The interaction of nitrogen and phosphorus on the growth, nutrient status and nodulation of Stylosanthes humilis H.B.K. (townsville stylo)

A one-year experiment was done in the field at Katherine, Northern Territory, to determine the influence of defoliation at different times (January, February, and March) and heights (5, 13 and 20 cm) on the growth and development of Townsville stylo (Stylosanthes humilis) in ungrazed swards grown with complete fertilizer and irrigation. Townsville stylo withstood repeated defoliation at 5 cm provided that cutting started in January, but, when the first defoliation was delayed, single cuts at 5 cm in either February or March killed 82 and 53 per cent of the swards. Defoliation to 5 cm early in the season reduced total cumulative yield by less than 450 kg ha-1, and did not affect pod yield or nitrogen and phosphorus concentrations at the end of the growing season. Immediately after defoliation nitrogen and phosphorus concentrations were reduced, but there was rapid recovery to higher levels with 5-cm and the same levels with 13-cm defoliation. Successive defoliation at 4 3 cm in February and March increased yield of pods. Defoliation at both 5 and 13 cm increased relative growth rate compared with the control and less frequently defoliated treatments. Defoliation to 5 cm each four weeks altered the stand morphology to a dense mat of foliage at cutting height. The ability of Townsville stylo to withstand continued defoliation suggests that sustained grazing during the growing season may be successful in controlling grass weeds vulnerable to grazing without greatly reducing pod yield or total dry matter production of Townsville stylo.

Effect of droughting and chilling on maturation and chemical composition of Townsville Stylo (Stylosanthes humilis)

Australian Journal of Agricultural Research ◽

10.1071/ar9710369 ◽

1971 ◽

Vol 22 (3) ◽

pp. 369 ◽

Cited By ~ 2

Author(s):

CT Gates ◽

WT Williams ◽

RD Court

Keyword(s):

Amino Acids ◽

Nutrient Content ◽

Major Effect ◽

Multivariate Techniques ◽

Soluble Nitrogen ◽

Nitrogen And Phosphorus ◽

Protein Nitrogen ◽

Stylosanthes Humilis ◽

Dry Conditions ◽

Townsville Stylo

The effects of droughting and chilling on maturing Townsville stylo plants was assessed in terms of growth, seed and leaf shed, nitrogen, phosphorus, and amino acid composition. The major effect was due to droughting. Temperature participated as a small temperature-droughting interaction, in that cold reduced growth and increased proline under moist, but not under dry conditions. With droughting under warm conditions seed and leaf shed were increased and the nutrient content of seed was raised, which resulted in more of the plant's nitrogen and phosphorus being lost in these fractions. Droughting increased soluble nitrogen at the expense of protein nitrogen, but the amino acids fell as a proportion of the soluble nitrogen. The interrelations of nine amino acids were examined by multivariate techniques and it was shown that proline and aspartic acid behaved atypically, and that while other amino acids fell, proline increased some 10-fold under drought or cold stress. These effects indicate that soluble nitrogenous components may both increase and change in composition in the maturing plant as a result of stress, so rendering the plant more susceptible under field conditions to leaching or breakdown caused by dew or by slight showers of rain.

The effects of superphosphate on the growth and development of Townsville stylo (Stylosanthes humilis) in pure ungrazed swards at Katherine, NT

Australian Journal of Experimental Agriculture ◽

10.1071/ea9700716 ◽

1970 ◽

Vol 10 (47) ◽

pp. 716 ◽

Cited By ~ 8

Author(s):

MJ Fisher

Keyword(s):

Growth And Development ◽

Dry Matter ◽

Maximum Yield ◽

Wet Season ◽

Nitrogen And Phosphorus ◽

Stylosanthes Humilis ◽

Relative Water ◽

Townsville Stylo ◽

Four Levels ◽

Yield Responses

The effects of four levels of superphosphate (0, 112, 224, and 448 lb an acre) on the growth and development of ungrazed Townsville stylo (Stylosanthes humilis) in pure swards were examined on virgin Tippera clay loam at Katherine, N.T. Yields and distribution of dry matter, nitrogen, and phosphorus, leaf area, and growth rate, were measured every two weeks. Leaf relative water content and soil water extraction were measured at the end of the wet season. Yield responses to superphosphate were curvilinear and fitted regressions of the form y = a nx + bx + c at all harvests. Superphosphate encouraged root exploitation of the soil volume, but phosphorus deficient swards were more resistant to drought. The maximum recovery of phosphorus was 20, 14, and 14 per cent respectively when 112, 224, and 448 lb an acre superphosphate was applied. Loss of 31 per cent dry matter, 34 per cent nitrogen, and 44 per cent phosphorus in the eight weeks following maximum yield was concluded to be due to translocation to the root system. Even with 448 lb an acre superphosphate the phosphorus content of standing material was below the the critical percentage quoted in the literature as indicating phosphorus sufficiency.

Performance of Townsville stylo (Stylosanthes humilis) lines in pure swards and with the annual grass (Digitaria ciliaris) under various defoliation treatments at Katherine, N.T

Australian Journal of Experimental Agriculture ◽

10.1071/ea9740495 ◽

1974 ◽

Vol 14 (69) ◽

pp. 495 ◽

Cited By ~ 3

Author(s):

JR Ive ◽

MJ Fisher

Keyword(s):

Dry Matter ◽

Certified Seed ◽

Phosphorus Concentration ◽

Annual Grass ◽

Nitrogen And Phosphorus ◽

Matter Production ◽

Stylosanthes Humilis ◽

Townsville Stylo ◽

Better Than ◽

Late Sowing

Townsville stylo (Stylosanthes humilis) selections collected from twelve naturalized populations, in Queensland and the Northern Territory, and certified seed of the Katherine ecotype ('lines'), were grown for three years in a field experiment at Katherine, N.T. (latitude 14.3�S). In the third year, the experiment was oversown with Digitaria ciliaris. Flowering of all lines was delayed by late sowing, but was hastened by drought. However, the order in which the lines flowered was basically the same for all three years, and similar to that at Lansdown, Queensland (latitude 19.7�S). Although seasonally dependent, highest dry matter production was associated with erect mid- or late mid-season maturity lines which were often lowest in nitrogen and phosphorus concentration. There were no differences between lines in their ability to compete with Digitaria. Grazing reduced the proportion of grass in the swards compared with the forage harvested and non-defoliated treatments largely because Townsville stylo appeared to withstand grazing and trampling better than Digitaria.

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

Australian Journal of Experimental Agriculture ◽

10.1071/ea9700442 ◽

1970 ◽

Vol 10 (45) ◽

pp. 442 ◽

Cited By ~ 2

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.

The influence of water stress on nitrogen and phosphorus uptake and concentrations in Townsville stylo (Stylosanthes humilis)

Australian Journal of Experimental Agriculture ◽

10.1071/ea9800175 ◽

1980 ◽

Vol 20 (103) ◽

pp. 175 ◽

Cited By ~ 15

Author(s):

MJ Fisher

Keyword(s):

Water Stress ◽

Phosphorus Uptake ◽

Phosphorus Concentration ◽

Nitrogen And Phosphorus ◽

Growth Stresses ◽

Stylosanthes Humilis ◽

Influence Of Water ◽

Nitrogen Concentrations ◽

Townsville Stylo ◽

Nitrogen And Phosphorus Uptake

The phosphorus concentrations of Townsville stylo (TS) grown in the Northern Territory are lower than in Queensland, and fall below the requirements of grazing cattle for much of the year. An explanation was sought by measuring N and P in swards subjected to water stress at various times during growth. Stresses during early vegetative (EV), late vegetative (LV) and flowering (F) stages were compared with a well watered control. While nitrogen concentrations were affected little, water stress greatly reduced phosphorus concentrations, the relative effects being EV > LV > F. The EV stress depressed phosphorus concentration to 0.08% compared with 0.20% in the control. Phosphorus level recovered on the relief of stress to the same level as the control. Phosphorus concentration in stems was more sensitive to stress than that in leaves. These results show that if chemical analysis of plants is to be used to indicate the phosphorus status of the soil, the analyses will be unreliable unless the plants have grown without water stress for at least six weeks.

GIS based Soil Nutrient Assessment of Available Macro and Micronutrients in Tommaladahalli Microwatershed of Chikkamagaluru District, Karnataka, India

International Journal of Current Microbiology and Applied Sciences ◽

10.20546/ijcmas.2021.1009.059 ◽

2021 ◽

Vol 10 (9) ◽

pp. 510-517

Author(s):

S. Anitha ◽

K. T. Gurumurthy Ganapathi

Keyword(s):

Interpolation Method ◽

Soil Nutrient ◽

Nutrient Status ◽

Nitrogen And Phosphorus ◽

Available Nitrogen ◽

Entire Study ◽

Available N ◽

Standard Procedures ◽

Entire Study Area ◽

Available Nutrient Status

An investigation was undertaken in Tommaladahalli (566.13 ha) micro-watershed of Tarikere taluk, Chikkamagaluru district of Karnataka to assess available nutrient status in the surface soils. About 118 surface soil samples were collected grid wise by using cadastral map at 250 m grid interval and were analyzed for their fertility status using standard procedures. Soil fertility maps were prepared by means of interpolation method called Krigging. The results revealed that the pH, electrical conductivity, and organic carbon were ranged from 5.37 to 9.06, 0.065 to 0.466 dS m-1 and 0.33 to 1.62 per cent respectively. The available N, P2O5, K2O were ranged from 175.6 to 545.6 kg ha-1, 11.8 to 61.1 kg ha-1 and 122.7 to 491.4 kg ha-1, respectively. The available nitrogen and phosphorus were low to medium, where as potassium content was medium to high in the entire study area. Micronutrients viz. zinc, iron and boron were sufficient and were ranged from 0.34 to 1.17 mg kg-1, 2.03 to 21.86 mg kg-1 and 0.30 to 0.89 mg kg-1 respectively.

The inheritance of flowering time in Townsville stylo (Stylosanthes humilis)

Australian Journal of Agricultural Research ◽

10.1071/ar9760825 ◽

1976 ◽

Vol 27 (6) ◽

pp. 825 ◽

Cited By ~ 7

Author(s):

DF Cameron

Keyword(s):

Flowering Time ◽

Dominant Gene ◽

Diallel Cross ◽

Early Flowering ◽

Multiple Alleles ◽

Locus Model ◽

Stylosanthes Humilis ◽

Townsville Stylo ◽

Maturity Groups ◽

Early Flowering Phenotype

The inheritance of flowering time was studied in F1, F2 and F3 populations derived from a diallel cross among nine naturalized Australian lines of Townsville stylo (Stylosnnthes humilis) and in F1 and F2 populations from a small number of crosses between naturalized Australian lines and introductions from Mexico and Brazil. Strong dominance for lateness of flowering was observed in both the (Australian x Australian) and the (Australian x Mexican/Brazilian introductions) crosses, and some F2 and F3 progenies included small numbers of extremely early plants, flowering up to 55 days earlier than the earliest parent. The flowering time distributions of the (Australian x Australian) crosses could be explained by a three-locus model with multiple alleles at two loci. Proposed genotypes for the four maturity groups are as follows: late, LLM2M2EE; late-midseason, LLmmEE; mid-season, l2l2M2M2EE; early, l1l1M1M1EE; very early, LLM2M2ee. Only one major dominant gene for lateness of flowering could be detected from the distribution of the two (Australian x introduced line) F2 populations, but the segregation of extremely early types and the low recovery of the early-flowering phenotype suggested that other gene loci were segregating.

Effect of time of cessation of wet season grazing on Townsville stylo-annual grass pasture at Katherine, N.T

Australian Journal of Experimental Agriculture ◽

10.1071/ea9730544 ◽

1973 ◽

Vol 13 (64) ◽

pp. 544 ◽

Cited By ~ 1

Author(s):

MJT Norman ◽

LJ Phillips

Keyword(s):

Dry Matter ◽

Recovery Period ◽

Dry Matter Yield ◽

Annual Grass ◽

Wet Season ◽

Active Growth ◽

Heavy Grazing ◽

Stylosanthes Humilis ◽

Dry Conditions ◽

Townsville Stylo

A Townsville stylo (Stylosanthes humilis)-annual grass pasture at Katherine, N.T., was subjected to a series of treatments in 1969-70 and 1970-71 under which plots were grazed heavily from the beginning of the wet season for a period and then allowed to recover undefoliated for the remainder of the season. The dates at which heavy grazing ceased were spaced at 2-week intervals from November 24 to March 16. At the end of the wet season, total dry matter yield was linearly related to length of recovery period. Townsville stylo yield declined as recovery period was reduced from 18 to 8 weeks, but showed little response to a further reduction to 4 weeks. In contrast, annual grass yield showed little change as recovery period was reduced from 18 to 8 weeks, but fell with a further reduction to 4 weeks. As a result, the proportion of Townsville stylo in the pasture at the end of the season was high with long and short recovery periods but reached a minimum with an 8 - 10 week recovery period. Dry conditions prevailed in the first half of both seasons. The evidence suggests that young Townsville stylo is sensitive to heavy grazing when under water stress, and that early grazing for grass control should be imposed only during periods of active growth.

Herbicides for weed control in grain sorghum crops in the Northern Territory

Australian Journal of Experimental Agriculture ◽

10.1071/ea9700588 ◽

1970 ◽

Vol 10 (46) ◽

pp. 588

Author(s):

IMW Wood

Keyword(s):

Good Control ◽

Dry Weight ◽

Grain Sorghum ◽

Northern Territory ◽

Research Station ◽

Wet Season ◽

Grain Yields ◽

Stylosanthes Humilis ◽

Townsville Stylo ◽

Grass Weed

In experiments conducted in the 1968-69 wet season at the Katherine Research Station, Northern Territory, a number of herbicides gave good control of the grass weed Pennisetum polystachyon in grain sorghum crops. Linuron at 3 lb a.i. an acre and PCP at 20 lb a.i. an acre as pre-emergence applications effectively controlled grasses with no apparent adverse affects on the crop. With both there were significantly higher grain yields than on unweeded control plots containing an average of 1378 lb dry weight of P. polystachyon an acre. Fluometuron at 3 lb a.i. an acre late pre-emergence and early post-emergence and chlorthal at 7 lb a.i. an acre pre-emergence controlled grasses but did not increase grain yields. Further investigations are warranted with these herbicides, as banded applications to the interrow may overcome the apparent problem of crop phytotoxicity. Chlorthal at rates that gave good grass control had no adverse effect on Townsville stylo (Stylosanthes humilis). This could be an important advantage when sorghum is sown in rotation with Townsville stylo pasture or where the crop is undersown with Townsville stylo.