four N levels (0, 60, 120 and 180 kg N ha−1 ) and two N timings (all at seeding time or 60 % at seeding and 40 % at anthesis) were combined in a factorial arrangement on a Bearbrook clay and a Ste-Rosalie clay. Residual soil NO3 -N levels were measured in the 0–20 and 20– 60 cm soil layers. The cultivars used have potential as bread wheats. Cultivar effects on soil nitrate levels existed only in the Ste-Rosalie soil, suggesting that the cultivars used were better adapted to the conditions on the Bearbrook soil. Changes in soil NC3 N levels over winter indicated that mineralization had occurred. Calculated balance-sheet values were larger than measured residual NO3 -N in the autumn of each year, indicating that NO3 -N was lost from the systems, possibly due to denitrification. Potential increases in, and thus potential pollution from, residual soil NO-N existed only at the 180 kg N ha−1 level. Overwinter changes in soil NO3 -N levels were proportional to the inverse of the fall NC3 N levels. Differences between sites were large for many of the variables measured. 相似文献
12.
Investigations about the effect of ammonium- and nitrate nutrition on the formation of yield and protein of oats genotypes
The formation of yield and proteins of three different oats genotypes (cv. Gambo, Flämingskrone, Caesar ) in dependence on ammonium or nitrate nutrition was investigated in pot trials over 2 years (from 1982 to 1983). On oats the NH4 -nutrition showed in comparison to NO3 nutrition increases in grain yield up to 20 % due to a favourable influence on the number of panicles per pot (s. Fig. 1).
Protein content and protein yield increased particularly by high fertilizing with NH4 -N (N3 - and Invariant); the best effect was ascertained by the N4 -variant increase of 4 % (D.M.). Among the protein fractions (albumins, globulins, prolamins, glutelins) the albumin- and prolamin-proteins increased after NH4 -fertilizing by 1–2 %, whereas at the same time the glutelins decreased by 1–4 %; the globulins showed no differences. 相似文献
The formation of yield and proteins of three different oats genotypes (cv. Gambo, Flämingskrone, Caesar ) in dependence on ammonium or nitrate nutrition was investigated in pot trials over 2 years (from 1982 to 1983). On oats the NH
Protein content and protein yield increased particularly by high fertilizing with NH
13.
Zhang Qinzheng Lan Xiafua Xi Haifu Zhu Xuequn Liu Yinhua 《Journal of Agronomy and Crop Science》1991,166(2):96-100
The conversion of SO2- 4 -S and changes in content of S in various constituents in leaves of rape seedlings transplanted were investigated by using (NH4 )2 35 SO4 as a tracer to exploit formation and accumulation of glucosinolates in oilseed rape. Seedlings grown under sandy culture absorbed 35 SO2- 4 which was added to the cultural solution and incorporated into amino acids, glucosinolates and proteins rapidly. Distribution of extractable 35 S with 70 % methanol in glucosinolates in leaves declined with time from labelling, while those in amino acids rised correspondingly. Per cents of 35 S incorporated into bound form in total 35 S increased linearly and those of 35 S into glucosinolates and amino acids decreased with time within five days from labelling. After that the relative amounts of 3S S in three constituents was basically constant. Content on dry weight basis of labelled glucosinolates and amino acids expressed as μmol S/g.d.w. increased linearly with time from labelling with absorption of 35 SO2- 4 from soil by the seedlings under soil culture. Compared with seedlings grown under sandy culture, more 35 S was incorporated into glucosinolates in leaves of seedlings grown under soil culture. 相似文献
14.
Nitrogen utilization and uptake patterns of wheat was studied using 15 N labelled fertilizer at four rates of application. Plants harvested at maximum tillering and at flowering indicated that plant N levels stabilized with time. Fertilizer N uptake and utilization of added fertilizer increased with time. However, uptake of soil N was not affected by rates of fertilizer at early stages. Increases were observed only at higher rates at the later harvest. 相似文献
15.
Pflanzenwachstum durch CO2 /HCO3 -Eintrag über die Wurzel 总被引:1,自引:0,他引:1
W. Schäfer 《Journal of Agronomy and Crop Science》1988,160(4):228-234
Plant Growth after Application of CO2 /HCO3 to the Roots
After applying H14 CO3 to the root system of summer wheat in hermetically sealed pots, absorption and incorporation of HCO3 in the sugar-, starch-, and fibre-fraction (approximately 50 % of the absorped 14 C) could be shown. This fraction reached 0.44–1.21 % of total C-assimilation of the shoot during growing stage F9/F10 on the Feeke-scala. 1/3 of the HCO3 -fraction resting in the soil was bound organically indicating that microorganisms may be able to utilize exogenous anorganic CO2 /HCO3 for their photosynthesis. 相似文献
After applying H
16.
The influence of undersown green manure crops for fallows – set-aside land – in view of vegetation-development and the dynamic of nitrate
In view of the establishment of rotational fallows - set-aside land - as well as the bridging of the vegetation-free winter period the suitability of different undersown grasses and legumes m winter cereals was investigated in field trials. Festuca rubra developed well in winter barley and winter wheat. The success of the cultivation of Lolium perenne, Trifolium pratense and Trifolium repens in winter cereals is uncertain because of the risk of light and water deficiences. Dactylis glomerata caused an negative influence on the yield of the cover crop. During the fallow period only low levels of nitrate could be found in the soil. Under fallow tilled repeatedly complete fallow- a nitrate accumulation could be observed during the fallow period. After ploughing up the fallow vegetation, nitrate concentrations - depth 0–150 cm – increased to 60 kg NO3 -N · ha-1 after the natural fallow without seeding, between 60 and 130 kg NO3 -N · ha-1 after Trifolium and between 160 and 210 kg NO3 -N · ha-1 after complete fallow. Lowest nitrate levels were observed from the grass-sites. Undersown Festuca rubra seems to be the best choice in order to compete with weeds, to form a dense sod and to prevent nitrate leaching. In general a seed rate of 8 kg · ha-1 can be recommended. 相似文献
In view of the establishment of rotational fallows - set-aside land - as well as the bridging of the vegetation-free winter period the suitability of different undersown grasses and legumes m winter cereals was investigated in field trials. Festuca rubra developed well in winter barley and winter wheat. The success of the cultivation of Lolium perenne, Trifolium pratense and Trifolium repens in winter cereals is uncertain because of the risk of light and water deficiences. Dactylis glomerata caused an negative influence on the yield of the cover crop. During the fallow period only low levels of nitrate could be found in the soil. Under fallow tilled repeatedly complete fallow- a nitrate accumulation could be observed during the fallow period. After ploughing up the fallow vegetation, nitrate concentrations - depth 0–150 cm – increased to 60 kg NO
17.
夏玉米施氮量对后茬冬小麦土壤氮素供应与利用的影响 总被引:1,自引:0,他引:1
在冬小麦施氮144 kg/hm2的基础上,研究了夏玉米4个施氮量(0,90,180,270和360 kg/hm2)对后茬冬小麦生长期间土壤硝态氮含量变化、无机氮供应以及小麦氮素吸收与利用的影响。结果表明:与玉米不施氮(简称不施氮)相比,玉米施氮(简称施氮)0~200 cm土壤硝态氮含量在冬小麦生长期间显著增加,自冬小麦拔节起,0~40,0~130和0~200 cm 3层深的土壤硝态氮含量均随着玉米施氮量(简称施氮量)的增加而明显递增;与冬小麦播种时相比,不施氮0~130 cm土壤无机氮减少156 kg/hm2,施氮90 kg/hm2该层土壤无机氮富积41 kg/hm2,且富积量随着施氮量继续增加而递增;随着施氮量增加,冬小麦收获时的植株吸氮量和子粒氮素积累量均增加;当施氮量低于180 kg/hm2时,植物氮素积累量在不同施氮量之间无显著差异;当施氮量低于270 kg/hm2时,不同施氮量的子粒氮素积累量差异不明显。在本试验条件下,冬小麦子粒氮肥利用率随着施氮量增加而递增,但差异不显著。 相似文献
18.
M. El.-D. Ibrahim S. Prochézka V. Borkovec 《Journal of Agronomy and Crop Science》1988,160(5):339-344
The transport and distribution of 14C- sucrose and 14C- BA were studied in internode segments with ear of two winter wheat cultivars with a different mass of kernels in the period of kernel formation. While M C-sucrose was transported and accumulated intensively in the developing ear, 14C- BA was transported much less and only a small part of it was found in the ear. With the ear development the accumulation of both 14 C-sucrose and 14 C-BA in the ear increased but the 14 C-BA distribution pattern (ratio of the internode/kernel and the rest of the ear) did not change significantly. In the period of one to two weeks after anthesis the accumulation of 14 C-sucrose and 14 C-BA was higher in the kernels of the Slavia cv., i.e. in the cultivar with a higher mass of kernels. 相似文献
19.
D. K. Papakosta 《Journal of Agronomy and Crop Science》1992,168(4):238-242
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
Treatments included six rates of B. japonicum , ranging from 2.5 × 10
20.
A lysimeter study was conducted to investigate how nitrogen uptake of spring wheat and oats and N leaching losses are differing when either oilseed rape or faba bean are grown as green manure. The experiment was conducted during 1982–1988, and fertilizer applied to the cereals was either farmyard manure, FYM, (6 and 12 g N/m2 /year) or mineral fertilizer, MiF, at a rate of 6 g N/m2 . On average of the 7 year period faba bean increased N uptake of the cereals fertilized with FYM at harvest by 3–4 g/m2 . Differences between the two application rates were negligible. N-leaching losses increased twofold when faba bean was grown instead of oilseed rape. Growing faba bean after cereals supplied with MiF, too, increased N uptake of the cereals and significantly increased leaching losses. 相似文献