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1.
Mahendra Singh 《Plant and Soil》1981,62(2):305-308
Summary The effects of Zn, P, N and CaCO3 on tryptophan concentration in rice grain were studied in greenhouse at Haryana Agricultural University. Zinc application
upto 20 ppm increased tryptophan concentration in rice grain. Zn-EDTA gave highest increase followed by ZnSO4 and then ZnO. Liming at the rate of 4 and 8 per cent decreased tryptophan concentration significantly. Phosphorus application
upto 100 ppm also decreased tryptophan significantly but Zn in combination with P increased tryptophan and overcame negative
effect of P. Nitrogen application upto 120 ppm increased tryptophan concentration. There was positive interaction between
Zn and N. Ammonium sulphate gave highest tryptophan followed by ammonium nitrate and then urea.
The tryptophan concentration ranged between 766 ppm and 2011 ppm in paddy grain. The lowest tryptophan concentration was in
the plants treated with 8 per cent lime in absence of added Zn and highest with 10 ppm Zn through Zn-EDTA.
Department of Soils. 相似文献
2.
In the humid tropics, legumes are harvested and surface applied as mulch or incorporated as green manure. Studies on N dynamics and budgets from these systems report unaccounted losses of N. Ammonia volatilization may account for a significant percentage of these unexplained N deficits. The main objectives of this study were to: 1) determine the rate and amount of ammonia volatilization from organic amendments, both incorporated (green manure) and unincorporated (mulch), 2) compare ammonia volatilization of organic amendments on both acid (unlimed) and limed soils, and 3) correlate quality, i.e. polyphenolic and lignin concentration and carbon-to-nitrogen ratio, of the organic amendments with ammonia volatilization and net N mineralization. In an incubation experiment, ammonia volatilization losses and net N mineralization were measured from fresh leaflets of 10 legumes over a three-week period. Ammonia volatilization losses for the 10 species ranged from 3.4 to 11.8% of the total N applied in the organic amendment. Lignin content was negatively correlated to ammonia volatilization. Ammonia volatilized from mulches but not green manures, on both unlimed and limed soils, suggesting that ammonia volatilization is a surface phenomenon and not affected by soil pH. Net N mineralization was affected by species and soil pH, but was unaffected by placement (green manure or mulch). For the farmer in low-input agriculture where N tends to be limiting, volatilization losses of N from legume mulch systems could be on the same order of magnitude as crop removal. 相似文献
3.
Summary Submergence caused similar changes in pH, redox potential, nitrogen, phosphorus, potassium, calcium, magnesium, iron, and manganese contents of soils as were observed in Part 1.Rice plants grown on pots at submergence and at field capacity with fertilization assimilated more nitrogen, phosphorus potassium, iron and manganese and as a result, grew better and tillered more than plants grown at field capacity without fertilizers. The grain yield at submergence and at field capacity with fertilizers were better compared to those at field capacity without fertilizers. All these observations lead to a conclusion that the additional application of nutrients in the form of fertilizers at field capacity condition can equate the benefits of submergence. 相似文献
4.
Distribution of different forms of Zn in 16 acid alluvial rice growing soils of West Bengal (India) and their transformation
on submergence were studied. The results showed that more than 84% of total Zn occurred in the relatively inactive clay lattice-bound
form while a smaller fractionviz. 1.1, 1.6, 11.1 and 2.0 per cent of the total occurred as water-soluble plus exchangeable, organic complexed, amorphous sesquioxide-bound
and crystalline sesquioxide bound forms, respectively. All these four Zn forms showed significant negative correlations with
soil pH (r=−0.48**, −0.39*, −0.61** and −0.67**, respectively), while the latter two Zn forms showed significant positive correlations with Fe2O3 (0.68** and 0.88***) and Al2O3 (0.89*** and 0.75***) content of the soils. The different Zn forms were found to have positive and significant correlations amongst each other,
suggesting the existence of a dynamic equilibrium of these forms in soil.
Submergence caused an increase in the amorphous sesquioxide-bound form of Zn and a decrease in each of the other three forms.
The magnitude of such decreases in water-soluble plus exchangeable and crystalline sesquioxide-bound forms was found to be
correlated negatively with initial pH values of the soils and positively with the increase in the amorphous sesquioxide-bound
form, indicating their adsorption on the surface of the freshly formed hydrated oxides of Fe, which view was supported by
the existence of significant positive correlation between the increase in the amorphous sesquioxide-bound form of Zn and that
in AlCl3-extractable iron. The existence of a positive correlation between the decrease in crystalline sesquioxide-bound Zn and that
in Fe2O3 content in soil suggested that on waterlogging the soil Zn occluded in the cry talline sesquioxide was released as a result
of reduction of Fe2O3. 相似文献
5.
G. R. Chaplin 《Plant and Soil》1972,37(3):511-520
Summary The yield responses to nitrogen uptake are described for water-sown IR8 rice grown in the wet season in northern Australia. Various patterns of nitrogen uptake were achieved by different times and amounts of nitrogen application in the range 0 to 300 kg per ha. Grain yields increased with nitrogen uptake at flowering stage up to approximately 120 kg per ha but decreased when uptake exceeded this level. The grain yield increase was associated mainly with increased panicle production, while grain yield decrease was associated with a reduction in the weight of ripened grain per panicle. Nitrogen concentration in grain over all experiments increased linearly with nitrogen uptake at flowering, but grain yield was reduced when grain nitrogen exceeded approximately 1.5 per cent. High nitrogen uptake at flowering was presumed to lead to depletion of carbohydrate reserves during the critical grain-ripening phase. 相似文献
6.
Laboratory and greenhouse experiments were conducted with two soilsviz., laterite and alluvial to study the transformation of applied Zn in soil fractions under submerged condition in the presence
and absence of added organic matter and its relationship with Zn nutrition of rice plants.
The results showed that application of organic matter caused a decrease in the concentration of Zn in shoot and root of rice
plants and helped in translocating the element from root to shoot. The per cent utilization of applied Zn by plants was also
found to increase by the application of organic matter. The transformation of applied Zn in different fractions in soils showed
that a major portion (53.6–72.6%) of it found its way to mineral fractions leaving only 1.0–3.3, 6.6–18.9, 11.0–21.6 and 2.3–8.8%
of the applied amounts in water soluble plus exchangeable, organic complexed, amorphous sesquioxides and crystalline sesquioxides
bound fractions respectively. Application of organic matter favoured such transformation of applied Zn into these fractions
except the mineral and crystalline sesquioxides bound ones.
Simple correlation and multiple regression analyses between applied Zn in different soil fractions and fertilizer Zn content
in plants showed that organic matter application increased the predictability of fertilizer Zn content in plants which has
been attributed to the higher per cent recovery of applied Zn in plant available fractions in soils in presence of added organic
matter. 相似文献
7.
8.
The effects of CaCO3, Zn sources and levels on the yield of submerged paddy and uptake of Zn, P and N to paddy were studied in green-house at Haryana Agricultural University, Hissar. Powdered CaCO3 was mixed at 0,4 and 8 per cent and Zn was added at 0,5 and 10 ppm through ZnSO4.7H2O, ZnO and Zn EDTA separately. Dry weight at tillering and heading and grain and straw at maturity decreased significantly with 4 and 8 per cent CaCO3 in comparison to the control. Increasing Zn application increased the dry weight and grain yield. Zn EDTA gave highest yield of paddy followed by ZnSO4.7H2O and ZnO.Increasing the application of CaCO3 from 0–8 per cent decreased the concentration and uptake of Zn and increasing Zn application from 0–10 ppm increased concentration and uptake of Zn in paddy at tillering, heading and maturity. Zn EDTA gave the highest concentration and uptake of Zn followed by ZnSO4.7H2O and ZnO. There was interaction between Zn sources and CaCO3.The concentration and uptake of N and P in paddy dry matter at tillering and heading and straw and grain at maturity decreased as compared to control with increasing CaCO3 addition. The concentration and uptake of N increased and that of P decreased in paddy dry matter straw and grain with increasing Zn application. The highest concentration of N was observed with ZnO, followed by ZnSO4.7H2O and Zn EDTA. But highest uptake of N was observed with Zn EDTA followed by ZnSO4.7H2O and ZnO. As regards concentration and uptake of P, it was highest with ZnO followed by ZnSO4.7H2O and Zn EDTA. 相似文献
9.
施氮和肥料添加剂对水稻产量、氮素吸收转运及利用的影响 总被引:6,自引:1,他引:6
在苏南太湖地区开展田间试验,研究了施氮和肥料添加剂对水稻产量、氮素吸收转运及利用的影响.结果表明:施氮对水稻产量、各生育时期植株累积吸氮量、阶段氮累积量和花后氮素转运量具有显著的促进作用(P<0.01),当施氮量高于200 kg·hm-2时,增施氮肥的增产效应不显著(P>0.05);花后氮素转运率和氮肥利用率均随施氮量的增加而降低.施用肥料添加剂可进一步提高水稻产量、累积吸氮量、花后氮素转运量和氮肥利用率,且该效应在高施氮量( ≥200 kg·hm-2)条件下表现更明显.本试验条件下不施用肥料添加剂时,施氮150kg·hm-2可同时获得较高的产量和氮肥利用率. 相似文献
10.
根表铁氧化物胶膜对水稻吸收Zn的影响 总被引:17,自引:1,他引:17
采用营养液培养方法研究了水稻根表形成的铁氧化物胶膜对水稻吸收Zn的影响.结果表明,在有Fe2+的嫌气环境中,由于根际氧化作用水稻根表会形成红色的铁氧化物胶膜,根表的铁氧化物胶膜影响水稻对Zn的吸收.铁膜数量较少时,由于对Zn的富集作用有限,其对水稻Zn的吸收虽有促进作用,但不明显.随着根表铁膜数量的增加,这种促进作用也相应增加,并且在铁膜数量增加到一定值时,对水稻吸收Zn的促进作用达到最大.而后,随着铁膜数量的进一步增加,铁膜反而阻碍水稻对Zn的吸收,成为水稻吸收Zn的障碍层.在此过程中,水稻的根分泌物,特别是其中的植物铁载体对覆有铁膜水稻根系吸收Zn有促进作用.这种促进作用随铁膜数量的增加而逐渐减弱.因此,根表铁氧化物胶膜对水稻吸收Zn并不总是起促进作用,其作用的方向和程度取决于铁膜的数量. 相似文献
11.
Summary The effects of water regime on the performance of rice were investigated in a greenhouse experiment and two field experiments. The greenhouse experiment involved four water regimes (continuous flooding, and soil drying for 16 days — begun 2, 5, and 8 weeks after transplanting — followed by reflooding), four soils, and 0 and 100 mg N/kg. Soil drying raised the redox potentials of all soils beyond the aerobic threshold. Averaged for soils and N levels, yields from treatments in which soil drying was begun at 2 and 5 weeks after transplanting were lower than that from the continuously flooded treatment, but the simple effects of soil drying on yield and N uptake depended on the soil and the growth stage of the plant. None of the soil-drying treatments had adverse effects in the soil high in N but soil drying at 2 and 5 weeks after transplanting had adverse effects in the soil low in N. The field experiments tested the effects of three water regimes (continuous flooding, alternate drying and flooding every 2 weeks, and soil drying for 2 weeks at 6 weeks after transplanting following by reflooding), and 0, 50, 100, and 150 kg N/ha on a nearly neutral clay soil, during two seasons. None of the soil-drying treatments depressed growth, yield, or N uptake by rice at any level of N in either season. Nitrate was absent after drying, so denitrification was not possible on subsequent flooding. The adverse effects on yield of alternate flooding and drying, attributed to nitrification-denitrification, may be insignificant in wetland fields carrying an actively growing rice crop. 相似文献
12.
A model is presented with which the contribution of longitudinal oxygen diffusion to total oxygen requirement of a root can be estimated. Oxygen transport in and respiration of the soil are taken into account. Given the air-filled root porosity, root diameter, coefficient of oxygen transfer between root and soil, root and soil respiration rate, and the coefficient for oxygen diffusion in the soil, the maximum length a root can attain with an adequate oxygen supply to the root tip can be calculated. Results show the importance of root porosity for root aeration, also in unsaturated soils. For thick roots (radius >0.03 cm), diffusion along the internal pathway can provide 50–75% of the total oxygen requirement even, at modest values of the root porosity. 相似文献
13.
Effect of gypsum,pressmud, fulvic acid and zinc sources on yield and zinc uptake by rice crop in a saline-sodic soil 总被引:1,自引:0,他引:1
Summary The application of fulvic acid to a saline-sodic soil augmented the solubility of zinc by thousands fold. Zinc fulvate when applied at levels equivalent to that of zinc sulphate was more effective in enhancing diffusion of zinc in the soil. Application of gypsum, zinc sulphate and fulvic acid significantly increased dry matter yield and uptake of zinc by rice crop in a saline-sodic soil. Application of gypsum with pressmud or with fulvic acid and zinc sulphate resulted in significantly higher yield and zinc uptake than in other treatments. 相似文献
14.
Summary Field experiments were conducted during 1979 and 1980 summer seasons on sandy loam soils of low moisture retentive capacity
to study the effect of high frequency irrigation at different levels of N on groundnut yield and nutrient uptake (NPK).
Four irrigation frequencies (irrigation at 2, 4, 6 and 8 cm cumulative can evaporation, corresponding to irrigation once in
3, 5, 7 and 10 days respectively) and four levels of nitrogen (0, 20, 40 and 60 kg N/ha) were tested in a factorial randomized
block design with three replications.
Pod yield of groundnut was maximum (3,293 kg/ha) when irrigations were scheduled at 4 cm cumulative can evaporation (once
in 5 days). Addition of N did not increase the pod yield. N and P uptake by the crop was maximum (180 kg N and 18 kg P/ha)
with high frequency irrigation of scheduling irrigation at 4 cm cumulative can evaporation. Highest uptake of N (183 kg/ha)
and P (19 kg/ha) was with a combination of 20 kg N/ha and high frequency irrigation (4 cm CCE). K uptake was low with low
irrigation frequency, while it was highest (67 kg K/ha) at 20 kg N/ha. 相似文献
15.
16.
I. J. Manguiat G. B. Mascariña J. K. Ladha R. J. Buresh J. Tallada 《Plant and Soil》1994,160(1):131-137
Field experiments were conducted under flooded soil conditions using Maahas clay amended with urea and rice straw-sesbania mixtures during the wet and dry seasons. Parallel laboratory incubation tests were done. The objectives were 1) to determine N mineralization patterns and establish the relationship between mineralization parameters and either N availability or grain yield, and 2) to correlate the results of organic N mineralization studies in the laboratory with data from field experiments. The N mineralization patterns of flooded soils in the laboratory followed a logistic function. In laboratory studies, mineralization potential was positively correlated with extractable soil NH4
+-N at the end of the incubation period (cumulative available N). Likewise, mineralization potential calculated from laboratory studies was positively correlated with N uptake and grain yield from field studies. Extractable (NH4
++NO3
–)-N in the field correlated positively with extractable NH4
+-N in the laboratory. The extractable NH4
+-N from laboratory incubations at 14 days after transplanting, panicle initiation, and maturity was also highly and positively correlated with grain yield from field experiments. 相似文献
17.
18.
Adsorption of zinc in rice soils was studied to define the functional relationship between quantity, intensity and buffering capacity factors of soil zinc to the growth and zinc uptake of rice crop. A supply parameter integrating the quantity, intensity and buffering capacity factors into a single unifying term was computed from the data on Zn adsorption in these soils. A green house experiment was conducted with three soils providing a matrix of different values of supply parameter of Zn to determine the optimum value of this parameter for the proper growth and zinc nutrition of rice crop. Results indicated that a value of this parameter around unity is optimum for sustaining proper growth and zinc nutrition of rice in these soils. The variations in dry matter yield and zinc uptake of rice in different soils may be related to the differences in the physical and chemical properties of the soils. 相似文献
19.
Summary In the summer of 1980, a field experiment was started to evaluate the direct and residual effect of applied zinc (as zinc
sulphate) on the yield and chemical composition of rice and wheat grown as crops in sequence, on an alkali soil. The treatments
comprised six rates of zinc 0, 2.25, 4.5, 9.0, 18.0 and 27.0 kg ha−1 applied either only once to the first crop, or repeated to each successive crop in a split plot design with 4 replications.
Gypsum at 14 t ha−1, was applied uniformly to all plots. The results show that with respect to increase of yield and available zinc content of
soil, an application of 2.25 kg ha−1 zinc frequently to each crop was better than a single high dose. A major portion of the applied zinc accumulated in the 0
to 10 cm soil layer; the movement of zinc to lower layers was negligible. Zinc applications increased the concentration of
exchangeable < complexed < amorphous sesquixoides-bound zinc > crystalline sesquioxide-bound zinc fractions. Amorphous sesquixoides
bound the major portion of the applied zinc compared to other fractions. Exchangeable and amorphous sesquioxide-bound zinc
fractions contributed significantly more to zinc uptake by rice, than the other fractions. DTPA extracted zinc more readily
from exchangeable and complexed fractions than from sesquioxides. Application of zinc increased the DTPA extractable zinc
and hence zinc uptake by plants. 相似文献
20.
Summary The influence of heavy applications of P (100, 200 and 400 ppm P) and Zn (12.5 and 25 ppm) fertilizers on their extractabilities, availabilities and uptake by corn grown in highly calcareous soil was investigated.A significant increase was found in the levels of (NH4)2CO3-EDTA-extractable Zn either by Zn-applications alone or together with P. The amounts of NaHCO3-extractable P were also increased with P additions and the influence of Zn applications was not clear.Phosphorus application generally increased the plant dry weight. In the soils treated with P and Zn fertilizers, that increase was mostly related to P rather to Zn.In the soils not treated with Zn, P additions increased Zn uptake by the plants. On the other side, in the soils treated with Zn, P additions decreased Zn uptake.Phosphorus concentration in the whole plant and/or in the different plant parts was increased by P application without being significantly affected by Zn addition. The plants showed greater response to 12.5 ppm Zn application than to 25 ppm.Plants grown for 4 weeks contained lower amounts of Zn relative to those grown for 8 weeks. The influence of plant age on P content was not as clear as occurred with Zn. 相似文献