Organic Weed Control Product
EcoCover Organically Certified Paper Mulch Mats

Definition of Organic Weed Control

"To reduce the incidence of or severity of, especially to innocuous levels using organic methods."

The most common definition of a weed is "a plant growing where it is not wanted, interfering with human activities."

It is estimated that there are approximately 250,000 different species of plants in the world. However there are only about 8000 species that are thought of as weeds in agriculture (3% of the total).

New research shows that with more carbon dioxide being released into the air, plants are growing faster, but weeds grow even faster. This is due to the world's rising carbon dioxide levels which are expected to rise some 30% above present levels over the next three decades.

Weeds can probably be best summarized as follows:

• Aggressive and competitive
• Adaptable
• Thrive in disturbed habitats
• Have efficient reproduction
• Survive unfavorable conditions
• Will strongly compete with plants for light, nutrients and water

EcoCover is exceptionally effective as an organically certified means suppressing and inhibiting weed growth, thereby reducing weeding and cultivation activities. EcoCover stops light reaching the soil thereby preventing photosynthesis and is rated as a weed stop. The life of the mat and therefore its effectiveness as a weed stop depends on local climatic conditions and the type of EcoCover supplied. Further labor and other cost savings can be made with the plowing under the soil of the mat, as opposed to removing the mat from the ground then storing or dumping where dumping is still permitted, which is a problem in many parts of the world with unsustainable plastic sheeting and film used as mulch.

The soil can also benefit from turning EcoCover into the soil with a gradual increase in soil organic matter. Higher nitrogen fertilization would be advantageous for the growth of newspaper-mulched crops since paper has a high carbon/nitrogen ratio.

Research has shown paper mulch to be exceptionally effective at suppressing weeds, especially Kraft paper.  Research has also confirmed that despite theoretical fears that the level of nitrogen in the soil may temporarily drop as microbes use up some nitrogen to process the cellulose in the paper no symptoms of nitrogen deficiency were found.

Kraft paper has been found to be even more effective at preventing weeds than newspaper. EcoCover uses a unique combination of both Kraft and newspaper.

Competition for nutrients and moisture in the soil makes the elimination of weeds essential for many crop applications. One such example is in the planting of tree seedlings for forestry. Benefiting from the mulch properties of being both an effective weed control and having excellent water conservation characteristics, mulch has been proven to reduce the mortality rate in early forestry plantings, especially in areas subject to low rainfall.

Although some weed seeds germinate in the dark, the majority of them require light for maximum germination. This signifies to the seed that it is not buried deeply and therefore will have enough food reserves for the shoot of the germinating seedling to reach full sunlight. An effective mulch will block out the light. Another benefit of paper mulches is that they are weed free, unlike bark, sawdust and similar mulches.

Some crops do not have suitable herbicides for effective weed control. The crop may be particularly sensitive to herbicides (e.g. water melons); or there may be a lot of weed species closely related to the crop species and so are not different enough from the crop to allow a selective herbicide to kill the weed without killing the crop.

One mistake that is made with mulches is to leave the perennial weeds intact and alive when the mulches are laid. EcoCover will kill weeds due to lack of light and this is certainly true for annual weeds and some perennials. Other weeds that have good storage organs will have sufficient sugars in these organs to be used to fuel regrowth from the new shoots that grow under the mulch until they reach light, either around the edges or through holes made at the base of the planting. There are a number of ways weeds can reinvade apart from regrowth from poorly controlled weeds. Lateral growth of perennials can occur from adjacent lawns or nearby weed areas. Once they emerge they are hard to kill without causing disturbance to the mulch. Perennial weeds should be properly killed before mulch is laid, either by thorough hand weeding or careful use of glyphosate. To avoid problems it is best to kill all weeds before laying mulch.

Once the EcoCover is correctly laid, a good strategy is to plant carpet forming ground cover species known as live mulches. Perennial evergreens are preferable for ground covers as they keep the garden or landscape covered in vegetation 12 months of the year. Many are small carpet forming herbaceous perennials such as aluminum plant and ivy. There are also low growing conifers with wide reaching branches that may be used.

Massey's research showed EcoCover was successful in suppressing many different weed species, both annuals and perennials. All weeds in EcoCover plots grew through the planting holes with no physical penetration of the mulch. Far fewer weeds grew through the EcoCover planting holes than through the black plastic planting holes, primarily due to the flexibility of the paper mulch that allows it to be folded back after slitting. No weed germination was apparent under the EcoCover mat throughout the trial, suggesting no light is able to infiltrate the mulch mat. As black plastic is lighter than EcoCover, re-growth of the weed ‘dock' (Rumex spp.) was able to lift the plastic material in places. A slight problem occurred with black plastic mulch covering crop plants when they were small, due to movement in the wind. EcoCover was superior in this respect.

Massey's research proved that EcoCover is a longer lasting weed control than some of the most persistent residual herbicides (for example terbuthylazine and hexazinone). EcoCover also gives longer weed control than knockdown herbicides with little residual activity, even if these are applied more than once. EcoCover is able to control a wide range of weeds, both annual and perennial, and will control more weeds in some crops than the herbicides available. For example, both triflurin and clethodim are used for weed control in cabbages, but these herbicides are unable to control a number of other weed species.

Number of weeds per m² in EcoCover mulch, black plastic and bare soil treatments.
Weeds were counted 6 weeks after mulch treatments were laid.

	Treatment
New Zealand Weed species	Bare soil	Black plastic
twin cress (Coronopus didymus)	228.9	0.0	0.3
chickweed (Stellaria media)	120.0	3.0	0.0
sow thistle (Sonchus oleraceus)	90.0	1.0	0.0
mallow (Malva spp.)	78.9	1.0	1.7
red dead-nettle (Lamium purpureum)	61.1	0.0	0.0
dock (Rumex spp.)	42.2	5.9	3.0
scrambling speedwell (Veronica persica)	38.9	7.0	0.7
groundsel (Senecio vulgaris)	35.6	0.3	0.0
white clover (Trifolium repens)	26.7	2.3	2.0
annual poa (Poa annua)	11.1	0.0	0.0
black nightshade (Solanum nigrum)	6.7	0.0	0.0
hawkbit (Leontodon taraxacoides)	5.6	0.0	0.0
milkweed (Euphorbia peplus)	3.3	0.0	0.0
scarlet pimpernel (Anagallis arvensis)	3.3	0.0	1.7
oxalis (Oxalis spp.)	2.2	0.0	0.0
prickly sow thistle (Sonchus asper)	2.2	0.0	0.0
daisy (Bellis perennis)	1.1	0.0	0.0
narrow-leaved plantain (Plantago lanceolata)	1.1	0.0	0.0
nettle (Urtica urens)	1.1	0.0	0.0
spurrey (Spergula arvensis)	1.1	0.0	0.0
broad-leaved plantain (Plantago major)	0.0	0.0	0.3
cleavers (Galium aparine)	0.0	0.3	0.0
Total weed number per m²	761.0	20.8	9.7

Dry weight (mg) per m² of weeds under treatments of EcoCover mulch, black plastic, and bare soil.

Weeds were harvested 23 weeks after mulches were laid and oven-dried at 75°C for 24 hours.
EcoCover has a small weed count due to weed growth through plant stem hole.

	Treatment
New Zealand Weed species	Bare soil	Black plastic
twin cress (Coronopus didymus)	126477	14	103
shepherd's purse (Capsella bursa-pastoris)	21952	0	0
scrambling speedwell (Veronica persica)	19029	2530	642
sow thistle (Sonchus oleraceus)	16183	286	222
red dead-nettle (Lamium purpureum)	15420	923	393
mallow (Malva spp.)	8689	14	23
white clover (Trifolium repens)	6522	437	122
groundsel (Senecio vulgaris)	5317	0	0
dandelion (Taraxacum officinale)	1699	0	0
bitter cress (Cardamine hirsuta)	977	49	0
spurrey (Spergula arvensis)	768	0	0
annual poa (Poa annua)	678	86	7
milkweed (Euphorbia peplus)	395	0	0
broad-leaved plantain (Plantago major)	363	0	0
toad rush (Juncas bufonius)	118	0	0
chickweed (Stellaria media)	56	195	332
cleavers (Galium aparine)	0	141	0
dock (Rumex spp.)	0	1175	289
broad-leaved fleabane (Conyza albida)	0	0	8
prickly sow thistle (Sonchus asper)	0	42	0
Total dry weight (g) per m²	280.3	5.89	2.14

Estimates have been calculated for the effect of weeds in New Zealand and a recent survey estimated weeds were costing the country as much as NZD340 million in lost production and NZD53 million in control measures per annum.

Problems Caused By Weeds In Gardens And Landscaping

Dense weed infestations reduce the air movement near the soil surface, thus raising the humidity and making ornamental plants more susceptible to disease problems. Weeds seldom get this dense in gardens; however the main problem caused by weeds in gardens is that they look unsightly. The level of weed control in gardens needs to be very high if they are to remain aesthetically pleasing, yet by clearing those weeds, no income is generated to pay for this. The same situation exists for most turf areas.

In public gardens, parks and reserves, there is usually a fixed budget available from the body responsible for the maintenance of these areas (e.g. from the local council, funded by rate payers). For home gardens of course generally the costs are only for materials such as mulch and herbicides, but the homeowner provides the labor. As the average homeowner does not enjoy using too many of their precious leisure hours pulling out weeds, techniques are sought to minimize the weeding necessary to maintain an attractive garden.

Picture Montage
EcoCover mulch mat used in domestic landscaping.

Preparation and pinning	Planting	Bark covering over mulch mat

Problems Caused By Weeds In Orchards

Competition is obviously a major issue. The trees and vines are generally taller than the weeds so the competition for light is often not a problem. However, there can be exceptions, such as tall weeds around young trees and vines in their first year, or clambering weeds that may cover a crop. But it is normally competition for water and nutrients that is the concern.

Competition for water will only be a problem at dry times of the year, and many orchards have irrigation systems to help out at these times. But a lot of vegetation under trees means that there is a large leaf area which can be losing water to the air by transpiration, resulting in the soil being dried out faster than if the soil was bare. Thus uncontrolled vegetation growing under trees can result in greater water requirements for an orchard, and so more irrigation will be needed during dry times of the year. Irrigation water can be scarce in summer, resulting in charges for water and possible rationing; keeping weeds under control can reduce water requirements.

Nutrients can be applied to orchards in the form of fertilizers, however weeds can take up nutrients very rapidly with many weed species taking up more nutrients than they actually require. Having a lot of weeds present under trees can result in nutrients being removed from the soil quite rapidly. Equally, if the orchard floor were just bare soil, nutrients would be more likely to leach down into the groundwater. This leaching results not only because of nutrients being left unabsorbed in the soil, but also because there is no vegetation to intercept rainwater and prevent it moving down through the soil, taking nutrients with it.

Where the soil is covered in vegetation, trees tend to have fewer roots near the soil surface than if the soil is bare. Competition with the roots of weeds and grasses results in trees positioning their roots deeper down. As nutrients exist at highest concentrations at the soil surface where fertilizers are applied, tree roots are not as well positioned to intercept these nutrients if they are growing deeper in the soil.

Uncontrolled weeds can grow up into the level of lower branches of trees sometimes shading fruit that are growing there and affecting their color. These weeds can allow insects to climb from the soil up on to the fruit. Tall weeds can impede good spread of water from irrigation sprinklers. Dense weeds can create a high humidity near the soil due to reduced air movement, which can increase the chances of disease organisms building up.

If the soil is left bare, the surface tends to become quite crusted and compacted from constant raindrop impaction and also passage of vehicles. Earthworm numbers decline dramatically as they have less plant material to feed on, and the burrowing activity of earthworms increases the macro porosity of the soil.

EcoCover can assist in keeping the soil structure, natural fertility and water holding capacity of the soil at optimum levels.

All bare soil can result in slippery conditions when it is wet and fairly dusty conditions when it is dry, with more heat being reflected up off the ground on sunny days. This heat reflection can be considered good by some growers though as it helps improve the color of fruit on lower branches.

With tree fruit and vine, mulches are generally only used in the first few years in the life of a crop when weed competition can have severe effects on the establishment of the crop. There are also fewer herbicide options due to the vulnerability of young crop plants to residual herbicides.

EcoCover can act as an insulation blanket, absorbing heat and releasing it at night, which will reduce the risk of frost damage at some times of the year.

Picture Montage
Massey University weed trials – lettuce and cabbage crops.

EcoCover plant stem hole minimizes weed growth. Polythene stem hole remains open and is subject to weed invasion. Refer Tables 4 and 5 below for respective weed count.

Bare soil	EcoCover
Polythene	Polythene. Lettuce competes with dock (Rumex spp) weed

Problems Caused By Weeds In Forestry

Forestry is a large user of herbicides. Competition between forest trees and weeds for light, nutrients and water is probably the main problem caused by weeds in exotic forests. This effect is of most importance during the first few years of the life of the forest, as the trees are most susceptible to the effects of competition at this stage. If competition is severe enough, trees can be killed during the first year after planting. If trees do survive the first year, major checks in growth at this stage can cause a delay in the development of the trees. Research has shown that trees are affected by the initial check in growth for quite a few years afterwards, causing a delay of several years before the trees will reach a harvestable size.

Case Study. A trial in which there was no weed control for the first year then excellent control for the following two years resulted in the mean volume per tree being 3180 cm³ after three years. In comparison, trees which had good weed control for all three years had a volume of 8674 cm³, 2.7 times that of the other trees. Although scrub weeds can be very competitive in establishing forests, perennial grasses can be just as damaging.

Loss of moisture is a problem to new planting as is frost damage in certain areas. Dense weeds around young trees can reduce air movement and thus increase humidity, which many lead to disease problems. Weeds can also attract pest and disease organisms into forests and lead to problems. Weeds can also make maintenance more difficult and forests more vulnerable to damage by fires.²⁴

Picture Montage
Massey University Pinus radiata weed trials comparing four different treatments.
Period 1 - at planting.

Bare soil	EcoCover
Polythene	Fluted cardboard

Picture Montage
Massey University Pinus radiata weed trials.
Period 2 - 6 months + after planting.

Bare soil	EcoCover
Polythene	Fluted cardboard

Radiata seedling without a mulch competing with
weeds for light, nutrients and moisture

Problems Caused By Weeds In Nurseries

Nurseries are keen to get plants to a saleable size as quickly as possible so they can be moved on and the next lot of plants grown. Weeds can slow down this process if they're allowed to establish, through competing with the young plants for light, nutrients and water. Although most nurseries are irrigated and a lot of fertilizer is used, weeds can grow very rapidly under these conditions and use up the water and nutrients sufficiently to limit growth by the desirable plants. Once the weeds are tall enough, light competition can occur.

Weeds growing around a nursery, can also act as a source of infection of pest and disease organisms, for new crops.

A weed free nursery gives buyer's confidence that the owners are efficient managers that produce high quality produce. Likewise. The public buying plants from a garden centre won't want plants with weeds growing in the bags, so Garden Centers won't buy weedy plants from the nursery.

Future R&D may provide nurseries with an EcoCover fertilizer enriched planter bag. Bury the entire container along with the plant – zero plastic waste.

Picture Montage
Nursery planter bag with a round EcoCover weed suppressant mat.

Other Weed Problem Areas

Pastures, turf, aquatic environments; roadsides and other waste areas (adjacent to railways lines and so on); and urban environments (footpaths etc).

Effectiveness of EcoCover mulch mat as a weed suppressant. Australian weed species.

	Time period. 3 weekly	Weed cover (%)
Bare soil	1	41%
	2	57%
	3	75%
	4	89%
	5	92%
	6	92%
	1	0%
	2	0%
	3	0%
	4	0%
	5	0%
	6	0%

Numbers of weeds per m² six weeks after mulch treatments were laid.
Refer Table 3 for New Zealand weed species type and count.
EcoCover has a small weed count due to weed growth through plant stem hole.

Treatment
Bare soil	Black plastic
761	21	10

Dry weight (mg) per m² of weeds.
Refer Table 4 for New Zealand weed species type and count.
Weeds harvested 23 weeks after mulches laid, oven dried at 750C for 24 hours.

Treatment
Bare soil	Black plastic
280.3	5.89	2.14

EcoCover (may) offer superior weed control compared to black plastic.

Would it have been a good thing for you to be in on the ground floor with Microsoft or Wall Mart or Home Depot or General Electric? If you are interested in a sustainable manufacturing opportunity producing organically certified products serving an essential industry with real growth ahead, the time to talk is now.

Learn more about the EcoCover ground floor opportunity.  Please contact me today.

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