Pattern analysis of Australia soil profiles for plant available water capacity

The plant available water capacity (PAWC) was measured for a range of soils (black earths, grey, brown and red clays, krainozems, yellow earths and solodized solonetz/solodics) used for dryland agriculture in the uplands of th,- eastern Darling Downs of Queensland. Using these data, two one-parameter models - one based on the electrical conductivity profile and the other on observable profile features - were derived for estimating the PAWC of the soil profile. The electrical conductivity profile model reliably estimated the PAWC for black earths and grey, brown and red clays. In the case of the deep, black earths, it accounted for 90% of the variation. The observable profile feature model reliably estimated the PAWC for black earths and grey, brown and red clays and in the case of the grey, brown and red clays accounted for 88% of the variation. The models for the solodized solonetz/solodics were not significant. In addition the profile feature model provided estimates of PAWC for the krasnozems (grouped with black earths) and for the yellow earths and solodized solonetz/solodics as a group. An alternative technique for the estimation of PAWC for krasnozems and yellow earths is also presented. The techniques will provide a rapid first appraisal of the PAWC of a soil profile.

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How well do we need to estimate plant-available water capacity to simulate water-limited yield potential?

Agricultural Water Management ◽

10.1016/j.agwat.2018.09.029 ◽

2019 ◽

Vol 212 ◽

pp. 441-447 ◽

Cited By ~ 3

Author(s):

Renye Wu ◽

Roger Lawes ◽

Yvette Oliver ◽

Andrew Fletcher ◽

Chao Chen

Keyword(s):

Yield Potential ◽

Water Capacity ◽

Available Water ◽

Available Water Capacity ◽

Plant Available Water

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PHYSICAL-HYDRICAL ATTRIBUTES AND CO2 EFFLUX FROM THE SOIL AS INDICATORS OF ENVIRONMENTAL SUSTAINABILITY IN PASTORAL SYSTEMS IN THE BRAZILIAN SEMI-ARID

10.22541/au.160828541.15390538/v1 ◽

2020 ◽

Author(s):

Vicente Pinto Simões ◽

Eduardo Souza ◽

Mauricio Luiz Leite ◽

Rodolfo Souza ◽

José Raliuson Silva ◽

...

Keyword(s):

Environmental Sustainability ◽

Livestock Grazing ◽

Co2 Efflux ◽

Arid Environments ◽

Tree Legume ◽

Water Capacity ◽

Available Water ◽

Available Water Capacity ◽

Plant Available Water ◽

Semi Arid

Soil degradation imposes significant environmental and economic impacts on the pastures of drylands worldwide, making livestock grazing systems often unsustainable under the present climate conditions. In this study, we aimed to compare the attributes of the soil of different grazing areas (pastures) using sensitive indicators of changes in the management of these areas, such as the physical-hydric properties and the CO efflux (ECO) from the soil. The study was carried out in three areas of exclosure grazing, understood by three land uses: a pasture of sabi grass (LU1), a silvopastoral system with sabi grass and tree legume (LU2), and an area with sabi grass and a herbaceous native legume (LU3). The measurements were undertaken over nine months and then grouped into three seasons (dry, transition, and rainy). The ECO and the ten indicators of soil physical-hydric quality were measured: macroporosity, aeration capacity, plant-available water capacity (PAWC), relative field capacity (RFC), characteristic pore radius, quantity of hydraulically active pores, sorptivity, saturated hydraulic conductivity, soil density, and soil resistance to penetration. The soils in the LU1 and LU3 areas showed limited plant available water capacity (0.10 PAWC < 0.15 cm cm) and was soil water-limited (RFC < 0.6). The advantages of using silvopastoral systems in semi-arid environments for environmental sustainability are not limited to improvements in the properties of soils, as these areas are also important carbon sinks.

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In a native pasture, landscape properties influence soil moisture more than grazing management

Animal Production Science ◽

10.1071/an16154 ◽

2017 ◽

Vol 57 (9) ◽

pp. 1799 ◽

Cited By ~ 5

Author(s):

D. C. Mitchell ◽

W. B. Badgery ◽

P. Cranney ◽

K. Broadfoot ◽

S. Priest ◽

...

Keyword(s):

Soil Moisture ◽

Soil Water ◽

Grazing Management ◽

Near Surface ◽

Water Capacity ◽

Available Water ◽

Available Water Capacity ◽

High Production ◽

Plant Available Water ◽

Production Zone

It has been proposed that changes to grazing systems, from continuous to rotational grazing, alter the pasture mass and composition, which are reflected in changes to stored soil water. Additionally, in highly variable landscapes, determining whether the variation in soil water is due to the inherent landscape properties rather than the imposed grazing management has long been a contentious argument. To address this question, soil moisture was measured across a highly variable landscape under three differing grazing treatments (1-, 4- and 20-paddock systems). From the soil-water measurements, plant-available water and plant-available water capacity were determined. Different production zones (high, medium and low) were identified in the landscape by visually estimating green herbage mass in late spring. There were no observed differences in the measured plant-available water capacity across the grazing treatments; however, significant differences occurred in plant-available water capacity across the three production zones (high-production zone, 114 mm; medium-production zone, 102 mm; low-production zone, 88 mm) within the study period. There appears to be a trend between the plant-available water capacity and near-surface gravel content as measured in production zones. The high production zones held more plant-available water than did the low production zones, enabling more biomass and longer pasture growth during spring and autumn. The plant-available water in the low production zones significantly decreased with time. In all, 22 of the 50 soil-moisture monitoring locations displayed high temporal stability and were identified as being catchment-average soil water-content monitoring locations. A majority of these locations occurred in the medium production zone, demonstrating that representative soil moisture can be measured in these landscapes.

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