田菁对大庆地区盐碱化土壤的改良效果

[目的]研究田菁对大庆地区盐碱化土壤的改良效果。[方法]设置种植田菁和不种田菁(CK)2个处理,于2014—2016年进行田间试验,探讨其对大庆地区盐碱化土壤的改良效果。[结果]田菁适应大庆地区气候条件和盐碱化土壤环境,种植田菁能有效促进地表其他植被生长,降低土壤pH、可溶性盐含量、电导率及土壤速效磷含量和速效钾含量,提高土壤有机质含量和碱解氮含量。[结论]田菁对大庆地区盐碱化土壤和独特气候环境具有较强的适应性,可作为盐碱土改良的先锋树种在大庆地区引种。     

The root-knot nematode problem in sesbania fallows and scope for managing it in western Kenya

Sesbania (Sesbania sesban), which is promoted as a short-duration-fallow species in eastern and southern Africa, is an alternative host to root-knot nematode (Meloidogyne spp.). Therefore, it is important to know the extent of sesbania infection by the nematode on farms and its effects to crops grown in rotation with sesbania. A survey of 14 farms in western Kenya indicated that sesbania was infected by root-knot nematode in all the farms. The potential to build up the nematode population was much greater on farms where maize (Zea mays) was previously intercropped with a susceptible bean (Phaseolus vulgaris). Screening of 30 single plant accessions of four sesbania provenances (Kakamega, Siaya, Kisumu, and Kisii) from western Kenya in pots indicated limited scope for selecting material resistant to the nematode. All four provenances were infested by the nematode, and they increased its population in soil and root. A rangewide collection of sesbania germplasm needs to be screened to determine the scope of finding nematode-resistant material. Transplanted seedlings produced in heat-sterilized, nematode-free soil showed less nematode infection than direct-seeded plants. However, both direct seeding and transplanting seemed to increase nematode population similarly. A number of Crotalaria spp. that were found resistant to nematodes can be considered as alternatives to sesbania-planted fallows, but further field-scale testing is necessary to select appropriate species based on biomass production. Among other species suitable for short-duration fallows, only pigeonpea (Cajanus cajan) and senna (Senna siamea) showed promise. Species such as neem (Azadirachta indica), casuarina (Casuarina junghuhniana), and grevillea (Grevillea robusta) that are suitable for boundary plantings were free from the root-knot nematode.This revised version was published online in November 2005 with corrections to the Cover Date.     

田菁翻压还田对滩涂土壤碳氮及微生物生物量的影响

为探讨不同施肥处理下田菁翻压还田对滩涂土壤的改良效果,通过田间小区试验对不同施肥处理(CK、SN1、SN2、SN3、SN4及SN4+OF对应的施氮量分别为N0、90、135、180、225kg/hm2及N 225 kg/hm2+有机肥)下田菁生物量、碳氮养分含量及翻压还田对土壤碳氮、微生物生物量的影响及各指标间的相关性...     

Root length and nitrate under Sesbania sesban: Vertical and horizontal distribution and variability

Measurements of root and nutrient distributions in agroforestry systems have often been obtained from unreplicated plots. We, therefore, measured the vertical and horizontal distribution of root length and soil nitrate in replicated plots of sesbania [Sesbania sesban (L.) Merr.] to assess plot-to-plot variation and identify appropriate sampling schemes. Sampling was on profile walls exposed from pits at two on-farm sites (Ochinga and Muange) in Kenya. At Ochinga, soil was sampled at 27 0.15-m depth intervals and eight 0.15-m-wide locations perpendicular to 2.25-m-wide rows of 19-month-old sesbania. At Muange, sampling was 18 months after establishment of sesbania from seedlings with a 1 m by 1 m spacing. Soil was sampled at 17 0.15-m depth intervals and nine 0.15-m-wide sampling locations – one exactly below the tree and four each on opposite sides of the tree. Root length density generally decreased with distance from sesbania and with soil depth. Soil nitrate, however, followed different trends in the four replications at Ochinga and the three replications at Muange. At Ochinga, nitrate above 2.5-m depth clearly increased with distance from the tree in two replications but followed no distinct trend in another replication. At Muange, nitrate above 1.2-m depth decreased with distance from the tree in one replication, increased with distance from the tree in another replication and followed no clear trend in another replication. The suitability of various sampling schemes for measuring root length and nitrate was accessed from percent bias between measured values at sampling locations in the scheme and actual values for an entire transect of sampling locations. Bias associated with selection of sampling locations tended to be higher within the 2.25-m-wide sesbania rows than the 1 m by 1 m sesbania spacing. Soil sampling in systems with rows of young trees should be at several locations along a transect perpendicular to tree rows in order to minimize bias. This revised version was published online in June 2006 with corrections to the Cover Date. This revised version was published online in June 2006 with corrections to the Cover Date.     

施氮对田菁翻压还田滩涂盐渍土碳氮及细菌群落结构的影响

为探讨不同施氮处理下田菁翻压还田对滩涂盐渍土的改良效果,通过田间小区试验研究了不同施氮水平下(CK、SN1、SN2、SN3、SN4对应的施氮量分别为0、90、135、180、225 kg/hm²)绿肥田菁还田对土壤碳氮、pH、水溶性盐和细菌群落结构的影响。结果表明:SN3处理下田菁生物量和碳、氮累积量最高,分别为41 882、3 756和101.5 kg/hm²。作绿肥翻压还田后,则以SN2处理土壤有机碳、全氮含量最高,分别为6.51 g/kg和0.637 g/kg。各施氮处理下,田菁翻压后土壤微生物生物量碳氮含量低于CK处理。随田菁翻压量的增加,土壤pH呈逐步下降趋势,而土壤水溶性盐总量则随施氮水平和翻压量的增加而上升,但较种植前明显降低。不同施氮处理田菁翻压后,土壤中具有一定有机降解功能的变形菌门、酸杆菌门、拟杆菌门、放线菌门和绿弯菌门等细菌类群占据主导地位,且相对丰度随田菁翻压量的增加呈一定变化趋势,但细菌群落结构变化不明显。土壤门水平优势菌群相对丰度与土壤碳氮含量、pH和水溶性盐总量等指标均呈一定的相关关系,其中以拟杆菌门、厚壁菌门、...     

田菁生育特性及其利用的研究

调查研究结果表明。夏播田菁的株高生长呈S形曲线。9月中旬达开花盛期,也是有效开花终止期。田菁荚果的长度、宽度、荚果内种子依次生长达最大值。田菁较耐盐。生长良好的田菁有明显抑制杂草作用。利用茎秆剥制纤维以结荚中期进行为好。     

不同豆科田菁属(Sesbania spp)绿肥对酸性土壤有机碳含量的影响

豆科植物是热带、亚热带地区重要的绿肥资源,为了探明我国豆科绿肥的培肥效果,笔者通过田间试验,研究施用7份野生豆科田菁属绿肥后酸性土壤有机碳含量随时间的动态变化。结果表明,施用绿肥后,不同种质绿肥对土壤有机碳含量的影响不同,且不同绿肥对土壤有机质碳含量的影响效果随着施用时间的变化而不断变化;虽然不同田菁绿肥对土壤有机质含量影响的效果不一,但在施用1年内均能显著(P0.05)增加土壤有机碳的含量,并在施用1个月后效果最好,但随着时间的延长,土壤有机碳含量不断降低。     

Performance of Sorghum Grown on a Salt Affected Soil Manured with Dhaincha Plant Residues Using a 15N Isotopic Dilution Technique

A field experiment was conducted on a salt-affected soil to determine the effect of application of three types of Dhaincha (Sesbania aculeata Pers.) residues (R, roots; L, shoots; L+R, shoots plus roots) on the performance of sorghum (Sorghum bicolor L.) using the indirect ¹⁵N isotopic dilution technique. Results indicated that sesbania residues (L and L+R), used as green manures, significantly increased grain yield, dry matter production, N uptake, and water use efficiency of sorghum. Percentages of nitrogen (N) derived from residues (%Ndfr) in sorghum ranged from 6.4% to 28%. The N recoveries in sorghum were 52%, 19.6% and 19.7% of the total amount contained in sesbania roots, shoots and roots plus shoots, respectively. The beneficial effects of sesbania residues are attributed not only to the additional N availability to the plants, but also to effects on the enhancement of soil N uptake, particularly in the L+R treatment. The findings suggest that the use of Sesbania aculeata residues, as a green manure, can provide a substantial portion of total N in sorghum. In addition, the use of sesbania green manure in salt-affected soils, as a bio-reclaiming material, can be a promising approach for enhancing plant growth on a sustainable basis.     

Effects of inoculation with Glomus mosseae, Azorhizobium caulinodans and rock phosphate on the growth of and nitrogen and phosphorus accumulation in Sesbania rostrata

A study was carried out to evaluate the influence of single or dual inoculation with Glomus mosseae and Azorhizobium caulinodans with and without rock phosphate on the growth of and N, P and K accumulation in Sesbania rostrata grown in sterilized soil. Height of plants inoculated with G. mosseae in combination with A. caulinadans and/or rock phosphate was significantly higher than that of uninoculated plants or plants inoculated with A. caulinodans alone before but not after 28 days. However, the oven-dry weight of shoots and roots from all treatments did not vary significantly. Generally, concentration and uptake of N and P but not K in shoots and roots of plants were improved by dual inoculation with G. mosseae and A. caulinodans plus or minus P. Mycorrhizal infection of roots was enhanced significantly by A. caulinodans. Received: 18 March 1996     

Symbiotic efficiency of Sesbania rostrata and S. cannabina as affected by agronomic practices

A field experiment was conducted to study the N₂ fixation efficiency of Sesbania rostrata and S. cannabina as affected by agronomic practices in semi-arid subtropical climate, Sowing seeds resulted in smaller numbers of nodules, lower dry weight, lower total biomass, less N uptake, and less N₂ fixation for S. rostrata than S. cannabina, while cut-stem planting improved the symbiotic efficiency. Flooding the soil increased the relative humidity of the crop micro-environment by 4–11% and induced early appearance of stem nodules in S. rostrata. Only 67 kg N ha^-1 was fixed by S. rostrata compared to 160 kg N ha^-1 by S. cannabina when normal agronomic practices (sowing and non-flooding) were followed. In contrast, planting stem cuttings and flooding resulted in greater biological N₂ fixation, 307 and 209 kg N ha^-1 by S. rostrata and S. cannabina, respectively. Therefore, S. rostrata can be successfully exploited as a green manure when stem cuttings are planted under flooded conditions.