Soil properties influencing growth of subterranean clover in the Coleambally Irrigation Area, NSW

1966 ◽  
Vol 6 (22) ◽  
pp. 283 ◽  
Author(s):  
J Loveday ◽  
DS McIntyre

The significance of physical soil factors in controlling the growth of subterranean clover under irrigation was assessed in a field experiment involving small plots scattered over a range of soils. Nutrient differences were reduced by a complete fertilizer dressing, so that as far as possible vegetative growth was controlled only by moisture supply and soil aeration under two watering treatments, one approximating the normal regional practice and the other a more frequent watering. Yield was increased by the latter and variation between sites due to soil differences was reduced. Spring yields from the plots watered at the normal regional level were significantly correlated with water increments at irrigation but not with available water capacity. Fifteen other soil properties showed significant simple correlations with spring yield and in multiple regression relationships a high proportion of yield variation could be accounted for in terms of the variation in selected properties. The best pair of variables for yield prediction, accounting for 59 per cent of variability, were per cent exchangeable sodium at 1-4 inches, and aggregate density at 1-4 inches. These variables were highly correlated with water increment at irrigation. On the more frequently watered plots, waterlogging induced in late winter depressed yield slightly and this, apparently, was not caused by poor aeration, but possibly by leaching of nutrients. Oxygen diffusion rates measured one day after irrigation were negatively correlated with yield. Spring yields from these plots were unrelated to total and air-filled porosity and air permeability. The evidence again pointed to moisture supply being responsible for the yield variation between sites.

Soil Research ◽  
1966 ◽  
Vol 4 (1) ◽  
pp. 55 ◽  
Author(s):  
J Loveday ◽  
DR Scotter

Using small plots set in the earthen floor of an open glasshouse, the emergence response of subterranean clover to dissolved gypsum has been determined on 10 soils covering a range of clay and exchangeable sodium levels. The response on a loam soil of low exchangeable sodium percentage (E.S.P.) has been examined at three times of differing evaporative potential. For loams and clay loams, the appearance of a response depends on the severity of evaporative conditions as well as on the E.S.P. On clay soils not naturally self mulching, some response is probably always obtained but, in general, the higher the clay content and the higher the E.S.P. and evaporative potential, the more likely is an emergence response to dissolved gypsum. Emergence was found to be highly correlated with the matric potential of the surface 1/2 in. at the time emergence began. From a consideration of the relationships between emergence and moisture status, the most significant effect of the gypsum treatment seems to be the delay of several days it causes in the air drying of the surface soil, probably because of improved transmission of moisture from beneath. Parallel effects on surface soil temperature to those on moisture can be explained in terms of differences in amount of evaporative cooling. Relationships found between emergence and emergence response to gypsum on the one hand and clay content and E.S.P. on the other are presumably a reflection of the relationship of these soil properties to porosity and moisture transmission.


Nematology ◽  
2019 ◽  
Vol 21 (5) ◽  
pp. 445-457 ◽  
Author(s):  
Arjun Upadhaya ◽  
Guiping Yan ◽  
Julie Pasche ◽  
Audrey Kalil

Summary Plant-parasitic nematodes restrict crop growth and cause yield loss in field pea (dry edible pea). A 4-year survey of commercial pea fields was conducted in North Dakota, one of the leading producers of field pea in the USA, to investigate nematode distribution, prevalence, abundance and association with soil properties. Beginning in 2014, a total of 243 soil samples were collected from 16 counties, and soil properties of 115 samples were analysed to determine the association of nematodes with soil factors (texture, organic matter, nutrients). The plant-parasitic nematode genera, Paratylenchus (absolute frequency = 58-100%; mean density = 470-1550 (200 g soil)−1; greatest density = 7114 (200 g soil)−1) and Tylenchorhynchus (30-80%; 61-261; 1980, respectively), were the most frequent and widely distributed. Pratylenchus and Helicotylenchus were identified in one-third of the counties surveyed with mean densities ranging from 43 to 224 and 36 to 206 (200 g soil)−1, respectively. Xiphinema was found relatively frequently but at low densities. Hoplolaimus and Paratrichodorus were rarely detected at lower densities. Canonical correspondence analysis revealed that soil factors explained 19% of the total variance of nematode genera abundance. The relationship between nematode abundance and soil sand content and pH was significant, while clay, silt, organic matter and nutrients were not significantly related to nematode abundance. This is the first multi-year study investigating nematodes associated with field peas and their relationship with soil factors in a major field pea production region of the USA.


1992 ◽  
Vol 6 (3) ◽  
pp. 583-586 ◽  
Author(s):  
John S. Wilson ◽  
Chester L. Foy

The soil organic matter and/or humic matter fraction was highly correlated with the adsorption of ICIA-0051 herbicide onto five soils; clay content and other soil factors were less correlated. The Freundlich equation was used to describe the adsorption of ICIA-0051 by the various soils. Based on the K constants, the general order for adsorption for each soil was Hyde silty clay loam > Frederick silt loam > Davidson clay = Bojac sandy loam > Appling loamy sand. Across all soils, 25 to 50% of the amount adsorbed was removed by two desorptions. Appling, Bojac, and Davidson soils retained less herbicide after two desorptions than did Frederick and Hyde.


1985 ◽  
Vol 25 (4) ◽  
pp. 758 ◽  
Author(s):  
DG Hall ◽  
EC Wolfe ◽  
BR Cullis

Pasture production, ewe and lamb growth, ewe wool production and diet quality were studied on lucerne-subterranean clover pastures at Wagga Wagga, New South Wales. Lucerne was sown at rates of 0.75 to 3.0 kg/ha, and the pastures were rotationally grazed with Border Leicester x Merino ewes at 9.6 or 12.7 sheep/ha, the ewes lambing in August- September. Lucerne density declined by 45% over the 3 years on all treatments. The clover cultivar sown, Woogenellup, had low persistence, particularly at 12.7 sheep/ha. The density of lucerne had little effect on annual wool and lamb production, although the ewes grew faster on the denser lucerne in summer and the sparser lucerne in winter. At 12- 7 sheep/ha, there was an extra 19% total lamb weight by the end of November and an extra 22% of finer wool (1 �m) annually, but the fleeces had a higher proportion of wool tenderness. The major limitations of the lucerne-subterranean clover pastures to sheep production were the low quality of the diet in early summer, and low pasture production in late winter. In early summer the lucerne was rapidly consumed, leaving only moderate quality clover and grass residues, which limited lamb growth, while in winter pregnancy toxaemia occurred, fleeces were tender and wool growth was low, particularly during a drought in 1976.


1987 ◽  
Vol 17 (12) ◽  
pp. 1565-1571 ◽  
Author(s):  
R. D. Kabzems ◽  
K. Klinka

Relationships between soil properties, understory vegetation, foliar properties, and site index were examined in some Douglas-fir ecosystems on Vancouver Island. Multivariate summaries of variation in understory vegetation and foliar properties were highly correlated with the soil properties (mineralizable N, total N, and exchangeable Ca and Mg) that best characterized soil nutrient regimes of the ecosystems. The increases in soil nutrient availability were correlated with increased foliar N concentrations of the current year foliage. A consistent correlation was found between increased soil nutrient availability (particularly N, Mg, Ca) and decreased foliar Mn and Al. Site index of Douglas-fir was significantly greater on sites with greater quantities of most nutrients (particularly N, Mg, Ca) when sites with equivalent soil moisture regime were compared.


1985 ◽  
Vol 25 (2) ◽  
pp. 455 ◽  
Author(s):  
GR Stirling ◽  
MF Wachtel

In south-eastern South Australia root-knot nematode (Meloidogyne hapla) caused losses to potato crops in fields that were sown once every 5- 15 years and were used for grazing in the intervening years. Although seed used by some growers was infested with M. hapla, the nematode also survived between potato crops on subterranean clover (Trifolium subterraneum), the dominant pasture species, and capeweed (Cryptostemma calendula). Subterranean clover was the most abundant alternate host. Nematodes invaded clover seedlings that established following rain in April and produced eggs about 12 weeks later. A second generation was produced in late winter and spring, so that a relatively high root-knot nematode population was present when potatoes were planted. The population increased rapidly on potatoes and numbers capable of causing severe root damage were observed 10- 15 weeks after planting. The growing of non-host crops, or the use of herbicides or cultivation to eliminate subterranean clover in the winter prior to the potato crop, should be investigated. In a nematicide trial, ethylene dibromide at 70 and 110 kg/ha increased yields of potato cv. Pontiac by about 90%.


1976 ◽  
Vol 27 (1) ◽  
pp. 19 ◽  
Author(s):  
WJR Boyd ◽  
NA Goodchild ◽  
WK Waterhouse ◽  
BB Singh

Variations in the regional means of a number of growing-season climatic variables, and combinations of them, are not highly correlated with the long-term regional distribution of mean wheat yields in Western Australia or with their variation between years. The data suggest that the growing season is characterized by a cyclical alternation of favourable and unfavourable conditions for crop growth. This oscillating pattern varies in amplitude and wavelength as a result of unpredictable 'between'- and 'within'-season variation in the regional distribution of rainfall. In the central zone of the study area, wheat production is subject mainly to between-season variation whilst in more marginal areas yield variation is confounded by opposing and reciprocating within-season effects. The consequences for plant breeding are that specific regional environments expected on the basis of climate do not occur predictably in the short term. It is argued that breeding objectives, selection strategies and regional testing should initially avoid complications associated with specific marginal environments by concentrating on general adaptability within the central zone, which monitors between-season variation only. Subsequent evaluation for additional adaptive features specific to marginal areas should be undertaken.


1994 ◽  
Vol 24 (5) ◽  
pp. 928-933 ◽  
Author(s):  
Joseph P. McFadden ◽  
Neil W. MacDonald ◽  
John A. Witter ◽  
Donald R. Zak

The relationship between fine-textured soil bands and forest productivity was studied by comparing three mixed-oak (Quercusrubra L. and Quercusalba L.) stands that had little or no fine-textured banding with three stands that had bands. The degree to which soil factors could account for differences in productivity between banded and unbanded stands was examined using two methods, one based on field observations (banding codes) and the other based on laboratory textural analysis. Because stand ages were not significantly different, overstory biomass was used as an index of productivity. Mean overstory biomass in the banded stands was 312 Mg/ha, significantly greater than 170 Mg/ha measured in the unbanded stands. Mean percent clay + silt and mean banding code also were significantly higher in banded than in unbanded stands. Linear regression analysis indicated that mean percent clay + silt accounted for 57% of the variation in overstory biomass, whereas mean banding code accounted for 40% of the variation. In the oak stands we studied, variation in productivity can be explained largely by differences in soil texture associated with fine-textured bands. We also found a positive relationship between mean banding code and mean percent clay + silt (r2 = 0.90), which suggests that the field method of quantifying banding can produce values that are highly correlated with soil texture and, by extension, forest productivity.


1999 ◽  
Vol 39 (5) ◽  
pp. 507 ◽  
Author(s):  
A. C. Schlink ◽  
G. Mata ◽  
J. M. Lea ◽  
A. J. M. Ritchie

The associations between fibre growth characteristics and wool staple strength were investigated in groups (n = 10) of Merino wethers with either low or high staple strength. Sheep grazed together on pastures based on subterranean clover and annual rye grass for about 13 months. The sheep were weighed and injected intradermally with [35 S]-cysteine at about 14-day intervals. Mid-side patches were harvested and dye bands placed in the wool at about 28-day intervals. Patch clean wool growth, pasture digestible dry matter/ha and pasture crude protein/ha had similar seasonal amplitudes of production (287, 286 and 267% of respective minimum). These were significantly higher than the seasonal amplitude in liveweight (24.5%). The seasonal amplitude in fibre diameter was significantly greater than that for rate of fibre elongation (71.4 and 41.4% respectively). This seasonality in fibre length and diameter resulted in statistically significant seasonal fluctuations in the ratio of fibre length growth to fibre diameter. Fortnightly variability in fibre diameter was not significantly related to variability in fibre length growth rate between sheep for individual time periods. However, for the pooled data over the experimental period a statistically significant relationship (R2 = 0.13, P<0.01) was improved with the addition of parameters for sampling time and staple strength group. Staple strengths for the low and high staple strength groups were 25.6 and 32.8 N/ktex respectively (P = 0.057). There were no significant differences between the staple strength groups in seasonal change in liveweight, wool production or fibre parameters measured in this study but the low staple strength group had longer fibres. Staple strength was most highly correlated with mid-side fibre diameter coefficient of variation (R2 = 0.50) followed by seasonal amplitude in liveweight.


Sign in / Sign up

Export Citation Format

Share Document