首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
ABSTRACT

Low concentrations of P and organic manure in savanna soils limit cowpea response to rhizobia. The study was conducted to determine the combined effect of P and organic manure on cowpea response to rhizobia in a factorial experiment arranged in randomized complete block design with three replications on smallholder farmers’ fields in northern Ghana in 2015. The factors were two levels of Bradyrhizobium inoculant, two levels of P fertilizer, three treatments of manure (fertisoil, cattle manure, and no manure). Addition of Bradyrhizobium inoculant to P and fertisoil significantly increased shoot biomass yield from 1677 kg ha?1 in the plots without Bradyrhizobium inoculation to 1913 kg ha?1. Likewise, the addition of Bradyrhizobium inoculant to P and cattle manure significantly increased shoot biomass from 1437 kg ha?1 to 1813 kg ha?1. Grain yield increases of 1427 and 1278 kg ha?1 were obtained over the control when either fertisoil or cattle manure and P, respectively, were added to Bradyrhizobium inoculant. The value cost ratio for adding Bradyrhizobium inoculant to phosphorus and fertisoil was two indicating that it could be attractive to risk-averse smallholder farmers. The study demonstrated the potential of the combined application of organic matter and P to improve cowpea response to Bradyrhizobium inoculation.  相似文献   

2.
 Phosphorus application decreased the sporulation frequency and number of sporocarps per plant in all the three Azolla species and 21 A. pinnata strains evaluated in this study. The number of megasporocarps tended to be more depressed than the number of microsporocarps. Nevertheless, the sporulation of A. caroliniana was less sensitive to P than that of A. pinnata and A. microphylla. Its sporulation frequency in the mineral medium did not decrease at 2.5 μg P ml–1 and remained unaffected between 5 and 20 μg P ml–1. The sporulation frequency and sporocarp number in this species in the soil culture also were not significantly affected by an increase in the dose of P from 10.7 to 21.4 or 21.4 to 32.1 mg pot–1. Large variations in the degree of inhibition of sporulation due to the application of P (21.4 mg pot–1) also occurred among the A. pinnata strains tested. Received: 20 October 1999  相似文献   

3.
Abstract

Even though Mg is an essential nutrient. the response of upland rice, common bean, and cowpea to Mg application has not been adequately documented in Brazilian oxisols. This study was conducted to examine the influence of Mg application on growth and nutrient uptake by upland rice (Oryza sativa L.), common bean (Phaseolus vulgaris L.), and cowpea (Vigna unguiculata L. Walp.) on an oxisol. Magnesium levels in the soil were created at sowing by application of MgO at rates of 0.30, 1.05, 1.15, 1.33, 3.52, and 6.22 cmol Mg/kg of soil. Application of Mg did not have a significant beneficial effect on dry weight of roots and tops of rice and cowpea. Common bean root and top dry weights were increased with Mg applications up to 1 cmol Mg/kg of soil. Uptake of N, P, K, Ca, Cu, Zn, Fe, and Mn by the three crops was significantly (P < 0.01) decreased by increasing Mg levels in the soil. Results related to changes in chemical properties of soil with the application of Mg are also presented.  相似文献   

4.
冬小麦-夏玉米适宜氮磷用量和平衡施肥效应   总被引:2,自引:0,他引:2  
在河北衡水对冬小麦-夏玉米适宜氮、磷用量及高产高效平衡施肥效应的研究表明,在土壤中等肥力水平下,冬小麦-夏玉米施用氮肥和磷肥均能显著增加产量和效益,冬小麦和夏玉米施用氮肥分别增产11.1%~32.2%(平均22.5%)和12.5%~24.1%(平均19.2%),分别增收853.50~2 775.00元/hm2(平均1 876.60元/hm2)和1 352.33~2 293.77元/hm2(平均1 651.04元/hm2);施用磷肥分别增产8.1%~14.0%(平均11.7%)和2.5%~13.2%(平均9.1%),分别增收563.4~1 380.6元/hm2(平均974.7元/hm2)和189.74~1 458.39元/hm2(平均765.31元/hm2).冬小麦-夏玉米适宜N用量范围分别为220~260 kg/hm2和220~280kg/hm2,适宜施氮水平的氮肥利用率分别为36.5%和26.3%;适宜P2O5用量分别为90~110 kg/hm2和95~115kg/hm2,适宜施磷水平的磷肥利用率分别为16.8%~17.3%和11.8%~20.5%.冬小麦-夏玉米高产高效平衡施肥较农民习惯施肥增产5.3%~9.0%,增收454.19~992.5元/hm2,提高氮肥利用率5.0~15.2个百分点.  相似文献   

5.
红豇豆根缘细胞对铝胁迫的响应   总被引:8,自引:1,他引:8  
以红豇豆(Vigna.ungniculata.ssp.sesquipedalis.cv.chuangfeng)为材料,采用悬空气培法,研究红豇豆根缘细胞产生的数目、活性及对铝胁迫的响应。结果表明,红豇豆的边缘细胞数目先随着根的伸长而迅速增加,到根长为10mm时达到最多,约为5300个;随后,边缘细胞数目稍有减少,且较为稳定。边缘细胞的存活率较高,都大于85%,随着红豇豆根长的伸长,边缘细胞的活性逐渐增高。根冠果胶甲基酯酶(PME)的活性随着根的伸长而减小,表明边缘细胞游离与根冠PME活性有着密切的相关性。离体边缘细胞的存活率随着Al3+处理浓度和处理时间的增加而降低。不同浓度Al3+液处理对相同根长红豇豆的根冠PME酶活性没有显著的影响。  相似文献   

6.
玉米根系对局部氮磷供应响应的基因型差异   总被引:2,自引:2,他引:2  
【目的】土壤养分具有异质性,揭示不同基因型玉米根系对于养分异质性的响应规律,对提高不同玉米品种氮、磷利用效率具有重要意义。 【方法】本试验在水培条件下,利用分根系统研究3个玉米杂交种苗期根系对氮、磷两种养分局部供应响应的基因型差异。 【结果】根系对局部供氮的响应存在基因型差异,浚单20和中农玉99侧根生长对局部供氮的响应较敏感,显著提高了局部供氮(+N)一侧的侧根长,增幅达到79%、50%,而NE15无显著响应;浚单20和中农玉99主要提高了+N一侧直径大于0.12 mm的侧根长度。根系生长对于局部供磷(+P)的反应同样存在基因型差异,NE15显著提高+P一侧根系生物量和轴根长,增幅达到38%和24%,中农玉99显著提高+P一侧的侧根长达到35%;在+P侧,浚单20主要增加了直径大于0.12 mm的侧根长度,NE15主要增加直径介于0.12~0.24 mm的侧根长度,而中农玉99主要增加直径小于0.12 mm的极细侧根长度。局部供氮对3个品种侧根生长的促进作用强于局部供磷,而对缺氮一侧根系生长的抑制作用均大于缺磷一侧。不同玉米基因型苗期根系生物量、侧根长(尤其是直径>0.12 mm的侧根)对于局部供应氮、磷存在显著的互作效应,局部供氮对浚单20的侧根生长(尤其是直径>0.12 mm的侧根)的促进作用显著高于局部供磷,而NE15的根系生长(尤其是根系生物量)对局部供磷的响应强度大于局部供氮。 【结论】对于不同养分特性的玉米杂交种,苗期根系对局部供应不同种类养分的响应存在显著的基因型差异,在生产中可以针对品种特性采取不同的施肥措施,以便发挥其生物学潜力。  相似文献   

7.
Abstract

Foliar application of phosphorus (P) may be a supplementary treatment to sustain adequate P-status of potato (Solanum tuberosum L.). However, the prediction of the potential benefits of foliar P supply is difficult, since several factors, such as weather conditions and plant P-status influence the effects. We determined the impact of soil moisture and soil P-supply on the responsiveness to foliar P-application under controlled environmental conditions. Plant dry matter yields, P-accumulation and phosphorus use efficiency (PUE) with or without foliar application were determined at five soil P-levels in combination with two soil moisture levels. The results suggest that water status is of importance for the responsiveness to foliar P-application and may be related to diffusion of P through the leaf cells, which require a good water status. The PUE was significantly improved with irrigation while adding P to the soil decreased the PUE.  相似文献   

8.
Abstract

Aluminum (Al) toxicity is one of the major factors limiting plant growth in acid soils. To determine the response of taro [Colocasia esculenta (L.) Schott] to Al‐toxicity, cultivars (cv.) Lehua maoli and Bun long were grown in hydroponic solution at six initial levels of Al (0, 110, 220, 440, 890, and 1330 uM Al). Increasing Al levels significantly depressed fresh and dry weights of taro leaf blades, petioles, and roots, as well as leaf areas and root lengths. No significant cultivar differences were found for plant dry weights. However, significant cultivar differences were found for expansion growth parameters, with cv. Lehua maoli exhibiting greater leaf fresh weights and root lengths in the presence of Al, compared to cv. Bun long. Apparently, differential response of taro cultivars to Al is related to the ability of the Al‐tolerant cultivar to maintain water uptake and cell expansion in the presence of Al. The initial solution Al level that resulted in the greatest separation of growth differences between taro cultivars in their response to Al was 890 μM Al.  相似文献   

9.
Abstract

One proposed mechanism of aluminum (Al)‐tolerance involves the ability of plants to maintain uptake of essential mineral elements in the presence of Al. To examine this hypothesis, taro [Colocasia esculenta (L.) Schott] cultivars (cv.) Lehua maoli and Bun long were grown in hydroponic solution at six initial Al levels (0, 110, 220, 440, 890, and 1330 μM Al), and plant mineral concentrations were determined after 27 days. Increasing Al levels significantly increased Al concentrations in taro leaf blades, petioles, and roots. This increase in Al concentrations in the leaf blades as solution Al levels increased was greater for Al‐sensitive cv. Bun long compared to cv. Lehua maoli, resulting in significant interaction between Al and cultivar effects. However, no significant cultivar differences were found for Al concentrations in the petioles or roots. Increasing Al levels in solution significantly depressed concentrations of calcium (Ca), magnesium (Mg), manganese (Mn), and iron (Fe) in taro leaf blades, and significantly depressed concentrations of Ca, Mg, copper (Cu), and zinc (Zn) in taro roots. Aluminum‐induced Ca deficiency appeared to be one possible mechanism of Al phototoxicity in taro, becvasue Ca concentrations in the leaf blades and roots at the higher Al levels were within the critical deficiency range reported for taro. Significant cultivar differences were found, in which Al‐tolerant cv. Lehua maoli had significantly greater Ca and Cu concentrations in the roots, and significantly greater potassium (K) concentrations in the leaf blades across all Al levels. Our results show that Al‐tolerance in taro cultivars is associated with the ability to maintain uptake of essential mineral nutrients, particularly Ca and K, in the presence of Al.  相似文献   

10.
Response of alfalfa (Medicago sativa L.), birdsfoot trefoil (Lotus corniculatus L.), and red clover (Trifolium pratense L.) to aluminum was evaluated in a nutrient culture system under controlled conditions. In each of the species, varietal differences were also compared. In the absence of Al stress, varieties of alfalfa and Tensas red clover produced more dry weight than the other legumes. However, among the legumes tested, alfalfa was the most sensitive to Al. Aluminum reduced the uptake of many of essential nutrients. Overall, red clover cultivars experienced the least reduction in elemental uptake, whereas alfalfa cultivars experienced the greatest reduction in uptake of elements under Al stress. The efficiency ratio (ER) assisted in differentiating legumes entries into efficient and inefficient utilizers of absorbed nutrients. The ER is defined as milligrams of dry shoot weight produced per milligram of element in the shoot. The presence of Al in the growth medium reduced the ER for all elements. With a few exceptions, ER for various elements, gave positive correlations with shoot weight. The species and cultivars used in this study showed inter‐ and intraspecific differences in growth, uptake of nutrients and nutrient efficiency ratios in the presence or absence of Al stress.  相似文献   

11.
Fertilization with nitrogen (N) or phosphorus (P) can improve plant growth in saline soils. This study was undertaken to determine wheat (Triticum aestivum L; cv Krichauff) response to the combined application of N and P fertilizers in the sandy loam under saline conditions. Salinity was induced using sodium (Na+) and calcium (Ca2+) salts to achieve four levels of electrical conductivity in the extract of the saturated soil paste (ECe), 2.2, 6.7, 9.2 and 11.8?dS?m?1, while maintaining a low sodium adsorption ratio (SAR; ≤1). Nitrogen was applied as Ca(NO3)2?·?4H2O at 50 (N50), 100 (N100) and 200 (N200)?mg?N?kg?1 soil. Phosphorus was applied at 0 (P0), 30 (P30) and 60 (P60)?mg?kg?1?soil in the form of KH2PO4. Results showed that increasing soil salinity had no effect on shoot N or P concentrations, but increased shoot Na+ and chlorine ion (Cl?) concentrations and reduced dry weights of shoot and root in all treatments of N and P. At each salinity and P level, increasing application of N reduced dry weight of shoot. At each salinity and N level P fertilization increased dry weights of shoot and root and shoot P concentration. Addition of greater than N50 contributed to the soil salinity limiting plant growth, but increasing P addition up to 60?mg?P?kg?1 soil reduced Cl? absorption and enhanced the plant salt tolerance and thus plant growth. The positive effect of the combined addition of N and P on wheat growth in the saline sandy loam is noticeable, but only to a certain level of soil salinity beyond which salinity effect is dominant.  相似文献   

12.
Climate change, as a result of increase in the concentration of greenhouse gases, influences growth and productivity of leguminous crops. A study was carried out to analyse the impacts of elevated carbon dioxide (CO2) and cyanobacterial inoculation on growth, N2 fixation and N availability and uptake in cowpea crop, under different doses of phosphorus. Cowpea crop was grown under ambient (400 µmol mol?1) and elevated (550 ± 20 µmol mol?1) CO2 levels using Free-Air Carbon dioxide Enrichment facility. Elevated CO2 level increased chlorophyll content in leaves, improved nodulation and nitrogen fixation by the crop. Increase in P dose up to 16 mg kg?1 soil enhanced nodule development and N2 fixation under high CO2 condition. Cyanobacterial inoculation increased nodule weight, leghaemoglobin content in nodules and total nitrogenase activity. Although nitrogen concentration in cowpea seeds decreased in high CO2 treatment, higher N uptake was recorded. Under elevated CO2 condition, cyanobacterial inoculation and higher P doses led to enhanced root growth and N2 fixation and availability of soil nitrogen. The study illustrated the synergistic effect of high CO2 and cyanobacterial inoculation in enhancing crop growth and availability of soil N, mediated by biological N2 fixation in cowpea under different levels of P.  相似文献   

13.
Abstract

Toxic levels of aluminum can cause severe yield reduction in alfalfa (Medicago sativa L.), especially in the presence of drought stress. Reactions to Al stress of alfalfa cultivars and germplasms, representing a broad genetic base and the entire range of dormancy types, were evaluated in a Monmouth soil study [26.2% Al saturation (pH 4.8) vs 2.8% Al saturation (pH 5.7)] and in two nutrient solution experiments (0 vs 111 μmol Al; pH 4.5). The soil study, Experiment 1, and Experiment 2 were harvested 28, 40, and 25 d after seeding, respectively.

In all studies, entries differed significantly in vigor and yields were reduced significantly by Al stress. In the soil study, only ‘Lahontan’ was not affected significantly by Al stress, although Lahontan, ‘Atlantic’, ‘B13‐A14’ (tolerant check), ‘Ladak 65’, and ‘Mesa‐Slrsa’ had comparable relative weights (dry weight stressed/dry weight unstressed). There were no statistically significant differential responses to Al stress in Experiment 1, however the relative weight of B13‐A13 (tolerant check) was considerably larger that those of the other entries. Many entries were not affected significantly by Al stress in Experiment 2; B13‐A14, ‘Moapa 69’, ‘Saranac’, and ‘Teton’ had the largest relative weights. Relative weights for Experiment 1 and Experiment 2 were significantly correlated (r=0.46?) as was mean dry matter production in the soil study and Experiment 2 (r=0.73??).  相似文献   

14.
Toxic levels of aluminum can cause severe yield reductions in many crop species, but sericea lespedeza [Lespedeza cuneata (Dum.‐Cours.) G. Don] has demonstrated considerable tolerance. Aluminum tolerances of six sericea lespedeza cultivars (Am 312, Appalow, AU Lotan, Interstate, Interstate 76, Serala) representing a broad genetic base were evaluated in a Monmouth soil [26.2% Al saturation (pH 4.8) vs. 2.8% Al saturation (pH 5.7)] and in nutrient solutions (0 vs 111 μM Al; pH 4.5). The soil and nutrient culture studies were harvested 30 and 27 d after seeding, respectively.

Aluminum stress did not reduce root and shoot growth significantly, nor were the pooled Al stress x cultivar interactions significant. Cultivars differed significantly in mean shoot and root vigor in nutrient solutions but not in soil. R‐esponses in soil were only weakly correlated with responses in nutrient solutions. Am 312 and Appalow had the lowest relative weight values (dry weight stressed/dry weight unstressed) in both media and Interstate and Interstate 76 the highest. Interstate 76 exhibited a significant positive response (5% level) to Al when evaluated in nutrient solutions.  相似文献   

15.
Abstract

Responses to aluminum phosphate (Al-P) and superphosphate (Sup-P) application in terms of dry matter production by pigeon pea and soybean were compared under field conditions. The effect of aluminum on growth and symbiotic dinitrogen fixation was examined under hydroponic conditions. In a field experiment, Al-P application significantly increased whole plant dry weight and P amount in pigeon pea, whereas in soybean, Al-P application had no significant effect on the two parameters. The results indicate that P absorption ability from Al-P is higher in pigeon pea compared to soybean. With Al-P application, leaf and whole plant Al concentration in pigeon pea significantly increased unlike in soybean.

Under hydroponic conditions, 50 nig L?1 Al application increased the plant weight of pigeon pea while it decreased that of soybean. This treatment decreased the total nodule activity of soybean more appreciably than that of pigeon pea. Under the Al treatment conditions, whole plant P amount increased in pigeon pea, whereas it decreased in soybean, and the amount of Al increased more appreciably in pigeon pea, most of which was deposited in roots.

These results suggest that compared to soybean, pigeon pea displays a higher ability to absorb P from P compounds with a low solubility i.e. Al-P and that it is more tolerant to Al toxicity.  相似文献   

16.
The objectives of this study were to determine and compare the Al tolerance of selected citrus rootstocks. Six‐month‐old seedlings of five citrus rootstocks were grown for 60 days in nutrient solutions. The solutions contained 7 levels of Al ranging from 4 to 1655 μM and similar P concentration of 28 μM. The nutrient solution pH was maintained at 4.0±0.1 and the temperature at 25±1°C. At high Al treatment levels, plants had thickened root tips and root caps covered with black gelatinous material. At high levels of Al treatments, seedlings of some rootstocks had yellow, mottled, and withered new leaves near end of experiment. New‐growth root lengths and shoot height responded differently to Al concentrations in the nutrient solution. New‐growth fresh weight of whole plants appeared to be the most sensitive indicator of Al tolerance. Based on response of fresh weight of whole plants to Al concentrations, relative Al tolerances of the rootstocks were Cleopatra mandarin > rough lemon > sour orange > Swingle citramelo > Carrizo citrange. The neutral or dividing Al concentrations in solution between beneficial and toxic effects were 371, 193, 189, 178, and < 100 μM Al, respectively, for the above rootstocks. Concentrations below or above the neutral Al levels caused either beneficial or toxic effects, respectively. The apparent optimum Al concentrations for the growth of whole plants were 163, 93, 89, 85, and <50 μM, respectively.  相似文献   

17.
Low soil phosphorus (P) availability and drought are the most recognized growth-limiting factors for the cotton production in arid regions. A pot experiment with P-efficient (Xinluzao19, X19) and P-inefficient (Xinluzao19, X26) cotton cultivars was conducted to investigate the effects of P and drought on dry matter accumulation and P efficiency. Results showed that biomass and chlorophyll content of leaves increased significantly with the increase in soil P content, whereas the root:shoot ratio decreased dramatically. Drought increased the root:shoot ratio, but the chlorophyll content of leaves remained stable. The yield of X19 increased with the increase in soil P content. For X26, the highest yield was attained under the medium P content. Under drought conditions, root P efficiency ratio, P absorption efficiency, and P transfer efficiency were all proportional to P concentration, whereas P utilization was inversely proportional. Compared with X26, X19 presented higher P absorption efficiency and P utilization but lower root P efficiency ratio and P transfer efficiency. It suggested thatthe application of phosphate fertilizer under drought could increase the root P efficiency ratio, P absorption efficiency, and P transfer efficiency, thereby enhancing the ability of stress resistance of cotton and significantly increasing biomass as well as cotton yield.  相似文献   

18.
不同土壤肥力水平下元白菜施氮、磷、钾和锌的效应   总被引:2,自引:0,他引:2  
对不同土壤肥力水平下元白菜施氮、磷、钾和锌肥的效应研究表明,不同土壤肥力水平下,元白菜施氮、磷、钾和锌均能显著增加产量,分别增产12.0%~35.8%(平均24.5%)、5.3%-14.1%(平均9.7%)、11.2%.15.3%(平均12.9%)和7.5%~11.3%(平均9.1%)。在较高、中等和较低土壤肥力水平下,元白菜经济最佳施氮(N)量分别为310.5、326.1~336.6和378.9kg/hm^2,适宜磷(P2O5)用量依次为60、60-90和90~120kg/hm^2。不同土壤肥力水平地块元白菜适宜施氮时,氮肥(N)利用率在15%~20%,适宜施磷时磷肥(P2O5)利用率在9.3%~11.0%;元白菜上钾肥利用率随土壤钾素水平的降低而呈增加的趋势,不同土壤肥力地块元白菜施K2O120kg/hm^2时钾肥(K2O)利用率平均为20.4%。  相似文献   

19.
通过14个大田试验,研究了湖北省棉花 P 肥效应及适宜用量。结果表明,适量施用 P 肥对棉花具有明显的增产增收效果,14个试验施P处理比对照处理增产子棉100 ~ 896 kg/hm2,平均增产347 kg/hm2;施P 处理增产率2.1% ~ 25.2%,平均增产率为10.4%;施P处理纯利润平均为1 764元/hm2,产投比平均为6.61;P 肥偏生产力和农学利用率平均分别为P2O5 51.27 kg/kg 和P2O5 4.15 kg/kg。根据肥料效应方程,在当前生产条件下,棉花生产的P肥经济用量平均为P2O5 112.7 kg/hm2,推荐幅度为 P2O5 42.9 ~ 183.2 kg/hm2。土壤有效P含量与棉花P肥经济推荐用量呈极显著负相关(r ﹦﹣0.7628**,n ﹦13),根据土壤有效P含量(x,单位为 mg/kg)水平,湖北省目前棉花生产适宜用P量(y,单位为 kg/hm2)可通过公式 y ﹦273.42﹣78.488 ln(x) 求得。  相似文献   

20.
The relationship between acid phosphatase activity (APA) and phosphorus (P) stress in two bean genotypes (Phaseolus vulgaris var Tacarigua and var Manuare) and in cowpea (Vigna unguiculata var TUY) are reported in this paper. Sand culture experiments were performed in a highly ventilated greenhouse where plants were drip feed with nutrient solutions with either 1.0 or 0.02 mM P. Acid phosphatase activity was determined in extracts from roots, young (apical) and mature leaves, and in leaf discs and root sections using o‐carboxyphenyl phosphate as substrate. Differences in total dry matter were found to be significant (P = 0.01) only for cowpea. However, reduction in leaf area was significant in both species and varieties. Differences in the P concentration in the dry matter, were large enough to suspect that plants were suffering from a mild P stress. Acid phosphatase activity was above the values reported for these species under P stress, however, APA in these legumes appears not to be inducible by the low P‐concentration level used in this study. A higher APA was found in young as compared to mature leaves, and the expression of APA also showed intraspecific variation. Acid phosphatase activity was related to the age of the leaves and was easily measured in leaf discs, specially for bean. This and the ratio of P concentration between young and mature leaves may be an alternative to absolute P‐status determination in plants.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号