Effect of gypsum on vertisols of the Gwydir Valley, New South Wales. 1. Soil properties and wheat growth

1989 ◽  
Vol 29 (1) ◽  
pp. 51 ◽  
Author(s):  
DC McKenzie ◽  
HB So
Keyword(s):  
Soil Properties ◽  
Soil Water ◽  
New South ◽  
New South Wales ◽  
Nitrogen Deficiency ◽  
Crop Productivity ◽  
Plant Response ◽  
Crown Rot ◽  
Soil Water Storage ◽  
South Wales

The effect of gypsum on the properties and crop productivity of 6 contrasting vertisols of the Gwydir Valley, New South Wales was investigated in 1978 and 1979. These soils are often used for dryland wheat production, although crop growth is generally restricted by their structural instability. In 2 of the soils used in our study, the surface aggregates were sodic and dispersive (poor soils), 2 were relatively stable when wetted (good soils), whilst the other 2 soils had surface aggregates that were intermediate in behaviour (intermediate soils). The effects of added gypsum at 4 rates (0, 2.5, 5.0 and 7.5 t ha-1) on soil water profiles, soil properties and the growth of wheat were monitored over a 2 year period. Dryland wheat grain yields were increased by as much as 230% following the application of gypsum. Benefits were most pronounced on clays with sodic topsoils, a high water-holding capacity and adequate nutrition; plant response to gypsum on nearby soils with non-dispersive surfaces was less pronounced. Yield increases were associated with better seedling establishment, greater tiller production, increased grain weight, and lower incidence of 'Crown Rot' disease. Plant response to gypsum was related to improved water penetration into the soil, allowing greater storage of water in the subsoil, rather than loss via evaporation and possibly runoff. Increases as high as 137% in the soil water storage to a depth of 1.2 m were observed. Crop performance was also strongly influenced by rainfall, time of sowing and weed control. Where nitrogen and, to a lesser extent, phosphorus, were deficient in gypsum-treated soil, they had to be added before the extra soil water could be utilised effectively by wheat. On the lighter textured clays, gypsum appeared to aggravate nitrogen deficiency, apparently because of enhanced leaching.

The availability of mineral nitrogen in a wheat soil from southern New South Wales

1962 ◽  
Vol 2 (6) ◽  
pp. 185 ◽  
Author(s):  
RR Storrier
Keyword(s):  
Nitrogen Uptake ◽  
New South ◽  
New South Wales ◽  
Nitrogen Deficiency ◽  
Ammonia Nitrogen ◽  
Mineral Nitrogen ◽  
Wheat Crop ◽  
Wagga Wagga ◽  
Emergence Period ◽  
South Wales

In a red-brown earth soil from Wagga Wagga the fluctuations in the level of mineral nitrogen (ammonia plus nitrate-nitrogen) and its availability to wheat under growing period rainfalls of 6 inches and 16 inches were studied. Ammonia-nitrogen did not exceed 8 lb nitrogen per acre 6 inches but showed statistically significant short term fluctuations. Mineral nitrogen decreased steadily from the 4-5 leaf stage of plant growth, reaching minimum values in the ear-emergence period when a temporary nitrogen deficiency occurred. Following rainfalls of about one inch or more, conditions favoured biological activity and nitrogen was mineralized, absorbed by the crop and/or leached down the profile. In one season a release of mineral nitrogen about two weeks before flowering contributed an estimated 20-30 per cent of the total nitrogen uptake of the crop. Nitrogen uptake by the wheat crop ceased after flowering and subsequent changes in mineral nitrogen level reflect the net result of mineralization and demineralization processes, and nitrogen uptake by weeds, particularly skeleton weed. Absorption of nitrogen from the profile depended upon seasonal conditions, with the surface 18 inches suppling the greater part of the nitrogen absorbed by the crop. This indicates the need to sample regularly to at least a depth of 18 inches, particularly during the period from 4-5 leaf to flowering, when studying the relation between mineral nitrogen and crop growth. The data suggest that the response of wheat, as measured by grain yield and protein content, to the higher levels of mineral nitrogen in the improved soils of southern New South Wales is determined by soil moisture levels, particularly in the post-flowering period.

Effects of continuous and seasonal grazing strategies on the herbage mass, persistence, animal productivity and soil water content of a Sirosa phalaris - subterranean clover pasture, North-West Slopes, New South Wales

2003 ◽  
Vol 43 (6) ◽  
pp. 539 ◽  
Author(s):  
G. M. Lodge ◽  
S. R. Murphy ◽  
S. Harden
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
New South ◽  
New South Wales ◽  
Subterranean Clover ◽  
Animal Production ◽  
North West ◽  
South Wales ◽  
Continuous Grazing

An experimental site was established in 1997 on the North-West Slopes of New South Wales to further investigate the use of strategic grazing management to improve the persistence of phalaris (Phalaris aquatica cv.�Sirosa) and subsequent effects on animal production and soil water content. The pasture was sown in 1992 to Sirosa phalaris, subterranean clover (Trifolium subterraneum var. subterraneum cv. Seaton Park) and lucerne (Medicago sativa cv. Aurora). Four grazing treatments were applied in a randomised 3-replicate design. Treatments consisted of continuous grazing at 12.3 sheep/ha (C12 or control); continuous grazing at 6 sheep/ha (C6), and 2� spring and autumn strategies of either resting from grazing for 6 weeks in each season (SAR0), or reducing stocking rate from 12.3 to 4.0 sheep/ha (SAR4). Despite annual applications of fertiliser and high clover content, Sirosa phalaris herbage mass in plots continuously grazed at 12.3 sheep/ha declined from a mean of 3300 kg DM/ha in spring 1997 to < 700 kg DM/ha by May 1998. At the end of the study (February 2001), Sirosa mean herbage mass in these plots was 670 kg DM/ha and lower (P < 0.05) than for the other treatments (mean value 5400 kg DM/ha). These marked changes in herbage mass, and the degradation of the Sirosa-based pasture to an annual pasture by continuous grazing at 12.3 sheep/ha, were not generally reflected in either short-term animal production or substantial differences in soil water content. Wool production (kg/head) was not significantly different among treatments each year. Compared with continuous grazing at 12.3 sheep/ha, sheep liveweights were higher (P < 0.05) in plots continuously grazed at 6.1 sheep/ha from November 1997 to February 1999. However, from February 1999 to 2001, sheep liveweights in the 2 treatments with the highest Sirosa phalaris content were lower (P < 0.05) than those continuously grazed at 12.3 sheep/ha. Only the soil water content for the C6 and SAR4 treatments at 0–30�cm was significantly different to the control treatment, but the differences were predicted to be < 2.5 mm/year. In the root zone (0–90 cm), mean soil water content ranged from 159 to 309 mm (mean 220 mm), while plant available water (soil water content – soil water content at –1500 kPa) was a mean of 79 mm, ranging from 11 to 168 mm.

Sustainable grazing systems for the Central Tablelands of New South Wales. 4. Soil water dynamics and runoff events for differently-managed pasture types

2006 ◽  
Vol 46 (4) ◽  
pp. 483 ◽  
Author(s):  
J. D. Hughes ◽  
I. J. Packer ◽  
D. L. Michalk ◽  
P. M. Dowling ◽  
W. McG. King ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Soil Water ◽  
New South ◽  
New South Wales ◽  
Ground Cover ◽  
Environmental Data ◽  
Quality Data ◽  
Water Runoff ◽  
South Wales ◽  
Management Factors

Soil water, runoff amount and quality, pasture production and environmental data were measured for a pastoral prime lamb enterprise in the Central Tablelands of New South Wales from 1998 to 2002. There were 4 pasture treatments: fertilised and sown chicory (CH), fertilised and sown introduced pastures (SP), fertilised naturalised pastures (FN) and unfertilised naturalised pastures (UN). Two grazing management regimes, tactically grazed (TG) and continuously grazed (CG) were imposed on the SP, FN and UN treatments. The CH treatment was rotationally grazed. To compare pasture and grazing system water use, maximum soil water deficit values (SWDMax) were calculated from neutron moisture meter data. SWDMax was influenced by both environmental and management factors. Management factors that influenced SWDMax were herbage mass of perennials, degree of perenniality, and the perennial species present. Environmental factors accounted for >50% of the variation in SWDMax. Inclusion of management factors (perennial herbage mass of C3 and C4 species and percentage perennial herbage mass), accounted for an additional 16% of variation. While the influence of pasture management appears to be relatively small, importantly, management is the only avenue available to land managers for influencing SWDMax. The UNTG and all sown treatments, with greater perennial herbage mass or greater C4 herbage mass consistently produced the highest SWDMax. Runoff amount and quality data are presented for ground cover percentages which generally exceeded 80% for the experimental period. Runoff as a proportion of rain received during the experiment was <3%. Environmental factors explained 47% of variation in runoff, while pasture herbage mass and ground cover percentage explained an additional 2% of variation. Water quality was monitored on 3 treatments (SPTG, FNTG and UNCG) for total nitrogen (N), total phosphorus (P) and total suspended solids (TST) over a 6-month period. The mean values for total N and P were below the acceptable contaminant concentration for agricultural irrigation water. An important outcome of this research is the concept of a practical Targeted Water Management Plan (TWMP) which devises a framework for optimum water usage and productivity at a landscape scale.

scholarly journals Digital mapping of soil erodibility for water erosion in New South Wales, Australia

Soil Research ◽  
2018 ◽  
Vol 56 (2) ◽  
pp. 158 ◽  
Author(s):  
Xihua Yang ◽  
Jonathan Gray ◽  
Greg Chapman ◽  
Qinggaozi Zhu ◽  
Mitch Tulau ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Soil Properties ◽  
Soil Loss ◽  
New South ◽  
New South Wales ◽  
Field Measurements ◽  
Soil Erodibility ◽  
South Wales ◽  
Australian Continent ◽  
K Factor

Soil erodibility represents the soil’s response to rainfall and run-off erosivity and is related to soil properties such as organic matter content, texture, structure, permeability and aggregate stability. Soil erodibility is an important factor in soil erosion modelling, such as the Revised Universal Soil Loss Equation (RUSLE), in which it is represented by the soil erodibility factor (K-factor). However, determination of soil erodibility at larger spatial scales is often problematic because of the lack of spatial data on soil properties and field measurements for model validation. Recently, a major national project has resulted in the release of digital soil maps (DSMs) for a wide range of key soil properties over the entire Australian continent at approximately 90-m spatial resolution. In the present study we used the DSMs and New South Wales (NSW) Soil and Land Information System to map and validate soil erodibility for soil depths up to 100 cm. We assessed eight empirical methods or existing maps on erodibility estimation and produced a harmonised high-resolution soil erodibility map for the entire state of NSW with improvements based on studies in NSW. The modelled erodibility values were compared with those from field measurements at soil plots for NSW soils and revealed good agreement. The erodibility map shows similar patterns as that of the parent material lithology classes, but no obvious trend with any single soil property. Most of the modelled erodibility values range from 0.02 to 0.07 t ha h ha–1 MJ–1 mm–1 with a mean (± s.d.) of 0.035 ± 0.007 t ha h ha–1 MJ–1 mm–1. The validated K-factor map was further used along with other RUSLE factors to assess soil loss across NSW for preventing and managing soil erosion.

Effect of gypsum on vertisols of the Gwydir Valley, New South Wales. 2. Ease of tillage

1989 ◽  
Vol 29 (1) ◽  
pp. 63 ◽  
Author(s):  
DC McKenzie ◽  
HB So
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Fuel Consumption ◽  
New South ◽  
New South Wales ◽  
Soil Strength ◽  
South Wales

An experiment was carried out to deter- mine the effect of applied gypsum on the ease of tillage in 3 vertisols of the Gwydir Valley, New South Wales. The soils were classified as 'poor' and 'good' on the basis of past dryland wheat yields and structural of their surface aggregates.Where gypsum had been applied 22 months earlier at a rate of 7.5 t ha-1, tractor fuel consumption per centimetre of soil tilled was reduced by as much as 37% (0.85 v. 0.54 L ha-1 cm-1). The effect was most marked on the more sodic clays. The reduction in fuel consumption due to gypsum was associated with instability creased soil water content (0.127 v. 0.224 kg kg-1) and lower soil strength (330 v. 140 kPa).

Growth and Carbon Partitioning in Rainforest and Eucalypt Forest Species of South Coastal New South Wales, Australia

1992 ◽  
Vol 40 (1) ◽  
pp. 13 ◽  
Author(s):  
DJ Barrett ◽  
JE Ash
Keyword(s):  
Leaf Area ◽  
Plant Biomass ◽  
New South ◽  
New South Wales ◽  
High Irradiance ◽  
Plant Response ◽  
Forest Species ◽  
Eucalypt Forest ◽  
South Wales ◽  
Canopy Species

Rainforest, ecotone and eucalypt forest species were grown for 22 weeks in glasshouse conditions under light, water and nutrient treatments. Plant biomass, leaf area and leaf biomass per plant increased in Eucalyptus sieberi, Eucalyptus fastigata, Pittosporum undulatum, Callicoma serratifolia, Elaeocarpus reticulatus, Backhousia myrtifolia and Ceratopetalum apetalum at high irradiance (1230-1670 μ-mol PAR m-2 s-1). Both E. sieberi and E. fastigata inhabit the relatively high light environments of northern aspects, upper southern aspects and ridge tops in the gully systems of south coastal New South Wales. Callicoma serratifolia, P. undulatum and E reticulatus are pioneer species of the ecotone around rainforest patches, and B. myrtifolia and C. apetalum are rainforest canopy species. Mean plant biomass under high irradiance was ranked: eucalypt species > ecotone species and B. myrtifolia > C. apetalum. At low irradiance (200-530 μ-mol PAR m-2 s-1) the trend observed was reversed where rainforest canopy and ecotone species produced greater plant biomass. Plant response to different water and nutrient treatments under glasshouse conditions showed that, while the light environment primarily governed plant response, interaction between treatments occurred which resulted in maximum plant biomass at relatively high levels of soil moisture and nutrients. Carbon partitioning was used as an indication of relative response to light treatments. The proportion of plant mass partitioned to leaves did not change between experimental treatments. The magnitude of the response of leaf area ratio and specific leaf weight to light treatment, however, was ranked: eucalypt species > ecotone species > rainforest canopy species. This suggested that species naturally growing outside the rainforest canopy maximised leaf area in proportion to plant mass for a given irradiance, presumably to maintain high growth rates.

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