Banding phosphorus and ammonium enhances nutrient uptake by maize via modifying root spatial distribution

2013 ◽  
Vol 64 (10) ◽  
pp. 965 ◽  
Author(s):  
Qinghua Ma ◽  
Hongliang Tang ◽  
Zed Rengel ◽  
Jianbo Shen

Localised supply of phosphorus (P) plus ammonium improves root proliferation and nutrient uptake by plants grown on calcareous soils, but how nitrogen (N) forms (ammonium and urea) and placements affect maize (Zea mays L.) root distribution and nutrient uptake is not fully understood. A soil column study was conducted with four N and P combinations including P plus urea (UP), mono-ammonium phosphate (MAP), di-ammonium phosphate (DAP) and P plus ammonium sulfate (ASP), and two fertiliser application methods (banding in the 10–25 cm layer or mixing throughout the 45-cm soil profile). Shoot N and P content increased by 11–31% and 14–37% in the treatments with banding P plus ammonium (MAP, DAP or ASP) compared with banding UP and the mixing treatments. Shoot N and P uptake rates per root dry weight or root length were higher with banding P plus ammonium than their respective mixing treatments. Banding P plus ammonium increased root-length density in the fertiliser-banded layer compared with banding UP and the mixing treatments. The results show that modifying root spatial distribution by banding P plus ammonium leads to an increase in N and P uptake rates, and consequently enhances nutrient accumulation by maize.

2021 ◽  
Author(s):  
Xiucheng Liu ◽  
Yuting Wang ◽  
Shuangri Liu ◽  
Miao Liu

Abstract Aims Phosphorus (P) availability and efficiency are especially important for plant growth and productivity. However, the sex-specific P acquisition and utilization strategies of dioecious plant species under different N forms are not clear. Methods This study investigated the responsive mechanisms of dioecious Populus cathayana females and males based on P uptake and allocation to soil P supply under N deficiency, nitrate (NO3 −) and ammonium (NH4 +) supply. Important Findings Females had a greater biomass, root length density (RLD), specific root length (SRL) and shoot P concentration than males under normal P availability with two N supplies. NH4 + supply led to higher total root length, RLD and SRL but lower root tip number than NO3 − supply under normal P supply. Under P deficiency, males showed a smaller root system but greater photosynthetic P availability and higher leaf P remobilization, exhibiting a better capacity to adaptation to P-deficiency than females. Under P deficiency, NO3 − supply increased leaf photosynthesis and PUE but reduced RLD and SRL in females while males had higher leaf P redistribution and photosynthetic PUE than NH4 + supply. Females had a better potentiality to cope with P deficiency under NO3 − supply than NH4 + supply; the contrary was true for males. These results suggest that females may devote to increase in P uptake and shoot P allocation under normal P availability, especially under NO3 − supply, while males adopt more efficient resource use and P remobilization to maximum their tolerance to P-deficiency.


2007 ◽  
Vol 2 (3) ◽  
pp. 405-414 ◽  
Author(s):  
Jasna Hrenovic ◽  
Tomislav Ivankovic

AbstractThe harmful effects of surfactants to the environment are well known. We were interested in investigating their potential toxicity in a pure culture of Acinetobacter junii, a phosphate (P)-accumulating bacterium. Results showed a high acute toxicity of sodium dodecyl sulfate (SDS) and hexadecyltrimethylammonium bromide (HDTMA) against A. junii. The estimated EC50 values of the HDTMA for the inhibition of CFUs in the pure culture of A. junii was 3.27 ± 1.12 × 10−7 mol L−1 and for the inhibition of the P-uptake rates 2.47 ± 0.51 × 10−6 mol L−1. For SDS, estimated EC50 values for the inhibition of CFUs in the pure culture of A. junii was 5.00 ± 2.95 × 10−6 mol L−1 and for the inhibition of the P-uptake rates 3.33 ± 0.96 × 10−4 mol L−1. The obtained EC50 values in the standardised yeast toxicity test using Saccharomyces cerevisiae were 3.03 ± 0.38 × 10−4 and 4.33 ± 0.32 × 10−5 mol L−1 for SDS and HDTMA, respectively. These results emphasized the need to control concentrations of surfactants entering the activated sludge system. The negative effects of these toxicants could greatly decrease populations of P-accumulating bacteria, as well as eukaryotic organisms, inhabiting activated sludge systems, which in turn could result in the decrease of the system efficiency.


1991 ◽  
Vol 48 (10) ◽  
pp. 1951-1959 ◽  
Author(s):  
Alan D. Steinman ◽  
Patrick J. Mulholland ◽  
David B. Kirschtel

Four treatments were imposed on eight laboratory streams in a factorial design to examine the roles of nutrient reduction and herbivory on periphyton communities. Treatments included two flow regimes (once-through flow or 90% recirculated water) and two levels of grazer density (1000 or 0∙m−2, using the snail Elimia clavaeformis). Periphyton biomass was significantly greater in streams without snails than in those with them, but water supply had no overall significant effect on biomass, even though inorganic P and N concentrations were significantly lower in recirculated than in once-through streams. Areal-specific P uptake rates (measured with 33P) were significantly greater on two dates in no-snail streams compared with snail streams, presumably because of the greater biomass levels in the former systems. Differences in biomass-specific P uptake rates were not significantly affected by either grazer density or water supply. Relative abundances of most algal species were unaffected by the water supply treatment, although percent biovolume of two Epithemia species was greater in no-snail, recirculated than in no-snail, once-through streams. Grazing activity dramatically reduced the percent biovolume of species with upright growth forms, resulting in dominance by species with prostrate growth forms.


Soil Research ◽  
2000 ◽  
Vol 38 (4) ◽  
pp. 837 ◽  
Author(s):  
Z. Rengel ◽  
C. Tang ◽  
C. Raphael ◽  
J. W. Bowden

Nitrification and nitrate leaching have been suggested to be major causes of soil acidification. However, it is unknown whether these processes cause subsoil acidification. Soil column experiments examined the effect of the addition of Ca(NO3)2 or (NH4)2SO4 to the topsoil horizon on subsoil acidification under nodulated lupins (Lupinus angustifolius L.) and subterranean clover (Trifolium subterraneum L.). Nitrate leaching was achieved by adding excess water to the surface of the columns. Where basal nutrients were applied only to the top 10-cm layer, about 60–70% of the total root length of lupin and over 50% of subterranean clover were distributed in that layer. Plants grown without added nitrate for 105 days decreased soil pH at all layers but more significantly in the top 20 cm (by up to 0.7 units); the decrease in pH correlated well with increased root length density of both species (r 2 = 0 .9 8 , n = 9). The addition of Ca(NO3)2 to the top 10-cm layer caused less acidification by about 0.1 pH units at all depths than the treatment without Ca(NO3)2 . Where basal nutrients were applied uniformly throughout the column, root length density of lupin and subterranean clover tended to increase with depth. The addition of (NH4)2SO4 in the top 10 cm significantly increased NO3– concentration in all layers but NH4+ was mainly retained in the top 30-cm layer. Lupin and subterranean clover grown without added NH4+ for 82 days decreased soil pH by 0.3 units at all depths. Compared with the plants receiving no (NH4)2SO 4 , lupin grown with (NH4)2SO4 at 0–10 cm depth in the column caused more acidification by 0.05–0.2 pH units in the top 10 cm but less acidification by 0.15–0.17 units at 10–40 cm depth in the column; subterranean clover grown with (NH4)2SO4 caused more acidification by 0.35–0.46 units in the top 10 cm and less acidification by 0.14–0.19 units in the 20–50 cm layer. The results suggest that the leaching of nitrate from topsoil is unlikely to cause subsoil acidification. In contrast, the uptake of nitrate by the roots reduces net acid production in subsoil layers.


1988 ◽  
Vol 68 (2) ◽  
pp. 425-432 ◽  
Author(s):  
Y. K. SOON

A field study was conducted in 1984 and 1985 to determine the spatial distribution with time of root length density of spring barley (Hordeum vulgare L.) growing in a Black Solod in northwestern Alberta. The weakly solonetzic Bnt horizon present in the solodic soil appeared not to inhibit root growth, and roots were present to 90 cm depth of soil. Drought in 1985 reduced root growth in general, and in particular in the surface soil (0 – 15 cm depth) between crop rows. Root growth in both years continued well after ear emergence and attained a maximum total length (14.5 and 9.5 km m−2 in 1984 and 1985, respectively) some time into grain-filling. Water uptake rates of up to 1.3 cm3 m−1 d−1 were observed; this maximum rate was associated with younger roots in the 60- to 90-cm depth in 1984. Low availability of subsoil water in 1985, however, resulted in low root density and water uptake rates in the 60- to 90-cm depth. The weighted mean uptake rate for the entire root system was slightly more than 0.4 cm3 m−1 d−1 in 1984 and about half that in 1985. Key words: Barley, Hordeum vulgare L., solonetzic soil, water inflow, root growth, root length density


2009 ◽  
Vol 59 (1) ◽  
pp. 57-64 ◽  
Author(s):  
M. Swinarski ◽  
J. Makinia ◽  
K. Czerwionka ◽  
M. Chrzanowska

Carbon source alternatives for denitrification belong to the highest research area priorities as they allow to optimize N removal within the existing capacities. In particular, some food industry effluents appear to be good candidates for such alternatives due to their high C/N ratios and high content of readily biodegradable organic fraction. The aim of this study was to determine the immediate effects of dosing different types of industrial wastewater on the denitrification capability of process biomass originating from the “Wschod” WWTP in Gdansk (northern Poland). Three types of industrial wastewater (effluents from a distillery, brewery and fish-pickling factory) were tested in two kinds of batch experiments. The results of this study revealed that the investigated industrial wastewater can be a potential external carbon source to improve denitrification efficiency. The observed single nitrate utilization rates (NURs) were ranging from 2.4 to 6.0 g N/(kg VSS·h) and were comparable to the rates associated with the utilization of readily biodegradable COD in the settled wastewater. When the NURs were measured during anoxic P uptake, the P uptake rates did not appear to be adversely affected by the addition of any carbon source.


Author(s):  
Christian W. Kuppe ◽  
Guy J D Kirk ◽  
Matthias Wissuwa ◽  
Johannes A Postma

Upland rice (Oryza sativa) is adapted to strongly phosphorus (P) sorbing soils. The mechanisms underlying P acquisition, however, are not well understood, and models typically underestimate uptake. This complicates root ideotype development and trait-based selection for further improvement. We present a novel model, which correctly simulates the P uptake by a P-efficient rice genotype measured over 48 days of growth. The model represents root morphology at the local rhizosphere scale, including root hairs and fine S-type laterals. It simulates fast-and slowly reacting soil P and the P-solubilizing effect of root-induced pH changes in the soil. Simulations predict that the zone of pH changes and P solubilization around a root spreads further into the soil than the zone of P depletion. A root needs to place laterals outside its depletion-but inside its solubilization zone to maximize P uptake. S-type laterals, which are short but hairy, appear to be the key root structures to achieve that. Thus, thicker roots facilitate the P uptake by fine lateral roots. Uptake can be enhanced through longer root hairs and greater root length density but was less sensitive to total root length and root class proportions.


Author(s):  
Edvaldo B. Santana Junior ◽  
Eugênio F. Coelho ◽  
Jailson L. Cruz ◽  
João B. R. da S. Reis ◽  
Diego M. de Mello ◽  
...  

ABSTRACT Trickle irrigation has been largely used for banana in Brazil, mainly due to the increase in water and fertilizer use efficiency. These irrigation systems have different options concerning number, type and flow rate of emitters as well as for hydraulics, number and location of lateral lines. The small area of soil wetted by these systems limits root spatial distribution of crops. This study aimed to evaluate the effect of different trickle irrigation systems on the root spatial growth and root spatial distribution of banana cv. Prata Gorutuba. Root length density and root length were evaluated in soil profiles of three micro-sprinkler systems, with emitter flow rates of 35, 53 and 70 L h-1 and of two drip irrigation systems, with one and two lateral lines per crop row. Trickle irrigation systems influence root spatial distribution, favoring a greater or smaller distribution of roots at different depth and distance from the plant according to micro-sprinkler flow rate and to the number of lateral lines per crop row. The effect on root spatial distribution is more accentuated for micro-sprinkler systems than for drip systems. The majority of the total root length (80%) was observed in the soil profiles from 0.33 to 0.57 m depth and at distances from the plants of 0.75 to 0.83 m.


2008 ◽  
Vol 3 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Jasna Hrenovic ◽  
Tomislav Ivankovic ◽  
Lavoslav Sekovanic ◽  
Mirela Rozic

AbstractThe antibacterial effect of cationic surfactants against the pure culture of phosphate (P)-accumulating bacterium Acinetobacter junii was investigated. The estimated EC50 values of the N-dodecylpyridinium chloride (DPC) for growth inhibition was 1.4±0.5 × 10−6 mol L−1 and for the inhibition of the P-uptake rates 7.3±2.6 × 10−5 mol L−1. The estimated EC50 values of the N-cetylpyridinium chloride (CPC) for growth inhibition was 4.9±1.3 × 10−7 mol L−1 and for the inhibition of the P-uptake rates 7.7±2.9 × 10−6 mol L−1. This suggests the importance of controlling the amounts of cationic surfactants in influent of the wastewater treatment systems in order to avoid the possible failure of the biological P removal from wastewaters.


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