1

NRCS

Technical Note TX-PM-03

United States Department of Agriculture

Natural Resources Conservation Service

Technical Note No: TX-PM-03

April 2010

Maintenance and Management of Conservation Plantings

Plant Materials Tech Note

Introduction

Proper maintenance and management are critical for successful establishment of conservation plantings

such as, but not limited to; reestablishment of native plants on previously cropped lands, vegetative 

barriers for windbreaks, nutrient uptake, and soil erosion, and the establishment of native plant species 

for livestock and wildlife habitat. Poorly managed or maintained plantings often result in weak stands 

which fail to meet conservation goals and waste resources. Warm season annual weeds can be very 

competitive and aggressive, especially in areas where tillage has been used. These weeds use vital soil 

moisture, nutrients, and often out compete slower growing perennials for sun light. Early control of 

these weedy pests is crucial for stand establishment as they produce copious amounts of seed, 

compounding the problem exponentially the next growing season. One should have an established plan

to deal with weed competition before planting.

Fertility

Soil fertility is an important part of any planting. Without proper nutrients, plants cannot survive. There 

are sixteen chemical elements known to be essential for the growth of most plants; Carbon, Hydrogen, 

Oxygen, Nitrogen, Phosphorus, Potassium, Calcium, Manganese, Magnesium, Molybdenum, Sulfur, Iron, 

Boron, Zinc, Copper, and Chlorine (Hartman et al. 1988). A soil test is necessary to determine the 

nutrient levels on site. Soil pH dictates the 

availability of these nutrients, and is an 

important part of any soil test. The 

accompanying chart lists some of the most 

important plant nutrients, and their 

availability according to soil pH. Soil 

amendments such as lime, used to reduce soil 

acidity, may be necessary to adjust the pH so 

that these nutrients are readily available for 

plant use. 

Complete fertilizers contain 3 primary 

nutrients; nitrogen, phosphorus, and 

potassium. The analysis of the fertilizer is 
2

NRCS

Technical Note TX-PM-03

represented by 3 numbers on the bag or bag label. The first number represents amount of nitrogen. 

The second number represents amount of phosphorus, and the last number represents the amount of 

potassium. It is important to note that these numbers represent pounds of nutrient per 100 pounds of 

fertilizer. If a land manager applied 100 pounds of 13-13-

13 fertilizer to a site, the actual application of nitrogen, 

phosphorus, and potassium would be 13 pounds each. 

When establishing perennial, warm season grasses, it is 

often best to defer fertilization until after the first growing 

season. Nitrogen fertilization favors the growth of annual 

grasses and broadleaf weeds over perennial native grasses

(USDA, 2003). Perennial plants invest much of the first 

year’s growth producing strong, deep root systems. As a 

result, annual weeds can produce more rapid top growth, 

and shade out the desired perennial. The addition of 

fertilizer during this early developmental stage contributes 

to stand reduction or loss via direct competition from 

annual weeds. The image on the left shows a comparison 

between two cool season grasses, intermediate 

wheatgrass, Thinopyrum intermedium, and annual 

wheat,Triticum aestivum. Note the difference in the amount of root material under the perennial on 

the left side of the picture and the annual on the right side of the picture.

Chemical Weed Control

Herbicides can be very effective tools for successful establishment of new conservation plantings. They 

may be liquids, aerosols, wettable powders, or granular, and require training and specialized equipment 

for their application. Information concerning their use, application rates, rain fastness, restrictions, 

tolerant crops, and weeds controlled may be found on the chemical label. It is imperative to follow all 

instruction on the label and read it thoroughly to prevent damage or injury to the crop, applicator, and 

environment. Application timing is critical, and best results are achieved when applied to young, 

actively growing weeds. If surfactant or crop oil is recommended, their use will greatly aid the 

chemical’s effectiveness. Applying the recommended rate is critical as using too little will not provide 

adequate control, promotes resistance, and too much may damage or kill the crop of interest. 

Applications should be uniform with no gaps in coverage to be most effective. For more information 

contact the manufacturer or you local county extension service. Herbicides may be broken down into 

two main categories, pre and post-emergent.

Pre-Emergent Herbicides

As the name implies, pre-emergent herbicides have little to no effect on plants that have already 

germinated. As previously stated, it is important to read the label and follow all directions. Preemergent herbicides usually require some form of disturbance or cultivation to be worked into the soil 

for maximum control. This may include, but is not limited to, shallow tillage, rainfall, or irrigation. These 

Figure 1. Root comparison between a perennial prairie grass on the 

left and annual wheat on the right.
3

NRCS

Technical Note TX-PM-03

chemicals typically form a shallow band under the soil surface and inhibit germination or kill seedlings as 

they germinate. They are generally non-selective, so it is important the desired crop stand be achieved 

before their application. 

Timely application is critical for maximum control. It is important to note the chemical’s length of 

activity, and make re-applications as needed. The applicator must also consider the proper form of 

chemical to use. Crop residues may inhibit liquid applications from reaching the soil surface and binding 

with soil particles. Granular chemicals may be the best option in this scenario as they can work their 

way through the residue and make contact with the soil surface. Controlling grassy weeds in a grass 

planting or broadleaf weeds in a forb or legume planting can be difficult, and pre-emergent chemicals 

are often the best method of control. 

Post-Emergent Herbicides

Post-emergent herbicides kill weeds that have emerged 

and are actively growing. Weeds are most easily 

controlled and require less chemical if the application is 

made while they are young, preferably the 2-6 leaf stage. 

Applications made to mature plants or during times of 

stress such as heat or drought can hinder the chemicals 

effectiveness. There are two categories of postemergent herbicides, Selective and Non-Selective.

Non-Selective Post-Emergent Herbicides

These chemicals typically damage or kill any plants they 

come into contact with. One of the most common 

herbicides in this group is glyphosate. These chemicals 

are most useful for treating sites before planting or crop emergence. They can greatly reduce the 

amount of competition in new plantings from established weeds. It is a good practice to allow weeds to 

make an initial flush on newly broken ground and treat with a broad spectrum herbicide before planting. 

This may be done multiple times if heavy infestations are anticipated. They may also be used in site 

preparation to chemically “burn down” planting sites. 

Broad-spectrum, post-emergent herbicides also have some 

specialty applications that are useful. They may be used

for spot applications in problem areas where some stand 

loss can be tolerated or is deemed acceptable to control 

highly invasive weeds. They may also be used in shielded 

sprayers to treat areas between rows in production fields. 

Herbicide wicks have been developed that mount to the 

front end loader of a tractor of bumper of an ATV. These 

are useful for treating weeds that are taller than the crop. 

They consist of a 4 to 6 inch diameter PVC pipe with small 

Figure 2. Weeds are best controlled with post emergent 

herbicides when applications are made to young, actively growing 

stands as represented by these Poor Joe, Diodella teres, seedlings

in the 2nd leaf stage.

Figure 3. ATV mounted herbicide wick applicator. 
4

NRCS

Technical Note TX-PM-03

holes drilled along its length. Tightly woven canvas or similar material is then wrapped and glued to the 

PVC pipe. One end of the pipe should have a faucet or ball valve. This is useful for emptying the 

chemical from the pipe and controlling the chemical’s rate of flow through the wick. The herbicide, 

usually a 50% water and glyphosate solution, should saturate the fabric without having any steady drips 

or dribbles. Some dripping is acceptable. The applicator then drives slowly through the field, allowing 

the wick to brush against taller weeds. The rate of flow or ground speed should be such that the wick 

never becomes dry. Plants should show a wet, oily appearance after the wick has brushed them. This is 

very useful on tall weeds, and the high concentration of chemical tends to be more effective on mature 

weeds than spray application rates. They are easily fabricated with materials found at local hardware 

stores, and when mounted to a hydraulic front end loader, the applicator can adjust the height on the 

fly while making the application.

Selective Post-Emergent Herbicides

Selective, post-emergent herbicides generally control 

monocots (grasses) in dicot (broadleaf) plantings or vice 

versa. The crop is tolerant the chemical and the weeds are 

not, thus selectively controlling them. There are many grass 

selective herbicides on the market, and they are very useful 

tools; especially for controlling aggressive, warm season, 

annual grasses in forb or legume plantings. Again, timely 

application is important. Best control is obtained when 

applied to very young weeds. 

Mechanical Control

Not all locations lend themselves to the use of chemicals for weed control due to proximity of sensitive 

areas, restrictions, or due to the lack of equipment or trained personnel. Timely mowing and burning 

are two mechanical management tools that allow the land owner or manager some options for 

controlling weeds.

Mowing

Mowing is one tool that most people should have access to. The goal of an annual plant is to germinate, 

grow, and produce seed for the next generation in a single growing season. It is important to know the 

weed’s life, and use mowing to break or stress this cycle. Mowing decreases competition for sunlight by 

removing the top growth from faster growing weeds. Perennial wildflower species that overwinter as a 

rosette of basal leaves close to the ground and late flowering native grasses can be mowed in the early 

spring, before elongation (USDA, 1995). This is particularly important because it does not damage the 

crowns of the crop, and specifically targets the faster growing annuals; causing them stress. Mowing 

should be used to control weed height and to inhibit weeds from making a viable seed. Allow the weed 

to flower, and start allocating its resources to seed production. Then mow the tops from these plants 

before the seed is set or viably mature. This stresses the plant for resources and time, limiting the 

Figure 4. ATV mounted herbicide sprayer
5

NRCS

Technical Note TX-PM-03

amount of re-growth and seed production. It is important to note that mowing too early may force 

some weeds into a more prostrate growth form, making them harder to control. Mowing can also be 

coupled to times of stress such as drought when there is little moisture for rapid re-growth or seed fill. 

Annual plants typically have shallower root systems and will be affected by environmental factors such 

as drought to a greater degree than deeper rooted perennial plants. If possible, always adjust the 

height of the mower so that it cuts the maximum amount of weed material and the minimal amount of 

crop. This may be done with hydraulics on a tractor when using a bush hog or similar rotary mower. It 

is always a good idea to chain the mowing deck at the desired height as hydraulics sometimes leak and 

can creep down while in use.

Prescribed Fire

Many of the native plants used in conservation plantings 

evolved in an environment with periodic wildfires. With 

the appropriate prescribed fire frequency, based on 

objectives, the native plant community can be 

maintained as a forest, woodland, savannah, shrub land, 

or grassland. The amount of time since a fire is the most 

important factor of a fire’s impact on vegetation 

structure and composition. Time of year has minimal 

impact on the native plant community (Weir et al. 

Oklahoma Cooperative Extension Service). Native 

Americans capitalized on this aspect and adapted plant communities to fit their needs. Perennial 

species, once established, have enough reserves in their roots to re-sprout after fire events where as an 

annual typically does not. Periodic prescribed burning can be a powerful tool to maintain the desired 

structure and plant communities within a conservation planting. Prescribed burning removes residues, 

improves soil qualities, controls brush species, and eliminates weedy pests by selecting for a fire tolerant 

plant community. It requires the use of trained professionals, and must be conducted on specific 

weather conditions. Prescribed burn plans need to be established that meet the desired conservation 

goal, provide adequate protection to surrounding areas and personnel, and follows the laws. 

Conclusion

There are many tools available to land managers to maintain conservation plantings. They may be used 

alone or together in management plans. It is important to inventory the available equipment and 

resources, and to have clearly defined goals. Choose the best management practices to achieve these 

goals. Proper set up and attention to detail in the beginning can limit the amount of future maintenance 

work. For example, planting Round Up® Ready Soybeans in advance of the conservation planting would 

improve soil quality, and limit weed pressure from the seed bank due to the use of glyphosate herbicide 

on the resistant soybeans. For more information on soil testing, herbicides, and burning, please contact 

your local county agent. 

Figure 5. Rapid green up of native plant production fields 

after a spring burn.
6

NRCS

Technical Note TX-PM-03

References

Hartman, T. Hudson, Kofranek, M. Anton, Rubatzky, E. Vincent, and Flocker, J. William. 1988. Plant 

Science Growth, Development, and Utilization of Cultivated Plants. Second Edition. Prentice-Hall, Inc. 

Englewood Cliffs, New Jersey.

US. Dept. Of Agriculture Natural Resources Conservation Service. 2003. Technical Note. Considerations 

for establishing native grasses from seed for restoration, revegetation, and erosion control in western 

Washington and western Oregon. Available at http://plantmaterials.nrcs.usda.gov/technical/publications/establishment-pubs.html#TN (accessed June 5, 2010). 

USDA-NRCS Portland, OR.

Wilke, J. Brook and Kunkle, Justin. 2009. What does agriculture have to do with climate change. 

Teaching Issues and Experiments in Ecology. 23, February 2009. vol 6. Available at 

http://www.google.com/imgres?imgurl=http://tiee.ecoed.net/vol/v6/figure_sets/climate_change/img/

Figure%25201d%2520Annual%2520Perennial%2520Roots.jpg&imgrefurl=http://tiee.ecoed.net/vol/v6/fi

gure_sets/climate_change/faculty1.html&usg=__5vKrHgrQM4IdCvhXR6KUU4gfYXA=&h=485&w=597&sz

=265&hl=en&start=8&um=1&itbs=1&tbnid=7_vxzZ0XgA8CLM:&tbnh=110&tbnw=135&prev=/images%3

Fq%3Dperennial%2Broot%2Bdiagram%26um%3D1%26hl%3Den%26sa%3DG%26tbs%3Disch:1 . 

accessed June 23, 2010.

Grabowski, M. Janet, US. Dept. Of Agriculture Natural Resource Conservation Service. 1995. Technical 

Note. Planting and Maintenance of wildflowers and native grasses in the midsouth. Available at 

http://plant-materials.nrcs.usda.gov/technical/publications/establishment-pubs.html#TN (accessed 

June 10, 2010. USDA-NRCS Coffeville, MS.

Weir, R. John, Elmore, Dwayne, Bidwell, G. Terrence, Engle, M. David, Carlson J. D., Fuhlendorf, D. 

Samuel. Oklahoma Prescribed Burning Handbook. E-1010. Pgs 1-2. Oklahoma Cooperative Extension 

Service. Division of Agricultural Sciences and Natural Resources. Oklahoma State University.