Phosphate response of mixed swards, at Mt. Cotton, south-eastern Queensland

1970 ◽  
Vol 10 (45) ◽  
pp. 431 ◽  
Author(s):  
CG Blunt ◽  
LR Humphreys
Keyword(s):  
Podzolic Soil ◽  
Nitrogen Concentration ◽  
Competitive Interactions ◽  
Phosphorus Concentration ◽  
Dihydrogen Phosphate ◽  
Nitrogen Response ◽  
Nitrogen Yield ◽  
South Eastern ◽  
Cotton South ◽  
Phosphate Response

Five levels of calcium dihydrogen phosphate were applied on a red-yellow podzolic soil to plots either unsown or sown to Kazungula setaria together with greenleaf desmodium, lotonis, stylo, or siratro. First season pasture yields varied from 2000 to 7400 lb an acre. Volunteer species and lotononis swards reached maximum yields at lower phosphate levels than the remaining legumes, which continued to respond at 80 lb P an acre. Maximum setaria yield occurred at 40 lb P an acre. Increasing phosphate level reduced nitrogen concentration of non-legumes, increased phosphorus concentration of all species, and substantially increased nitrogen yield of legumes (1.0-1.9 lb nitrogen response per lb P applied). Seasonal yield patterns and competitive interactions are discussed.

Effects of nitrogen and lime on growth of Leucaena leucocephala cv. Cunningham on a red-yellow podzolic soil in south-eastern Queensland

1986 ◽  
Vol 26 (1) ◽  
pp. 23 ◽  
Author(s):  
S Sivasupiramaniam ◽  
R Akkasaeng ◽  
HM Shelton
Keyword(s):  
Podzolic Soil ◽  
Nitrogen Concentration ◽  
Dry Weight ◽  
Maximum Growth ◽  
Field Application ◽  
South Eastern ◽  
Shoot Dry Weight ◽  
Application Rates ◽  
Lime Application ◽  
Low Nitrogen

Field and glasshouse experiments were conducted on an acidic red-yellow podzolic soil of low nitrogen status from south-eastern Queensland to examine the use of nitrogen and lime in promoting leucaena growth. In the field, application of 25 kg nitrogen ha-l at planting increased shoot dry weight by 77, 88, 52 and 51% at weeks 5, 15, 32 and 52 respectively. Equivalent responses to lime (2.5 t ha-1) were 8, 3 1, 64 and 74% respectively. In the glasshouse, shoot, root and nodule dry weights were increased by nitrogen application rates of 50, 100 and 200 kg ha-1. Number, size and dry weight of nodules were suppressed at the highest rate (400 kg ha-1). Nitrogen concentration in youngest fully expanded leaves was increased to over 5% by nitrogen, and a critical nitrogen content of 4.5% (90% of maximum growth) is suggested. Inexplicably, lime application reduced shoot, root and nodule weights at high nitrogen applications. The apparent partial effectiveness of commercial leucaena Rhizobium and the implications of starter nitrogen and lime for leucaena establishment are discussed.

Influence of time and level of urea application on seed production of Paspalum plicatulum at Mt. Cotton, south-eastern Queensland

1973 ◽  
Vol 13 (62) ◽  
pp. 275 ◽  
Author(s):  
PA Chadhokar ◽  
LR Humphreys
Keyword(s):  
Podzolic Soil ◽  
Nitrogen Concentration ◽  
Seed Viability ◽  
Moisture Stress ◽  
Early Summer ◽  
Nitrogen Supply ◽  
Floral Initiation ◽  
Plant Nitrogen ◽  
Cotton South ◽  
Tiller Density

Five levels of urea were applied as single or split dressings in early summer, at floral initiation (about Febraury 14), or at inflorescence exsertion to Paspalum plicatulum cv. Rodds Bay grown in rows on a red-yellow podzolic soil. All components of seed yield-tiller density, tiller fertility, raceme number and seed number, and seed size-were influenced by external nitrogen supply. The effects of adequate nitrogen supply during one development phase usually persisted subsequently when differences in plant nitrogen concentration had disappeared. Nitrogen applications during the vegetative and floral initiation stages were most influential. The efficiency of response varied from 5.6 kg additional crude seed produced per kg N at the 50 kg N ha-1 level to 1.2 at the 400 kg N ha -1 level. High levels of urea (200 or 400 kg N ha-1) induced lodging and poor recovery of seed at harvest during a wet year, accentuated moisture stress during a dry year, but improved seed viability.

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.

Alley cropping kenaf (Hibiscus cannabinus) with leucaena (Leucaena leucocephala) in south-eastern Queensland

1988 ◽  
Vol 28 (4) ◽  
pp. 481 ◽  
Author(s):  
RC Gutteridge
Keyword(s):  
Leucaena Leucocephala ◽  
Alley Cropping ◽  
Phosphorus Deficiency ◽  
Hibiscus Cannabinus ◽  
Row Spacing ◽  
Lower Yield ◽  
South Eastern ◽  
Fresh Material ◽  
Cotton South ◽  
Cutting Height

Kenaf (Hibiscus cannabinus) was intercropped for 3 seasons between hedgerows of leucaena (Leucaena leucocephala) spaced 3 or 5 m apart on an infertile soil at Mt Cotton, south-eastern Queensland. The leucaena was cut at a height of25 or 50 cm, 2 or 4 times per season and the fresh material spread as a mulch between the rows of kenaf. The yield of kenaf from mulched plots was compared with that from plots fertilised with nitrogen as urea at 0, 50 or 100 kg N/ ha.year. In the third season, kenaf yield from the mulched plots was maintained at about 4.7 t DM/ha, whereas that from the control and urea fertilised plots declined by about 30%. However, phosphorus deficiency in the unmulched plots was suspected and this may have contributed to the lower yield. Leucaena row spacing had no significant effect on kenaf yield. Leucaena yield ranged from 2 to 4 t DM/ha per season. Cutting height had no significant effect on leucaena yield, but less frequent pruning gave a higher yield in the second and third seasons. The results confirm the potential of alley cropping to sustain arable crop yield at a moderate level without high inputs of inorganic fertilisers.

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.

Response of chickpea accession to row spacing and plant density on a vertisol on the Darling Downs, south-eastern Queensland. 1. Dry matter production and seed yield

1988 ◽  
Vol 28 (3) ◽  
pp. 367 ◽  
Author(s):  
DF Beech ◽  
GJ Leach
Keyword(s):  
Seed Yield ◽  
Plant Density ◽  
Nitrogen Concentration ◽  
Yield Potential ◽  
Row Spacing ◽  
Moisture Regime ◽  
South Eastern ◽  
Eastern Australia ◽  
Market Opportunities ◽  
Average Water

Six accessions of chickpea (Cicer arietinum L.), representing both desi and kabuli types, were grown at a range of row spacings (180-710 mm) in 3 experiments on a vertisol at Dalby, south-eastern Queensland to assess their adaptation and yield potential. Row spacing and sowing density (28-1 12 seeds m-2) were confounded in 2 experiments where intra-row density was constant, but were varied independently in the third. Differences in yield between accessions were either small or not significant in 1979, with above-average water availability (mean seed yield: 253 g m-2), and in 1980, when water was severely limited (mean seed yield: 79 and 120 g m-2 in the 2 experiments). However, the proportion of seed that was machine-harvestable was highest in the commercial cv. Tyson (71%), and also at the closest row spacing (83%). Seed nitrogen concentration was about 0.5% higher in cv. Tyson than in other accessions. It declined with an increase in row spacing and was associated with a higher proportion of small seeds. We conclude that there will be scope for alternatives to cv. Tyson as new market opportunities develop. Furthermore, the flexibility in its growth pattern makes chickpea well suited to the variable moisture regime of the wheatlands of subtropical eastern Australia.

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.

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