Effect of phosphorus application on seasonal changes in nitrogen and phosphorus concentrations of four perennial Stylosanthes accessions

1986 ◽  
Vol 26 (1) ◽  
pp. 49 ◽  
Author(s):  
ME Probert ◽  
J Williams
Keyword(s):  
Growing Season ◽  
Nutrient Concentrations ◽  
Nitrogen And Phosphorus ◽  
Heteropogon Contortus ◽  
Red Earth ◽  
P Application ◽  
Phosphorus Application ◽  
Intensive Sampling ◽  
Plant Shoots ◽  
Semi Arid

Four perennial Stylosanthes accessions (S. hamata cv. Verano, S. scabra cv. Seca, cv. Fitzroy and CPI558 18) were grown for 4 years on a red earth soil in the semi-arid tropics with fertilizer phosphorus applications of 0 to 40 kglha. The concentrations of nitrogen (N) and phosphorus (P) in plant shoots were measured at monthly intervals from January to July in one season, with less intensive sampling in the other years. Some measurements were also made of N and P concentrations in litter. Phosphorus concentrations in shoot, leaf, stem and litter increased with increasing rate of application of P, but N concentrations in plant tissue were virtually independent of the rate of P application. The concentrations of both N and P in the shoots of all accessions declined during the growing season. Differences in nutrient concentrations between Verano and the S. scabra accessions were relatively small. Even without application of P, these legumes always had substantially higher concentrations of N and P than the native grass Heteropogon contortus, and could be expected to provide an improved diet for grazing animals.

Residual effects of phosphorus fertiliser in a stylo-native grass pasture on a duplex red earth soil in the semi-arid tropics of North Queensland

1994 ◽  
Vol 34 (2) ◽  
pp. 173
Author(s):  
KA Shaw ◽  
MA Gilbert ◽  
JD Armour ◽  
MJ Dwyer
Keyword(s):  
Soil Analysis ◽  
Residual Effects ◽  
Native Grass ◽  
Soil P ◽  
Initial Application ◽  
Red Earth ◽  
P Application ◽  
Stylosanthes Scabra ◽  
Phosphorus Application ◽  
Establishment Phase

A field experiment was established to define the phosphorus (P) requirement for establishment and maintenance of a mixed legume pasture (Stylosanthes scabra cv. Seca, S. hamata cv. Verano, S. guianensis cv. Graham, Macroptilium atropurpureum cv. Siratro) introduced into a native grass pasture on an infertile duplex red earth. Rates of 0, 5, 10, 20, and 40 kg P/ha were applied to separate plots in year 1 (1982), 2, and 3. In year 5 (1986 growing season), half of each plot that had received 20 and 40 kg P/ha in year 3 was refertilised at the original rate to ensure that maximum yields were defined. Bicarbonate- or acid-extractable soil P concentrations of 8 mg/kg were sufficient for 80% maximum legume yield. The residual value of applied P in the surface soil, as measured by soil analysis, decreased exponentially, but an initial application of 40 kg P/ha was still sufficient to produce near-maximum legume yield after 5 years. Phosphorus application increased the dry matter yield of legume. During the establishment phase (years 1 and 2 after planting) yields reached maximum at 10 and 20 kg P/ha, respectively, but increased linearly in subsequent years. When the original rates were reapplied in year 5, peak yield occurred at 20 + 20 kg P/ha, and there was no difference between this yield and that from plots receiving 40 kg P/ha in year 1. Native grass yields increased with P application only in years 4 and 5 of the experiment. Stylos demonstrated good tolerance to low P supply. In year 1, 80% of the total legume yield consisted of Graham stylo and Siratro, whereas in subsequent years, Seca and Verano made up 70 and 20%, respectively, of the total, irrespective of treatment. Yield of legume at nil P, relative to maximum, increased from 5% in year 1 to 42% in year 5.

Effect of rates and methods of phosphorus application on herb and oil yields and nutrient concentrations in Japanese mint (Mentha arvensis L.)

1987 ◽  
Vol 108 (3) ◽  
pp. 691-693 ◽  
Author(s):  
S. K. Kothari ◽  
Virendra Singh ◽  
Kamla Singh
Keyword(s):  
Soil Surface ◽  
Nutrient Concentrations ◽  
P Availability ◽  
Mentha Arvensis ◽  
Soil P ◽  
Japanese Mint ◽  
Use Efficiency ◽  
P Application ◽  
Phosphorus Application ◽  
Placement Depth

Japanese mint (Mentha arvensis L.), one of the important essential-oil-bearing crops of India, is a potential source of natural menthol which is widely used in various pharmaceutical and cosmetic preparations. Generally under intensive cultivation, the application (broadcast with incorporation) of phosphorus leads to enhanced herb and oil yields of different mint species (Rao, Rao & Singh, 1983; Singh et al. 1983; Vadivel & Sampath, 1981), but the knowledge that P-adsorption to soil surface reduces plant availability suggests that a P application method limiting soil-P contact may improve P availability and use efficiency (Phillips & Webb, 1971). Therefore, the placement depth and method may be an important factor in the proper use of applied phosphorus. Since uptake of P is reduced in dry soils (Reichman & Grunes, 1966; Simpson, 1960), P placed deeper in the soil would remain more available because of increased soil moisture. Another factor involved is the positional availability of the P source (Cooke, 1954). If placed too close to the surface, the roots may not come in contact with the fertilizer or too few would contact the band to maximize uptake.

Effects of moisture supply in the dry season and subsequent defoliation on persistence of the savanna grasses Themeda triandra, Heteropogon contortus and Panicum maximum

1992 ◽  
Vol 43 (2) ◽  
pp. 241 ◽  
Author(s):  
JJ Mott ◽  
MM Ludlow ◽  
JH Richards ◽  
AD Parsons
Keyword(s):  
Growing Season ◽  
Close Correlation ◽  
Dry Season ◽  
Carbon Gain ◽  
Panicum Maximum ◽  
Wet Season ◽  
Themeda Triandra ◽  
Heteropogon Contortus ◽  
Moisture Conditions ◽  
Sheath Material

The close correlation between grazing-induced mortality and major climatic patterns in Australian savannas, led us to the hypothesis that moisture conditions during the dry, non-growing season could affect sensitivity to grazing in the subsequent growing season. Using three widespread savanna species (Themeda triandra, Heteropogon contortus and Panicum maximum), this hypothesis was tested experimentally and the mechanisms controlling this response examined and quantified. In T. triandra drought during the dry season led to major mortality in defoliated plants in the next growing season. This mortality was caused by a synchrony of tillering at the commencement of the wet season, leaving few buds for replacement once parent tillers were killed by defoliation. T. triandra was also the most sensitive species to defoliation. This sensitivity was due to the poor ability of the plant to maintain positive carbon gain after defoliation. Several factors contributed to this poor ability, including: low total photosynthetic rate, low specific leaf area, and a large proportion of sheath material with poor photosynthetic capacity remaining after cutting. Both H. contortus and P. maximum growing under irrigated and fertilized conditions did not display any effects of previous moisture treatments when defoliated during the next wet season and were much less sensitive to defoliation than T. triandra.

Bacterioplankton, Phytoplankton, and Zooplankton Communities in a British Columbia Coastal Lake Before and After Nutrient Reduction

1986 ◽  
Vol 43 (8) ◽  
pp. 1504-1514 ◽  
Author(s):  
F. Joan Hardy ◽  
Ken S. Shortreed ◽  
John G. Stockner
Keyword(s):  
British Columbia ◽  
Sockeye Salmon ◽  
Inorganic Nitrogen ◽  
Size Fraction ◽  
Growing Season ◽  
Nutrient Reduction ◽  
Nitrogen And Phosphorus ◽  
Coastal Lake ◽  
Before And After ◽  
High Concentrations

Inorganic nitrogen and phosphorus were applied weekly during the growing season from 1980 to 1982 and twice weekly in 1983 to Hobiton Lake, a warm monomictic coastal lake in British Columbia. The lake was not fertilized in 1984. Average numbers of bacteria during the growing season decreased from a high of 1.53 × 106∙mL−1 in the fertilized condition to 0.84 × 106∙mL−1 in the unfertilized condition. Chlorophyll a concentrations decreased from a maximum seasonal average of 2.69 μg∙L−1 (1981) to 1.30 μg∙L−1 (1984), and algal numbers decreased from 5.83 × 104∙mL−1 (1983) to 2.29 × 104∙mL−1 (1984). Although the numbers of phytoplankton in each size fraction (picoplankton, nanoplankton, or microplankton) decreased in the unfertilized condition, the greatest change was an almost fourfold decrease in picoplankton, which consisted of 90% cyanobacteria (primarily Synechococcus spp.). Abundance of the large diatoms Rhizosolenia spp. and Melosira spp. increased in 1984, resulting in an increase in average seasonal algal volume. Average densities of medium (0.15–0.84 mm) and large (0.85–1.5 mm) zooplankton were greatest in 1982, while rotifers and small zooplankton (0.10–0.14 mm) were most dense in 1984 following nutrient reduction. The lake had relatively high concentrations of planktivorous juvenile sockeye salmon (Oncorhynchus nerka) that appeared to minimize any direct effect of nutrient additions on zooplankton densities.

scholarly journals Nitrogen and Phosphorus Uptake Dynamics in Tropical Cerrado Woodland Streams

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1080 ◽  
Author(s):  
Nícolas Reinaldo Finkler ◽  
Flavia Tromboni ◽  
Iola Boëchat ◽  
Björn Gücker ◽  
Davi Gasparini Fernandes Cunha
Keyword(s):  
Nutrient Uptake ◽  
N Uptake ◽  
Pollution Abatement ◽  
Phosphorus Uptake ◽  
Soluble Reactive Phosphorus ◽  
Nitrogen Retention ◽  
Water Velocity ◽  
Nutrient Concentrations ◽  
Nitrogen And Phosphorus ◽  
Lotic Ecosystem

Pollution abatement through phosphorus and nitrogen retention is a key ecosystem service provided by streams. Human activities have been changing in-stream nutrient concentrations, thereby altering lotic ecosystem functioning, especially in developing countries. We estimated nutrient uptake metrics (ambient uptake length, areal uptake rate, and uptake velocity) for nitrate (NO3–N), ammonium (NH4–N), and soluble reactive phosphorus (SRP) in four tropical Cerrado headwater streams during 2017, through whole-stream nutrient addition experiments. According to multiple regression models, ambient SRP concentration was an important explanatory variable of nutrient uptake. Further, best models included ambient NO3–N and water velocity (for NO3–N uptake metrics), dissolved oxygen (DO) and canopy cover (for NH4–N); and DO, discharge, water velocity, and temperature (for SRP). The best kinetic models describing nutrient uptake were efficiency-loss (R2 from 0.47–0.88) and first-order models (R2 from 0.60–0.85). NO3–N, NH4–N, and SRP uptake in these streams seemed coupled as a result of complex interactions of biotic P limitation, abiotic P cycling processes, and the preferential uptake of NH4–N among N-forms. Global change effects on these tropical streams, such as temperature increase and nutrient enrichment due to urban and agricultural expansion, may have adverse and partially unpredictable impacts on whole-stream nutrient processing.

Frost hardiness and winter photosynthesis of Thujapiicata and Pseudotsugamenzlesll seedlings grown at three rates of nitrogen and phosphorus supply

1995 ◽  
Vol 25 (1) ◽  
pp. 18-28 ◽  
Author(s):  
B.J. Hawkins ◽  
M. Davradou ◽  
D. Pier ◽  
R. Shortt
Keyword(s):  
Net Photosynthesis ◽  
Douglas Fir ◽  
Frost Hardiness ◽  
Nutrient Concentrations ◽  
Nitrogen And Phosphorus ◽  
Red Cedar ◽  
Air Temperatures ◽  
Foliar Nutrient ◽  
One Year ◽  
P Supply

One-year-old seedlings of western red cedar (Thujapiicata Donn ex D.Don) and Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were grown for one season in five nutrient treatments with nitrogen (N) supplied in solution at rates of 20, 100, or 250 mg•L−1 and phosphorus (P) supplied at rates of 4, 20, or 60 mg•L−1. Growth, onset of dormancy, frost hardiness on six dates, and foliar nutrient concentrations in autumn and spring were measured. Midwinter rates of net photosynthesis and transpiration were measured at air temperatures of 4, 7, and 11 °C in seedlings from all nutrient treatments. Recovery of net photosynthesis and transpiration in whole seedlings from the three N treatments was assessed at intervals for 28 days after the seedlings were frozen to −5, −15, and −25°C. Foliar N content differed significantly among nutrient treatments and was positively correlated with supply. Mitotic activity ceased earliest in plants with low N supply. Douglas-fir seedlings in the low-N treatment also ceased height growth earliest. These differences in growth had no significant correlation with frost hardiness. No consistent differences in frost hardiness among nutrient treatments were observed. Higher rates of N and P supply resulted in higher rates of winter net photosynthesis. Net photosynthesis was reduced dramatically by night frost, with greater damage occurring at lower temperatures. Net photosynthesis recovery occurred most quickly in seedlings with the midrate of N and P supply.

scholarly journals Effects of repeated phosphorus fertilisation on field crops in Finland 2.Sufficient phosphorus application rates on silty and sandy soils

2008 ◽  
Vol 15 (4) ◽  
pp. 423 ◽  
Author(s):  
I. SAARELA ◽  
H. HUHTA ◽  
P. VIRKAJÄRVI
Keyword(s):  
Relative Yield ◽  
Sandy Soils ◽  
Application Rate ◽  
Application Rates ◽  
P Application ◽  
The Mean ◽  
Yield Responses ◽  
Phosphorus Application ◽  
Phosphorus Fertilisation ◽  
Annual Application

In order to update fertilisation recommendations for Finnish silty and sandy soils, the effects of repeated phosphorus (P) fertilisation on the yields of cereals, grasses and other crops were measured at ten sites for 9 to 18 years. Results of some earlier studies were also used in examining the relationships of the yield responses to applied P and to the soil test values measured by the Finnish ammonium acetate method (PAc). Significant effects of P fertilisation were observed at all sites that had low or medium PAc values; in the case of potatoes, even at sites with fairly high values. The mean relative yield without applied P divided by yield with 60 or 45 kg P ha-1 of the ten sites was 81% (mean PAc 11.6 mg dm-3) varying from 55% at the PAc value of 4.7 mg dm-3 to 100% at the highest PAc values. In order to achieve a relative yield of 97%, which is considered the optimum for cereals and leys, the required mean annual application of P in the later parts of the experiments was 25 kg ha-1 (variation 0-42 kg ha-1). On the six soils that had low or medium PAc values (4.5-9.1 mg dm-3, mean 8.0 mg dm-3), relative yield was 97% at the P application rate of 35 kg ha-1 (variation 22-42 kg ha-1), while 11 kg P ha-1 (variation 0-25 kg ha-1) sufficed on the four soils that had higher PAc values (mean 20.8 mg dm-3, variation 11.7-35.2 mg dm-3). Reasons for the poor availability of P in silty and sandy soils were discussed.;

Characteristics of Arboreal Marsupial Habitat in the Semi-Arid Woodlands of Northern Queensland.

1996 ◽  
Vol 23 (2) ◽  
pp. 185 ◽  
Author(s):  
SA Munks ◽  
R Corkrey ◽  
WJ Foley
Keyword(s):  
Water Concentration ◽  
Basal Area ◽  
Faecal Pellet ◽  
Nutrient Concentrations ◽  
Brushtail Possum ◽  
Phascolarctos Cinereus ◽  
Foliar Nutrient ◽  
Foliar Nutrient Concentrations ◽  
Arboreal Habitat ◽  
Semi Arid

The distribution of the koala (Phascolarctos cinereus) and the common brushtail possum (Trichosurus vulpecula) within the Prairie-Torrens Creek Alluvials province of the Desert Upland region of north-western Queensland was examined. The optimum habitat for each species as indicated by the occurrence of faecal pellet groups was found to be that associated with creek-lines. However, other land types were also used by each species to varying degrees. The relationship between various habitat variables and pellet group counts was investigated using Multiple regression and a Generalised linear model. Proximity to creek-bed, total basal area of trees, species richness and Acacia basal area (negative) best explained the occurrence of koalas. Proximity to creek-bed, Acacia basal area (negative), total basal area of trees, and available water (negative) best explained the occurrence of brushtail possums. In contrast to studies of arboreal species in the moist-south-eastern forests of Australia no relationship was found between foliar nutrient concentrations and the occurrence of koalas or brushtail possums. However, a significant relationship was found between leaf water concentration and the occurrence of koalas. It is suggested that water availability is the paramount factor defining preferred arboreal habitat in arid and semi-arid woodlands.

Long term nitrogen and phosphorus application to veld

1984 ◽  
Vol 1 (2) ◽  
pp. 27-32 ◽  
Author(s):  
C.H. Donaldson ◽  
G. Rootman ◽  
D. Grossman
Keyword(s):  
Nitrogen And Phosphorus ◽  
Phosphorus Application
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