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subsurface acidity

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Catalogue: GRDC Updates
The practice has corrected surface acidity but values of subsurface (typically 10-20 cm) pHCa< 4.5 are now common, leading to development of an acid throttle, sandwiched between the limed surface and the naturally neutral or alkaline subsoil... On the basis of three experiments in 2007, where we injected lime into acid (pHCa 4.0 - 4.3) subsurface layers, apparently not much... The uniformity of the effect of lime injection was measured at Milvale and found to be uneven across the rip-lines, with an increase of pHCa from 4.3 to >6 in the rip lines, but little change between the rips...
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Catalogue: Ground Cover
Grower groups band together on acidity.. Factors being considered include which lime products to use, freight costs, application rates, whether to incorporate lime, how to best incorporate lime, lime quality (including neutralising value and particle distribution), effects on nutrient availability and subsequent fertiliser costs, labour costs and machinery costs... The Liebe Group is assessing the effectiveness of lime sand, dolomite, liquid lime and granular lime used in combination with different incorporation methods (including mouldboard ploughing, spading, deep ripping, grizzly discs and offset discs)...
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Catalogue: Ground Cover
Grower groups band together on acidity.. Factors being considered include which lime products to use, freight costs, application rates, whether to incorporate lime, how to best incorporate lime, lime quality (including neutralising value and particle distribution), effects on nutrient availability and subsequent fertiliser costs, labour costs and machinery costs... The Liebe Group is assessing the effectiveness of lime sand, dolomite, liquid lime and granular lime used in combination with different incorporation methods (including mouldboard ploughing, spading, deep ripping, grizzly discs and offset discs)...
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Catalogue: GRDC Final Reports
The cost of soil acidity to agriculture is recognised as being great, especially in Western Australia where the most recent analysis estimates 30% of dryland agricultural soils have subsurface acidity - or are at high risk of developing subsurface acidity - which causes a decline in wheat yield of between 20 and 40% (GRDC Project UWA00081)... The most recent analysis estimates that 30% or 5-6 million hectares of dryland agricultural soils have subsurface acidity or are at high risk of developing subsurface acidity which causes a decline in wheat yield of between 20 and 40% (GRDC Project UWA00081)... The experience and machinery developed as a result of this work is currently being passed on and used by the SIP08 project UWA00081 and will be used where applicable by Wal Anderson's new GRDC project 'Enhancing paddock profitability - a collaborative diagnostic approach to cropping systems research'...
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Catalogue: GRDC Media
Subsurface acidity is a major constraint to crop and pasture productivity across Western Australia's grainbelt and is estimated to erode potential crop yields by 9 to 12 per cent, worth $500 million annually... About 14.25 million hectares of WA grainbelt soils are acidic or at risk of becoming acidic to the point of restricting crop yields, and lime use has increased in recent years to address acidic soils with low pH levels... Region West < Keep browsing 0 Responses to New resource delves into soil acidity and lime..
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Catalogue: Ground Cover
The reliability and economics of deep-ripping with lime incorporation are being studied by the West Midlands Group... Long-term WA research has consistently shown that lime most effectively arrests subsurface acidity (low pH) and lifts crop yields when applied to a depth of at least 30 centimetres and strictly adheres to soil test data... Mechanically incorporating lime deeper into the soil profile will dissolve the lime more rapidly when it contacts the acid soil layer "Larger slots behind the deep-ripping tynes will hold the slot open for longer and deliberately direct the flow of loose limed topsoil into the slot," he says...
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Catalogue: GRDC Updates (West)
Mention of a trade name or company in this publication does not imply endorsement of any product or company by the Department of Agriculture... I was educated by a group of farmers at Varley in 1982, to the importance of Crop Updates is a partnership between the Department of Agriculture, Western Australia and the Grains Research & Development Corporation 22.. Advisers and consultants should highlight the management options available to their clients, do sensitivity analyses which in effect, tell the client 'what happens to production, quality and profitability, if he chooses a certain management option ' and show how that changes with input levels, season, soil type, prices going up/down, etc...
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Catalogue: GRDC Final Reports
pH measurements taken from wet and dry soils can vary if we measure the pH in water because the soil has a "background" salt concentration... To minimise the effect of salt concentration in soil on pH values, pH is now measured in 0.01 molar calcium chloride... As soil testing for phosphorus was originally conducted on the top 10 cm of soil, so the soil pH was only measured for the top 10 cm...
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Catalogue: Ground Cover
Frequent application of lime is the only practical method of managing soil acidity By Chris Gazey, Department of Agriculture and Food, Western Australia, Northam, WA, and Dr Stephen Carr, general manager, Precision SoilTech, WA Understanding pH down the soil profile is critical, and bringing soil pH into the optimal range in the top 10 centimetres can be achieved quite easily by surface applications of lime... Lime (alkalinity) is then available to move down the soil profile and lift the subsurface pH. We have observed the soil pH of un-limed plots decreasing by as much as 0.5 pH units to a depth of 30cm over eight years... Long-term Department of Agriculture and Food, Western Australia (DAFWA) lime trials indicate that the old recommendation of 1t/ha every 10 years is too low and many soils that have been limed in the past are continuing to acidify...
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