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1.
A new fertilization method with deep placement of slow‐release N fertilizers, such as coated urea and lime nitrogen (LN) (calcium cyanamide) at 20 cm depth was found to promote soy bean seed yield. In the present study, the effect of deep placement of LN was investigated on different parameters such as growth, N accumulation, N2 fixation activity and yield of soy bean by applying LN at different rates in the rotated paddy field of Niigata, Japan. In addition to the basal fertilizer, ammonium sulphate (16 kg N ha?1), deep placement of LN was conducted by applying various amounts such as 50 kg N ha?1 (A50), 100 kg N ha?1 (A100) and 200 kg N ha?1 (A200) at 20 cm depth in separate plots. A 15N‐labelled LN fertilizer was also employed for each of the above treatments to calculate N utilization from LN in separate plots. Soya bean plant growth and N2 fixation activity were periodically analysed. Both plant growth and N accumulation were found to increase with LN treatment compared with control plants. An increase in N2 fixation activity was found in the A100 plots. The total seed yield was the highest in the deep placement of LN with A100 (73 g per plant) compared with other treatments. The visual quality of harvested seeds also showed that A100 enhanced the quality of seeds compared with other treatments. Thus, it is suggested that N fertilization management with particular reference to optimum amount of fertilizers is important for maximum growth, N2 fixation and enhancement of seed yield of soy bean.  相似文献   

2.
为了探讨几种缓/控释肥在宁夏淡灰钙土上的氮素释放特性和生物学效应,寻求合适的缓/控释组合材料。通过盆栽试验,在氮磷钾等养分供应下研究了5个施肥处理对春玉米生长发育和氮素吸收利用的影响,同时探讨了几种缓/控释肥在土壤中的氮素释放规律。结果表明,相对不施氮处理,施用缓/控释肥可提高春玉米株高、地上部生物量和总生物量,同时也能显著促进地上部氮、根系氮和总氮吸收量,其氮肥利用率达33.9%~39.7%,较NPK平衡施肥(31.5%)提高了2.4%~8.2%。自研制缓/控释肥在土壤中的氮素释放天数在65天左右,释放高峰在第32天前后;而商品包膜尿素的氮素释放高峰在第17天前后,65天后依然有较高的氮素释放。因此,与商品包膜尿素相比,自研制缓/控释肥的氮素释放周期有待延长,但其对春玉米生育前期的氮素供应相对充足。  相似文献   

3.
铅污染土壤上施用氮肥对小麦POD酶活性及铅吸收的影响   总被引:1,自引:0,他引:1  
针对日益严重的土壤Pb污染,采用盆栽土培方法,比较尿素、碳酸氢铵对Pb污染土壤上有效态Pb、小麦吸收积累Pb及其体内POD酶活性的影响,为指导Pb污染土壤上施肥提供依据。结果表明,两种氮肥的施用提高了土壤有效Pb的含量,小麦根中积累的Pb显著高于茎叶。低用量氮肥(0.1~0.3g/kg)均促进了小麦生长和根对Pb的吸收,高用量氮肥(0.5~0.7g/kg)抑制了小麦的生长,但小麦茎叶中Pb的含量均降低。小麦茎叶中Pb的积累与土壤有效Pb变化无相关性。施用尿素、碳酸氢铵处理下小麦幼苗POD酶活性变化呈下降趋势。对比认为施用低浓度处理尿素更能减少铅污染土壤上在地上部的Pb积累,促进小麦的生长。  相似文献   

4.
Two experiments of soil N-fertilization and Rhizobium inoculation were conducted in 1981 and 1982 at Giza, Egypt. Soybean was sprayed with a commercial micronutrients mixture, and with urea.
In the first experiment, soil N-fertilization 0, 142.8 and 214.2 kg N/hectare were applied to uninoculated plants, whereas, in the second one, local inoculum was used alone or along with addition of a starter dose of N (47.6 kg N/hectare).
Urea applications were at pod filling period (R4, R5 and R6 stages), whereas, micronutrients mixture was applied at 25 days from planting.
Plant dry weight, leaf area/plant, plant height, pod and seed number/plant, seed weight/plant, seed yield and crude seed protein content increased significantly with nitrogen application to uninoculated soybean plants; whereas the starter dose of N had no significant effect on any of these traits under the inoculated soybean plants.
Foliar application of micronutrients caused significant increases in plant DW, LA, pod and seed number/plant, seed index and seed yield of fertilized and inoculated plants.
Foliar application of urea, to inoculated and uninoculated plants, caused significant increments in plant dry weight, 1A, seed protein content and particular seed index and seed yield.  相似文献   

5.
This study was conducted to elucidate the crop physiological basis for yield differences frequently observed in experiments comparing top‐dressing of N fertilizers with injection of ammonium or ammonium/urea solutions into the soil. The effects of diammonium phosphate (NH4‐N) injected at the two‐leaf stage, calcium nitrate (NO3‐N) broadcasted and incorporated before sowing, and a control without N fertilization (‐N) were assessed from measurements of growth, N‐uptake and N‐partitioning, light interception, gas exchange, leaf anatomy and the activity of key enzymes of N‐metabolism. The experiment was performed with spring barley (Hordeum vulgare L.) grown in 80‐l containers in a vegetation hall in Braunschweig, Germany. The plants in the NH4‐N treatment produced a 20 % higher grain yield than those in the NO3‐N treatment. The grain yield superiority of the NH4‐N plants was attributable to a higher number of ears per plant (+13 %) and more grains per ear (+6 %). The NH4‐N plants exhibited lower concentrations of inorganic cations than plants supplied with NO3‐N. In the NH4‐N treatment, the light penetrated more deeply into the crop canopy and the NH4‐N plants exhibited a higher leaf carbon exchange rate at the different leaf layers than the NO3‐N plants. It is concluded that as opposed to predominantly nitrate nutrition, provision of a persistent source of ammonium enables plants to take advantage of the positive yield effect of mixed N nutrition.  相似文献   

6.
有机质包膜尿素对冬小麦产量和氮肥利用率的影响   总被引:2,自引:1,他引:1  
此文利用盆栽试验研究了3类有机质包膜尿素对冬小麦的产量、氮肥利用率与农学效率、氮素生理效率与收获指数的影响。结果表明:在等氮量条件下,有机质包膜尿素可显著提高冬小麦产量和氮肥利用率。在含N 0.10 g/kg土和含N 0.20 g/kg土水平下,YU2(有机质包膜尿素2)处理较普通尿素分别增产12.7%和19.4%,氮肥的利用率分别提高14.8%和10.8%,效果最为显著。在含N 0.20 g/kg土水平下,与普通尿素相比,3类有机质包膜尿素不同程度的提高了氮肥的农学效率、氮素生理效率和收获指数,YU3(有机质包膜尿素3)对氮素生理效率和收获指数的影响最大,分别提高了0.83 kg/kg和2.56%;YU2处理对提高氮肥农学效率的效果最显著,在含N 0.10 g/kg土和含N 0.20 g/kg土水平下,每千克氮分别增产4.04 kg和3.64 kg小麦籽粒。  相似文献   

7.
包膜尿素对甜瓜产量、氮素吸收和氮肥利用率的影响   总被引:4,自引:0,他引:4  
采用基质盆栽试验研究了包膜尿素与普通尿素对甜瓜产量、氮素吸收和氮肥利用率的影响.包膜尿素-次性接触施肥于幼苗根部.结果表明:包膜尿素处理的甜瓜产量显著(P<0.01)高于常规施氮处理,增产19.2%-19-4%;相比常规施氮,施用包膜尿素显著降低了果实硝酸盐含量(P<0.05);常规施氮处理的植株叶片叶绿素含量在追肥前后出现较大波动.而包膜尿素处理在甜瓜生长期间均比较稳定;甜瓜植株氮素吸收曲线与包膜尿素氮素释放规律吻合;施用包膜尿素较常规施氮提高氮肥利用率1.1~20.6个百分点.综上所述,施用包膜尿素能实现增产、提高氮肥利用率以及改善品质的目的,是一种有应用前景的新型肥料.  相似文献   

8.
为确定合理的包膜尿素用量以指导黄瓜育苗施肥,采用生产中常用的草炭:蛭石(2:1)为育苗基质,研究了包膜尿素不同用量对黄瓜幼苗生长、养分吸收及氮平衡的影响。结果表明:包膜尿素用量在125~375 mg N/株的情况下,可协调黄瓜幼苗地上部和地下部的生长,促进幼苗对磷、钾的吸收;移栽时,基质中的氮素残留总量90.5~250.3 mg N/株,其中,残留的包膜氮素占75.4%~82.3%,可实现带肥移栽;育苗期间可产生31.9~121.5 mg N/钵的氮素表观损失。  相似文献   

9.
Increased application of nitrogen (N) fertilizer top-dressing during growth is an effective option for enhancing N supply to soybean plants. SS2-2 was characterized by the superior ability of symbiotic N2 fixation at the level of 30 kg N ha−1. But, the response of nitrogen fixation ability of supernodulating soybean mutant, SS2-2, to N fertilizer application rate remains unclear. The objective of this experiment was to compare the response of N fertilizer top-dressing on N accumulation and N2 fixation between supernodulating mutant, SS2-2, and wild-type, Sinpaldalkong 2. The effect of N fertilizer top-dressing (0.6 g N pot−1 top-dressing) on the nitrogen accumulation and redistribution were compared between SS2-2 and Sinpaldalkong 2. N fertilizer top-dressing at R1 stage increase in plant dry weight, relative growth rate (RGR), net assimilation rate (NAR), nitrogen harvest index (NHI), and N redistribution (NR). SS2-2 showed highest N concentration, 65.0 mg N g DW−1, followed by Sinpaldalkong 2 and En1282, and the N content per plant did not show a significant difference between SS2-2 and Sinpaldalkong 2. The N2 fixation rate was significantly reduced by N top-dressing, but the amount of N2 fixation was not changed due to an improved dry weight without changes of N concentration. In addition, SS2-2 showed higher NHI, NR and NRE than Sinpaldalkong 2. These results suggested that supernodulating soybean mutants, SS2-2, could be characterized by high N concentration and N2 fixation regardless of N fertilizer top-dressing due to a higher nitrate tolerance of supernodulating mutants than that of wild-type.  相似文献   

10.
A field experiment was conducted with sorghum variety CSH-9 in kharif season of 1983 and 1984 to find out the efficiency of coated urea fertilizers over urea alone. The coated urea fertilizers used were neem cake coated urea, neem extract coated urea, coaltar coated urea, 10% didin coated urea along with ordinary urea. Four rates of urea application viz 50, 100, 125 kg N/ha were used along with control in single and split application.
The dry matter yield was recorded to be higher with ordinary urea at initial growth stage of sorghum. However the coated urea fertilizers recorded more dry matter at advancing growth stages. The dry matter accumulation increased with increasing N rates. Split application of N registered higher dry matter. The grain yield was increased due to coating of fertilizers. The neem cake coated urea and 10 % didin coated urea produced highest grain yield which was about 1.5 times more over urea alone. The grain and fodder yields were increased with increasing N rates, the highest yields being with 120 kg N/ha application. N concentration in plant was decreased with advancing growth stage. The concentration, uptake and N recovery were highest with 10% didin coated urea in 1984 and with neem cake urea in 1983. Coated urea fertilizers and split application of N resulted in increasing the N use efficiency over single application.  相似文献   

11.
不同控释肥品种对大白菜产量、氮素吸收和品质的影响   总被引:12,自引:0,他引:12  
采用田间试验研究了不同控释氮肥品种(脲醛、线型和S型包衣尿素)一次性基施对大白菜产量、氮肥利用率和品质的影响。与常规施氮措施中尿素300 kg/hm2的施用量相比,脲醛、线型和S型包衣尿素的施氮量分别为300,240(减量20%)和225 kg/hm2(减量25%),其中S型包衣尿素处理中的化学氮肥由33%的普通尿素和67%的S型包衣尿素均匀混合而成。结果表明:在大白菜上施用氮肥(有机肥和化肥)均会不同程度地增产,其中施用有机肥增产8.22%,在有机肥的基础上施用化学氮肥的增产效果不明显,普通尿素、脲醛、线型和S型包衣尿素分别增产1.15%,4.27%,4.62%和4.97%。有机氮的利用率为33.0%,在有机肥基础上施用化学氮肥的利用率降低,普通尿素的氮肥利用率不到1%,脲醛、线型和S型包衣尿素的氮肥利用率分别为8.9%,13.1%和8.4%。施氮对大白菜的品质影响不大,各处理的鲜菜硝酸盐和Vc含量差异不明显。  相似文献   

12.
Estimates of N2 fixation in segregating populations of bean plants based on 15N-isotope methods are technically demanding and expensive; therefore, indirect measures based on related traits including total seed N were used to select for improved N2 fixation and yield. In 1985, six populations of F2-derived F3 families resulting from six parental lines crossed to a common tester were grown in field trials on a low-N soil. In 1986, 25 selected half-sib families and two populations of full-sib F4 families were grown under similar conditions. Parents and a non-nodulating soybean line were included both years. Narrow sense (HNS) heritability estimates based on parent-offspring regressions ranged from 0.57 for total seed N to 0.39 for shoot biomass in one population, but were near zero for all measured traits in a second population. Among the criteria used to identify parental lines with superior potential for producing progenies with high total seed N, testcross population means combined with estimates of realized heritability were the most reliable. Selection of the best F3 families for total seed N resulted in F4 families with increased total seed N and higher seed yields, while seed protein percentage was unchanged. When plants are grown on low-N soils, selection for total seed N offers a useful alternative to selection for increased N2 fixation based on 15N-isotopic or total-N-difference method.  相似文献   

13.
Field experiments were carried out on grey‐brown podzolic soil in the four consecutive growing seasons (1998–2001) at Krzeslice Farm, central‐western Poland. The effect of seven N fertilization treatments (in kg N ha?1): 80NF + 80CAN; 80NF + 50CAN + 30CN; 80CAN + 80CAN; 80CAN + 80CAN + 30CN; 80AN + 80AN; 80AN + 50AN + 30CN, where, NF – nitrofos NPK, CAN – calcium‐ammonium nitrate, AN – ammonium nitrate, CN – calcium nitrate and control (without N) on N uptake dynamics and N efficiency was studied. Mineral fertilizers were applied at the start of spring regrowth, beginning of stem elongation and at the flower‐bud‐visibility stage. The study revealed two distinct strategies of oilseed rape plants’ adaptation to timing and N fertilizer application sequences. Both strategies based on nitrogen uptake rate (NUR), were analysed at different plant growth stages. Ammonium nitrate (AN) applied in the two‐split system gave the highest NUR (387 mg m?2 day?1) during stem elongation (for comparison, a value of 166 mg m?2 day?1 was obtained in the control). In the case of calcium‐ammonium nitrate (CAN), a moderate level of NUR was obtained (304 mg m?2 day?1) but N uptake lasted 12 days longer compared with the AN treatment. Hence, N accumulation in leaves at the end of flowering explained about 81 % of yield variability. The second adaptation strategy was attributed to the three‐split N treatment. Plants fertilized with AN and CAN fertilizers showed an inconsistent pattern of NUR with time. Nitrogen accumulation in stems at the beginning of maturity, explained 69 % of yield variability. Nitrogen‐use efficiency did not show any response to N treatments.  相似文献   

14.
Drought can drastically reduce cowpea [Vigna unguiculata (L.) Walp.] biomass and grain yield. The application of plant growth‐promoting rhizobacteria and arbuscular mycorrhizal fungi can confer resistance to plants and reduce the effects of environmental stresses, including drought. Seed coating is a technique which allows the application of minor amounts of microbial inocula. Main effects of the factors inoculation and water regime showed that: severe or moderate water deficit had a general negative impact on cowpea plants; total biomass production, seed weight and seed yield were enhanced in plants inoculated with P. putida; inoculation of R. irregularis significantly increased nitrogen (N) and phosphorus (P) shoot concentrations; and R. irregularis enhanced both chlorophyll b and carotenoids contents, particularly under severe water deficit. Plants inoculated with P. putida + R. irregularis had an increase in shoot P concentration of 85% and 57%, under moderate and severe water deficit, respectively. Singly inoculated P. putida improved potassium shoot concentration by 25% under moderate water deficit. Overall, in terms of agricultural productivity the inoculation of P. putida under water deficit might be promising. Seed coating has the potential to be used as a large‐scale delivery system of beneficial microbial inoculants.  相似文献   

15.
Waterlogging causes long‐lasting damage to wheat (Triticum aestivum). Root growth and respiration were investigated after heading in waterlogged, pot‐grown, wheat plants and also in hydroponically grown, wheat seedlings exposed to a hypoxic treatment. In the pot experiment, plants were subjected to 8 days of waterlogging after heading. This period of waterlogging resulted in reduced shoot and root growth through to maturity. The root CO2 emission rates of previously waterlogged and well‐drained plants were about 220 and 140 nmol g?1 per s, respectively, with the rate differences persisting from 10 days after anthesis through to maturity. In the hydroponic experiments, seedlings (Feekes stage 2.0) were exposed to root‐zone, hypoxic treatment for 10–19 days. The roots showed 27 % higher CO2 emission rates and 37 % higher O2 consumption rates, compared with untreated roots. In whole root systems, the high respiration rates found during hypoxic treatment disappeared during recovery under aerated conditions as a result of the appearance of newly initiated roots. However, measurements of the respiration of the previously hypoxic roots showed abnormally high respiration rates. In roots exposed to hypoxic treatment, total sugar concentrations were 3.6‐times higher than in untreated roots indicating that this elevation of sugar may be responsible for the continued high respiration rate. This study shows that roots exposed to waterlogging or to hypoxic treatments do not increase their weights and thus recover from the metabolic disturbances resulting from these treatments.  相似文献   

16.
The nitrogen (N2)‐fixing bacterial inoculant strain for soybean [Glycine max (L.) Merrill] is not indigenous to South African soils. The interaction between soybean genotype, soil type and inoculant strain, however, has a definite influence on soybean production and compatibility should be optimized. This paper reports a growth chamber study using three different soybean genotypes (Barc‐9, Avuturda and Talana), three Bradyrhizobium japonicum inoculant strains (WB108, WB112 and WB1) and three soil types (Avalon, Arcadia and sand) to evaluate the effectiveness of N2 fixation by different genotype × soil type × inoculant strain combinations, using different measuring parameters. These parameters included nodule fresh mass (NFM), amount of N2 fixed (Pfix), as determined by the ureide method, seed protein content (SPC), average seed mass per plant (SMP) and average foliar N content (FNC). The comparison amongst the three‐way interactions, genotype × soil type × inoculant strain, did not differ significantly for the parameters used. Significant two‐way interactions were soil × inoculant for FNC, Pfix and SMP; soil × genotype for FNC and SMP, and inoculant × genotype for FNC (P < 0.05). The soil × inoculant strain interaction was significant for Pfix (P < 0.05). NFM, Pfix, FNC, SMP and SPC correlated positively with soil pH and negatively with soil clay content and soil NO3 and NH4+ content (P < 0.05). SPC was significantly different (P < 0.05) for soil type, genotype and inoculant strain. Pfix and NFM did not reflect the protein content of the seeds, indicating that nodule evaluation should be used with caution as a N2 fixation parameter. Low soil pH and high mineral N content inhibited N2 fixation. NFM correlated negatively with the clay content of the soil. This finding confirms that soybean production in South Africa can be improved by appropriate selection of genotypes and inoculant strains for their compatibility in different soils.  相似文献   

17.
为探究缓/控释肥在不同水分条件下提高氮素利用率及增产机制。本研究以杂交中稻F优498为试验材料,在180 kg hm-2施氮量基础上,采用两因素裂区设计: 主区设控灌、干湿交替灌溉、传统灌水灌溉3种水分管理方式,副区设尿素一道清、尿素常规运筹、硫包膜缓释肥、树脂包膜控释肥4种氮肥种类,研究缓/控释肥和水分管理方式对水稻干物质量和氮素吸收、运转、分配和产量的影响及其互作效应。结果表明, 缓/控释肥和水分管理方式对水稻主要生育期干物质量和氮吸收、转运、分配及产量具显著影响及互作效应,产量构成因素与氮素在结实期转运总量及其分配呈显著正相关。干湿交替灌溉和缓/控释肥均能提高干物质量、氮素吸收及产量并表现出显著互作效应,施用缓/控释肥氮素表观利用率达42%~53%,相较于尿素一道清和传统的尿素常规运筹,氮肥偏生产力提高6%~23%,氮素农学利用率提高26%~71%,增产8%~19%。控灌条件下,缓/控释肥处理氮素有效性高,保证足穗、促进重穗;干湿交替灌溉条件下缓/控释肥处理能保持氮素的高效释放,有利于高产群体的形成,从而提高稻株氮素积累、协调氮素分配;淹水灌溉条件下,缓/控释肥处理无效分蘖减少,氮素入渗、淋溶降低,成穗率提高。综合产量与氮素吸收、运转的表现,干湿交替灌溉条件下施用缓控释肥为本试验最佳处理,能有效提高氮素利用率,促进高产形成。  相似文献   

18.
Low temperature seriously depresses seed germination and seedling growth in winter wheat (Triticum aestivum L.). In this study, wheat plants were sprayed with abscisic acid (ABA) and fluridone (inhibitor of ABA biosynthesis) at 19 days after anthesis (DAA) and repeated at 26 DAA. The seeds of those plants were harvested, and seed germination and offspring's seedling growth under low temperature were evaluated. The results showed that exogenous ABA application decreased seed weight and slightly reduced seed set and seed number per spike. Under low temperature, seeds from ABA‐treated plants showed reduced germination rate, germination index, growth of radicle and coleoptile, amylase activity and depressed starch degradation as compared with seeds from non‐ABA‐treated plants; however, activities of the antioxidant enzymes in both germinating seeds and seedling were enhanced from those exposed to exogenous ABA, resulting in much lowered malondialdehyde (MDA) and H2O2 concentrations and production rate. In addition, the maximum quantum efficiency of photosystem II was also enhanced in ABA‐treated offspring's seedlings. It is concluded that exogenous ABA treatment at later grain‐filling stage could be an effective approach to improve cold tolerance of the offspring during seed germinating and seedlings establishment in winter wheat.  相似文献   

19.
为探讨不同密度和施肥量对油菜毯状苗形成壮苗的关键生物学指标的影响,以探索适合机械移栽的油菜毯状苗培育方法,为生产上培育高质量油菜毯状苗提供依据。本文以甘蓝型油菜品种宁杂1818为材料,设置播种密度和施肥水平二因素试验,分析其对秧苗存活率、绿叶数、干物质积累和根冠比等指标的影响。结果表明,密度增大,秧盘存苗数显著降低,叶片数、绿叶数减少,地上部干重减少,地下部干重减少的幅度更大,根冠比下降;同时,根颈和苗高变长,秧苗充实度下降。密度过小,虽然毯状苗的素质提高,但不利于秧苗成毯和移栽,移栽后的密度也不能保证。因此,综合考虑毯状苗素质、适合机械化移栽和栽后的效果等方面,在晚稻茬口需要苗龄为30~40 d左右时,播种密度在800粒盘-1的基础上喷施3 g L-1尿素溶液是培育毯状苗壮苗的合理组合。  相似文献   

20.
Responses of maize and triticale seedlings, differing in the susceptibility to soil density stress, and grown under low (LD) or high (HD) soil density and poor (PN), high (HN) or control (CN) nitrogen content in soil were investigated in relation to changes in physiological parameters—dry matter of shoot (S), root (R), shoot to root ratio (S/R), relative growth ratio of shoot and root (RGR), chlorophyll content (SPAD), total roots number and length (TRN, TRL), root penetration ability (RPA) and ratio of deep rooting (RDR). The seedlings grown under high soil density (HD) and control N‐soil content (CN) in comparison with LD and CN treatments showed a decrease in all measured parameters. Under poor and high nitrogen content, changes in the traits were higher for triticale than for maize. Higher differences between resistant and sensitive genotypes in TRN, TRL, RPA and RDR were observed particularly in the seedlings grown under HD treatment. Differences in parameters values between seedlings grown under control and nitrogen‐rich soil may be considered as a positive interaction between stresses. Our results suggest that the type of root structure (scattered, dimorphic) would be helpful in enhancing modelling and agronomic management for improved of plant stress tolerance.  相似文献   

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