Effects of phosphorus and superphosphate on the growth of Urochloa species

1984 ◽  
Vol 24 (127) ◽  
pp. 571 ◽  
Author(s):  
JG McIvor
Keyword(s):  
Field Trial ◽  
Nitrogen Concentration ◽  
Phosphorus Concentration ◽  
Stylosanthes Hamata ◽  
Phosphorus Requirements ◽  
Phosphorus Application

Six Urochloa accessions (U. mosambicensis cv. Nixon, CPI 46876, CPI 47167; U. oligotricha CPI 45607, CPI 47122, CPI 47 124) were grown in pots of phosphorus-deficient soil with varying rates of added phosphorus and their phosphorus requirements and responses compared. The same six accessions were grown in swards at Lansdown near Townsville with Stylosanthes hamata cv. Verano and S. scabra cv. Seca and their responses to superphosphate measured over a five-year period. All accessions gave large responses, both to phosphorus in pots and superphosphate in the field, with only small differences between accessions in their phosphorus requirements. Phosphorus application increased phosphorus concentration in the tops, from 0.11 to 0.17% without phosphorus, to 0.56-0.70% at 200 kg P/ha, but had little effect on nitrogen concentration. In the final year of the field trial, superphosphate did not significantly affect yield of the sown legume but yields of Urochloa were significantly increased by superphosphate application. This resulted in the nil superphosphate plots being legume dominant (mainly S. hamata) and the high superphosphate plots being Urochloa dominant.

Seasonal changes in chemical composition of heavily fertilized Kikuyu pasture and their potential effects on the mineral nutrition of grazing cattle

1979 ◽  
Vol 19 (97) ◽  
pp. 183 ◽  
Author(s):  
AS Awad ◽  
DG Edwards ◽  
DO Huett
Keyword(s):  
Nitrogen Concentration ◽  
Nutrient Content ◽  
Early Summer ◽  
Phosphorus Concentration ◽  
Late Winter ◽  
Grazing Cattle ◽  
Nitrogen Concentrations ◽  
One Year ◽  
High Level ◽  
Phosphorus Application

was sampled at two week intervals over a period of one year. The concentrations of calcium throughout the year (0.15-0.28%) and phosphorus from late winter to early summer (0.20-0.28%) were well below the values normally considered to be required by milking cows and some classes of beef cattle. The nitrogen concentrations reached minimal values of 1.8-2.2% in winter, which appear to be adequate for milk production. From summer through to the end of winter, the ratio of K/(Ca + Mg) was much higher, and the Ca/P ratio was much lower, than those values reported to be associated with the occurrence of grass tetany in grazing cattle. Very high nitrogen concentratians in early summer (up to 5.2% N where 672 kg N ha-1 year-1 was applied) were in the range that has been associated with grass tetany in cattle. Lime application increased the nitrogen, phosphorus and calcium concentrations in the herbage throughout the year. The effect of lime in increasing nitrogen concentration in the herbage was maximal in late autumn and winter, at which time fertilizer nitrogen had little or no effect. The increased nitrogen concentration in the herbage through application of lime was associated with the development of a naturalized white clover component in the sward. Lime also increased the phosphorus concentration in the herbage, particularly from mid-winter to early summer, over which period phosphorus application per se had minimal effect. The application of lime allied with 134 kg N ha-1 year-1 maintained a high level of dry matter production as well as a more adequate and better balanced nutrient content in the kikuyu pasture throughout the year, and particularly in winter, when cattle grazing kikuyu pastures suffer a serious feed gap.

Effects of variation in density and phosphate application on growth and composition of Townsville stylo (Stylosanthes humilis)

1970 ◽  
Vol 10 (45) ◽  
pp. 442 ◽  
Author(s):  
KG Rickert ◽  
LR Humphreys
Keyword(s):  
Nitrogen Concentration ◽  
Phosphorus Concentration ◽  
Dihydrogen Phosphate ◽  
Positive Density ◽  
Nitrogen And Phosphorus ◽  
Area Index ◽  
Stylosanthes Humilis ◽  
Plant Densities ◽  
Townsville Stylo ◽  
Phosphorus Application

Townsville stylo (Stylosanthes humilis) was grown at Brisbane from February to June 1967 at initial densities of 10, 50, 250, 1250, and 6250 plants per m2 in boxes of sand which received basal nutrients and applications of 0, 10, and 50 kg P per hectare as calcium dihydrogen phosphate. Plots were irrigated frequently. Wide differences in dry matter yield between plant densities and a positive density phosphorus yield interaction persisted throughout the experiment. Peak yield was 1050 g per m2 with leaf area index (LAI) of 6.8. Intraspecific plant competition was evident in high densities 35 days after emergence, extending to the lower densities by 58 days. Plant mortality at the highest density was independent of phosphorus treatment. Maximum growth rates were reached earlier at high than at low plant densities ; the subsequent decreases in growth rate were expressed through drifts in both LA1 and NAR and were associated with progressively more unfavourable environmental conditions for growth. Nitrogen and phosphorus concentration of both shoots and roots decreased with increasing density. Phosphorus application did not affect nitrogen concentration. Exploitation of native soil phosphorus and recovery of applied phosphorus was greatest in high density swards. The data illustrate the loss in potential production which may occur in sparse swards of Townsville stylo and the limitations to efficient phosphorus response inherent in low density swards.

scholarly journals Reducing Nitrogen and Phosphorus Losses from Different Crop Types in the Water Source Area of the Danjiang River, China

2019 ◽  
Vol 16 (18) ◽  
pp. 3442 ◽  
Author(s):  
Mengjing Guo ◽  
Tiegang Zhang ◽  
Jing Li ◽  
Zhanbin Li ◽  
Guoce Xu ◽  
...  
Keyword(s):  
Total Nitrogen ◽  
Total Phosphorus ◽  
Unit Area ◽  
Nitrogen Concentration ◽  
Source Area ◽  
Water Source ◽  
Nutrient Loss ◽  
Phosphorus Concentration ◽  
Nitrogen And Phosphorus ◽  
Bare Land

Nitrogen and phosphorus are essential for plant growth and are the primary limiting nutrient elements. The loss of nitrogen and phosphorus in agricultural systems can cause the eutrophication of natural water bodies. In this paper, a field simulated rainfall experiment was conducted in a typical small watershed of the Danjiang River to study the nutrient loss process of nitrogen and phosphorus in slope croplands subjected to different crops and tillage measures. The characteristics of the runoff process and nutrient migration of different slope treatments were studied, which were the bare-land (BL, as the control), peanut monoculture (PL), corn monoculture (CL), bare land (upper slope) mixed with peanut monoculture (lower slope) (BP), corn and peanut intercropping (TCP), corn and soybean intercropping (TCS), downslope ridge cultivation (BS) slope, and straw-mulched (SC), respectively. The results showed that the runoff of CL, SC, TCS, BS, BP, PL and TCP slope types were 93%, 75%, 51%, 39%, 28%, 12%, and 6% of the those of the bare land, respectively. The total nitrogen concentration in runoff on different slope types decreased in the order of BP > PL > BS > SC > TCP > BL > CL > TCS. The BL was characterized with the highest NRL-TN (the loss of total nitrogen per unit area), with the value of 1.188 kg/hm2, while those of the TCP is the smallest with the value of 0.073 kg/hm2. The total phosphorus concentration in runoff decreasd in the order of BS > BP > PL > BL > TCP > SC > CL > TCS. The PRL-TP (the loss of total phosphorus per unit area) of BL is the largest (0.016 kg/hm2), while those of TCP is the smallest (0.001 kg/hm2). These indicate that the loss of nitrogen is much higer than that of phosphorus. The loss of nitrogen in runoff is dominated by nitrate nitrogen, which accounts for 54.4%–78.9% of TN. Slope croplands in the water source area should adopt the tillage measures of TCP and PL.These measures can reduce 85% of the runoff of nitrogen and phosphorus compared to the bare land. The results may assist in agricultural non-point source pollution control and help promote improved management of the water environment in the Danjiang River’s water source area.

Effects of nitrogen fertilizer, plant population and irrigation on sugar beet: II. Nutrient concentration and uptake

1971 ◽  
Vol 76 (2) ◽  
pp. 269-275 ◽  
Author(s):  
A. P. Draycott ◽  
M. J. Durrant
Keyword(s):  
Sugar Beet ◽  
Nitrogen Fertilizer ◽  
Nutrient Concentration ◽  
Field Experiments ◽  
Nitrogen Concentration ◽  
Plant Size ◽  
Plant Population ◽  
Sugar Yield ◽  
Phosphorus Concentration ◽  
Wide Range

SUMMARYThe concentration of nitrogen, phosphorus, potassium, sodium, calcium and magnesium was measured in the dry matter of sugar beet from four field experiments (1966–9). All combinations of four amounts of nitrogen fertilizer (0–1·8 cwt/acre), four plant populations (8800–54000 plants/acre) and irrigation were tested, which gave a wide range of plant size and yield. Nutrient concentration and uptake by the crop were also greatly affected by the treatments.Nitrogen fertilizer and irrigation increased uptake of nitrogen by the crop but increasing the plant population had little effect on uptake and decreased the concentration of nitrogen. Sugar yield was related to the total nitrogen concentration in tops and roots and to uptake. There were optimal values of nitrogen concentration for maximal sugar yield, but the optima were greatly affected by plant population. Leaf colour was a good guide to nitrogen concentration.Phosphorus concentration was affected little by the treatments but cation concentrations were greatly affected. In general, uptake of all the elements was increased by all treatments – the exception was sodium, which decreased as the plant population increased but this was balanced to somo extent by increased potassium uptake.

scholarly journals Nutrient enrichment effect on macroinvertebrates in a lowland stream of Argentina

2015 ◽  
Vol 105 (2) ◽  
pp. 228-234 ◽  
Author(s):  
Agustina Cortelezzi ◽  
Carolina Ocón ◽  
María V. López van Oosterom ◽  
Rosana Cepeda ◽  
Alberto Rodrigues Capítulo
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Global Climate ◽  
Nitrogen Concentration ◽  
Nutrient Concentrations ◽  
Phosphorus Concentration ◽  
Lowland Stream ◽  
Pampean Streams ◽  
High Concentrations ◽  
Intensive Land Use

ABSTRACT One of the most important effects derived from the intensive land use is the increase of nutrient concentration in the aquatic systems due to superficial drainage. Besides, the increment of precipitations in South America connected to the global climate change could intensify these anthropic impacts due to the changes in the runoff pattern and a greater discharge of water in the streams and rivers. The pampean streams are singular environments with high natural nutrient concentrations which could be increased even more if the predictions of global climate change for the area are met. In this context, the effect of experimental nutrient addition on macroinvertebrates in a lowland stream is studied. Samplings were carried out from March 2007 to February 2009 in two reaches (fertilized and unfertilized), upstream and downstream from the input of nutrients. The addition of nutrients caused an increase in the phosphorus concentration in the fertilized reach which was not observed for nitrogen concentration. From all macroinvertebrates studied only two taxa had significant differences in their abundance after fertilization: Corbicula fluminea and Ostracoda. Our results reveal that the disturbance caused by the increase of nutrients on the benthic community depends on basal nutrients concentration. The weak response of macroinvertebrates to fertilization in the pampean streams could be due to their tolerance to high concentrations of nutrients in relation to their evolutionary history in streams naturally enriched with nutrients. Further research concerning the thresholds of nutrients affecting macroinvertebrates and about the adaptive advantages of taxa in naturally eutrophic environments is still needed. This information will allow for a better understanding of the processes of nutrient cycling and for the construction of restoration measures in natural eutrophic ecosystems.

Sulphur and phosphorus fertilizers increase the yield of barrel medic (Medicago truncatula) five-fold in native pasture on a traprock soil

1989 ◽  
Vol 29 (4) ◽  
pp. 527 ◽  
Author(s):  
NM Clarkson ◽  
IF Swann ◽  
NP Chaplain
Keyword(s):  
Medicago Truncatula ◽  
Elemental Sulfur ◽  
Nitrogen Concentration ◽  
Nutrient Concentrations ◽  
Phosphorus Concentration ◽  
First Year ◽  
Yield Increase ◽  
Barrel Medic ◽  
Yield And Quality ◽  
Native Pasture

A single application of sulfur and phosphorus in the first year produced a 5-fold yield increase in barrel medic (Medicago truncatula cv. Jemalong), every year for 3 years, on traprock country in southern inland Queensland. In the first year, the yield of medic increased from 400 (untreated) to 1300 kg/ha with sulfur alone (at 40 kg/ha), and to 2300 kg /ha with sulfur and phosphorus together (both at 40 kg/ha). In the second and third years, sulfur and phosphorus together increased yields from 300 to 1400 kg/ha, and from 800 to 4000 kg/ha, respectively. The experiment tested factorial combinations of sulfur and phosphorus, both at 0, 10 and 40 kg/ha, 3 sources of sulfur (gypsum, superphosphate fortified with elemental sulfur and called 'super and sulfur', and elemental sulfur) and agricultural limestone at 2500 kg/ha. Seed and fertiliser were broadcast into a native pasture at the start of the experiment. Elemental sulfur was inferior to gypsum and 'super and sulfur' in the first year, but equally effective thereafter. There was no response to lime. Fertilising with sulfur and phosphorus together increased the sulfur concentration in medic tops from 0.10 to 0.23%, the phosphorus concentration from 0.19 to 0.23%, and the nitrogen concentration from 2.12 to 2.82%. Nutrient concentrations in plant and soil were examined as an aid to diagnosing deficiencies at other sites. We concluded that adequately fertilising medic with sulfur and phosphorus can greatly improve pasture yield and quality, and allow higher stocking rates on traprock country.

The residual effectiveness of phosphorus for stylosanthes pastures on red and yellow earths in the semi-arid tropics

Soil Research ◽  
1985 ◽  
Vol 23 (2) ◽  
pp. 211 ◽  
Author(s):  
ME Probert ◽  
J Williams
Keyword(s):  
Soil Phosphorus ◽  
Fertilizer Application ◽  
Yield Data ◽  
Stylosanthes Hamata ◽  
Phosphorus Requirements ◽  
Term Maintenance ◽  
Semi Arid ◽  
Residual Effectiveness ◽  
Extractable Soil

A mathematical description is presented of the effects through time of phosphorus fertilizer application on the growth of Stylosanthes hamata cv. Verano and on changes in extractable soil phosphorus on a red and a yellow earth in the semi-arid tropics. For the five years of observations, the models used provided reasonable descriptions of both aspects. It was not possible, however, to clearly demonstrate which of two functions tested better described the decreasing effectiveness of phosphorus with time. The simpler exponential function provided as good a fit to the yield data as did the function proposed by Barrow, whilst for the extractable phosphorus data the latter did explain a significantly higher proportion of the variance, but its coefficients could not be estimated with great precision. The results show that the phosphorus requirements of such pastures on these soils are modest. Extractable soil phosporus levels of approximately 12 �g g-1 in either 0.005 M H2SO4 or 0.5 M NaHCO3 are indicated as being adequate to ensure near-maximum yields of the legume. Long-term maintenance fertilizer needs as predicted by the models are discussed.

A study of phosphorus nutrition and water supply on the early growth and survival of buffel grass grown on a sandy red earth from south-west Queensland

1975 ◽  
Vol 15 (73) ◽  
pp. 239 ◽  
Author(s):  
EK Christie
Keyword(s):  
Seedling Growth ◽  
Growth Rates ◽  
Phosphorus Concentration ◽  
Root Penetration ◽  
Buffel Grass ◽  
Phosphorus Absorption ◽  
South West ◽  
Red Earth ◽  
Drought Survival ◽  
Phosphorus Application

The influence of phosphorus application on the growth and drought survival of buffel grass on a sandy red earth in south west Queensland was studied in a series of pot experiments. An omission nutrient trial showed phosphorus was the principal nutrient limiting seedling growth, the severity of the deficiency increasing with time. A further pot experiment showed that at rates greater than 24 kg P ha-1 luxury consumption occurred. The critical phosphorus concentration for the plant was estimated to be 0.26 per cent. The available (0.01 NH2SO4 extractable) soil phosphorus concentration corresponding to this critical tissue concentration was 25 p.p.m. Beyond the 2-leaf seedling stage, the seedling depended increasingly on external phosphorus for growth. Under conditions of phosphorus deficiency, phosphorus absorption rates were insufficient to maintain tissue phosphorus at the concentrations necessary for healthy growth, and relative growth rates were low. In the presence of phosphorus, absorption and growth rates increased. Maturity of phosphorus deficient plants was characteristically delayed but with little yield loss. The addition of phosphorus increased seedling growth rate, root development and drought survival. The depth of root penetration is considered to be the major factor responsible for survival.

scholarly journals Hydrogen Peroxide Can Be a Plausible Biomarker in Cyanobacterial Bloom Treatment

2021 ◽  
Author(s):  
Takashi Asaeda ◽  
Mizanur Rahman ◽  
Helayaye Damitha Lakmali Abeynayaka
Keyword(s):  
Hydrogen Peroxide ◽  
Laboratory Experiments ◽  
Antioxidant Activities ◽  
Nitrogen Concentration ◽  
Cyanobacterial Bloom ◽  
Phosphorus Concentration ◽  
Fixed Nitrogen ◽  
Combined Stresses ◽  
Increasing Trend ◽  
Phosphorous Concentration

Abstract The effect of combined stresses, photoinhibition and nutrient depletion, on the oxidative stress of cyanobacteria was measured in laboratory experiments, to develop the biomass prediction model. Phormidium ambiguum was exposed to various photosynthetically active radiation (PAR) intensities and phosphorous concentrations with fixed nitrogen concentration. The samples were subjected to stress assays by detecting hydrogen peroxide (H2O2) concentration and antioxidant activities of catalase (CAT) and superoxide dismutase (SOD). H2O2 concentration decreased to 30 µmolm-2s-1 of PAR, then increased further with higher PAR intensity. Regarding phosphorus concentration, H2O2 concentration generally decreased with increasing phosphorus concentration. SOD and CAT activities were proportionate to the H2O2 protein-1. No H2O2 concentration detected outside of cells indicated the biological production of H2O2, and the accumulated H2O2 concentration inside cells was parameterized with H2O2 concentration protein-1. Over 30 µmolm-2s-1 of PAR, H2O2 concentration protein-1 had a similar increasing trend with PAR intensity, independently of phosphorous concentration. Meanwhile, with increasing phosphorous concentration, H2O2 protein-1 decreased in a similar pattern regardless of PAR intensity. Protein content decreased with increasing H2O2 gradually up to 4nmol H2O2 mg-1protein, which provides a threshold to restrict the growth of cyanobacteria. With these results. an empirical formula was developed to obtain the cyanobacteria biomass.

Sign in / Sign up

Export Citation Format

Share Document