Phosphorus nutrition of ectomycorrhizal and arbuscular mycorrhizal tree seedlings from a lowland tropical rain forest in Korup National Park, Cameroon

The relationship between mycorrhizal colonisation and phosphorus acquired by seedlings of the arbuscular mycorrhizal tree Oubanguia alata Bak f. (Scytopetalaceae) and the ectomycorrhizal tree Tetraberlinia moreliana Aubr. (Caesalpiniodeae) was evaluated at low and high inorganic phosphorus availability. AM colonisation was positively correlated with phosphorus uptake by O. alata at low, but not at high phosphorus availability. Seedlings growth was positively related to arbuscular mycorrhizal colonisation at both low and high phosphorus availability, suggesting that growth promotion by arbuscular mycorrhizas is not simply related to an increase of phosphorus uptake. In contrast, phosphorus uptake by T. moreliana was correlated with EM colonisation at both low and high phosphorus availability, but there was no relationship between growth and ectomycorrhizal colonisation. Promotion of phosphorus uptake by arbuscular mycorrhizas and ectomycorrhizas at low phosphorus availability is consistent with the co-occurrence of the two types of mycorrhiza in tropical rain forests where available soil phosphorus is low. However, ectomycorrhizal colonisation may also be of advantage where inputs of phosphorus rich litter raise the phosphorus status of the soil, as seen in the groves of ectomycorrhizal trees in Korup National Park, and may be one of the factors reinforcing local dominance by these trees

Effects of Biochar Amendment and Arbuscular Mycorrhizal Fungi Inoculation on Availability of Soil Phosphorus and Growth of Maize

A glasshouse experiment was conducted to study the interactive effects of biochar amendment and arbuscular mycorrhizal fungi (AMF) inoculation on phosphorus uptake by maize (Zea mayze L.) grown on a calcareous soil of Kupang, East Nusa Tenggara. The biochar was made of cow dung. Twelve treatment combinations (three biochars levels of 0, 5 and 7.5 g/kg of soil, and four AMF inoculation levels of 0, 5, 10 and 15 spores / kg of soil) were arranged in a completely randomized block design with three replicates. Results of the study showed that at 8 weeks after transplanting, the biochar and mycorrhizal treatments increased the availability soil phosphorus and phosphorus uptake by maize. Application 4.5 and 7.5 g biochar/kg of soil combined with inoculation of 10-15 AMF spores / kg of soil provided to high value of phosphorus uptake by maize. Application of biochar alone, however, did not significantly improve maize growth and phosphorus uptake by maize

EFFECTS of FOUR RATES of THREE NITROGEN SOURCES on YIELD and CHEMICAL COMPOSITION of MANCHAR BROMEGRASS FORAGE in the MATANUSKA VALLEY

Paper copies available in Archives, Acc# 2013-0059List of Tables -- List of Figures -- Summary --Introduction -- Experimental Procedure -- Results and Discussion: Yield, Nitrogen Percentage, Nitrogen Uptake, Nitrogen Recovery, Phosphorus Percentages, Phosphorus Uptake, Phosphorus Recover, Potassium Percentages, Potassium Uptake, Potassium Recovery, Calcium Percentages, Calcium Uptake, Magnesium Percentages, Magnesium Uptake, Sodium Percentages and Uptake, Aluminum, Barium, Boron, Chromium, Copper, Iron, Manganese, Molybdenum, Strontium, Zinc -- Acknowledgment -- Literature Cite

Some effects of boron to the growth and chemical composition of sainfoin (Onobrychis viciaefolia scop.) : a thesis presented in partial fulfilment of the requirmeents for the degree of Master of Agricultural Science in Plant Science at Massey University, Palmerston North, New Zealand

Some effects of boron on the growth and chemical composition of sainfoin (Onobrychis viciaefolia Scop.) plants cv Fakir were evaluated in a glasshouse. The growth and development of sainfoin plants was not affected by the different levels of boron applied but was affected by nitrogen application and inoculation due to the nodulation failure of the latter. Generally, the root showed the highest dry matter yield and the fastest relative growth rate. Similarly, the total nonstructural carbohydrates of the sainfoin plants were not affected by the different levels of boron. Nitrogen application reduced the total nonstructural carbohydrates of the whole plant. Moreover, when 1 ppm boron was applied, both the shoot and the root yielded the highest total nonstructural carbohydrates. Likewise, root and shoot total nonstructural carbohydrates were reduced by the application of nitrogen. Roots gave a higher total nonstructural carbohydrate yield than the shoot. Boron content of the whole sainfoin plant, the shoot and the root ranging from 0-55 µg/g increased in proportion with the increment of boron applied. Similar results were obtained from boron uptake of the whole plant, the shoot and the root. There was a depression of boron concentrations and boron uptake of the whole plant, the shoot and the root, when nitrogen was applied, implying a deficiency situation. Although nonsignificant effects of boron levels were obtained from nitrogen and phosphorus concentration and uptake, respectively, of both shoot and root, application of 2 ppm boron reduced the concentration of nitrogen but not nitrogen uptake, and reduced phosphorus concentration and phosphorus uptake. Application of nitrogen increased shoot and root nitrogen contents and nitrogen uptake but decreased root and shoot phosphorus concentrations and phosphorus uptake. It was concluded that levels of 2 ppm boron concentration were not adequate to support satisfactory growth when plants were supplied with sufficient levels of other nutrients. Keywords: Boron, nitrogen, Rhizobium, total nonstructural carbohydrates (TNC

Growth studies with hemp (Cannabis sativa L.) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Horticultural Science at Massey University

The effect of latitude, sowing date and density on yield, height and growing time were studied by sowing two varieties of hemp for seed at three sites in New Zealand. Predation and poor germination hampered results. Latitude effects on height could not be confirmed but Anka, unlike Finola, suffered a reduction in height with later sowing. Anka was the larger plant with higher seed yield, but the dwarfed Finola gave a higher harvest index. Thus seed yield for later sowing is reduced for cv Anka, unchanged for cv Finola. Plant density data allowed estimated yields at 30, 60 and 90 plants.m-2 to be determined. At 30 plants.m-2, seed yield in both varieties was reduced with later sowing, and confirmed Anka with the greater gross yield against Finola having the higher harvest index. At 60 and 90 plt.m-2, the results confirmed only that Anka is the bigger plant. Earlier sowing than the 1st sowing in our trial (October) could be an advantage. Higher sowing rates than 40-50 plt.m-2 would be of little advantage for Anka, but rates higher than 90 plt.m-2 should be explored for Finola. The asymptotic yield maximum for Anka falls dramatically with later sowing, whereas Finola does not. This suggests double cropping might be explored, with an early sowing of Anka followed by Finola. Growing time data indicated the lower latitude site had longer growing times overall. Day length sensitivity (shorter growing time with later sowing) was confirmed for Anka, but Finola was unaffected. This suggests Finola is a day-length neutral plant. Leaf production in both varieties was higher at higher latitudes, and was reduced by later sowing date. A second experiment examined the nitrogen and phosphorus uptake of a fibre hemp cultivar (EIL1) with respect to three sowing dates and two latitudes. Harvests were taken monthly to establish growth trends. From biomass figures, equations were established for leaf/stem relationships. Uptake values (on a dry matter basis) tended to stabilize as the plant matured at: N(stem) 3.04%, N(leaf) 4.5%, p(stem) 0.26% and P(leaf) 0.45%. High initial concentration of both N and P fell rapidly. For maximum uptake seed should be sown early (October or earlier) and plants grown as long as possible (5 months or more)

Phosphorus efficiency in brazilian soybean cultivars.

The primary goal of this study was to evaluate the phosphorus uptake and use efficiency in Brazilian soybean cultivars, besides root morphology and architecture characteristics related to phosphorus uptake, carrying out two greenhouse experiments. The experiment 1 was completely randomised, with 56 treatments (soybean cultivars) and 3 replicates. Experiment 2 was completely randomised design with three replicates, and the ten cultivars (greater and lower efficiency) were selected for this assay according to their ability to absorb phosphorus less available determined in experiment 1. The study was carried out at Center of Nuclear Energy in Agriculture, University of São Paulo, Brazil, between February 2011 and August 2012. The isotopic dilution technique was used in the first experiment to assess the phosphorus availability in the soil and to determine the ability of plants to access labile phosphorus by measuring the specific activity of plants grown in soil labeled with radioactive phosphorus. Nine cultivars showed greater phosphorus uptake and used efficiency. The second experiment evaluated the root morphology and architecture. The cultivars with greater uptake efficiency have root morphology and architecture characteristics that favour acquisition of phosphorus from soil compartments that are inaccessible to other cultivars. Phosphorus uptake by plants was not affected by soybean seeds phosphorus content. Identification of these cultivars is very important because it could enable soybean farming in low fertility soils, reducing fertiliser dependence

Influence of the hyporheic zone on the phosphorus dynamics of a large gravel-bed river, Garonne River, France

Phosphorus (P) concentrations in sediments and in surface and interstitial water from three gravel bars in a large river (Garonne River, southern France) were measured daily, downstream of a wastewater treatment plant for a city of 740 000 inhabitants (Toulouse). Measurements were made of vertical hydraulic gradient (VHG), total dissolved phosphorus (TDP), soluble reactive phosphorus (SRP) and total phosphorus (TP) in water and of three extractable forms of phosphorus (water extractable, NaOH extractable and H2SO4 extractable) in hyporheic sediments from the gravel bars. Dissolved phosphorus was the major contributor to TP (74–79%) in both interstitial and surface waters on all sampling dates, and in most cases surface water P concentrations were significantly higher than interstitial concentrations. Hyporheic sediment TP concentrations ranged between 269 and 465 μg g -1 and were highest in fine sediment fractions. Acid-extractable P, a non-bioavailable form, represented at least 95% of sediment TP. A positive relationship was observed between VHG and TP in two of the gravel bars, with wells that were strongly downwelling having lower TP concentrations. These results suggest that in downwelling zones, hyporheic sediments can trap surface-derived dissolved P, and that much of this P becomes stored in refractory particulate forms. Bioavailable P is mainly present in dissolved form and only occupies a small fraction of total P, with particulate P comprising the majority of total P

Effect of influent nutrient ratios and hydraulic retention time (HRT) on simultaneous phosphorus and nitrogen removal in a two-sludge sequencing batch reactor process

A laboratory-scale anaerobic–anoxic/nitrification sequencing batch reactor (A2N- SBR) fed with domestic wastewater was operated to examine the effect of varying ratios of influent COD/P, COD/TN and TN/P on the nutrient removal. With the increased COD/P, the phosphorus removals exhibited an upward trend. The influent TN/P ratios had a positive linear correlation with the phosphorus removal efficiencies, mainly because nitrates act as electron acceptors for the phosphorus uptake in the A2N-SBR. Moreover, it was found that lower COD/TN ratio, e.g. 3.5, did not significantly weaken the phosphorus removal, though the nitrogen removal first decreased greatly. The optimal phosphorus and nitrogen removals of 94% and 91%, respectively were achieved with influent COD/P and COD/ TN ratios of 19.9 and 9.9, respectively. Additionally, a real-time control strategy for A2N-SBR can be undertaken based on some characteristic points of pH, redox potential (ORP) and dissolved oxygen (DO) profiles in order to obtain the optimum hydraulic retention time (HRT) and improve the operating reliabili

Verkenning van de mogelijkheden om de opname van bodemfosfaat door blijvend grasland te verhogen

This literature study gives an overview of the possibilities to increase the soil phosphorus uptake of permanent grassland by practical measure