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Frequently Asked Questions   Below are a list of our most frequently asked questions, if you have a different question not listed, you can ask us a question by completing the form below.   Why will Reduced Cultivation succeed now, when it failed in the ‘70’s? Surely the cheapest method of establishment is the one you already have? Any expenditure only benefits the machine manufacturers? How do you control grass weeds such as barren (or sterile) brome and black-grass without a plough? Will Reduced Cultivationing send my slug control bill sky high? What is the long term impact on compaction and natural drainage? Are there any soil types not suited to Reduced Cultivation methods? Should light and heavy soils be managed differently? How effective is Reduced Cultivation equipment at incorporating bulk organic matter products such as sewage sludge cake and paper waste? Can you increase yields from a Reduced Cultivation system? What are the pros and cons of different Reduced Cultivationing drills? Which one is best for me? How do I improve my plough tillage? What´s the situation of No-tillage in UK? How does one maintain soil sustainably? what is bad about not tillng as much how do crop rotations reduce weeds why do you suggest cereals should be drilled at 1.6 inches? what area of the uk is min till at present does limex 70 have a beneficial effect to soil structure when applied even where the Ph is at a cceptable levels Has any research been done on shallow ploughing ie 75-100mm? Can power harrow drills, used in existing plough based systems also be used in good conditions for minimal tillage, for example after light discs or a subsoiler, or will they not work deep enough? what is kuyper marl natural drainage Where can I find a document call a Soil Management Plan? what is sub-soil water movement? natural drainage contribution to improve the sustainability in uk the use of direct drilling and reduced tillage ideal ph for weeds Why does eastern parts of england get soil erosion? how do you control take-all by organic methods cost of installaion of drainage Is minimal tilling appropriate deserts? why do earthworms go on the top of the soil ofter a rainfall? why direct drill not cultivation why is sub-soiling needed in soils with clay pans? Infiltration rates what is fissuring action on discs do what is fissuring How can I treat acid soil? soil infiltration rates for UK what does minimal tillage do? soil management plan# introductuion for reservior tillage what effectdoes a high proportion of rock fragments have on soil consistency? what are the typical levels of lead found in contaminated land? How can animal life help soil structure and texture? What effect does a high proportion of rock fragments have on soil chemistry the advantages and disadvantages of minimum tillage How do I get hold of a " Visual Soil Assessment " Book. How does the cost of min-til compare to the cost of plough and combi drill 1. How effective is minimal tillage at protecting below-ground archaeology? Are there any minimal tillage equipments on farms in Devon or Cornwall? I understand they are expensive. is it true that numers of broad leaved weeds will decrease under a min till programme? Simba Solo the way forward? will farmers be paid to adopt min till under the single farm payment? where can trials data be found regarding weed emergance under min till vs plough systems? why will BLW decrease under min till? CAN NITROGEN PLACEMENT BE JUSTIFIED IN OCTOBER IN AN NVZ WITH DIRECT DRILLING? e.g cross slot Does minimum tillage increase arable diseases through presence of unburied trash? control of onion couch what is the stale seebed tehcnique soil capping, what is it? how can you improve soil conditions what is min till what are the advantages and disadvantages of direct drilling seed? Measuring soil moisture, at different soil depths, relating to compaction caused by cultivation machinery, has anyone charts of this what is sub soil Will direct drilling work on heavy kuyper marl clay? I am concerned that the slots won`t close, seed to soil contact, slugs and water logging will take their toll, thanks What are your thoughts on Biosolids WHAT ARE THE DIFFERENT ADAPTIVE TILLAGE OPERATIONS? Is autocasting considered different to non-inversion tillage? do lime has any other effects than stabilize acidity of the soil? if the soil has ph value about 8.5, can be used lime in this case? how to calculate norms of lime to the soil? what causes soil capping what is reduced cultivation Which is the best way to establish oilseed rape what is beter way mintill or plow how can infiltration rates be measured crop residue - pros and cons slug pellets earthworms How much of the UK is currently direct drilled cost of crop establishment I have been offered some poultry manure, are there any problems in applying it prior to my min till, autumn sown cereal crops? should we keep ploughing? power harrows and soil structure what are the advantges and disadvantges of sandy coarse soil texture what is the effect of soil compaction on soil fauna what is the ph of Cotswold Brash how do yields compare with reduced tillage what is the effect of minimum tillage on soil moisture in loamy sand infiltration referring to no tillage silty soil cultivation define soil texture what is a stale seedbed Using disces to 4 inches i find the straw residue seems to effect the cereal establishment and development, 2 weeks behind in the spring, why is this and is there any data on the different crop straw causing different effects soil management plan reduced tillage in loamy sand Would Direct Drilling Work better in spring? Direct Drilling was popular in Canada when I visited this Spring Where do I get my soil analysised visual soil assessment What causes soil degration why are parts of eastern england affected by soil erosion when it is windy what are possible causes for soil capping What are the advantages of ploughing? what is cotswold brash how does liming improve structure in clay soils why does soil erode cost per acre autocasting osr What does GAEC and ELS stand for? what is an action plan that can be used to repair damage from wind and water errosion? why is top soil useful reaserch on autocasting will a pasture slitter be as effective as subsoiling sandy soils under grass to relieve compaction or are there better tools for loosening these light soils? do i need nitrogen when i am drilling rape What is the aeration like in silty soils when to cultivate silty soil cost of powerharrow drill a ha WHAT IS DEEP-SHALLOW PLOUGH? WHAT DOES DEEP TILLAGE TO 6-8" MEAN? WHAT DOES REDUCED TILLAGE 4-6" (TINE/DISC) MEAN? WHAT IS DIRECT DRILLING? effect of over exploitation on soil profile why is sub-soiling is needed in clay pans factors that determine the planting methods to follow as well as the choice of planting material how does soil structure influence crop growth AUTOCASTING COSTS VERSUS DRILLING Using named examples discribe how soil management in crop production can influence soil stability in the long term effects of capping on plant growth effects of poaching on plant growth what causes soil degration? Minimum tillage generally involves the incorporation of straw: what nutrient values does this provide to the next crop? Apart from wind howelse do farmers lose their soil? what is kuyper marl We have recently installed a new pipeline through arable fields and segregated the topsoil and subsoil. What would be the best form of sub-soil preparation prior to replacing the topsoil? what is a soil pan what is the reservior tillage? how to improve nutrient level in dry soil what are simba solos performances top soil quaility how important? What are the disadvantages of minimum cultivations? what are the advantages and disadvantages of direct drilling? Cost of establishment/ ha on 1000ha arable, traditional tillage vs min tillage what is direct drilling what is the need for lime in horticultural cultivation and cropping capping What are the advantages and disadvantages of ploughing? why is sub-soiling needed in soils with clay pans? why should we add well decayed organic matter and basal fertilizer to the soil before transplanting seedlings or grafted plants of perennial crop species? how well does min till work for organic crop establishment? how soil consistency affect crops what is an aggregate why are parts of eastern england affected by soil erosion when it is very windy cotswold brash tilling properities of cotswold expected yeilds on cotswold land what is current practice of mole ploughing maize yeilds on cotswold soils alittude of the cotswold what is the effect of initial soil clod diameter and liming on the stability of soil aggregate best soil moisture content for cultivating land what is the effect of tillage change on the stability of soil aggregate disadvantage of power harrows advantages of ploughing how to control problem weeds such as Blackgrass, Sterile Brome and Annual meadow Grass in non inversion tillage how does soil erode what is the potash value of chopped wheat straw what are the main Characteristics of cotswald brash advantages of ploughing What is the minimum depth of soil required for cow grass on a roof top? There is underground drainage.   Ask a Question   My Question is:   Why will Reduced Cultivation succeed now, when it failed in the ‘70’s?   We are not talking about direct drilling this time. The system is flexible. We know the risks - grass weeds, herbicide resistance etc. You can still plough. Cultivation technology has improved. · Heavier discs, sometimes in partnership with tines, which do not lead to smearing and panning are available. · Presses are better and more available to ensure that there is good consolidation. · Cultivator drills are available which work well in a range of conditions. Herbicide technology has improved. · Grass weed herbicides for non-cereals crops. · Range of residual and foliage applied herbicides in cereals. · New herbicides in pipeline. Back to top Surely the cheapest method of establishment is the one you already have? Any expenditure only benefits the machine manufacturers?   Yes it might be. If you only have capacity for one system, then what you have might be right. But make sure you know the costs of the current system. You may be able to use it more effectively. · Are all passes justified? · Do you do recreational cultivation? · An extra pass costs money - it is not free just because someone is available. · Is the current system increasing costs elsewhere - need for sub-soiling, loss of crop and nutrients due to erosion. Often investing in larger capacity and reducing numbers of machines can save labour costs, establishment costs and growing costs. May be harder for smaller farms to justify extra expense. Consider sharing with neighbours, or contracting the operation in, or offering your services as a contractor to others. Progressive adoption of the technique is both practical and a way of reducing costs of adopting it - consider cultivator/press first to replace power harrow but to provide seedbed for a variety of drills; then replace drill and finally plough (or consider retaining it for rotational ploughing). Back to top How do you control grass weeds such as barren (or sterile) brome and black-grass without a plough?   The key is to create a programmed approach both prior to drilling and in the crop and to utilise both cultural and chemical control methods; - create a good consolidated stale-seedbed soon after harvest - wait for good weed germination prior to spraying off prior to drilling - drill a good competive crop - apply a pre-em and post-em. herbicide programme. - rotate crops to allow room for stale seedbeds and also use of a variety of herbicides - rotational use of the plough can be useful if there is a high weed seed return in one year. Back to top Will Reduced Cultivationing send my slug control bill sky high?   Again this is a potential risk. The key to minimising this is: · A good straw chop. · Good spread of chaff. · Get a well structured seedbed by working from top down. · Consolidate the stale seedbed. · Remove green material pre-sowing with non-selective herbicide. · Try and make sure drilling is at 4cm (1.6 inches). · Consolidate the seedbed maximise crop emergence and eliminate slug 'motorways' Back to top What is the long term impact on compaction and natural drainage?   Check for and correct existing problems before you start with reduced cultivation. Only sub-soil when needed and ensure depth is correct for problem. The undisturbed soil will begin to develop its own natural structure with pores and cracks through cycles of wetting and drying. Soil fauna will increase and their activity will increase the natural structure and porosity. Incorporation of organic material will help to stabilise the structure and support the soil fauna. Plough pans and smeared surfaces will begin to break up but rotational sub-soiling on less well structured soils or where required is vital. Improved structure and porosity improves natural drainage. Improved drainage reduces soil erosion, ponding and increases the loading strength of the soil. Back to top Are there any soil types not suited to Reduced Cultivation methods? Should light and heavy soils be managed differently?   It should be possible on most soils, but the machinery and management and will be different. Reduced tillage is ideally suited to the well structured (especially clays) soils. ·  Greater choice of suitable equipment may already be available. Benefits from a drill with more cultivation capability which in turn gives flexibility to use more cultivator options. ·  Autumn cropping dominates and autumn cultivation will be the norm, even before spring crops. On less well structured soils (such as silts, sands) more care is required. ·  Correcting soil structure before you start is essential. Monitoring soil structure as you progress is also vital. ·  Lighter wider equipment (discs or tine cultivators) required, also lighter wider presses. Ideally consider a drill which does less cultivation. ·  Before autumn sown crops, autumn cultivation is successful, especially in dry autumns when moisture conservation is important. ·  Leave seedbed coarser. ·  Prior to spring sown crops, spring cultivation is normally best. In a dry spring this conserves moisture over deeper cultivation. Back to top How effective is Reduced Cultivation equipment at incorporating bulk organic matter products such as sewage sludge cake and paper waste?   Growers are successfully incorporating large amounts of organic manure and sewage sludge. You do not need to get rid of the organic matter, just to incorporate it and get good crop establishment. Incorporating less than 8 t/ha of chopped dry wheat straw has not been a problem. Back to top Can you increase yields from a Reduced Cultivation system?   Depends where you are starting from! If you are doing everything right now, possibly not. Advantage may only be to reduce costs. Also remember that if costs are reduced more than yield that overall it will increase profit margin. Aim to reduce costs of production whilst maintaining or increasing yield. Yes there is potential to increase yields. Examples include: · Dry years when moisture conservation increases establishment · Increased crop area being established at the optimum time (see later re weeds as well). If you let grass weeds dominate, then as we all know yields may suffer. This risk increases as years go on and from early drilling. It is very important to balance potential yield increases from early drilling with yield losses from increased grass weeds from early drilling. Also note that in high take all risk situations (such as second, third or fourth wheats) that later drilling will reduce take all and improve yields. Back to top What are the pros and cons of different Reduced Cultivationing drills? Which one is best for me?   Tine cultivator drill: ·  Good on cost and flexibility ·  Does not leave slots ·  Less wear ·  Potentially very accurate depth of drilling control ·  Can handle higher volumes of surface trash. Disc cultivator drill: ·  Minimal soil disturbance and therefore opportunity for further weed germination ·  Most expensive ·  Does not cope as well in wet, can leave slits which favours slugs and can push straw into the slit which leads to poor soil seed contact and hence emergence. Disc direct drill: ·  Traditional direct drill. ·  Cheaper that disc cultivator drill and as good with similar issues. ·  However, no soil movement or consolidation at all so can leave straw in slit giving very anaerobic conditions if wet which kills crops. Can also lead to greater compaction. Normal coulter drill: ·  Unsuitable in presence of a lot of straw or clods. ·  Disc coulters better way into a reduced cultivation system. Back to top How do I improve my plough tillage?   The key is to: 1. avoid cultivating under wet conditions where smearing and compaction will bring run-off, and 2. avoid over-cultivating the soil which leads to slumping, capping, runoff, and wet fields. Reducing the amount of tillage is possible by shallower ploughing if you have a narrower bodied plough, and/or moving away from repeated passes of a power harrow or tine or disc to 1-2 passes with a cultivator press. A coarser consolidated seedbed is useful and not only stabilises the soil but can facilitate a stale seedbed prior to planting. The use of a surface profiling tool like press rings or technique of reservoir tillage can also increase water infiltration and minimise run-off on finer soils prone to capping. Finally you may consider rotational use of the plough combined with some form of conservation tillage practice. Back to top What´s the situation of No-tillage in UK?   No- tillage, more commonly known in the UK as direct drilling, has a place, but is more a niche than mainstream for most growers. It's best fit is on stable soils, with a good crop rotation and minimal grass weeds. However, growers with direct drills will often drill crops like Oilseed rape or first wheat where soil conditions are often suitable and crop residue minimal. Back to top How does one maintain soil sustainably?   Treat your soil with respect: feed it correctly and use tender loving care. So replace organic matter and make cultivation decisions based on the philosophy of 'for this field, for this crop on this day'. Remember not to be afriad of changing the management if conditions change at lunchtime. Build organic matter and biological health of the soil, work with the soil by cultivating/ travelling when conditions are suitable. Abuse will lead to rapid deterioration of soil structure.' Back to top what is bad about not tillng as much   Although reducing the amount of tillage can be beneficial in my case on stable soils, on less stable soils there is more risk of compaction or tightening of the soil. Sands and silts tend to tighten with rainfall and traffic, and shallow cultivations cannot loosen this always alone. So other measure like sub-soiling will be needed. Back to top how do crop rotations reduce weeds   The use of crop rotations help in several ways; 1. Correctly chosen, they can provide more time for stale seedbeds. 2. Allow use of alternative herbicides. and 3. Change the selection pressure on weeds. Unfortunately, the UK focus of autumn planted cereals with less rotation has been a major driver for the development of annual grass weeds. Back to top why do you suggest cereals should be drilled at 1.6 inches?   The primary reason is to do with the management of slugs. Research by IACR at Long Ashton showed that a key aspect of management is accurate drilling of cereals at 4cm (1.5") so as to protect the seed. Combine this with control of green material prior to drilling and consolidation of the seedbed and slug damage is dramatically reduced. Back to top what area of the uk is min till at present   There are no published figures on this, but estimates of 30-35% of the arable area under reduced tillage systems in 2002/3, more on the big farms. Back to top does limex 70 have a beneficial effect to soil structure when applied even where the Ph is at a cceptable levels   Spreading chalk at rates of 50t/ha plus was traditional in many parts of Eastern England in the 19th century and there are some soils which, though naturally acid, still contain 1-2% of calcium carbonate. The objective was to make the soils more easy to cultivate. There is some evidence that excess calcium carbonate may reduce the cohesion between clay particles in moist clods and reduce the size of water-stable crumbs in a soil. Improvement could also be due to a slow stabilisation of structure as the calcium carbonate initially dissolves and is then reprecipitated as films around clay particles. Improvements in soil structure have also been reported following the application of high rates of gypsum. Limex supplies a finely divided source of calcium carbonate and is therefore effective in raising soil pH as it has a large reactive surface area. High rates of application of any form of calcium carbonate would be needed to have a long term effect. Applying high rates of a liming material increases the risk of trace element deficiencies, particularly manganese and boron, and may by raising soil pH also reduce the availability of other nutrients. Back to top Has any research been done on shallow ploughing ie 75-100mm?   We are not aware of any research, and this could be an area for future funding. Most modern wide bodied ploughs cannot plough shallowly, However, new designs are becoming available. Back to top Can power harrow drills, used in existing plough based systems also be used in good conditions for minimal tillage, for example after light discs or a subsoiler, or will they not work deep enough?   Be very careful with power-harrow drills and reduced tillage. Those with Suffolk coulter tines will tend to block with straw and struggle to penetrate consolidated seedbeds and produce poor results on heavier soils. However, careful use with straw removed on loose lighter soils can work as long as the seedbed is consolidated after drilling. However, the best answer, if you want to adapt the current drill is, if possible, to change to disc coulters. The target however, should be use/ purchase of an appropriate cultivator drill or direct drill. Back to top what is kuyper marl   A red clayey geological deposit found in a band from east Nottinghamshire down to SW England. The typical soil type is the Worcester series (see appropriate soil survey publications for more details) Back to top natural drainage   Natural drainage in soils comes from development of a healthy soil. Channels are made in the soil by; earthworms, in particular those made by Lumbricus terrestris that burrow 1-2m deep, but also by plant roots that later decay. In soils with a high clay content drying induces deep cracking and fissuring that help break up compacted layers and aids water infiltration. Presence of trash in surface layers reduces capping and increased organic matter improves soil structure aiding drainage. Back to top Where can I find a document call a Soil Management Plan?   DEFRA provide guidance on completing an ELS Soil Management Plan. Guidance for a GAEC soil management plan will come shortly. It is upto each farmer to complete the basic soil management plan for 2006 and implementation by 2007. An ELS soil management plan is required if the field soil assessment indicates problems that need resolution. Back to top what is sub-soil water movement?   Water can move downward in soils by fissure flow or via larger pores. The speed of flow depends on soil texture and structure being fast in sandy soils and extremely slow in some clayey soils. Some horizontal movement is also possible and again this is texture and structure related and mainly occurs when the water table is within the soil profile. On some silty soils, such as those in the fens, water may also move upwards through the subsoil by capillary flow. Back to top natural drainage   The movement of water down through the soil profile. Water follows exisiting channels made by worms, left by dacayed roots or through natural fissures. Back to top contribution to improve the sustainability in uk the use of direct drilling and reduced tillage   Correct implementation of conservation tillage systems like these can bring huge environmental benefits; stable healthy productive soils, reduced risk of compaction and erosion, less leaching, less run-off, more invertebrates, even more birds. For these and many other reasons the adoption of conservation tillage is encouraged by subsidy/ grants in several other countries (USA, Spain, Italy, Germany.....) Back to top ideal ph for weeds   Many weeds, favour a pH of around 7 where nutrient availability is maximal. However, certain weeds are more typical of a high pH found on limestone or Chalk (Onion couch, many annual broadleaves). More acid conditions restrict crop growth and with less competition grass weeds like blackgrass can thrive. Drier acid soils also favour Corn Marigold and Corn Spurrey. Back to top Why does eastern parts of england get soil erosion?   Soil erosion occurs across the UK, and with intense rainfall is more common. Erosion can result from soil degradation caused by; overworking the soil, compaction, capping where conditions impeed water infiltration. The resulting run-off carries soil and nutrients and pesticides off the fields contaminating water courses, covering roads as well as leaving rivulets/gullies in fields. Wind erosion can also occur. This is seen on light blowing sands in some years as wind scours out loose soil. Back to top how do you control take-all by organic methods   Take-all management without the use of chemistry ie. in Organic agriculture is possilbe to some extent. Keep the soil profile/ seedbed consolidated to reduce oxygen levels and slow fungal development. Use a good rotation and avoid 2nd/ 3rd cereals after grass or OSR. Increase nitrogen levels by appropriate muck/FYM to promote good cereal root growth. Choose an earlier maturing vigorous variety. Back to top cost of installaion of drainage   This depends very much on the scale and type of project concerned so one cannot generalise. More detail to come. Back to top Is minimal tilling appropriate deserts?   Minimum tillage offers excellent opportunity to conserve moisture; minimal or no soil disturbance, consolidated, trash mulch. Tight soil profile aids capillary action up through soil. These benenfits are very useful where rainfall is limiting in continental climates, but cannot make up for NO rain in a desert. Back to top why do earthworms go on the top of the soil ofter a rainfall?   To feed, often looking for organic material which is dragged back into their tunnels. By contrast when it's dry they burrow deeper to stay in moist soil. Back to top why direct drill not cultivation   Less cultivation encourages beneficial insects (beetle and spider predators) as well as allowing the build up a larger earthworm population and biomass. Shallower cultivation/ direct drilling keeps trash on the soil surface which helps to stabilise soils and also builds soil health and structure which can reduce the risk of soil erosion if done correctly. However, direct drilling has a narrower fit than minimum tillage or ploughing, and as with any tillage system should be used appropriately to ensure best practice in soil care and crop establishment. Back to top why is sub-soiling needed in soils with clay pans?   Where a pan exists, drainage/ water infiltration, and crop rooting may be impeded. This can not only reduce crop yields, but also affect crop management and adversely affect the environment if run-off results. If problems with cropping/ drainage dig a soil pit and investigate the pan. Sub-soiling, if needed and conducted under the right soil conditions, can break the pan and alleviate problems. Back to top Infiltration rates   Infiltration rate of a soil is affected by its texture and structure and also by cultivation and seedbed quality, and presence of crop roots, trash and worm burrows. When establishing a crop; maximise the infiltration rate by ensuring a firm open seedbed of medium quality. Avoid capping, smearing or compaction - so don't overwork unstable soils or work soils when wet. Without crop cover leave the soil open with rough ploughing/ cultivation and do not prepare a fine seedbed. Back to top what is fissuring action on discs do   As disc harrows are pulled through the soil the forces of the blade on the soil that is moved fissure the soil breaking it up or putting cracks in it so it breaks up later. This action is what help discs make a tilth in the soil. Back to top what is fissuring   The natural cracking of the soil along lines of weakness. Happens under repeated wet and driying of soil through seasons. Enables structures of soil to be seen and aids drainage and aeration of the soil. Back to top How can I treat acid soil?   Apply lime, amount required depends on pH and texture. Good table in Defra booklet 'Fertilisers for Arable and Horticultural Crops' RB209 Back to top soil infiltration rates for UK   There are no typical figures. However, to illustrate differecnes by soil type; infiltration rates (cm/hr) are 80 for coarse sands, 50 for loamy sand, 15 for sandy loam, 4 for silt loam, 3 for clay loam and 2 for clay. However there will be a wide range about these figures depending on land use and state of cultivation. (ref ADAS Advisory Paper 18 'Techniques for Measuring Soil Physical Parameters'). Back to top what does minimal tillage do?   When managed correctly minimum tillage (2-3" depth) allows a more natural soil structure to build up over time. Crop residues are incorporated by worms and other organisms and with less intense cultivation help to build soil organic matter and structure. Increased worm numbers and size helps improve soil and in particualr drainage. Surface crop residue intercepts rain drops and increases water infiltration. Soils stabilise and allow trafficking under a wider range of conditions easing crop protection. On the downside, there is potential for more annual grasses, but more planning; stale-seedbed, break-crops, herbicide programmes can manage this. Back to top soil management plan#   These will be a requirement under Cross-compliance for SFP in 2006 for implementation in 2007. They are the farmers plan on how he/she will meet the cross compliance terms as regards soils with respect to his/her situation. The aim being to minimise soil erosion, maintain soil organic matter and soil structure. They will be based on some form of risk assessment and then an action plan to resolve/ prevent any problems with a review. Back to top introductuion for reservior tillage   There is a good place for use of resevoir tillage behind power-harrows, or in place of rolling on lighter soils subject to wind or water erosion, or with soils left over winter without a crop. Resevoir tillage (Simba Aqueel) creates small indentations able to hold a litre of water that aids water infiltration, reduces cross slope water movement and also minimises wind blow. Back to top what effectdoes a high proportion of rock fragments have on soil consistency?   A high proportion of rock fragments lightens a soil making it freer draining and easier working. For example a Cotswold Brash soil with granular limestone chunks may contain upto 60% clay, but behaves more like a clay loam. The consistency varies depending on the proportion of clay and rock in the mix together with organic matter content. There are three aspects of soil consistency which can be measured. The shrinkage limit, plastic limit and liquid limit. All are measured on soil which has been dried and ground to less than 2mm in diameter therefore the presence of rock fragments greater than 2mm in diameter will have little effect. The main influences are clay and organic matter contents. Any good soil physics textbook such as Baver, Gardner & Gadner or Kohuke (both called 'Soil Physics') will give details of the tests. Engineering textbooks can also be useful. Back to top what are the typical levels of lead found in contaminated land?   There is no such thing as a typical level of lead in contaminated soils because the contamination could come from a range of sources, e.g. waste applied to land or mine spoil. The upper range for total lead in uncontaminated soil (Berrow and Burridge, MAFF RB 326, 1977) is 200ppm. In areas where lead mining occurred in the past levels into the thousands are possible (In the Nordrach series (now known as Malham) in the White Peak near mining disturbance levels of between 870 and 4200 were found (Soils In Derbyshire SK17, Soil Survey record No.4). Reference should also be made to the 'Sludge (use in agriculture regulations) 1989' which give guidance on the maximum levels allowed in soils where sewage sludge is to be applied - in the case of lead, where the soil pH is above 5.0, the figure is 300 mg/kg, there are certainly soils in some areas where this level is exceeded naturally because of underlying lead bearing parent materials. Back to top How can animal life help soil structure and texture?   Soils contain a diverse range of micro and macro-organisms that contribute to improving soil health and structure. Soil fauna (microfauna; mesofauna; macrofauna) each contribute in different ways. Microfauna inhabit the soil solution and utilise organic compounds of low molecular weight. They contribute to the formation of a stable soil structure as filamentous fungi and actinomycetes entrap soil particles to form aggregates that are stabilised by polysaccharides, lipids and proteins from microbial degradation of plant residues and soil humus. Mesofauna inhabit the pore system and feed upon fungi, decomposed plant material and mineral particles. They principally contribute to nutrient recycling and create micro aggregates that provide soil structural stability Macrofauna (e.g earthworms) live between soil micro-aggregates feeding upon the soil substrate, soil microflora and fauna, soil organic matter and surface flora and fauna. Physical structure is modified by the creation of burrows, which can penetrate the subsoil and aid drainage. Gastropods, isopods and myriapods consume and bury green organic matter and their faeces encourage microbial activity leading to the formation of soil aggregates and humus. Note: texture is a function of the content of particles of sand silt and clay, whilst their aggregation forms different soil structures. Back to top What effect does a high proportion of rock fragments have on soil chemistry   It all depends on the type of rock. Chert will have no effect but rock containing mica will release potash for example. Back to top the advantages and disadvantages of minimum tillage   Advantages when well practiced include:- reduced cost/ha, quicker establishment; moisture conservation, more consistent seedbed, better crop establishment; improved soil organic matter, improved soil structure, better water infiltration; higher populations and larger worms; reduced run-off, reduced erosion, reduced leaching, carbon sequestration; fewer losses to slugs, grass weeds, aphids x BYDV and take-all. Disadvantages include:- needs investment if you do not have appropriate equipment; needs a period of learning best practice; there will be teething problems; soils take time to adapt to straw and to consolidate without compaction; without best practice in implementation soil compaction, wet weather, trash management, slugs and grass weeds can cause problems. With bad practice there will be a higher need for slug pellets and herbicides. Back to top How do I get hold of a " Visual Soil Assessment " Book.   Contact Vaderstad on 01476-581900 Back to top How does the cost of min-til compare to the cost of plough and combi drill   Why not download our cost calculator and put in your details. Back to top 1. How effective is minimal tillage at protecting below-ground archaeology?   It would all depend on what depth one cultivates. However, minimal tillage is normally carried out at 2-3" (5-7cm) considerably less than mould-board ploughing typically 6-10" (14-25cm) so damage to hidden archeological remains would be reduced. Similarly, by maintaining deeper soil structures intact adding trash, encouraging earthworms, soil structure will improve so long as there is no compaction. Back to top Are there any minimal tillage equipments on farms in Devon or Cornwall? I understand they are expensive.   Yes, minimum tillage equiment is found in many places in the SW. Whilst there is an initial invetstment, choice and correct use of the appropriate equipment means considerable cost savings and improved soil management which can improve profitability when combined with necessary refinement of how the farm is run. Please note, however, minimum tillage is not for everyone or every soil, so check it is right for you. Back to top is it true that numers of broad leaved weeds will decrease under a min till programme?   Comparative trials show that annual broadleaved weed numbers tend to be lower with minimum tillage and higher with plough tillage. Of course the conserse can be true with annual grass weeds unless good management is put in place. Perennial broadleaf weeds tend to be more of a problem with direct drilling. Back to top Simba Solo the way forward?   The Simba Solo, as with the Vaderstad Top Down and Gregoire Besson discordon can be useful tools in the early years of adopting reduced tillage, and can suit the larger farm or contract operation. These machines offer greater flexbility under more difficult conditions and deeper tines remove disc smearing. However, investment and horse power requirements can be high. Back to top will farmers be paid to adopt min till under the single farm payment?   No, sadly not, although in some other European countries farmers adopting conservation tillage do gain subsidy payments to help. Back to top where can trials data be found regarding weed emergance under min till vs plough systems?   Most recent work in Sapio link project #2469 (LK0923) 'Improving crop profitability by using minimum cultivation and exploiting grass weed ecology' DEFRA (SA LINK), HGCA, Simba, Monsanto, Syngenta, JC Mann Trust, Velcourt. Lead by ADAS Boxworth. Hutcheon JA, STRIDE CD and Wright KJ. Aspects of Applied Biology 51, 1998. Weed Seedbanks:Determination, Dynamics & Manipulation. Manipulation of weed seedbanks in reduced tillage systems for sustainable weed control. Stride CD and Wright PJ BCBC conference Weeds 1997. ECOtillage: A sustainable management programme which reduced the costs of crop establihshment and weed control whilst providing environmental benefits. Back to top why will BLW decrease under min till?   Annual broadleaves probably decline as the surface seedbank is not renewed with good weed control and deeper seeds stay below cultivation depth. However, perennial broadleaves (thistles, docks, cow parsley, willow herb) can increase under minimum tillage and particularly under direct drilling so beware and use glyphosate judiciously. Back to top CAN NITROGEN PLACEMENT BE JUSTIFIED IN OCTOBER IN AN NVZ WITH DIRECT DRILLING? e.g cross slot   Old versions of RB209 gave a seedbed nitrogen recommendation for direct drilled crops but the latest version does not mention the subject of direct drilling. It is possible that after crops which have received low levels of N fertiliser or very high yielding crops which have removed a lot of nitrogen that a small dressing might be justified. After oil seed rape, peas or milling wheat the chance of a unique response to autumn N is reduced. Back to top Does minimum tillage increase arable diseases through presence of unburied trash?