Soybean Nutrient Uptake Research Articles

The Effect of Nutrient Seed Priming on Nutrient Concentration and Uptake of Soybean

This study aimed to evaluate the impact of nutrient seed priming on the nutrient concentration and uptake in soybeans’ and experiment was carried out two consecutive years at research farm of Oilseed Research Station, Latur under VNMKV, Parbhani, during kharif, 2018 and 2019 in randomized block design (RBD) with 12 treatments which were replicated thrice. The soil of experimental field was clayey in texture (Vertisols),The treatments comprises T1: absolute control,T2: Only RDF,T3:RDF + Zn@ 3g kg-1 seed,T4 :RDF + B @ 3g kg-1 seed,T5: RDF+ Fe@ 3g kg-1 seed.,T6: RDF + S @ 3g kg-1 seed,T7: RDF + Zn+ B each @ 3g/kg-1 seed,T8: RDF + Zn+ B +Mo each @ 3g kg-1 seed ,T9:RDF + Zn+ B + Mo + Fe each @ 3g kg-1 seed ,T10: RDF + Zn+ B + Mo + Fe+ S each @ 3g kg-1 seed ,T11:RDF + Rhizobium +PSB each @ 10 ml kg-1 seed ,T12: Without RDF + Zn+ B + Mo + Fe + S each @ 3g kg-1 seed. The results indicated that the priming of Zn+ B + Mo + Fe+ S each @ 3g kg-1 seed along with RDF proved its superiority over rest of treatments, however, Priming with a combination of Zn, B, Mo, Fe, and S along with RDF resulted in a significant increase in nutrient concentration and nutrient uptake of soybean over alone nutrient application and control treatment.

Utilizing Rice Hull Ash and Biomass as Ameliorants Enhanced Soybean Yield and Nutrient Uptake in Tidal Swamps Under Saturated Soil Culture

Saturated soil culture (SSC) is a promising technology for cultivating soybeans in acidic soil in tidal swamps. The objectives of this study were to measure nutrient uptake in the soybean plant using a saturated soil culture technique and to assess the impact of ameliorant addition in the form of rice biomass and rice hull on soybean yield. Two factors, rice biomass, and rice hull ash, were used in a split plot factorial design to set up the experiment. Four levels in the main factor included without biomass immersion, one immersion of short (3 cm above the root) rice stubble, one immersion of regular (panicle harvested only) rice straw, and two immersions of regular rice straw cut in the soil. The four levels in the subfactor were 0 t ha-1, 0.25 t ha-1, 0.50 t ha-1, and 0.75 t ha-1 of rice hull ash doses. Ameliorant in the form of biomass and rice husk increases soil quality in tidal swamps by enhancing pH, soil nutrients (N, P, K, S), CEC, cations, and base saturation, also reducing toxic compounds and improving soil texture. Application of ameliorant also increases soybean nutrient uptake and eventually increases the productivity of soybeans in tidal swamp acid soil. The best treatment of the first and second factors was one immersion of biomass with a regular cut of rice straw and 0.5 t ha-1 ash rice hull ash addition to the tidal swamp soil, respectively.

Co-inoculation of Soybean Seedling with Trichoderma asperellum and Irpex laceratus Promotes the Absorption of Nitrogen and Phosphorus.

Soybean are one of the main oil crops in the world. The study demonstrated that co-inoculation with Trichoderma asperellum(Sordariomycetes, Hypocreomycetidae) and Irpex laceratus (Basidiomycota, Polyporales) isolated from Kosteletzkya virginica can promote the growth of soybean seedlings. The two fungi were found to produce various enzymes, including cellulase, amylase, laccase, protease, and urease. Upon inoculation, T. asperellum mainly colonized within the phloem of the roots in soybean seedlings, while I. laceratus mainly in the xylem and phloem of the roots. Physiological parameters, such as plant height, root length, and fresh weight, were significantly increased in soybean seedlings co-inoculated with T. asperellum and I. laceratus. Moreover, the expression of key genes related to N and P absorption and metabolism was also increased, leading to improved N and P utilization efficiency in soybean seedlings. These results indicate that the two fungi may have complementary roles in promoting plant growth, co-inoculation with T. asperellum and I. laceratus can enhance the growth and nutrient uptake of soybean. These findings suggest that T. asperellum and I. laceratus have the potential to be used as bio-fertilizers to improve soybean growth and yield.

Response of Bacillus megaterium and Bacillus mucilaginosus Strains on Growth and Nutrient Uptake of Soybean

The current study aimed to investigate the Response of Bacillus megaterium and Bacillus mucilaginosus strains on growth attributes and uptake of soybean (Glycine max (L.) Merrill.) at All India Coordinated Research Project (AICRP) on Integrated Farming System Research at College of Agriculture, Indore, Madhya Pradesh, India during kharif, 2019 & 20. The study was carried out in randomized block design (RBD) with 8 treatments, viz. Control with 75% RDF (T1), Control with 100% RDF (T2), 75% RDF with Bacillus megaterium and Bacillus mucilaginosus strains as seed treatment (T3), 100% RDF with Bacillus megaterium and Bacillus mucilaginosus strains as seed treatment (T4), 75% RDF with Bacillus megaterium and Bacillus mucilaginosus strains as foliar application at 30 and 45 DAS (T5), 100% RDF with Bacillus megaterium and Bacillus mucilaginosus strains as foliar application at 30 and 45 DAS (T6), 75% RDF with Bacillus megaterium and Bacillus mucilaginosus strains as seed treatment + foliar application of Bacillus megaterium and Bacillus mucilaginosus strains at 30 and 45 DAS (T7) and 100% RDF with Bacillus megaterium and Bacillus mucilaginosus strains as seed treatment + foliar application of Bacillus megaterium and Bacillus mucilaginosus strains at 30 and 45 DAS (T8). Among all the treatments, growth parameters, NPK uptake by grain and straw and total uptake by crop were observed highest with 100% RDF with Bacillus megaterium and Bacillus mucilaginosus as seed treatment + foliar application of Bacillus megaterium and Bacillus mucilaginosus at 30 and 45 DAS.

Role of phosphorus and molybdenum on root growth, nodulation and nutrient uptake of soybean [Glycine max (L.) Merr.

A field investigation was carried out during kharif 2015 to study the response of soybean to phosphorus and molybdenum nutrition. Results revealed that the interaction effect of phosphorus application (60 kg P2O5/ha) and molybdenumseed treatment @ 6 g/kg seed recorded significantly higher vigourindex-I (2305), vigour index- II (90), root length (21.26 cm), root volume (12.70 cm3), effective nodules/plant (37), nodule dry weight (50.73 mg), oilcontent (19.43 %) and molybdenum uptake by seed (4.10 g/ha). The leghaemoglobin content was highest (249 mg/g fresh weight) with P application @ 60 kg/ha and it was unaffected due to Mo seed treatment and interaction of P and Mo. Among the P levels, protein content and seed yield were significantly higher (41 % and 1784 kg/ha) with 60 kg/ha and with Mo seed treatment @ 6 g/kg seed (40.2 % and 1572 kg/ha).

Rhizosphere nutrient availability and nutrient uptake of soybean in response to biochar application

Biochar application in agricultural soils can be highly beneficial to crop productivity in numerous ways. Rhizosphere nutrient dynamics and its relation to nutrient uptake of crops under biochar amendment remain unclear. Therefore, the present study investigated the combined effect of biochar application and incubation on growth, yield, and rhizosphere nutrient availability of soybean (Glycine max L.) plant. A pot experiment was conducted with two biochar applications (with and without biochar) and two incubation conditions (with and without incubation) in a glasshouse. A separate soil column leaching experiment was conducted to test the nutrient retention ability of soil once biochar is amended. Irrespective of the incubation condition, biochar application made a significant increase in pod dry weight. The total nutrient uptake by soybean greatly increased under biochar amendment compared with the plants grown without biochar. When incubation is not done, soybean increased its P and K uptake respectively by 52% and 48% under biochar amendment compared to those without biochar. With incubation, the relevant increases were 42% and 32% respectively. The results from soil column leaching experiment suggest that the application of biochar in planting media could be an effective way to retain soil N by reducing the leaching losses.

Effects of Soil Texture and Nutrients Application On Soybean Nutrient Uptake, Growth and Yield Response

Soybean is a good source of protein and calories and therefore important for food security. Soybean yields in small scale farmers field stand at less than 1.0 t ha-1 against a potential of 3 to 3.6 t ha-1. This has been attributed to low soil fertility. Although a lot of work has been carried out on Soybean nitrogen (N) and phosphorus (P) nutrition, but research findings indicate that yields are still low, raising suspicion that other nutrients could also be limiting. To investigate this, a nutrient omission trial was used in the greenhouse to find out the nutrients that limit soybean production in four distinct soil textures - clay loam, sandy clay loam, sandy clay and sandy loam following the recommended rate of 20:40:20:5:20 Kg/ha for N,P,K,Zn, and S respectively. Similarly we applied 1 ton/ha of poultry manure with thirty six treatments combinations arranged in a completely randomized design. The results revealed that soybean performance and nutrient uptake varied significantly (p<0.05) between the soil texture andnutrients application. Sandy clay loam and sandy loam textures respond significantly to nitrogen, phosphorus, potassium and manure application whereas zinc and NPK nutrients limits soybean performance and uptake in sandy clay and clay loam soils. In conclusion, to increase soybean production in sandy loam and clay loam of Sudan savanna of Nigeria, fertilizer formulations containing N, P, K and Zn should be used. Manure may be used to improve soybean production in sandy clay and sandy clay loam together with application of NPK fertilizer.

Soil Compaction Effects on Soil Physical Properties and Soybean (Glycine max.) Yield in Ogbomoso, Southwestern Nigeria

Compaction is one of the major threats to soil sustainability as it can have negative effects on soil physical properties. Therefore, field experiments were conducted at Ladoke Akintola University of Technology Teaching and Research Farm, Ogbomoso, Southwestern Nigeria, in 2015 and 2016 to evaluate the influence of soil compaction on selected soil physical properties, growth, yield and nutrient uptake of soybean (Glycine max.). The experiment was arranged in a randomized complete block design and replicated three times. There were four treatments which consisted of 0 (no pass of tractor wheel), 4, 8, and 14 passes of tractor wheel totaling 16 treatments. Soil physical properties determined were; bulk density, total porosity, macroporosity and saturated hydraulic conductivity. While data recorded on soybean were plant height, stem girth, number of leaves, biomass and grain yield. Data collected were subjected to Analysis of Variance and significant means were compared using Least Significant Difference at 5% level of probability. Although not significant, soil physical quality decreased with increased levels of soil compaction in both years of study. Growth of soybean was significantly reduced by soil compaction with 14 passes producing the shortest plant (91.46, 29.10 cm) compared to the control (103.96, 30.27 cm), respectively, for 2015 and 2016. Grain yield of soybean significantly decreased by 12, 27, and 44% respectively, for 4, 8 and 18 passes of tractor wheel. The study indicates that soil compaction as a result of tractor wheel passes should be minimized on agricultural fields to reduce the adverse effects on soil physical properties, soybean growth and yield.

​Effect of Organic and Inorganic Sources of Nutrients on Growth, Yield Attributes and Nutrient Uptake of Soybean in Vertisols of Rajasthan

Background: Soybean [Glycie max (L.) Merril] is a very important oil seed and protein rich crop. It has the specific character to fix atmospheric nitrogen through root nodule bacteria in symbiotic relationship. A field experiment was conducted during kharif, 2019 at ARS farm, College of Agriculture, Ummedganj, Kota (Rajasthan). To find out the effect of organic and inorganic sources of nutrients on growth, yield attributes and nutrient uptake of soybean in Vertisols of Rajasthan. The soil of the experimental field comes under Vertisols with clay loam texture having low to medium fertility status and good porosity. Methods: The experiment consisted of 10 treatments viz. T0- Control (Absolute), T1- RDF (20-40-40), T2- 75% RDF + FYM (2.0 t ha-1), T3- 50% RDF + FYM (4.0 t ha-1), T4- 75% RDF + FYM (2.0 t ha-1) + Rhizobium, T5- 50% RDF + FYM (4.0 t ha-1) + Rhizobium, T6- 75% RDF + Vermicompost (1.0 t ha-1), T7- 50% RDF + Vermicompost (2.0 t ha-1), T8- 75% RDF + Vermicompost (1.0 t ha-1) + Rhizobium, T9- 50% RDF + Vermicompost (2.0 t ha-1) + Rhizobium. The experiment was laid out in randomised block design and was replicated thrice. Result: Among the nutrient management treatment, application of 75% RDF + Vermicompost (1.0 t ha-1) + Rhizobium (T8) resulted into maximum plant height (58.70 cm), branches plant-1 (5.60), chlorophyll content (2.84 mg g-1), total nodules per plant (47.40), effective nodules (31.59) and dry weight (84.20 mg), pods plant-1 (41.90), seeds pod-1 (3.47), grain yield (1380 kg ha-1), haulm yield (1885 kg ha-1), biological yield (3325 kg ha-1), protein (42.25%) and oil content (19.92%), N, P, K content and their uptake, with maximum gross return (53042.71 Rs ha-1), net return (28980.71 Rs ha-1) and B:C ratio (2.20) in soybean crop.

Response of physiological traits, antioxidant enzymes and nutrient uptake of soybean to Azotobacter Chroococcum and zinc sulfate under salinity

Globally, one of the key restrictions on agricultural production is salinity and its impact is expected to increase. As a result, it is necessary to improve crop salinity tolerance. One promising approach is the use of plant nutrition technologies such as the application of zinc sulfate (Zn) and Azotobacter chroococcum (Az) which may improve plant survival under environmental stresses. A greenhouse experiment was conducted with three replications and included four levels of salinity (0, 40, 60 and 80 mM NaCl) in combination with four treatments [control, 2 mM zinc sulfate foliar application (Zn), inoculation with Azotobacter chroococcum (Az) and co-application of Az and Zn (Az+Zn)]. The results indicate that exposure to salinity increased soybean contents of anthocyanin, malondialdehyde (MDA), osmolytes, sodium ion (Na+), and the activities of antioxidant enzymes However, the amount of chlorophyll and carotenoid, relative water content (RWC), maximum quantum yield of photosystem II (PSII; Fv/Fm), membrane stability index (MSI), and ion contents decreased. Application of Zn and inoculation with Az enhanced the chlorophyll (a, b and a+b), carotenoid, RWC, Fv/Fm, MSI, anthocyanin, osmolytes, N, K+, P contents, and K+/Na+; the activities of CAT, SOD, POX, and APX as well as MDA and Na+ contents were reduced. Overall our results reveal that combined Zn and Az application was the most effective treatment for alleviating the negative effects of salinity stress in soybean.

Consequence of resource conservation practices on yield and nutrient uptake of soybean under cotton-soybean rotation in vertisols

The present study was undertaken during 2016-17 at Research farm, Dr. PDKV, Akola. The experiment was laid out in Randomized Block Design with nine treatments replicated three times in Vertisols. The objectives were to evaluate the effect of different resource conservation practices on yield and nutrient uptake by soybean. The cotton based soybean rotation was followed since 2011-12. The present experiment was superimposed on soybean during 2016-17. The treatments comprised for soybean crop was recommended dose of fertilizer (RDF) alone and their compensation with organics viz., FYM, phosphocompost (PC), neemcake, bio mulch (farm waste) and green leaf manuring. The results of the present experiment indicated that, comparatively higher seed (27.20 q ha-1) and straw yield (31.25 q ha-1) of soybean was recorded with RDF alone to soybean and 25% N through Neemcake + RDF compensation to cotton crop under cotton-soybean rotation. The application of RDF alone with 25% N through Neemcake + RDF compensation to cotton crop recorded higher N (187.6 kg ha-1), whereas, application of RDF + PC with 100% N (FYM) + compensation of P through phosphocompost to cotton recorded higher P uptake (18.41 kg ha-1). The K (51.78 kg ha-1) uptake was influenced significantly with the application of RDF with 25% N through Dhaincha loppings + RDF compensation to cotton. Hence, combined application of organic sources along with inorganic fertilizers is the most vital way to maintain yield of soybean relatively at higher level and uptake under cotton-soybean rotation in Vertisol.

Soybean yield, nutrient uptake and stoichiometry under different climate regions of northeast China

Climate and soil fertility influence seed yield, nutrient uptake, and nutrient stoichiometry in the plant. We collected soybean [Glycine max (L.) Merr.] data were collected from field experiments in northeast China (warm and cold regions) to study the effect of temperature variations during the crop growing season on seed yield, nutrient uptake and stoichiometry from 2001 to 2017. Soybean seed yield has been increased in the cold region but not in the warm region, where average seed yield was higher. The indigenous nitrogen (N) supply followed the same trend as yield, greater in warmer environments but also increasing over time. The internal efficiency (IE) of N and potassium (K) performed similarly in both climate regions, but phosphorus (P) IE was 30% greater in the warm region than the cold region. For soybean nutrient uptake ratio, the N/K ratio was similar between both regions; however, the N/P ratio was greater in the warmer region relative to the colder region. Overall, the higher temperature experienced in the warm region increased soybean seed yield relative to the cold region, and high soil P accumulation caused soybean P luxury uptake in the cold region of northeast China.

Influence of Foliar Application of Nutrient on Growth, Yield, Economics, Soil Nutritional Status and Nutrient Uptake of Soybean

A field experiment was carried out during kharif season of 2016 and 2017 at an experimental farm of MACS Agharkar Research Institute, Pune, India to study the influence of foliar application of nutrient on growth, yield, economics, soil nutritional status and nutrient uptake of soybean crop. An experiment was laid out in randomized block design (RBD) comprising of three replications and nine treatments. Recommended dose of fertilizers (RDF) was applied as basal application to all treatments. Seven treatments consisted of different doses of nutrients as foliar application at pod initiation stage. Water spray at pod initiation stage and RDF alone were treated as control. The results revealed that, growth attributes, nodulation and its weight, morpho-physiological parameters, yield and its attributes, nutritional parameters and economics significantly differed by various foliar nutrition treatments except control and RDF + water spray. RDF + Urea 2% (3098 kg ha-1) gave significantly higher seed yield over control (2704 kg ha-1) and RDF + water spray (2686 kg ha-1) but was at par with RDF + DAP 2% (3050 kg ha-1), RDF + MOP 0.5% (2992 kg ha-1) and RDF + Molybdenum 0.5% (2955 kg ha-1). The increase in seed yield with foliar application of 2% Urea along with RDF was 14.57% over control and 15.34% over RDF + water spray. Higher net returns (Rs. 49,006/- ha-1) and benefit: cost ratio (2.23:1) was obtained in treatment RDF + Urea 2% followed by RDF + DAP 2% foliar spray. Availability of N, P and K was significantly higher with treatment RDF + Urea 2% foliar spray over control and RDF + water spray. N and P uptake by soybean plants was significantly higher in treatment RDF + 2% Urea over RDF + water spray and RDF alone (control).

Effects of lime and steel slag application on soil fertility and soybean yield under a no till-system

Steel slags can be used in agriculture, as they are composed of CaO, MgO, SiO2, and compounds such as P2O5, FeO, and MnO. The solubility of slag may be higher than that of lime, which can make this residue an excellent source for soil acidity correction in no-till systems. However, there are few studies reporting their benefits when applied to the soil surface. This study evaluated slag amendment effects on soil chemical attributes and on the yield and nutrient uptake of soybean following surface application and/or incorporation of different types of slag, in comparison to lime, on a tropical, acidic soil under a no-till system. The trial was performed in Botucatu, SP, Brazil. Six soil-acidity corrective materials were incorporated or surface-applied, including steel slag, ladle slag, stainless-steel slag, wollastonite, dolomitic lime, and calcined dolomitic lime, plus a negative control. Each material dose was calculated to raise the base saturation to 70%. Slags can be applied in a no-tillage system with efficiency similar to that of lime for the neutralization of soil acidity, for adequate nutrition and yield of the soybean crop. Slags and limes showed similar effects on increased pH, decreased Al3+concentration, and increased base saturation up to the 0.40 and 0.20-m soil layers at 12 and 23 months, respectively, after the application of treatments, regardless of surface or incorporated application. The by-product application has an additional advantage, depending on the type of slag, that is the provision of phosphorus and/or silicon.

Characteristics of Yield and Harvest Index, and Evaluation of Balanced Nutrient Uptake of Soybean in Northeast China

The balance between fertilizer application and plant nutrient demand is essential for ensuring agricultural production because it is effective to prevent nutrient deficiency and excess, especially for soybean. This study used data from 29 sites of field experiments carried out in the soybean planting area of Liaoning province, China in 2011 to 2013. We (i) study the characteristics of yield, nutrient concentration, and harvest index to (ii) valuate the balanced nutrient uptake at different potential yield levels for soybean. The grain yield ranged from 804 to 4484 kg/ha, and average N, P, and K concentrations in grains were 45.7, 5.0, and 10.1 g/kg, respectively, while those in straw were 14.1, 1.8, and 6.7 g/kg, respectively. Average harvest index values of N, P, and K were 0.69, 0.65, and 0.52 kg/kg, respectively, while approximately 69% N and 65% P of the plant were stored in soybean grain, and 48% K was stored in straw. The two boundary lines of the QUEFTS (quantitative evaluation of the fertility of tropical soils) model were aN = 10.5, dN = 20.6, aP = 65.6, dP = 289.6, aK = 30.4, and dK = 162.7 as model parameters. The QUEFTS model estimated the balanced nutrient uptake with yield targets increased following a linear–parabolic–plateau curve. A continual linear increase in grain yield with 65.5 kg N, 7.0 kg P, and 13.9 kg K was required to produce 1000 kg grain, until the yield target reached approximately 60–70% of the potential yield, and the corresponding ratio of N, P, and K was 9.35:1:1.8. Results could be used to estimate balanced nutrient uptake to prevent excessive fertilizer being applied and reduce environment risk for ensuring sustainable agricultural development.

Productivity and Nutrient Uptake of Soybean (Glycine max) - Onion (for seed) (Allium cepa) Cropping Systems as Influenced by Integrated Nutrient Management Practices

Productivity and Nutrient Uptake of Soybean (Glycine max) - Onion (for seed) (Allium cepa) Cropping Systems as Influenced by Integrated Nutrient Management Practices

Variety specific relationships between effects of rhizobacteria on root exudation, growth and nutrient uptake of soybean

The purpose of this research was to compare root exudation of major organic components, effects of PGPR on root exudates and the response of different soybean varieties to inoculation with PGPR to understand variety-dependent relationships between these traits. Growth and root exudation of soybean varieties Nice-Mecha, Bara and Svapa in the absence and presence of PGPR Pseudomonas oryzihabitans Ep4 was studied using gnotobiotic hydroponic system and UPLC techniques. Rhizobacterial effects on growth, seed yield quality, nodulation by Bradyrhizobium japonicum 634b and uptake of nutrients was investigated under field conditions. Genotypic differences between soybean varieties in root exudation, rhizobacterial effects on exudation and interactions with Ps. oryzihabitans Ep4 were revealed. Variety Bara had greatest root biomass with least root exudation and least Ps. oryzihabitans Ep4 colonisation. In both hydroponic experiments and field trials, the varieties Nice-Mecha and particularly Svapa responded more actively to Ps. oryzihabitans Ep4 than the variety Bara. Several mechanisms related to root exudation rate, exudate composition, bacterial production of siderophores and auxins are proposed to explain variety dependent interactions of plants with PGPR. The variety specific plant response to PGPR is mediated by genotypic differences in root exudation and the ability of PGPR to metabolize and/or transform the exuded organic acids, sugars and amino acids.

Weed control in soybean (Glycine max L.) through resource management strategies and its influence on yield and nutrient uptake

A field experiment was conducted during kharif season of 2011 at Research Farm, Sher-e-Kashmir University of Agricultural Sciences and Technology, Chatha, Jammu to evaluate the effect of weed management prac-tices on yield and nutrient uptake of soybean utilizing different resource management strategies. The lowest weed density and dry matter of weeds was recorded with hand weeding at 15 and 35 days after sowing (DAS) which was equally effective as imazethapyr @ 75 g ha -1 (PoE) fb hoeing at 35 DAS and quizalofop-ethyl @ 40 g ha-1 (PoE) fb hoeing at 35 DAS. All weed control treatments had significant effect on yield and nutrient up-take of soybean. Among the different weed control treatments, lowest N, P and K uptake by weeds were recorded in hand-weeding (15 and 35 DAS) which was statistically at par with imazethapyr @ 75 g ha -1 fb hoeing at 35 DAS. The maximum uptake by seed and straw were recorded in weed free which was statistically at par with twice hand weeding at 15 and 35 DAS, imazethapyr @ 75 g ha-1 fb hoeing at 35 DAS and quizalofop-ethyl @ 40 g ha-1 fb hoeing at 35 DAS. The highest seed and straw yield of soybean was harvested with hand-weeding (15 and 35 DAS) followed by imazethapyr @ 75 g ha -1 fb hoeing at 35 DAS. For the first time, soybean crop has been introduced in Jammu region for research purpose. Weed management varies with agro-climatic conditions. The study would be helpful to understand weed menace in this particular climatic condition of Jammu and to manage them combinedly and efficiently.

Effect of combined fertilization with rock phosphate and elemental sulphur on yield and nutrient uptake of soybean

Greenhouse pot experiments were carried out in 2013 and 2014 at the University of Bonn, Germany, to study the effect of combined fertilization of rock phosphate (RP) with elemental sulphur (ES) on growth, grain yield and nutrient uptake of soybean. Treatments included RP, ES, combined application (RPES), triple superphosphate (SP), magnesium sulphate (MgS), SP and magnesium sulphate (SPMgS) and an unfertilized control. Combined fertilization (RPES) resulted in a significant increase of soil-plant analysis development (SPAD) values, grain yield, yield components and nitrogen and in part phosphorus uptake of the shoot. Single application of RP or ES only tended to affect crop growth and nutrient uptake. Application of MgS and/or SP significantly increased grain yield in both years suggesting an effect of sulphate.

Effect of Inoculating Bradyrhizobium on Phosphorus Use Efficiency and Nutrient Uptake of Soybean Intercropped with Sugarcane in Calcareous Soil of Metahara, Central Rift Valley, Ethiopia

At a soil pH value of above 7.0, inorganic phosphorus (P) is highly susceptible to precipitation as insoluble form that is unavailable to the plants. Hence, a field experiment was conducted at Metahara Sugar Estate under irrigation during the 2014/15 cropping season to evaluate the effect of inoculating Bradyrhizobium on P uptake and P use efficiency of soybean intercropped with sugarcane. The treatments consisted of three levels of inoculation (Legumefix, SB6B1 and uninoculated) and four rates of P (0, 23, 46 and 69 kg P2O5 ha-1). The experiment was laid out as a randomized complete block design (RCBD) in a factorial arrangement and replicated three times. Analysis of the data indicated that Bradyrhizobium inoculation significantly increased plant N concentration and P uptake compared to the uninoculated treatment. But the effect of P rates and its interaction with inoculation was not significant on N concentration and P uptake but significantly increased total P uptake at the application of 69 kg P2O5 ha-1. P use efficiency indices were improved in response to inoculating the crop with Bradyrhizobium. The higher AE (13.6 kg kg-1), PRE (31.8%) and PUE (10.6 kg kg-1) were obtained by SB6B1 inoculation and higher PE (117.2 kg kg-1) and APE (161.7 kg kg-1) were obtained by Legumefix inoculation all at 23 kg P2O5 ha-1 except PE which recorded at 69 kg P2O5 ha-1. Thus, it can be concluded that SB6B1 isolate will be used as the best inoculant followed by Legumefix isolate with 23 kg P2O5 ha-1 of P fertilizer rate. However, strategies for increasing P use efficiency by adopting best management practices like co-inoculation of phosphate solubilizing microorganism or mycorrhiza with these Bradyrhizobium inoculants should be adopted to enhance P use efficiencies.