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1.
Crop establishment, determined by shoot and root growth during early growth is a vital component in procuring desired plant populations and high yields in rainfed tropical smallholder farming systems, where green manures help maintain soil fertility and sustainability. As green manure incorporation could affect early seedling growth, studies were conduced in a plant house using soils from fields, to evaluate the impact of incorporating two popular tropical green manures (Crotalaria juncea and Tithonia diversifolia) into soil under rainfed field conditions over 3 years, on selected physico‐chemical properties of the soils and on establishment and early shoot and root growth of maize (Zea mays), with and without inorganic fertilizers. In a given year, green manure was grown in one season while maize was grown in the other. A soil that did not receive green manures but was left fallow during the period of green manure cultivation was used as the control treatment. The incorporation of green manures over the 3 years showed trends of increasing soil physical properties, and also the available nitrogen, phosphorus and potassium contents. Incorporation of Crotalaria, with its higher nitrogen content, promoted shoot growth, while Tithonia induced the development of an extended root system. The use of inorganic fertilizers stimulated the beneficial impact of the green manures in promoting shoot and root growth. The use of green manures, especially Tithonia, promoted the development of seminal and nodal roots of maize seedlings, both in the form of length and thickness (based on root surface area) and root length densities, which could assist in successful crop establishment and resource utilization, rather than primary roots. The benefits of using green manures, especially Tithonia, in promoting root growth and Crotalaria in shoot development of maize seedlings even without inorganic fertilizers is presented.  相似文献   

2.
Stress susceptibility indexes (SSI) of eight maize and eight triticale genotypes for their ability to cope with soil compaction (SC) combined with drought (D) or waterlogging (W) were estimated through the determination of changes in dry matter of the shoot (S), root (R) and whole plant (S+R) grown at three levels of soil compaction (1.1, 1.3 and 1.6 g cm?3) and exposed to D or W stress for 7 or 14 days. The SSI values showed variation between and within maize and triticale genotypes, and it was possible to divide genotypes into groups of sensitive and resistant ones. The correlation coefficients (r) between stress susceptibility indexes of soil compaction (SCSI) and drought (DSI) or waterlogging (WSI) and between DSI and WSI were statistically significant. This indicates that genotypes resistant to soil compaction (SC) were resistant to drought (D) or waterlogging (W) stresses and that genotypes resistant to D were also resistant to W. Seedlings grown under the stresses showed changes in S to R ratio (S/R). Sensitive genotypes had higher S/R ratio than resistant ones. Decrease of S/R ratio depends on the duration of stresses, and it may be considered an adaptation mechanism to stress. After 7 days of recovery for D and W treatments, we observed only a partial return of growth traits to the level of control plants.  相似文献   

3.
为明确AM真菌Glomus versiforme在缓解连作障碍中的潜力,以黄瓜为试验材料,于黄瓜播种同时接种G.versiforme,并设立相应对照,苗龄40天时,将幼苗分别移栽至自然连作土与灭菌连作土上,研究2种土壤条件下G.versiforme对黄瓜幼苗的生长,氮磷养分吸收及根际微生物群落组成的影响。结果表明:G.versiforme对幼苗地上部与根系生长的影响因土壤条件而异。出苗第55天时,连作土上接种G.versiforme的幼苗地上部生物量是其相应对照的1.81倍,且该处理与灭菌土上菌根化处理间差异不显著。同时,灭菌土上接种G.versiforme的幼苗根系生物量是连作土上菌根化处理的1.22倍,是连作土上非菌根化处理的2.11倍。连作土上菌根化幼苗地上部生物量的显著积累与G.versiforme对幼苗叶片中氮营养的改善有关,与此同时,灭菌土上G.versiforme可促进根系对磷的吸收。此外,接种G.versiforme可在一定程度上改善土壤环境,使连作土中的细菌数量增加,真菌数量降低。土壤灭菌处理或将菌根化幼苗移栽于连作土壤上均可有效缓解设施黄瓜连作障碍。  相似文献   

4.
为确定黄瓜幼苗对氮素用量及氮素形态的响应特性以指导育苗期间合理施肥,以硝酸铵磷（NO3--N:NH4+-N为0.9:1.0）为供试肥料,研究同时提供NO3--N和NH4+-N的情况下,不同氮素用量对黄瓜幼苗生长及养分吸收的影响。结果表明：与不施氮对照相比,氮素施用可显著增加植株叶面积和株高,但各施氮处理之间差异不明显（50~200 mg N/株）;植株幼苗茎粗和地上部干物质累积量不同处理间差异不显著;施用氮素黄瓜幼苗根系的根长、根表面积和干物质累积量降低（尤其氮用量100 mg/株）,根系直径在0.5~1.3 mm和1.8~2.6 mm范围内的根长下降明显。氮素用量显著影响了地上部氮、磷、钾的浓度及吸收量,对根系的磷、钾浓度和氮、磷、钾的吸收量影响较小;综合地上部和根系的生长状况,氮素用量在50 mg/株及150 mg/株时,黄瓜幼苗的生长健壮。  相似文献   

5.
机插稻超秧龄秧苗的生长特点研究   总被引：23，自引：2，他引：23  
水稻机插移栽中秧苗不能及时机插而生长过度, 形成超秧龄秧苗。本试验以扬粳9538为供试品种, 在不同床土培肥条件下, 观测了超秧龄秧苗的生长特征。在超秧龄初期阶段(至播种后28 d), 秧苗地上部仍维持一定的生长, 秧苗干重和单位苗高干重尚有一定增加, 尚能维持糖氮代谢。但秧苗叶色(SPAD值)迅速下降, 地下部生长停滞, 根长、根数停止增加, 根系活力迅速下降, 根冠比明显降低。在严重超秧龄阶段(至播种后36 d), 苗高依然快速增加, 单位苗高干重大幅下降, 秧苗叶色维持在较低水平。根系活力低, 根系生长处于最低水平。超秧龄生长过程中秧苗糖代谢反应敏感, 氮代谢相对稳定, 糖氮比在严重超秧龄时大幅下降。床土肥力显著影响超秧龄秧苗生长, 高培肥水平下的秧苗茎基粗没有显著变化, 但苗高迅速增加, 单位苗高干重大幅降低, 地下部生长较低培肥处理更弱, 根数和根长较低, 根系活力下降迅速, 根冠比与低培肥处理相比大幅减小。床土培肥水平对秧苗的碳氮代谢影响显著, 高培肥处理的超龄秧苗营养状态更为劣化。以上结果表明, 超秧龄阶段特别是在严重超秧龄阶段的秧苗生长, 很大程度上取决于育秧阶段(适栽期)的育秧条件和生长状况, 低培肥处理的秧苗在超秧龄生长中糖氮比能维持相对较高的水平, 从而维持秧苗相对较好的营养状态。  相似文献   

6.
The development of an extensive root system enables plants to overcome water stress. However, there is little information on the response of food legumes to soil moisture, especially during early growth, which determines crop establishment. Thus, an experiment was conducted under controlled conditions to identify the effect of soil moisture and fertilizer potassium on root and shoot growth of french beans ( Phaseolus vulgaris L.) seedlings. The seedlings were grown in a sand medium under a high and low soil moisture regime and with 0.1, 0.8 or 3.0 mM potassium.
Root lengths, dry weights and numbers of root hairs were greater under low soil moisture conditions. Potassium increased root growth irrespective of soil moisture regimes. The impact of potassium on root length was more pronounced under a high soil moisture regime. In contrast, potassium increased root dry weights and root hairs to a greater extent when plants were grown under dry conditions. The lack of adequate soil moisture increased specific leaf weights, and this phenomenon was reduced by the application of potassium. Shoot:root ratios also showed a similar phenomenon. The development of an extensive root system by french bean seedlings under dry conditions to extract a greater quantity of available soil moisture fur establishment and plant growth and the ability of potassium to promote this phenomenon is presented in this study.  相似文献   

7.
Abstract The objective was to study soil water conservation and physiological growth of wheat (Triticum aestivum L.) using composted cattle manure applied either as mulch or incorporated with soil at 20 Mg ha?1. Haruhikari, a relatively drought‐sensitive and Hongmangmai, a relatively drought‐tolerant wheat, were the cultivars studied under both adequate and deficit irrigation. Fourteen weeks after sowing (WAS), the number of tillers and leaves was significantly reduced by 19 % and 30 % respectively under deficit irrigation and Hongmangmai produced slightly (10 %) more tillers than Haruhikari. Unlike mulching, the incorporation of manure had favourable effects on plants in terms of shoot dry mass (SDM) by 36 % and number of tillers and leaves by 40 %. Haruhikari produced substantially (29 %) greater root mass under adequate irrigation but Hongmangmai produced slightly (2.7 %) more roots and responded much better to manure use whether under adequate or deficit irrigation. As a result, Hongmangmai suffered less severe reductions in tillers and biomass under water stress. In comparison, the mulched manure treatment saved 15 % and 64 % respectively more water than the control and the treatment incorporating manure, but this advantage in water‐saving did not translate to superior plant growth. Leaf water potential (ψl) under adequate irrigation significantly exceeded that under deficit irrigation by 27 % and the ψl of Haruhikari exceeded that of Hongmangmai by 15 %. However, Hongmangmai may be considered more tolerant of dehydration since it maintained much higher net photosynthetic rates (PN) even with a lower leaf water potential. The reduction in the PN and intracellular carbon dioxide concentration (Ci) of the cultivars under deficit irrigation was on account of decreasing stomatal conductance (gs) and transpiration rate but on average, the gs of Hongmangmai significantly exceeded that of Haruhikari by as much as 0.53 under adequate irrigation and 0.22 under deficit irrigation. In conclusion, we suggest that the drought tolerance of Hongmangmai was related to its superior root growth and greater ability than Haruhikari, to efficiently utilize incorporated manure for growth under water stress.  相似文献   

8.
Nineteen annual Medicago genotypes from eight species were grown in Mt. Compass sand at three levels of soil Zn application (0, 0.1 and 0.9 mg Zn kg-1) to achieve Zn status from deficiency to adequacy. Genotypes differed in growth response: under Zn deficiency, those classified as Zn-efficient had less reduction in shoot growth, a higher root mass, greater concentration of Zn in the shoot and total Zn content per plant, and a stable shoot/root ratio compared with Zn-inefficient genotypes. While seed Zn content did not influence the Zn-efficiency ranking, it did affect yield, and so it plays an important role in yield response and Zn accumulation as Zn supply decreases. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

9.
Seed size is an important parameter for plant growth and yield. The effects of seed size and water potential on seed water uptake, germination and early growth of lentil ( Lens culinaris Medik. cvs. Jor-1 and Jor-2) were investigated. Rate of water uptake by seed size (small, medium and large) from solutions containing different water potentials (0, –0.5 and –1.0 MPa, as polyethylene gly-col-8000) was higher in large than in medium or small seeds of both cultivars, regardless of water potential. Rate of water taken into seeds was higher in Jor-2 than in Jor-1. Decreasing water potential (more stress) had adverse effects on rate of water uptake by seeds in both cultivars. In another experiment, with lentils grown in a greenhouse at different soil metric potentials (–0.03, –0.15 and –0.30 MPa), seed size or cultivar had no effects on germination percentage (GP), but GP was reduced as soil water potential decreased (more stress), in greenhouse soil, shoot dry matter (SDM), root dry matter (RDM), plant height, total root length (TRL) and number of primary branches per plant of 35-day-old plants from large seeds were larger than those of plants from medium and small seeds of both cultivars. Increasing soil water deficit progressively decreased each of these traits. Plants from large seeds had higher SDM, RDM and TRL than those from small seeds at intermediate soil water potential (–0.15 MPa) in comparison with the control (–0.03 MPa) or severe (–0.30 MPa) soil water potentials. Larger seeds produced larger plants than smaller seeds, and this appeared to be more pronounced under intermediate than well-watered or more severe water-stressed conditions. Faster early growth of plants from larger seeds may be advantageous in establishing plants under semiarid conditions.  相似文献   

10.
Common bean (Phaseolus vulgaris L.), an important food crop in Europe, America, Africa and Asia, is thought to fix only small amounts of atmospheric nitrogen. It contributes significantly to the sustainability of traditional cropping systems because of the predominance of small-scale farmers who cultivate beans in those areas. The objectives of this work were to evaluate bush bean varieties under common agronomic cropping systems and to evaluate breeding lines under low N-fertility sole cropping and intercropping systems. The purpose of the study was to characterize the genotype and cropping system's variability in symbiotic and plant characters and to identify the most suitable genotypes to establish an effective symbiosis with indigenous strains of Rhizobium. No significant differences among the bush bean varieties evaluated under typical fertilization practices were observed for N2-fixation and plant traits except for seed nitrogen. Significant differences among the bean lines studied under low N-fertilization conditions were detected for plant growth,plant component and N2-fixation traits. A significant interaction of bean genotype x cropping system was found for number of nodules per plant and nodule moisture on the bush bean varieties studied, and for days to emergence, days to flowering, end of flowering, shoot length, root dry weight and shoot nitrogen on the bean lines evaluated. Nodulation parameters were correlated positively with the yield components, shoot and root parts and duration of flowering, and correlated negatively with seed crude protein, pod and seed dimensions and seed dry weight. These observations indicate that it may be possible to increase both the symbiotic N2-fixation and seed yield through plant breeding. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

11.
王晔  田晓莉 《作物学报》2013,39(10):1843-1848
以中棉所41和辽棉17为材料，采用单接穗双砧木嫁接的方法构建分根体系，在营养液培养条件下研究棉花幼苗钾吸收的系统反馈调节。分根处理6 d后，高钾侧(2.50 mmol L–1)根系(Sp.+K)的吸收能力受到低钾侧(0.01 mmol L–1)K+需求信号的诱导，吸收动力学参数Imax (最大吸收速率)与整根高钾对照(C.+K)相比增加了79%~92%；低钾侧根系(Sp.-K)的Imax则受到高钾侧K+供应信号的抑制，与整根低钾对照(C.-K)相比下降了27%~40%。中棉所41分根处理3 d后去除低钾侧根系，保留的高钾侧根系失去K+需求信号的诱导，其Imax下降。棉花幼苗K+吸收的这种反馈调节与地上部和根系的K+含量关系不大。  相似文献   

12.
Stagnant flooding (SF) during vegetative growth triggers stem elongation usually at the cost of tiller production in rice, reducing grain yield. To explore physiological mechanisms associated with tillering suppression under SF, three contrasting genotypes (Swarna and Swarna‐Sub1, both sensitive and IRRI154, tolerant) were evaluated under standing water depths of 0, 5, 30 and 50 cm. SF significantly suppressed tiller formation but increased plant height, root biomass, shoot elongation (ratio of plant height before and after flooding), leaf emergency and non‐structural carbohydrate (NSC) concentration (in root–shoot junction) in all genotypes at the early stage of development. Chlorophyll concentration in the upper leaves (upper most fully expanded leaf at top) was higher than in lower leaves (lowest green leaf at base), but decreased under SF in both. SF increased hydrogen peroxide (H2O2) at the early stage of treatment, with concomitant increase in malondialdehyde (MDA) production by stems and leaves. MDA concentration in root–shoot junction increased but delayed. Tiller number correlated negatively with plant height, shoot elongation, leaf emergency, MDA concentration in leaves and root–shoot junction, root biomass, and NSC concentration in the root–shoot junction. The results suggested existence of compensatory mechanisms between tiller growth and shoot elongation in rice for resilience under SF, where energy is mainly diverted for shoot elongation to escape flooding. The SF‐tolerant genotype produced less H2O2 and maintained energy balance for higher survival and better growth under stagnant flooding.  相似文献   

13.
The effects of deep placement (supplied at 20 cm depth from soil surface below plants) of 100 kg N ha?1 of N fertilizers, urea, coated urea or calcium cyanamide (lime nitrogen) on the growth, nitrogen fixation activity, nitrogen absorption rate and seed yield of soybean (Glycine max L. Merr.) plants were examined by comparing them with control plots without deep placement of N fertilizer in sandy dune field. In addition, three different inoculation methods of bradyrhizobia were used for each N treatment: (1) transplantation of 10‐day‐old seedling in a paper pot with vermiculite inoculated with Bradyrhizobium japonicum USDA110, (2) direct transplantation of inoculated 10‐day‐old seedlings, and (3) transplantation of 10‐day‐old seedlings in a non‐inoculated paper pot. The deep placement of N fertilizers, especially calcium cyanamide and coated urea, markedly increased the growth and total N accumulation in shoot, roots and nodules, which resulted in an increase in seed yield. Daily N2 fixation activity and N absorption rate were estimated by relative abundance of ureide‐N analysed from the concentration of N constituents (ureide‐N, amide‐N and nitrate‐N) in root bleeding xylem sap and increase in total N accumulation in whole plants at R1, R3, R5 and R7 stages. The total amount of N2 fixation was about 50 % higher in the plants with calcium cyanamide and coated urea deep placements compared with control plants. Deep placement of slow release fertilizers kept nodule dry weight higher in the maturing stage of seed, possibly through abundant supply of photoassimilate to the nodules by supporting leaf area and activity until late reproductive stages. The results indicate that deep placement of calcium cyanamide or coated urea enhances N2 fixation activity, which ultimately increases the seed yield. The promotive effect was observed with the seedlings transplanted in paper pot with inoculum of bradyrhizobia within any treatments, although nodulation by indigenous rhizobia was observed in the plants transplanted with non‐inoculated paper pot.  相似文献   

14.
The penetration capability of different rye and triticale varieties in dependence on the soil bulk density By means of a laboratory test the primary roots of 9 rye and 4 triticale varieties were tested for their capability of penetrating overcompactions. The roots served as “natural probes” and as a mark of genotypic differences. The test was carried out in the stages 1.50, 1.65 and 1.80 g/cm3 of soil bulk density. The soil substrate (faint loamy sand) consisted of 5.4 % of clay, 13.8 % of silt, 80.8 % of sand and 0.6 % of total Ct. The tested corn roots respond to compacted soil structures with considerable differences in the rootability. These level differences are not only specific marks for species but also for varieties within the species. Though most of the tested corn varieties respond with restricted root growth in compacted soil, the results cause the expectation that single varieties have a good adaptability to overcompacted soil and can tolerate it better than other ones. At the specific bulk density limit of faint loamy sand (1.50 g/cm3) all tested varieties have an intensive root growth. The rootability of triticale varieties is clearly reduced at the bulk density of 1.65 g/cm3; the roots of rye varieties, however, grow without essential restrictions in this range. Against all expectations the root growth of single rye varieties is similarly intensive as in loose soil at the bulk density of 1.80 g/cm3. Other rye varieties respond very sensitively and with considerable restrictions in root growth in this range. Since a characteristic increase of roots' diameter is to be observed with increasing bulk density, no differences in the root dry matter, caused by bulk density, can be found out. The applied experimental method permits a first selection of plant varieties, which could be interesting in future in view of the mark “Penetration performanc” of primary roots.  相似文献   

15.
干旱胁迫下一氧化氮对小麦离体根尖离子吸收的影响   总被引：2，自引：0，他引：2  
为阐明干旱胁迫下一氧化氮(NO)对植物的保护机制,利用干旱敏感性不同的3个小麦(Triticum aestivum L.)品种的离体根尖,比较了NO对干旱胁迫的响应及其对离子吸收的影响。在干旱胁迫下, 耐旱品种陇春8139根尖中大量产生NO, K+和Ca2+被大量吸收, 而Cl-1被排出体外, 质膜H+-ATPase活性升高; 而干旱敏感品种甘麦8和定西24的根尖中NO、离子含量和质膜H+-ATPase活性的变化呈相反趋势。NO供体硝普纳(SNP)处理使3个品种根尖中的K+和Ca2+含量增加,Cl-1含量下降,并能提高质膜H+-ATPase活力;NOS抑制剂Nω-nitro-L-arginine(LNNA)和NO清除剂2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl- 3-oxide(PTIO)能够逆转这一效果。Na+含量在所有处理下都没有明显变化。试验结果证明,NO能够通过调节质膜H+-ATPase活力影响植物对离子的选择吸收,从而提高耐旱性。  相似文献   

16.
为阐明干旱胁迫下一氧化氮(NO)对植物的保护机制,利用干旱敏感性不同的3个小麦(Triticum aestivum L.)品种的离体根尖,比较了NO对干旱胁迫的响应及其对离子吸收的影响。在干旱胁迫下, 耐旱品种陇春8139根尖中大量产生NO, K+和Ca2+被大量吸收, 而Cl-1被排出体外, 质膜H+-ATPase活性升高; 而干旱敏感品种甘麦8和定西24的根尖中NO、离子含量和质膜H+-ATPase活性的变化呈相反趋势。NO供体硝普纳(SNP)处理使3个品种根尖中的K+和Ca2+含量增加,Cl-1含量下降,并能提高质膜H+-ATPase活力;NOS抑制剂Nω-nitro-L-arginine(LNNA)和NO清除剂2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl- 3-oxide(PTIO)能够逆转这一效果。Na+含量在所有处理下都没有明显变化。试验结果证明,NO能够通过调节质膜H+-ATPase活力影响植物对离子的选择吸收,从而提高耐旱性。  相似文献   

17.
采用湿润育秧,研究了不同育秧方式(秧盘不垫铺麻纤维膜育秧和秧盘垫铺麻纤维膜育秧)和育秧肥不同施用方式(100%秧土混施、50%秧土混施+50%秧土底部撒施、100%秧土底部撒施)下水稻机插秧苗的形态、干质量、根系活力、植株可溶性糖和硝态氮含量、发根力,以探索秧盘垫铺麻纤维膜结合育秧肥底部撒施应用于水稻机插育秧的可行性,以进一步改进麻纤维膜水稻机插育秧技术。结果表明,秧盘垫铺麻纤维膜明显提高了水稻机插秧苗素质,相比秧盘未垫铺麻纤维膜的处理,秧盘垫铺麻纤维膜处理的秧苗表现为秧苗壮实,秧苗根冠比、根系活力、植株可溶性糖含量、发根力均有所提高。育秧肥底部供应提高了秧苗地下部生物量和根冠比,提高了秧苗植株可溶性糖含量而降低了硝态氮含量。随着育秧肥底部撒施比例的增加(从100%秧土混施到100%秧土底部撒施),秧盘未垫铺麻纤维膜秧苗的单株地下部干质量提高了69.2%,根冠比增大了60.3%,可溶性糖含量增加了38.6%,硝态氮含量降低了8.2%;秧盘垫铺麻纤维膜秧苗的单株地下部干质量提高了6.8%,根冠比增加了2.6%,可溶性糖含量增加了41.3%,硝态氮含量降低了7.8%。水稻秧苗根系活力和发根力均在育秧肥50%秧土混施+50%秧土底部撒施方式下达到最高值。研究表明,相比混施于育秧土中,育秧肥底部撒施可以提高水稻机插秧苗素质,可与麻纤维膜很好地结合起来应用于水稻机插育秧。  相似文献   

18.
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   

19.
生物有机液体混合肥对甜高粱根系形态特征的影响   总被引：1，自引：1，他引：0  
为揭示生物液体有机混合肥对陕北农牧交错区青贮饲草作物根系形态特征的影响,通过盆栽控制试验,以甜高粱(Sorghum bicolor L.)为材料,设置不同浓度的生物活性水(BMW)(B1、B2、B3和B4)和Aidoora溶液(A1、A2和A3)处理,并测定甜高粱幼苗期的根系形态特征。结果表明:在大多数单一液体肥和混合液体肥下,甜高粱的根系生物量(RB)、根冠比(RSR)、根系体积(RV)、总根长(TRL)、根系表面积(RSA)、平均根直径(RAD)、比根长(SRL)和比根面积(SRA)均显著高于CK,表明BMW和Aidoora溶液有利于促进甜高粱苗期根系生物量积累和根系吸收能力;甜高粱的RB、TRL和RSA两两间均呈明显的正相关关系,表明根系表面积和总根长均随着根系生物量的升高而增加。综上分析表明,B3A2和B3A3相对于其他BMW和Aidoora混合液体肥,有利于促进甜高粱幼苗根系生物量积累和根系形态建成。  相似文献   

20.
A field experiment was carried out to assess the impact of elevated carbon dioxide (CO2) and temperature on phosphorous (P) nutrition in relation to organic acids exudation, soil microbial biomass P (MBP) and phosphatase activities in tropical flooded rice. Rice (cv. Naveen) was grown under chambered control (CC), elevated CO2 (EC, 550 μmol mol−1) and elevated CO2 + elevated temperature (ECT, 550 μmol mol−1 and 2 °C more than CC) in a tropical flooded soil under open top chambers (OTCs) along with unchambered control (UC) for three years. Root exudates were analyzed at different growth stages of rice followed by organic acids determination. Rhizospheric soil was used for analysis of soil phosphatase, MBP and available P. The total organic carbon (TOC) in root exudates was increased by 27.5% and 30.2% under EC and ECT, respectively over CC. Four different types of organic acids viz. acetic acid (AA), tartaric acid (TA), malic acid (MA) and citric acid (CA) were identified and quantified as dominant in root exudates, concentration of these was in the order of TA > MA > AA > CA. The TA, MA, AA and CA content were increased by 34.4, 31.1, 38.7 and 58.3% under ECT compared to that of UC over the period of 3 years. The P uptake in shoot, root and grain under elevated CO2 increased significantly by 29, 28 and 22%, respectively than CC. Soil MBP, acid and alkaline phosphatase activity was significantly higher under elevated CO2 by 35.1%, 27 and 36%, respectively, compared to the CC. Significant positive relationship exists among the organic acid exudation, MBP, phosphatase activities and P uptake by rice. The enhanced organic acid in root exudates coupled with higher soil phosphatase activities under elevated CO2 resulted in increased rate of soil P solubilization leading to higher plant P uptake.  相似文献   

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