|RIP Weeding – The use of new ergonomically designed hand tools for field scale weeding. Many categories of land management now restrict or forbid the use of chemicals for the control of plants listed in the 1959 Weeds Act because of environmental and health concerns over pesticide use. These categories include Countryside Stewardship schemes, organic farming and horticulture, Sites of Special Scientific Interest, municipal parks, and private gardens. Apart from dangers to our environment, pesticide use can also be questioned on the grounds of its financial costs. One solution to weed control that (a) satisfies organic standards, and (b) is economically viable, is the application of a technique using ergonomically designed hand tools that has become known as the “Removal of Individual Plants”, or RIP. When joined with other appropriate land management techniques, this method of weed control can be cost-effective and efficient in a range of agricultural and conservation situations.
Correctly performed, the RIP method enables the complete extraction of plants from the ground at an early stage of their development. The ergonomic design of the tools minimises bending and enables professionally led weeding teams to operate efficiently under a range of conditions. There are four main tools: the L-D Chisel hoe, the L-D General purpose Leverage fork, the L-D Ragwort fork, the improved L-D Weedhook. The Leverage fork consists of a frame that enables any one of three fork attachments to be used according to the predominant weeds and prevailing soil conditions. The fork is securely attached to the frame by a single bolt that can be easily removed using a hexagon key supplied with the tool. A two-pronged fork, small three-pronged fork, large three-pronged fork, are all available (See Appendix 5).
The RIP method is particularly suitable for the removal of dock (Rumex sp.), ragwort (Senecio jacobaea), spear thistle (Cirsium vulgare), marsh thistle (C. palustre), and creeping thistle (C. arvense), and it is these species with which the present work is concerned. Other less widespread but sometimes locally important weeds that can sometimes be controlled by RIP are hogweed (Heracleum sphondylium), hemlock (Conium maculatum), bracken (Pteridium aquilinum), burdock (Arctium lappa), and Japanese knotweed (Reynoutria japonica).
The environmental benefits of the method are significant because pesticide dependence for weed control is eliminated. Moreover, the method requires none of the capital or overhead costs, or training, personal protection, safety or disposal issues that are associated with pesticides and pesticide application equipment.
After several years of work, and with each new year of field work, more is being learned about when and where the RIP method is appropriate. The value of RIP weeding in terms of cost-effectiveness has also been well established. This research has been supported by demonstrations, shows, talks, and publications in agricultural and conservation journals (see Appendix 1) and is now encouraging wider uptake of the technique. Research is also addressing other vital issues such as: (1) finding and employing labour for weeding (See website report), (2) the use of weeds in composting, (3) highlighting where improvements in grazing and land management practices can aid weed control, and (4) improvements to the tools themselves.
Analysing the Weed Problem
The RIP method involves a thorough and systematic approach to weed removal. Firstly, the weed problem needs to be assessed. This can only be done by visual inspection in the field when the weed density is measured in terms of the average number of weeds in three 5m x 5m squares. Factors affecting the work rate are also considered at this time. These include such things as topography, soil type, weed density and distribution, height and density of any surrounding vegetation, and weather conditions. For example, flat areas of easily visible weeds in short grass on moist loam will be easier to work than slopes where weeds are hidden by long grass in limestone brash. Based on experience, we have been able to compile work rate and cost predictor charts for given weeds based on weed density and other considerations (See Appendix 2).
On larger areas, weeding is facilitated by sub-dividing the work area into strips using vehicle wheelings or other markers. Alternatively, a team of individuals one meter apart in a line can work systematically across the field.
A third practical component of the RIP system requires the collection and removal of dock and ragwort from the field. Dock is relatively unpalatable to stock and is capable of continued growth, even lying on the soil surface, so its removal from the field is recommended. On a positive note, dock is a valuable source of green material for hot composting and should be collected for this purpose. Ragwort should be removed from the field because it is poisonous to stock.
As part of our DEFRA-funded work, a trial was performed to remove dock from a 3-hectare pasture (used for spring grazing and hay) at Hill Top Farm, Spaunton, between 27 April and 14 May 2004. A total of 10,183 docks were removed in 102 man-hours at a cost f £260 per hectare (£100 per acre). Much value can be placed on this work: hay could be cut without risk of spreading dock seed any need for pasture topping was removed the land was made suitable for arable cropping without the risk of exacerbating the weed problem from cultivations dock removed from the field provided around 6 tonnes of fresh green material for windrow composting with straw bedding follow-up work cost £20 per hectare and removed another 1200 small plants this work will not need to be repeated annually on the same scale and therefore compares favourably in cost with chemical control of dock at £25 per acre annually
Based on our experience, we have been able to make a number of recommendations for the control of weeds in grazing and arable situations. We stress the importance of an integrated approach to weed control because factors other than simply the removal of weeds from a site can influence weed infestations. The following points should therefore be considered:
Avoiding the vegetative spread of weeds like creeping thistle, couch and dock that re-grow from root fragments after ploughing or rotovating Practicing efficient grazing management to optimise pasture use. In particular, avoid overgrazing during winter as poaching exacerbates the proliferation of weeds
“Hot composting” – allowing the compost to reach temperatures of between 60 and 65oC before turning to reactivate the process – to destroy weed seeds
Removing plants before seed set – an obvious but neglected practice
Choosing drilling times and seed rates to enable rapid, early and full crop cover in order to achieve some weed suppression
Avoiding the spread of weed seeds in hay and silage
Encouraging weed control on neighbouring land
At very high levels of weed infestation pasture topping, mowing, and cultivations may be more appropriate weed control measures, at least initially
Many weed problems could be drastically reduced by tackling them early.
A second general point is that effective weeding, particularly using the RIP method, depends on motivated workers who can operate well together and who can recognize weeds at their various stages of growth. This requires training and practice. Appropriate weed control techniques for a given site need to be integrated into a weed control strategy for the farm. This requires an intimate understanding of the land, of its weeds, and how other activities on the farm, such as grazing and cultivating, influence plant populations. Advice, education, planning, and experimentation are all vital in this respect. Progress lies in attention to detail.
A clear understanding of the nature of the individual weeds and how they can best be dealt with using RIP methods is also vital for effective control. Our findings are outlined below.
Dock & Cultivations
Dock will grow from seed and from cut root sections. Therefore aim to remove the whole plant before seed is shed.
Try to remove dock from land before ploughing and certainly before power harrowing otherwise the plant will be spread vegetatively throughout the field from cut root sections. A chisel harrow can sometimes be used after ploughing to drag dock root clusters to the soil surface. Roots can then be collected.
Consider Spring/Summer fallowing
Weeds should also be removed from fence lines and, ideally, from neighbouring land to avoid spread from wind-borne seed.
Try to provide early crop cover to suppress dock (and other weeds).
A forage break crop after grass can provide a further opportunity to remove dock before a cereal crop. Incidentally, this will also eliminate leatherjackets in the cereal.
After potatoes, it is worth separating and collecting any dock roots from the potato haulms left by the harvester.
Dock & Grazing
Hay or silage contaminated with dock seed will lead to the spread of the weed since it survives its passage through the gut. Contaminated feed should, if possible, be fed in yards or buildings. Bedding can then be hot composted in windrows.
Hot composting is best carried out using windrows up to 2m wide, 1.5m high, and of any convenient length. The windrow should then be thoroughly turned over every day for the first week, then every 3 to 4 days subsequently until no re-heating of the heap occurs. This will take between 8 and 12 weeks. The heap should be moist but never saturated, and should not be allowed to dry out. Windrow composting in a building with a water supply is ideal. For composting in the open, a proprietary covering sheet such as “Top Tex” can be used to protect the heap from the elements.
Overstocking land in the winter will leading to poaching. This will exacerbate weed problems by denuding ground of grass and providing opportunities for weeds to spread. Poaching occurs particularly badly around ring feeders in the field. These should either be moved regularly or placed on a concrete plinth in order to minimise pasture damage.
Removing Dock by RIP Method
The ease with which individual dock plants can be removed using LD tools depends largely on the age of the plant and on the degree of infestation. Young 1st year plants are difficult to locate and difficult to lift due to their small size. On the other hand, older plants with large root systems are very satisfactory to lift. In practice, plants of a range of age and size co-exist in the field. This can mean that forks may need to be changed from time to time to suit the job, although the large three-pronged is often the most versatile attachment, and the one preferred by many operators for a range of tasks. Locating the weed, and familiarity with the use of the tool, are skills that can only be developed with practice. Inexperienced operators who persevere with small areas soon become acquainted with the use of the tool. Experienced operators can efficiently clear large areas of weeds daily throughout the year.
Most dock control should be carried out during autumn, winter and spring when soil conditions are usually moist, and the weeds easy to locate. Weeding is also made easier in grassland grazed by sheep – again, dock is easy to locate.
Spear Thistle (See website Field Trial Report T.00 )
Spear thistle is a biennial that can infest winter crops, new seeds, pastures, field margins, and fence lines. In one case, we calculated that over a third of a 6 ½ acre pasture was rendered virtually ungrazable due to spear thistle. However, two years later, it took only two hours to clear the whole area of the 1st year rosettes that had arisen from seed following tight sheep grazing.
Spear thistle responds to cutting by producing short tillers, each one of which forms a new seed head. It is therefore important to remove spear thistle when young, at the two-leaved or small rosette stage. This is facilitated during autumn, winter and early spring when the ground is moist. The two-pronged fork is the ideal attachment for this work. There is no need to remove the plant from the field. As with dock, mark out the work area with wheel markings, work methodically, and carry out later follow-up work to remove missed plants or those that have germinated since the first pass. Again, be aware of seed blowing from neighbouring land.
Ragwort (Senecio jacobaea)
A biennial or short-lived perennial, ragwort can be removed during all stages of its development during summer, autumn and early spring. The ragwort fork enables the removal of even ground level rosettes without the need to bend. Both new and previous year ragwort growth is normally clearly visible by mid-May (and much earlier in southern England). Ragwort removal at this time will enable the elimination of the current, and next year’s flowering population but weeding can continue to be effective into the autumn or as long as the rosettes are visible. We have cleared sites of Ragwort rosettes as early as February/March, a highly recommended practice that almost eliminates the bulkier task of weeding during a hot summer, when the ground is hard.
One of the advantages of using hand tools for weeding is that operators look very closely at the field – much more closely, for example, than a sprayer operator. Hence, ragwort can often be removed at the same time as dock or spear thistle i.e. in one pass. In fact, RIP operators have consistently provided ragwort control at a lower cost than operators of spot sprayers. It is advisable to wear gloves for handling ragwort since the plant produces toxic alkaloids with a cumulative effect on the liver. The toxins can be absorbed through the skin or through the gut following ingestion. The weed must therefore be removed from the field for burning or burial.
Several other factors are important in the effective control of ragwort:
Deer, sheep, and horses – animals that graze very close to the ground – are normally associated with ragwort infestation. Winter stocking should be reduced to prevent pasture damage, and stock should be excluded from areas recently cleared of ragwort. Light grazing with cull sheep is one option to allow turf regeneration following ragwort removal.
Areas where grazing is habitually concentrated should be managed by fencing, or by moving watering and feeding areas regularly.
Moist autumn and spring soil conditions facilitate the complete removal of the root, sections of which can re-sprout if left in the soil. The roots are more difficult to remove from dry soil in the summer.
Creeping Thistle (Circium arvense)
Creeping thistle produces an extensive rhizomatous root system from which vertical flowering stems arise. Each below-ground bud of the root system is capable of giving rise to a stem. Mowing this plant will induce vigorous branching. Cutting the roots will stimulate the formation of new growth from each cut section of root. This can lead to an infestation of the weed.
The RIP method achieves control by repeated cutting just below soil level, at or near the point of growth. This puts the greatest demand on the energy reserves of the plant to make new growth. Plant vigour is therefore significantly reduced from year to year. Furthermore, re-growth following such treatment rarely reaches maturity. Chisel hoeing can be carried out effectively up until the appearance of seed heads. Chisel hoeing creeping thistle with the LD tool throughout the year has a number of advantages:
Re-growth is softer and helps reduce the incidence of orf in sheep because the nose is not scratched during grazing
Pastures can be kept clear for improved grazing over the year
New growth reaches maturity only infrequently
Chisel hoeing has a cumulative effect on weed control and shows significant annual improvements
The all-steel chisel hoe is designed to have no vertical flex so that the blade enters the ground without the bounce that is associated with wooden shafts. If the operator adopts a forward rotary motion, and keeps the blade sharp, then thistles can easily be removed from the ground at the growing point at a rate of around 35 plants per minute. At this rate, two experienced operators should clear 3.5 ha of moderately infested pasture in a day. The work will certainly need to be repeated during the season in order to see significant improvements the following year because new shoots are produced throughout the year as part of the normal cycle of development of the plant.
The plant thrives in moist conditions, therefore drainage could also be considered as an aid to control.
Economic evaluation of RIP weed control
Much of our work suggests that RIP weeding is a cost-effective method of weed control, as this summary of actual weeding contracts indicates:
Dock in 3.5 ha municipal parkland – £370 per ha
Dock in grazing and conservation pasture (see Section 2) – £240 per ha
Dock and spear thistle in grazing and arable land at ADAS, High Mowthorpe – £80 per ha
Dock, spear thistle & ragwort in Countryside Stewardship land, ADAS, High Mowthorpe – £40 per ha
Spear thistle in pasture at Hill Top Farm – £30 per ha
Spear thistle, dock, and ragwort in Countryside Stewardship wild flower meadows – £40 per ha
See Appendix 3 for details of individual RIP weeding contracts.
Publication in peer-reviewed journals
Publication in peer-reviewed journals is an important route for the dissemination of information. To date, RIP weeding using LD tools has been entirely practically based, but we have accumulated a significant amount of data on efficacy and costs that could be presented in the form of a formal paper of interest to specialists in weed science, ergonomics, organic farming, land management, conservation, and rural economics. A formal paper could also address the following issues:
Issues surrounding availability of labour
We are anxious to emphasise the possibilities for providing rural employment for RIP weeding. Recruitment and training are time-consuming, yet essential, elements for the wider uptake of this weeding system. There is a need not only to promote the benefits of this method of weeding, but also to develop the idea that this is skilled manual work. There is a need to overcome a cultural aversion to manual work in farming.
As with any system of work, training needs to be linked with an understanding of the value and purpose of the job, and an understanding of the ergonomic advantages of the tools. Providing one-to-one instruction for new tool users would greatly aid the uptake of the method.
Field-scale weeding can produce several tonnes of green material suitable for composting each year. For this reason weeds removed from the field should be regarded as a valuable resource rather than a waste product. We have successfully composted 6 tonnes of fresh dock with straw bedding in windrows. We wish to develop the concept of harvesting weeds as compost crops.
In collaboration with HDRA, we have already shown that windrow composting of dock with bedding from winter-housed sheep completely destroys weed seeds. We also wish to investigate the possibilities of using composting as a method of disposing of ragwort.
RIP weeding using ergonomically designed hand tools has been shown to be a cost-effective, efficient, and environmentally sound method of weed control in agriculture, conservation, and other areas of land management, when used under appropriate conditions. The method also has great application for weed control on highway verges, many of which are presently routinely sprayed.
There are, of course, cases where RIP is inappropriate. At high levels of weed infestation, for example, RIP weeding can be effective but not cost-efficient. The same is true of herbicides when weed infestation is high. Under these conditions we recommend pasture topping as a preliminary treatment.
The method provides employment opportunities, and requires skilled operators.
There are other vital but less obvious advantages of RIP weeding:
Pastures can often be cleared before the main growing season
The method enables selective plant removal rather than indiscriminate eradication
RIP using ergonomically designed tools minimises bending and heavy lifting enabling work to be carried out efficiently and without undue fatigue. In fact, ground level rosettes can normally be lifted and bagged without bending.
Handwork enables operators to develop an more intimate knowledge of the land upon which they are working. We believe this is a vital aspect of successful farming and conservation.
Further details of RIP weeding, tools, projects, on-line shop, tool catalogue, and other information can be found at the website: www.lazydogtools.co.uk
6.1 Publications arising from the project
Organic Farming article
Conservation Land Management article
Gazette & Herald articles
[Colour photocopies here]
6.2 Work Rate Predictors
*750 plants per 25m2 = 30 plants per m2
Size and age of dock influence working rates. Three dock types are recognised for predicting work rates:
Type 1. Seedling docks up to 1 year old. Smaller, less well-established plants with tap roots less than 3cm in diameter.
Type 2. Mixed seedlings with mature plants up to 5 years old. Well-established, mature plants, often with forked tap root up to 5cm in diameter.
Type 3. Mostly older or larger established plants. Often growing in multi-stem clusters with multiple forked tap roots up to 10cm in diameter.