Home About us Contact
|
Home About us Contact | ||
|
|
||
Kg P (kg + p)
Selected AbstractsSex-specific association between leptin receptor polymorphisms and leptin levels and BMI in healthy adolescents,ACTA PAEDIATRICA, Issue 10 2010P Riestra Abstract Aim:, To examine the relationship of three common polymorphisms in the leptin receptor (LEPR) gene, implicated in the regulation of body weight, with leptin levels and obesity-related phenotypes in a population-based sample of healthy pubertal children in Spain. Methods:, The study included 806 boys and girls aged 12,16 whose anthropometrical data and body composition were recorded. Serum leptin levels were determined by ELISA. The LEPR Q223R, K109R and K656N polymorphisms were determined by TaqMan® allelic discrimination assays. Results:, When analysing the Q223R polymorphism, we observed that female carriers of the RR genotype had significantly higher plasma leptin levels (18.2 vs. 15.1 ng/mL p = 0.016) and significantly higher mean BMI values (22.5 vs. 21.3 Kg/m2 p = 0.032) than QR carriers. Furthermore, the frequency of the RR genotype in overweight-obese girls was significantly higher than that found in normal-weight girls. No significant differences were observed in boys. Neither boys nor girls showed significant differences when comparing leptin levels, anthropometric variables or body composition by K109R or K656N genotype. Conclusion:, The fact, that the Q223R polymorphism in the LEPR gene is significantly associated with leptin levels and BMI only in girls, suggests a sex-specific influence of this polymorphism on these variables. [source] Preferential phosphorus leaching from an irrigated grassland soilEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 2 2005G. S. Toor Summary Intact lysimeters (50 cm diameter, 70 cm deep) of silt loam soil under permanent grassland were used to investigate preferential transport of phosphorus (P) by leaching immediately after application of dairy effluent. Four treatments that received mineral P fertilizer alone (superphosphate at 45 kg P ha,1 year,1) or in combination with effluent (at , 40,80 kg P ha,1 year,1) over 2 years were monitored. Losses of total P from the combined P fertilizer and effluent treatments were 1.6,2.3 kg ha,1 (60% of overall loss) during eight drainage events following effluent application. The rest of the P lost (40% of overall loss) occurred during 43 drainage events following a significant rainfall or irrigation compared with 0.30 kg ha,1 from mineral P fertilizer alone. Reactive forms of P (mainly dissolved reactive P: 38,76%) were the dominant fractions in effluent compared with unreactive P forms (mainly particulate unreactive P: 15,56%). In contrast, in leachate following effluent application, particulate unreactive P was the major fraction (71,79%) compared with dissolved reactive P (1,7%). The results were corroborated by 31P nuclear magnetic resonance analysis, which showed that inorganic orthophosphate was the predominant P fraction present in the effluent (86%), while orthophosphate monoesters and diesters together comprised up to 88% of P in leachate. This shows that unreactive P forms were selectively transported through soil because of their greater mobility as monoesters (labile monoester P and inositol hexakisphosphate) and diesters. The short-term strategies for reducing loss of P after application of dairy effluent application should involve increasing the residence time of applied effluent in the soil profile. This can be achieved by applying effluent frequently in small amounts. [source] Balances of phosphorus and nitrogen in carp pondsFISHERIES MANAGEMENT & ECOLOGY, Issue 1-2 2000R. Knösche The impact of carp pond effluents on natural waters was investigated in the German federal states of Brandenburg, Saxony and Bavaria, and in Hungary. Data from 38 ponds (size = 0.25,122 ha) were available for the calculation of inlet,outlet differences. An average difference of 0.51 kg phosphorus (P) ha,1 year,1 was obtained. This means that every hectare of pond surface releases 510 g P less than it receives from the incoming water. This result was independent of the amount of fish harvested (, 1500 ha,1 year,1). The average retention of P (P-balance) was 5.71 kg P ha,1 year,1. Phosphorus retention increased with increasing intensity of production. Nitrogen (N) retention increased with production intensity from 78.5 kg ha,1 year,1 in German standard ponds to >,290 kg N ha,1 year,1in pig-cum-fish ponds in Hungary. A predominantly mineralized sludge suspension is released during harvesting at loads below 1% of the retention capacity of the pond. Under usual pond management regimes, the sludge load during harvesting ranged from 50 to 200 L ha,1, equivalent to 0.3,9.3 g dry matter ha,1. The present study suggests that ponds are not a burden on the environment. By contrast, these water bodies improve water quality. Therefore, pressures to reduce the intensity of pond production cannot be justified on the basis of supposed impacts on water quality. However, even if loads during harvesting are low compared with the retention capacity of the pond, more effort should be carried out to reduce the pollution of streams by pond outlets downstream. This can be done by limiting pond drainage to periods when the suspended material has settled or by short-term sedimentation of the sludge in a settling pond downstream of the rearing facility. [source] Nutrient constraints to tropical agroecosystem productivity in long-term degrading soilsGLOBAL CHANGE BIOLOGY, Issue 12 2008SOLOMON NGOZE Abstract Soil degradation is one of the most serious threats to sustainable crop production in many tropical agroecosystems where extensification rather than intensification of agriculture has occurred. In the highlands of western Kenya, we investigated soil nitrogen (N) and phosphorus (P) constraints to maize productivity across a cultivation chronosequence in which land-use history ranged from recent conversion from primary forest to 100 years in continuous cropping. Nutrient treatments included a range of N and P fertilizer rates applied separately and in combination. Maize productivity without fertilizer was used as a proxy measure for indigenous soil fertility (ISF). Soil pools of mineral nitrogen, strongly bound P and plant-available P decreased by 82%, 31% and 36%, and P adsorption capacity increased by 51% after 100 years of continuous cultivation. For the long rainy season (LR), grain yield without fertilizer declined rapidly as cultivation age increased from 0 to 25 years and then gradually declined to a yield of 1.6 Mg ha,1, which was maintained as time under cultivation increased from 60 to 100 years. LR grain yield in the old conversions was only 24% of the average young conversion grain yield (6.4 Mg ha,1). Application of either N or P alone significantly increased grain yield in both the LR and short rainy (SR) seasons, but only application of 120 kg N ha,1 on the old conversion increased yield by >1 Mg ha,1. In both SR and LR, there was a greater average yield increment response to N and P when applied together (ranging from 1 to 3.8 Mg ha,1 for the LR), with the greatest responses on the old conversions. The benefit,cost ratio (BCR) for applying 120 kg N ha,1 alone was <1 except on the old conversions, while BCRs were>1 for applying 25 kg P ha,1 alone at all levels of conversion for both seasons. Application of both N (120 kg N ha,1) and P (25 kg P ha,1) on the old conversions resulted in the greatest BCRs. This study clearly indicates that maize productivity responses to N and P fertilizer are significantly affected by the age of cultivation and its influence on ISF, but that loss of productivity can be restored rapidly when these limiting nutrients are applied. Management strategies should consider ISF and economic factors to determine optimal N and P input requirements for achieving and sustaining profitable crop production on degraded soils. [source] The response of manured forage maize to starter phosphorus fertilizer on chalkland soils in southern EnglandGRASS & FORAGE SCIENCE, Issue 2 2000Withers The impact of various starter phosphorus (P) fertilizers on the growth, nutrient uptake and dry-matter (DM) yield of forage maize (Zea mais) continuously cropped on the same area and receiving annual, pre-sowing, broadcast dressings of liquid and semi-solid dairy manures was investigated in two replicated plot experiments and in whole-field comparisons in the UK. In Experiment 1 on a shallow calcareous soil (27 mg l,1 Olsen-extractable P) in 1996, placement of starter P fertilizer (17 or 32 kg ha,1) did not benefit crop growth or significantly (P > 0·05) increase DM yield at harvest. However, in Experiment 2 on a deeper non-calcareous soil (41 mg l,1 Olsen-extractable P) in 1997, placement of starter P fertilizer (19 or 41 kg P ha,1), either applied alone or in combination with starter N fertilizer (10 or 25 kg N ha,1), significantly increased early crop growth (P < 0·01) and DM yield at harvest by 1·3 t ha,1 (P < 0·05) compared with a control without starter N or P fertilizer. Placement of starter N fertilizer alone did not benefit early crop growth, but gave similar yields as P, or N and P, fertilizer treatments at harvest. Large treatment differences in N and P uptake by mid-August had disappeared by harvest. In field comparisons over the 4-year period 1994,97, the addition of starter P fertilizer increased field cumulative surplus P by over 70%, but without significantly (P > 0·05) increasing DM yield, or nutrient (N and P) uptake, compared with fields that did not receive starter P fertilizer. The results emphasized the extremely low efficiency with which starter P fertilizers are utilized by forage maize and the need to budget manure and fertilizer P inputs more precisely in order to avoid excessive soil P accumulation and the consequent increased risk of P transfer to water causing eutrophication. [source] Field Pea Seeding Management for Semi-arid Mediterranean ConditionsJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 2 2004A. M. Tawaha Abstract The effects of seeding rate (30, 60 and 90 seeds m,2), seeding date (14 January, 28 January and 12 February), seed weight (0.18 and 0.25 g seed,1), seeding depth (3 and 6 cm), and phosphorus fertilization rate (17.5, 35.0 and 52.5 kg P ha,1) and placement method (banded or broadcasted) on field pea (Pisum sativum L.) development and seed yields were investigated in irrigated field experiments conducted in northern Jordan in 2000 and 2001. Results and treatment responses were consistent in both years. Seeding rate, seeding date, seed weight and rate and method of phosphorus fertilization had significant effects on most traits measured; planting depth however did not affect any of the traits. Generally a positive correlation was observed between each factor and seed yield and yield components, with the exception of a negative correlation between seeding rate and yield components, and seeding date and yield and yield components. Increase in seeding rate from 30 to 90 seeds m,2, and increase in P fertilization from 17.5 to 52.5 kg ha,1 alone increased seed yields by 50 and 41 %, respectively. Each delay of 2 weeks for seeding from mid-January resulted in reductions of 12 % in seed yields. Overall, the results revealed that a combination of early seeding (14 January), of large seeds at an high seeding rate (90 seeds m,2), with P fertilizer banding (52.5 kg P ha,1) maximize field pea yields in irrigated fields in semi-arid Mediterranean environments. With such management pea seed yields can be as high as 2800 kg ha,1. [source] Impact of Phosphorus from Dairy Manure and Commercial Fertilizer on Perennial Grass Forage ProductionJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 6 2003E. A. Mikhailova Abstract Increased recovery and recycling of manure phosphorus (P) by crops on dairy farms is needed to minimize environmental problems. The main objective of this study was to compare P utilization by orchardgrass (Dactylis glomerata L.) and tall fescue (Festuca arundinaceae Schreb.) from dairy manure or inorganic fertilizer. The study was conducted from 1994 to 2000 at the Cornell University Baker Farm, Willsboro, NY, on a somewhat poorly drained Kingsbury clay (very,fine, illitic, mesic Aeric Epiaqualfs). The design was a split-plot in a randomized complete block with two manure rates (16 800 and 33 600 kg ha,1) and one nitrogen (N) fertilizer rate (84 kg N ha,1 at spring greenup and 56 kg N ha,1 prior to each regrowth harvest) as the main plots and grass species as subplots replicated six times. Fertilizer P [Ca(H2PO4)2] was applied to the fertilizer treatment in 1995 and 1996 at 11 kg P ha,1 year,1. Orchardgrass P removal averaged 21 % higher than tall fescue P removal for the spring harvest, but orchardgrass averaged 24 % lower P removal than tall fescue removal for all regrowth harvests from 1995,99. Phosphorus herbage concentration in the fertilizer treatment was in the range of 1.9,2.7 g P kg,1 compared with 2.2,5.3 g P kg,1 in the manure treatments. Seasonal P removal ranged from as low as 9.2 kg P ha,1 to as high as 48.5 kg P ha,1. Morgan extractable soil P in the top 0,0.20 m remained high through 1999, with 29.1 kg P ha,1 at the highest manure rate in tall fescue compared with 8.4 kg P ha,1 measured in 1993 prior to the experiment. In 2000, soil P at the highest manure rate in tall fescue dropped to 10.1 kg P ha,1, following cessation of manure application in 1998. Intensively managed harvested orchardgrass and tall fescue have the potential to remove large quantities of manure P. [source] Spatial variation of soil test phosphorus in a long-term grazed experimental grassland fieldWeijun Fu1, 2JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 3 2010Hubert Tunney Abstract The spatial variation of soil test P (STP) in grassland soils is becoming important because of the use of STP as a basis for policies such as the recently EU-introduced Nitrate Directive. This research investigates the spatial variation of soil P in grazed grassland plots with a long-term (38 y) experiment. A total of 326 soil samples (including 14 samples from an adjacent grass-wood buffer zone) were collected based on a 10 × 10 m2 grid system. The samples were measured for STP and other nutrients. The results were analyzed using conventional statistics, geostatistics, and a geographic information system (GIS). Soil test P concentrations followed a lognormal distribution, with a median of 5.30 mg L,1 and a geometric mean of 5.35 mg L,1. Statistically significant (p < 0.01) positive correlation between STP and pH was found. Spatial clusters and spatial outliers were detected using the local Moran's I index (a local indicator of spatial association) and were mapped using GIS. An obvious low-value spatial-cluster area was observed on the plots that received zero-P fertilizer application from 1968 to 1998 and a large high-value spatial-cluster area was found on the relatively high-P fertilizer application plots (15,kg ha,1 y,1). The local Moran's I index was also effective in detecting spatial outliers, especially at locations close to spatial-cluster areas. To obtain a reliable and stable spatial structure, semivariogram of soil-P data was produced after elimination of spatial outliers. A spherical model with a nugget effect was chosen to fit the experimental semivariogram. The spatial-distribution map of soil P was produced using the kriging interpolation method. The interpolated distribution map was dominated by medium STP values, ranging from 3 mg to 8 mg L,1. An evidently low-P-value area was present in the upper side of the study area, as zero or short-term P fertilizer was applied on the plots. Meanwhile, high-P-value area was located mainly on the plots receiving 15,kg P ha,1 y,1 (for 38 y) as these plots accumulated excess P after a long-term P-fertilizer spreading. The high- or low-value patterns were in line with the spatial clusters. Geostatistics, combined with GIS and the local spatial autocorrelation index, provides a useful tool for analyzing the spatial variation in soil nutrients. [source] Mulberry nutrient management for silk production in Hubei Province of ChinaJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 2 2009Fang Chen Abstract The silk industry is important for south China's rural economy. Leaves of mulberry (Morus spp.) are used for silkworm production. Hubei province is one of the main silk-producing provinces in China. The objectives of this research were to survey the fertilization practices in the mulberry-producing regions in the province and to determine the best nutrition-management practice for mulberry plantations. A survey and a series of field experiments with N, P, K, and micronutrients were conducted from 2001 to 2002. In addition, a silkworm-growth experiment was also conducted by feeding leaves harvested from various fertilization treatments. The results indicate that poor soil fertility and unbalanced fertilization were the main factors limiting mulberry-leaf yield and quality in Hubei province. Nitrogen fertilization of mulberry has reached a high level (454,kg ha,1 y,1) in Hubei province, but P- and K-fertilization rates have not been matched with N-fertilization rates as farmers are not aware of the significance of P and K. Balanced fertilization showed positive nutrient interactions with respect to mulberry yield and quality. Potassium application increased yield and quality (protein and sugar concentration) of mulberry leaves. Silkworm growth and cocoon quality were improved when silkworms were fed with the leaves derived from K-fertilized plants in comparison with those taken from control plots. Application of Mg, S, and B also significantly improved leaf sugar, essential and total amino acid concentrations, but did not increase leaf yield significantly. It is concluded that a fertilizer dose of 375,kg N ha,1, 66,kg P ha,1, and 125,kg K ha,1 is suitable for the cultivation of mulberry in the Hubei province along with Mg, S, and B, wherever necessary, for the improvement of yield and quality of mulberry leaves. [source] Glycosidases in soils as affected by cropping systemsJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 6 2005Daniel E. Dodor Abstract Glycosidases are a group of soil enzymes that play a major role in degradation of carbohydrates. This study was conducted to assess the impact of crop rotation and N fertilization on the activities of ,- and ,-glucosidases and ,- and ,-galactosidases in plots of two long-term field experiments at the Clarion-Webster Research Center (CWRC) and Northeast Research Center (NERC) in Iowa. Surface-soil (0,15 cm) samples were taken in 1996 and 1997 in corn (Zeamays L.), soybean (Glycinemax (L.) Merr.), oats (Avenasativa L.), or meadow (alfalfa) (Medicago sativa L.) plots that received 0 or 180,kg N ha,1, applied as urea before corn, and an annual application of 20,kg P ha,1 and 56,kg K ha,1. Activities of the four glycosidases were significantly affected by crop rotations in both years at the two sites but not by nitrogen application. In general, higher activities were observed in plots under meadow or oat and the lowest in continuous corn (CWRC) and soybean (NERC). Four-year rotation showed the highest activity, followed by 2-year rotation and monocropping systems. Linear-regression analyses indicated that, in general, the activities of the glycosidases were significantly correlated with microbial-biomass C (r > 0.302, p , 0.05) and microbial-biomass N (r > 0.321, p , 0.05), organic-C (r > 0.332, p , 0.05) and organic-N (r > 0.399, p , 0.01) contents of the soils. Results of this work suggest that multicropping stimulated the activities of the glycosidases. The specific activities of the glycosidases in soils of the two sites studied, expressed as g p -nitrophenol released per,kg of organic C, differed among the four enzymes. The lowest values were obtained for ,-galactosidase and ,-glucosidase, followed by ,-galactosidase and ,-glucosidase. Glycosidasen in Böden unter dem Einfluss von Bewirtschaftungssystemen Glycosidasen stellen eine Gruppe von Bodenenzymen dar, welche eine entscheidende Rolle im Abbau von Kohlenhydraten spielen. Ziel dieser Untersuchungen war die Erfassung des Einflusses von Fruchtfolge und N-Düngung auf die Aktivitäten von ,- und ,-Glucosidasen und ,- und ,-Galactosidasen in zwei Langzeitfeldversuchen, dem Clarion-Webster-Versuchsfeld (CWRC) und dem Northeast-Versuchsfeld (NERC) in Iowa. In den Jahren 1996 und 1997 wurden Oberbodenproben (0,15 cm) von Parzellen unter Mais (Zeamays L.), Sojabohne (Glycine max (L.) Merr.), Hafer (Avena sativa L.) oder Luzerne (Medicago sativa L.) entnommen, welche vor Mais 0 oder 180,kg N ha,1 in Form von Harnstoff sowie jährliche Düngergaben in Höhe von 20,kg P ha,1 und 56,kg K ha,1 erhielten. Über zwei Jahre wurden die Aktivitäten der vier Glycosidasen in beiden Feldversuchen signifikant von der Bewirtschaftung beeinflusst, jedoch nicht von der N-Düngung. Im allgemeinen wurden höhere Enzymaktivitäten in Parzellen unter Luzerne oder Hafer festgestellt und die geringsten unter Maismonokultur (CWRC) bzw. Sojabohne (NERC). Vierjährige Fruchtfolgen zeigten die höchsten Aktivitäten, gefolgt von zweijährigen Fruchtfolgen und Monokulturen. Analysen mittels linearer Regression weisen auf eine Korrelation zwischen Glycosidaseaktivitäten und C (r > 0.332, p , 0.05) und N der mikrobiellen Biomasse (r > 0.321, p , 0.05) sowie den Gehalten an org. C (r > 0.332, p , 0.05) und N (r > 0.399, p , 0.01) hin. Die Ergebnisse dieser Untersuchungen deuten darauf hin, dass die Aktivitäten von Glycosidasen durch mehrjährige Fruchtfolgen stimuliert wurden. Die spezifischen Glycosidaseaktivitäten in den Böden der zwei Feldversuche, berechnet als freigesetztes p -Nitrophenol (g (kg org. C),1), variierten zwischen den vier Enzymen. Die geringsten Werte wurden für ,-Galactosidase und ,-Glucosidase festgestellt, gefolgt von ,-Galactosidase und ,-Glucosidase. [source] Evaluation of residual values of different fertilisers at various rates used in phosphorus recapitalisation of an acid tropical soilJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2006Esther W Gikonyo Abstract The success of ,phosphorus (P) recapitalisation' depends on the changes in residual value (RV) over time. RVs of triple superphosphate (TSP), Gafsa phosphate rock (GPR) and Christmas Island phosphate rock (CIPR) were determined with and without manure bimonthly for 14 months. RV was calculated as the amount of previously applied fertiliser required to produce yield X divided by the amount of freshly applied TSP required to produce the same yield. Dry matter yield (DMY) response curves were curvilinear, with maximum DMY (11 t ha,1) occurring between 150 and 200 kg P ha,1 at 6 months and declining with time to 2,4 t ha,1 (14 months). Manure/fertiliser combinations increased DMY for CIPR but depressed DMY for TSP and GPR in all harvests except the first one. This can be attributed to nutrient imbalance caused by high P levels. RVs declined with time for fertilisers alone from 100,140% to 10,20% (14 months), while for fertiliser/manure combinations they declined from 110,180% to 10,20% (14 months). Increasing P rates from 100 to 300 kg P ha,1 resulted in the depression of initial RVs (100,140%) to 20,60% and later to 10,20% (14 months). Therefore P recapitalisation was not beneficial and hence annual P application would be recommended at 100,150 kg P ha,1. The phosphate rocks could effectively substitute for TSP. Copyright © 2006 Society of Chemical Industry [source] Factors influencing anthocyanin content in red cabbage (Brassica oleracea var capitata L f rubra (L) Thell)JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2002Roberta Piccaglia Abstract In North and Central Italy an experiment was conducted for two consecutive years to optimise the anthocyanin yield of red cabbage. Two hybrids (,Roxy' and ,Gradur') were grown under a factorial combination of increasing rates of potassium sulphate (0, 50, 100,kg K ha,1) and superphosphate (0, 39, 78,kg P ha,1) applied before planting. Cabbages were transplanted at the beginning of August and harvested in winter. Anthocyanins were extracted from cabbage heads with HCl in methanol (1% v/v solution) and quantified by absorption spectrophotometry at 530,nm. Results showed that red cabbage can give high yields of anthocyanins (more than 90,kg,ha,1) which are characterised by strong acylation and therefore, presumably, by good stability. However, differences over sites and years were marked. In the first year, yields in North Italy were reduced by a heavy infection of soft rot disease. The choice of variety, linked to a different anthocyanin content in the heads, appeared to be the major factor for a successful crop. P and K fertilisation had only a small influence. On clay soils in Central Italy the highest rates of both elements had a negative effect on the anthocyanin concentration in cabbage heads. © 2002 Society of Chemical Industry [source] Physiological changes in soybean (Glycine max) Wuyin9 in response to N and P nutritionANNALS OF APPLIED BIOLOGY, Issue 3 2002YINBO GAN Summary Phosphorus deficiency is a very common problem in the acid soil of central China. Previous research has shown that starter N and N topdressing at the flowering stage (Rl) increased soybean (Glycine max) yield and N2 fixation (Gan et al, 1997, 2000). However, there is little information available concerning soybean response to P-fertiliser in soybean production in central China (Gan, 1999). A field experiment was conducted to investigate the response to P (0 kg P ha,1, 22 kg P ha,1, 44 kg P ha,1 before sowing) and N fertiliser application (N1: 0 kg N ha,1, N2: 25 kg N ha,1 before sowing, N3: N2 + 50 kg N ha,1 at the V2 stage and N4: N2 + 50 kg N ha,1 at the R1 stage) on growth, yield and N2 fixation of soybean. Both N and P fertiliser increased growth and seed yield of soybean (P < 0.01). Application of basal P fertiliser at 22 kg P ha,1 or 44 kg P ha,1 increased total N accumulation by 11% and 10% (P < 0.01) and seed yield by 12% and 13% (P < 0.01), respectively, compared to the zero P treatment. Although application of starter N at 25 kg N ha,1 had no positive effect on seed yield at any P level (P > 0.05), an application of a topdressing of 50 kg N ha,1 at the V2 or R1 stage increased total N accumulation by 11% and 14% (P < 0.01) and seed yield by 16% and 21% (P < 0.01), respectively, compared to the zero N treatment. Soybean plants were grown on sterilised Perlite in the greenhouse experiment to study the physiological response to different concentrations of phosphate (P1: 0 mM; P2: 0.05 mM; P3: 0.5 mM; P4:1.0 mN) and nitrate (N1: 0 mM with inoculation, N2: 20 mM with inoculation). The result confirmed that N and P nutrients both had positive effects on growth, nodulation and yield (P < 0.01). The relative importance of growth parameters that contributed to the larger biomass with N and P fertilisation was in decreasing order: (i) total leaf area, (ii) individual leaf area, (iii) shoot/root ratio, (iv) leaf area ratio and (v) specific leaf area. The yield increase at N and P supply was mainly associated with more seeds and a larger pod number per plant, which confirmed the result from the field experiment. [source] | |||||||||||||