Changes in soil nitrogen following different establishment procedures for Townsville stylo on a solodic soil in north-eastern Queensland

1972 ◽  
Vol 12 (56) ◽  
pp. 274 ◽  
Author(s):  
BJ Crack
Keyword(s):  
Total Nitrogen ◽  
Soil Nitrogen ◽  
Nitrate Nitrogen ◽  
Fertilizer Application ◽  
Soil Nitrate ◽  
Soil Total Nitrogen ◽  
North East ◽  
Stylosanthes Humilis ◽  
North Eastern ◽  
Townsville Stylo

The effect of the legume Townsville stylo (Stylosanthes humilis) on soil nitrogen status was studied under mown plots with different conditions of establishment and fertilizer application on a solodic soil in north- east Queensland. Increase in soil total nitrogen 0-7.5 cm of 180 kg N per ha and total nitrogen accession (plant and soil) of 460 kg N per ha was measured over a four year period where the legume was sown into existing spear grass and fertilized with superphosphate at 375 kg per ha per year. Soil nitrogen increases did not occur until the pasture was legume dominant and main increases took place where superphosphate was applied. Under these conditions there was also a dry season accumulation of soil nitrate nitrogen.

RELATIONSHIP OF YIELD AND TOTAL NITROGEN UPTAKE OF BRUSSELS SPROUTS PLANTS GROWN IN THE GREENHOUSE TO AVAILABLE SOIL NITROGEN

1969 ◽  
Vol 49 (3) ◽  
pp. 313-318 ◽  
Author(s):  
D. C. Munro
Keyword(s):  
Total Nitrogen ◽  
Soil Nitrogen ◽  
Nitrogen Uptake ◽  
Nitrate Nitrogen ◽  
Soil Samples ◽  
Moist Soil ◽  
Available Nitrogen ◽  
Air Drying ◽  
Brussels Sprouts ◽  
Relationship Of

Initial nitrate-nitrogen content of the soil gave a correlation coefficient (r) of 0.93 with yields and with total nitrogen uptake of Brussels sprouts plants (Brassica oleracea var. gemmifera DC., Jade Cross). Soil nitrogen extracted with 0.01 M NaHCO3 gave r values of 0.76 with yields and 0.75 with nitrogen uptake. Nitrate incubation results from leached, moist soil samples gave r values of 0.59 with yields and 0.56 with nitrogen uptake. However, air-drying of soil samples prior to leaching and incubation resulted in r values of only 0.15 and 0.11 with yields and nitrogen uptake, respectively. Available nitrogen determined by incubation without previous leaching of the soil samples gave high r values because of the influence of the initial nitrate nitrogen in the soil.

A spectral parameter for the estimation of soil total nitrogen and nitrate nitrogen of winter wheat growth period

2020 ◽  
Author(s):  
Juanjuan Zhang ◽  
Qinqin Wei ◽  
Shuping Xiong ◽  
Lei Shi ◽  
Xinming Ma ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Total Nitrogen ◽  
Spectral Parameter ◽  
Nitrate Nitrogen ◽  
Growth Period ◽  
Wheat Growth ◽  
Soil Total Nitrogen

Influence of growing various crops in five different fixed rotations on the changes in nitrate and total nitrogen content of soils

1985 ◽  
Vol 104 (3) ◽  
pp. 609-613 ◽  
Author(s):  
K. N. Sharma ◽  
A. L. Bhandari ◽  
M. L. Kapur ◽  
D. S. Rana
Keyword(s):  
Nitrogen Content ◽  
Total Nitrogen ◽  
Soil Nitrogen ◽  
Nitrate Nitrogen ◽  
Balance Sheet ◽  
Total Nitrogen Content ◽  
Soil N ◽  
Total N ◽  
Soil Layers ◽  
Total Soil N

SummaryThe results on the influence of various crops in five different fixed rotations on the ohanges in nitrate and total N content of soils are reported. Groundnut contributed largely to the accumulation of nitrate nitrogen in the soil profile (to a depth of 120 cm). Bajra fodder exhausted the soil nitrogen reserve to a great extent. Wheat and maize, in a rotation, reduced nitrate leaching to deeper soil layers. Summer moong also left a large amount of unabsorbed nitrate in the profile. Total nitrogen content of the soil decreased after the harvest of cereals. Maximum depletion occurred after the harvest of bajra crop. Potato (a crop which received a heavy dressing of N fertilizer) and legumes contributed to the soil N reserve. A balance sheet of N indicated net gains of total soil N in four of the five cropping sequences. A net loss of 75 kg N/ha was observed in bajra fodder-potato-wheat rotation.

Effect of plant growth and form of nitrogen fertilizer on denitrification from four South Australian soils

Soil Research ◽  
1972 ◽  
Vol 10 (2) ◽  
pp. 183 ◽  
Author(s):  
RC Stefanson
Keyword(s):  
Nitrous Oxide ◽  
Plant Growth ◽  
Soil Nitrogen ◽  
Nitrate Nitrogen ◽  
Ammonium Nitrogen ◽  
Soil Nitrate ◽  
Calcareous Sand ◽  
Nitrogen Gas ◽  
Brown Soil ◽  
Growth Chambers

In measuring losses of volatile nitrogen in sealed growth chambers, four major wheat-growing soils were used, namely, a mallisol, a red-brown earth, a calcareous sand, and a grey-brown soil of heavy texture. The rate of loss varied from 1 to 15 mg nitrogen/(kg soil/week) when nitrate nitrogen was applied to the soil; when ammonium nitrogen was used, losses were 1-4 mg nitrogen/(kg soil/week) over a 6-week period. The major component of these losses was nitrogen gas with lesser quantities of nitrous oxide. Both gases were produced by biological denitrification of soil nitrate. This was confirmed with an incubation experiment which used a portion of the same samples of soil. When nitrate nitrogen was applied to the soil, denitrification was increased by increasing soil water content and plant growth. These effects were greatest in the heavy textured soils. The application of ammonium nitrogen to the red-brown earth, mallisol, and grey-brown soil of heavy texture reduced the losses of soil nitrogen as nitrogen gas and nitrous oxide. Considerable losses of soil nitrogen were recorded for the calcareous sand when ammonium nitrogen was applied. Plant growth did not affect the losses of soil nitrogen from those soils receiving ammonium nitrogen.

Studies on some neutral red duplex soils (Dr 2.12) in north-eastern Queensland. 3. Availability of phosphorus in the C-horizon

1975 ◽  
Vol 15 (76) ◽  
pp. 689
Author(s):  
ME Probert
Keyword(s):  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Neutral Red ◽  
Available Phosphorus ◽  
Panicum Maximum ◽  
Stylosanthes Humilis ◽  
North Eastern ◽  
Coarse Grains ◽  
Phosphorus Status ◽  
Townsville Stylo

The C horizon phosphorus in neutral red duplex soils derived from granodiorite is shown by electron microprobe analysis to be present as coarse grains of apatite. Glasshouse experiments failed to show any contribution from this phosphorus to the nutrition of the test crops (Townsville stylo Stylosanthes humilis and green panic Panicum maximum). Since this phosphorus is soluble in 0.01 N H2SO4, this extractant grossly overestimated the available phosphorus status whereas extraction with 0.5 M NaHCO3 indicated the non-availability of the C horizon phosphorus in these soils.

Mechanisms of interference between hay-scented fern and black cherry

1993 ◽  
Vol 23 (10) ◽  
pp. 2059-2069 ◽  
Author(s):  
Stephen B. Horsley
Keyword(s):  
Soil Water ◽  
Soil Nitrogen ◽  
Nitrate Nitrogen ◽  
Soil Phosphorus ◽  
Photon Flux ◽  
Black Cherry ◽  
Soil Nitrate ◽  
Tree Roots ◽  
The Impact ◽  
Overstory Tree

Hay-scented fern (Dennstaedtiapunctilobula Michx.) interferes with establishment of black cherry (Prunusserotina Ehrh.) in the Allegheny hardwood forest of Pennsylvania. In stands where fern cover is dense, black cherry seeds germinate, but seedlings do not become established. Allelopathy was eliminated as the cause of interference in previous work; the present studies evaluated the resources of soil water, soil phosphorus, soil nitrogen, and light. The impact of hay-scented fern on the level of each resource, the availability of each resource to black cherry seedlings, and the growth response of black cherry seedlings to changes in resource availability were evaluated. Hay-scented fern had little effect on soil moisture levels, nor did it affect plant availability of soil water. The level of soil phosphorus was not reduced by the presence of hay-scented fern nor was phosphorus availability to black cherry seedlings less when they grew with fern. Both the speed and degree of mycorrhizal infection and the foliar phosphorus concentrations were similar in seedlings growing with or without fern cover. Hay-scented fern had no effect on rates of ammonium- or nitrate-nitrogen production nor was the soil concentration of ammonium affected. The presence of hay-scented fern significantly reduced the soil nitrate-nitrogen concentration in the first year after a shelterwood seed cut, but not in the second. Overstory tree roots were more important than hay-scented fern in removing soil nitrate. Availability of soil nitrogen was unaffected by the presence of hay-scented fern or overstory tree roots. Black cherry seedlings grew more where ferns were absent, regardless of whether overstory tree roots were present or absent. Competitive reduction in light was the key mechanism of fern interference with black cherry. Hay-scented fern caused dramatic reductions in both the photon flux density and the ratio of red to far-red light beneath it. Black cherry seedlings survived and grew poorly in the presence of fern foliage shade. Survival and growth similar to that above fern could be restored by restraining fern foliage, allowing light to reach black cherry seedlings from above.

Superphosphate and stocking rate effects on a native pasture oversown with Stylosanthes humilis in central coastal Queensland. 5. Bone phosphorus levels in grazing cattle

1979 ◽  
Vol 19 (101) ◽  
pp. 645 ◽  
Author(s):  
DA Little ◽  
NH Shaw
Keyword(s):  
Fertilizer Application ◽  
First Year ◽  
Potassium Fertilizer ◽  
Heteropogon Contortus ◽  
Grazing Cattle ◽  
Stylosanthes Humilis ◽  
Rate Effects ◽  
Townsville Stylo ◽  
One Year ◽  
Phosphorus Levels

The influence of fertilizer on bone phosphorus levels in grazing cattle was examined on native spear grass (Heteropogon contortus) pastures in central coastal Queensland oversown with Townsville stylo (Stylosanthes humilis). The first experiment compared superphosphate at nil, 125 or 250 kg ha-1 annually (F0, F1, F2, respectively), at three stocking rates. In the eighth and final year of this experiment, bone samples from Brahman-cross cattle obtained by rib biopsy were analyzed for their phosphorus content. Analyses of pasture samples indicated that Fo provided a diet deficient in phosphorus, but that F1 and F2 were adequate. Animals on F0 grew slowly, and after one year bone from the twelfth rib contained 121.5 mg P cm-3 In contrast, bone samples from cattle on F1 and F2 contained over 150 mg P cm-3 . At the end of the year there was no difference in bone phosphorus levels between animals on F1 and F2, although a significant advantage of F2 over F0 became apparent earlier in the year than that for F1. It is suggested that levels around 120 mg P cm-3 in bone from the twelfth rib indicate a deficiency of phosphorus, and that levels over 150 mg P cm-3 indicate adequacy. The diet selected from F0 was apparently deficient in protein for six months of the year. However, the quality of herbage selected from the fertilized pasture was much higher throughout the year, probably mainly through the consequent availability of much greater amounts of Townsville stylo. A second experiment, involving potassium fertilizer plus superphosphate, was run for three years following the development of potassium deficiency in the legume. During the first two years only small changes in bone phosphorus were observed, but in the third year, highly significant increases in bone phosphorus occurred in all fertilizer treatments. In a third experiment, changes in bone phosphorus were measured in animals grazing pasture dressed with superphosphate for the first time. After the first year, F2 produced higher levels of bone phosphorus than did F1, but no difference occurred in the second year. The results suggested that for the promotion of bone phosphorus storage, the higher rate of fertilizer application was of only short-term advantage.

Evaluation of a Solid-State Electrode for the Rapid Detection of Soil Nitrate-Nitrogen

2011 ◽  
Vol 422 ◽  
pp. 96-101
Author(s):  
Miao Zhang ◽  
S. Simon Ang ◽  
Mao Hua Wang ◽  
Gang Liu
Keyword(s):  
Solid State ◽  
Nitrate Nitrogen ◽  
Low Cost ◽  
Simultaneous Detection ◽  
Fertilizer Application ◽  
Laboratory Evaluation ◽  
Soil Nitrate ◽  
Negative Drift ◽  
Fluidic Control

In recent years, the prolific usage of nitrogenous fertilizers in the agricultural area of China has resulted in inefficient nitrogen usage, environmental pollution and the degradation of the soil fertility. As such, a rapid, low-cost and reliable soil detection method is urgently needed. This study reported on the laboratory evaluation of a solid-state ion-selective electrode, based on a nitrate doped polypyrrole polymer (PPy(NO3-)), for the simultaneous detection of soil nitrate-nitrogen. The potentiometric slope of these PPy(NO3-) electrodes for nitrate was found to be -(53.3±0.8) mV/decade over a linear range of three decades of concentration 10-4～10-1mol/L. It was also found that these electrodes had a nitrate detection limit of 5.0 ×10-5 mol/L. Impacts of soil extractant conditions were also tested. The electrodes displayed better performances for nitrate solutions with pH lower than 7.0. The potentiometric responses of electrodes exhibited a negative drift tendency of 0.6 mV/°C, which was probably caused by changes of the polymer morphology and the solution ionic activity. In order to reduce the interferences of coexisting anion, deionized water was chosen as soil extractant. It is shown that a fast determination of soil nitrate levels for site-specific control of fertilizer application could be realized using the PPy(NO3-) electrodes together with an automatic fluidic control system.

The influence of submesoscale eddies on hydrochemical parameters and structural and functional characteristics of phytoplankton in the north-eastern part of the Black Sea

2019 ◽  
pp. 24-40
Author(s):  
Sergey B. Kuklev ◽  
Vladimir A. Silkin ◽  
Valeriy K. Chasovnikov ◽  
Andrey G. Zatsepin ◽  
Larisa A. Pautova ◽  
...  
Keyword(s):  
Anticyclonic Eddy ◽  
The Black Sea ◽  
Hydrochemical Parameters ◽  
North East ◽  
The North ◽  
Seasonal Thermocline ◽  
North Eastern ◽  
Quantitative Indicators ◽  
The City ◽  
North Eastern Part

On June 7, 2018, a sub-mesoscale anticyclonic eddy induced by the wind (north-east) was registered on the shelf in the area of the city of Gelendzhik. With the help of field multidisciplinary expedition ship surveys, it was shown that this eddy exists in the layer above the seasonal thermocline. At the periphery of the eddy weak variability of hydrochemical parameters and quantitative indicators of phytoplankton were recorded. The result of the formation of such eddy structure was a shift in the structure of phytoplankton – the annual observed coccolithophores bloom was not registered.

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