Growing
Vegetables
Organically
Prepared by George E. Boyhan, Darbie Granberry, W. Terry Kelley, and Wayne McLaurin
| |
Growing Prepared by George E. Boyhan, Darbie Granberry, W. Terry Kelley, and Wayne McLaurin |
Contents
Garden Location
Garden Planning
Irrigation
Soil Preparation
Composting
Green Manures
Soil Solarization
Starter Solutions
Successive Planting and Crop Rotation
Crop and Variety Selection
Mulching
Fertilization
Insect and Disease Control
The garden should have a southern exposure (south side of your home) or be in an open field if at all possible. There should be a minimum of six hours of direct sunlight at the chosen location. A well-drained site even after a heavy rain is ideal. Poor drainage may be improved by regrading, digging ditches, installing a tile drain field, or adding organic matter.
Nearby trees and shrubs may have extensive root systems that may interfere with water and nutrient uptake of plants at your site. Locate the site to minimize or avoid this problem. As a last resort, consider removal of trees and shrubs that may interfere with production.
Land with a slope of 1.5 percent or greater (18-inch elevation change in 100 feet) should be avoided or terraced to prevent runoff and soil erosion. Contour planting, which is setting the rows to follow the contour of the land, can also help with runoff problems.
The site should also have a water supply nearby. Sites with serious weed problems such as nutsedge, Bermuda grass, or kudzu should be avoided unless adequate measures are taken to control them. This does not preclude using these sites, but considerable work is required to remove and control these weeds.
You should consider fencing the site if you have a significant wild animal population nearby. Deer, raccoons, and rabbits, to name a few, may become problems. Domestic animals such as dogs may also become a problem because many like to dig. Fences as high as 6 feet, an electric fence, or some combination may be required to control animals such as deer. Finally, for convenience, a location near the house is desirable.
The size of your garden will determine, in part, many aspects of your garden plan. Large gardens where tractors will be used can be worked more easily with long rows; small gardens may be worked more easily in small beds with footpaths surrounding them.
There are many other things to consider in planning your garden. Fertility requirements vary with the crop, so heavy feeders and light feeders may be grouped separately to help manage fertilization. Long-season crops such as eggplant, tomato, pepper, and okra should be planted so they don't interfere with replanting short-season crops such as beans and cole crops. Tall-growing crops such as pole beans, tomatoes, and corn should be planted so they don't shade shorter crops. You may not be able to accommodate all of these recommendations in your garden, but you should try to accommodate as many as possible to help insure a successful garden.
An important part of garden planning is record keeping. General information about soil amendments used and weather information (particularly rainfall and first and last frost dates) can be useful, especially when tracked from year to year. Specific information about a particular vegetable can also be helpful for future planning.
Information such as variety selection, planting date, days to harvest, disease, and insect problems should be noted. This data can help you determine which vegetables and varieties are best for your location.
Watering, fertilizing, and any cultural practices should also be recorded. This helps in determining what should be done in the garden from day to day.
Finally, keep track of what is grown where in your garden. This information will help with successive plantings and crop rotation as noted elsewhere in this publication.
When to plant is also an important part of garden planning. Table 6 lists the hardiness and days to maturity for several vegetables. Vegetables can be classed into two broad categories: warm- and cool-season crops. Warm-season crops can be further subdivided into tender and very tender vegetables, and cool-season crops can be subdivided into hardy and half-hardy crops. Very tender crops cannot stand any frost and will not do well under cool nighttime temperatures (below 55°F). Tender crops also don't like frost but can stand cooler night temperatures. Hardy cool-season vegetables can withstand frost and can be grown during the winter in all but the coldest northern parts of Georgia. Half-hardy cool-season vegetables can withstand cool temperatures and light frosts, but hard freezes and heavy frost can be detrimental.
Growing a crop without irrigation is possible, but your success is enhanced with irrigation. Several different methods of irrigation can be used, with overhead and trickle irrigation the most common. Trickle irrigation is the most water-use efficient because water is delivered directly to plant roots with a low volume soaker hose, drip tape, or emitters. The disadvantage of trickle irrigation is cost of installation and maintenance. For more detailed information on irrigation see Irrigation for Lawns & Garden, Bulletin 894 from Georgia's Cooperative Extension Service.
Organic gardening requires a long-term outlook with respect to soil preparation. In fact, the key to successful organic gardening is to feed the soil with organic matter, which feeds the plant, rather than to feed the plant with inorganic fertilizer as in conventional production. An ideal soil would have equal parts of sand (0.02 to 2.0 millimeters), silt (0.002 to 0.02 millimeters) and clay (0 to 0.002 millimeters), and contain about 5 percent organic matter. Most mineral soils in Georgia will have less than 2 percent organic matter and are rarely ideal. However, with work, most soils can be improved and made productive.
Because it takes a long-term outlook to build a good soil, don't be disappointed if your results are less than ideal the first year or two. New sites should have all plant matter removed or turned under. Areas with Bermuda sods or other invasive plants should have the plants removed to the compost pile (see "Composting" in this publication) and the soil turned under to expose roots and rhizomes to desiccation. In addition, soil solarization (see "Soil Solarization" in this publication) can help control these hard-to-control weeds.
Some soils may have hardpans, which are impervious layers several inches under the soil. These hardpans are often found on old farmland or new home sites where equipment has compacted the soil. In either case, these hardpans must be broken up. On clay soils this can be very difficult.
Soils should be turned to 10 to 12 inches deep. One method is to double dig the garden. Dig a trench 6 to 8 inches deep along one side of the garden, placing the soil on the outside edge of the garden. Then use a spade or garden fork to loosen the soil 6 inches deep at the bottom of the trench. Soil adjacent to the trench on the inside edge of the trench is moved to fill the existing trench, creating a new trench in its place. Again with a spade or garden fork, loosen soil in the bottom of this trench to a 6-inch depth. Continue in this fashion until the entire garden has been double dug. The soil from the first trench can then be moved into the last trench. This method of garden preparation will leave a deep turned soil but is very labor intensive. Alternatives include use of equipment such as tractor-mounted plows or a Rototiller set to the deepest depth. Organic matter should be added during this deep-turning process.
Organic matter in soil is important for two reasons. First, as it breaks down, it releases nutrients that crops can utilize, and second, it improves the water- and nutrient-holding capacity of the soil. The amount of organic matter to add varies with the chosen material, the type of soil, and weather conditions. On sandy soils in tropical and subtropical regions, as much as 2,300 to 4,600 pounds per 1,000 square feet may be required to gain a benefit from the addition of organic matter. On heavier soils in regions with cooler climates and less rainfall, as little as 200 pounds per 1,000 square feet may be sufficient.
As an example, an acre of dry soil 6 inches deep weighs about 2 million pounds, which means that 1,000 square feet of soil to the same depth weighs approximately 46,000 pounds. If we wished to raise the organic matter of this soil 1 percent, we would have to add 460 pounds of organic matter. The amount of material required may actually be quite a bit more because most organic sources have a high water content, as much as 50 percent or more. In addition, many have high ash (nonorganic residues) content, as high as 25 percent or more. Organic matter with 50 percent water content and 25 percent ash would require 1,840 pounds applied to 1,000 square feet to raise the organic fraction of the soil 1 percent. This may be impractical both in terms of obtaining the necessary organic matter and the fact that organic matter must be added each year to sustain the increase. Low rates (200 pounds per 1,000 square feet) of organic matter can have a noticeable improvement in soil tilth. Additions of 500 to 1,000 pounds of organic matter per 1,000 square feet per year can have a beneficial effect on soil tilth and plant growth. Table 1 lists the minimum amounts of several types of organic matter that should be added to the soil. It is highly recommended that you have the organic matter tested for its nutrient content so that application rates can be adjusted accordingly. In all cases, fresh material should be composted to kill harmful pathogens and weed seed. In addition, fresh material can damage plants and be hazardous to the environment through runoff.
Compost is an excellent source of organic material for your garden. It has the added benefit of reducing the amount of waste your household generates. All organic kitchen and garden waste except animal products can be composted. Material such as bones and animal scraps should be avoided because they attract vermin, flies, and scavenging animals. A convenient size for a compost pile is 4 feet wide by 5 feet long by 5 feet high. A frame made of pressure treated lumber can be built to hold the compost, but this is not really necessary. Begin the compost by adding 12 inches of organic matter (kitchen scraps, yard waste, etc.). Then apply 1 to 2 pounds of high-nitrogen organic fertilizer such as dried blood, guano, or poultry manure. Finally, add 2 inches of soil. Continue building the compost pile in this layered fashion as you generate organic matter. The center of the pile should be concave to hold rain water. The center of the pile should begin to heat up within a couple of weeks. The composting process should be complete within two to three months, depending on material and outside temperature.
Large material such as tree limbs, corn stalks, etc., should be chopped into smaller pieces to facilitate decomposition. Some materials, such as lawn clippings, will decompose very rapidly; others will require turning the compost pile (which aerates the pile) and adding more high-nitrogen organic fertilizer. This will restart the heating and decomposition process.
Any crop grown on land with the intent of turning it into the soil is called a green manure. Generally, legumes and various grasses are grown as green manure. Turning under a crop can provide a number of benefits, including increasing organic matter of the soil, decreasing certain disease problems, and increasing the nutrient level in the soil. After the green manure is turned under, it decomposes and adds nutrients and organic matter to the soil.
When used as a green manure, grasses and small grains can decrease the incidence of nematodes. Nematodes are microscopic worms that feed on certain plant roots, weakening the plants.
Using various legume crops can increase the amount of nitrogen in the soil. The amount of nitrogen will depend on the crop, the time of year, and when in the crop cycle the plants are turned under. Anywhere from 30 to 125 pounds of nitrogen may be added to the soil when a legume crop is turned under. Table 2 lists several crops that can be used as green manures.
Difficult-to-control weeds and soilborne pathogens may be controlled with soil solarization. Soil solarization should, however, be reserved for solving these specific problems in your garden because it can also kill beneficial microorganisms and insects.
Soil solarization involves covering the soil surface with clear plastic for four weeks or longer. To begin with, all plant material and crop residue, as is practical, should be removed. The soil should be turned to break up any clods of soil and raked smooth. The area should be watered thoroughly so the soil is saturated. The area then should be covered with a plastic sheet. The sheet can be secured along the edges with soil or rocks. Soil solarization works best when air temperatures are high and sunlight is most intense during the summer months. Soil solarization is not effective during extended periods of cool temperatures or overcast weather.
Starter solutions can help get transplants and newly emerged seedlings off to a good start. These starter solutions are often referred to as manure teas. High phosphorus is particularly important in these solutions because it encourages root growth. A good homemade solution consists of 3 pounds of poultry manure plus 3 pounds of steamed bone meal in 25 gallons of water. Stir the mixture often over several days; then strain off the liquid. Use one cup of liquid for each transplant. Fresh manures can contain harmful bacteria, so be sure to wash up after handling.
Successive Planting and Crop Rotation
Because of the relatively long growing season in Georgia (particularly South Georgia), it is possible to produce more than one crop a year on the same land. Planting a second or third crop on the same land within the same growing season is called successive cropping. Crop rotation, on the other hand, refers to planting different vegetables on the same land from year to year. Related vegetables should not be planted on the same land in succession or rotation. For example, squash should not be followed with a related vegetable such as watermelon, cantaloupe, or cucumber. This practice helps minimize insect and disease problems and helps maintain soil fertility. Table 3 lists related vegetables.
One of the most important decisions an organic grower makes is crop and variety selection. Not all vegetables do well in all locations. Vegetables commonly grown in your area are your best bet for success. Trial and error will also help determine which vegetables are best suited to your area. As you try different varieties, keep records so that this information can be used in planning subsequent years. Climate, disease, and insect problems will be important criteria when selecting vegetable crops. It should be pointed out, however, that one year's results may not be enough to determine the success of a particular vegetable. For example, a mild winter may result in a greater insect problem than one might expect the following season. On the other hand, a cold winter may result in sufficient suppression of the insect to make for a successful year.
Variety selection is another important
consideration when selecting crops to be grown. When available, varieties with
disease and insect resistance are best. Resistance, however, is seldom 100 percent,
and the plant may show some symptoms but less severe symptoms than susceptible
varieties.
Varieties can be grouped into two broad categories based on how they were developed.
F1 hybrids are developed from crossing lines that have been inbred for several generations. These varieties have advantages of increased uniformity and, often, increased yield compared with open-pollinated varieties. The disadvantage of these varieties is that the seeds are more costly and seed saved from hybrids will not perform as well if planted (they are said not to be true to type). In addition, F1 hybrid varieties are constantly being changed by the seed companies. Not all vegetables lend themselves to F1 production. Because of the low amount of seed produced from each cross, beans and peas are not usually available as F1 hybrids.
Open-pollinated varieties are less expensive, and popular open-pollinated varieties will remain in the market for years. In addition, these seed will remain true to type from one year to the next. Most older varieties are open-pollinated types. Very old varieties are often referred to as heirloom varieties, and many can be dated to the previous century and beyond. These varieties are often sources of unusual colors, shapes, and flavors.
Several vegetables are reproduced vegetatively; that is, from parts of the plant itself. These would include things such as sweet potatoes and Irish potatoes. To improve your results with these crops, buy certified slips for sweet potatoes and seed pieces for Irish potatoes. The certification process insures true-to-type, disease-free material.
Mulching serves several purposes in organic production including reducing weed growth, conserving soil moisture and nutrients, regulating soil temperature, helping prevent soil erosion, and reducing water splashing on plants (which keeps them cleaner and reduces the spread of disease). An added benefit comes from organic mulch: As it decomposes, it increases the amount of organic matter in the soil. Almost any organic matter can be used successfully as mulch. This can include things such as old hay, straw, leaves, sawdust, paper, or bark. Avoid materials that may have a lot of seed such as fresh-cut hay or overgrown grass clippings. Fresh material, particularly sawdust, can rob your soil and thus your plants of nitrogen. In addition, avoid organic material that may be contaminated with toxic chemicals or herbicides because these may damage your plants.
Mulches should not be applied too early in the spring because this can delay soil warming. Wait until the soil is 65°F to a depth of 4 inches before applying. Solid materials such as newspapers should be weighted with soil to prevent them from blowing away. Weed control with mulches may require the continual addition of new material to smother weeds as they emerge. Keep all mulches 2 to 3 inches back from the stems of plants.
You must have accurate information about your soil to fertilize properly. First, the pH of the soil is important in determining nutrient availability to the crop. Optimum pH for most vegetables is between 6.0 and 6.5. Irish potatoes are a notable exception with a desired pH of 5.0 to 5.5. Soil testing is the only accurate method of determining the soil pH. Such tests will offer recommendations on the amount of lime to apply if the soil pH is too low. Approximately 1 ton of lime is required to raise the pH of an acre 1 point. This is about 5 pounds per 100 square feet. The actual amount of lime required, however, will vary based on soil texture, the crop grown, and the buffering capacity of the soil.
In order to determine proper fertilization, it is important to know the nutrient status of the soil, which a soil test will provide. To illustrate using Tables 4 and 8, assume you are planting only heavy feeders in your garden and plan to use horse manure as an organic fertilizer. Heavy feeders require 3 pounds of nitrogen per 1,000 square feet (Table 4). Horse manure contains 0.3 percent nitrogen (Table 8). Convert 0.3 percent nitrogen to its decimal equivalent by dividing 0.3 by 100 to get .003. Calculate the pounds of horse manure required to provide 3 pounds of nitrogen by dividing 3 by .003 to get 1,000 pounds. If your garden is smaller or larger than 1,000 square feet, adjust the amount accordingly.
The best first-line method of reducing insect and disease pressure is to use resistant varieties when available. A good example is VFN tomatoes, where the VFN stands for Verticillium-, Fusarium-, and nematode-resistant material. Your local county Extension office or seed supplier will have the latest information on available resistant varieties.
Keep the garden as free of diseases as possible. Plants with disease symptoms should be removed and destroyed. A properly constructed compost pile, which should heat up in the center, can control many diseases.
Keeping your plants dry will help reduce disease pressure. Using trickle irrigation rather than overhead will reduce the amount of time plants remain wet and also conserve water. Of course, there's nothing we can do about the rain.
Crop rotation also can be an important method of controlling some but not all soilborne diseases. The proper crop rotation can substantially reduce nematodes in the soil but will do little to reduce southern blight.
Insect control begins with healthy plants. Don't bring problems into your garden - buy insect-free transplants. Timing is also important. Insect populations tend to increase as the season progresses, so planting early can avoid many insect problems. Encourage beneficial insects to stay in your garden. This can be as easy as nailing a horizontal board to a fence to encourage wasps to build a nest.
Finally, there are many organically
acceptable products that can be applied to your crops. Check with your local
county Extension agent, who can give you the latest information on these products.
|
Material |
Rate/1000 Sq. Ft.1 |
||
|
Cattle manure |
150-500 lbs. |
||
|
Compost |
4 bushels |
||
|
Horse manure |
100-200 lbs. |
||
|
Poultry manure |
50-200 lbs. |
||
|
Sheep manure |
75-100 lbs. |
||
|
Swine manure |
75-100 lbs. |
1 Rates are minimum initial applications; you may wish to experiment with more or to have the material analyzed for actual nutrient content and adjust application accordingly. In addition, you may wish to have your soil tested to determine the amount of organic matter in it.
Table 2. Green manure crops, season of growth, amount of seed, and type|
Crop |
Season |
Seed (lbs./acre) |
Type |
Nitrogen (lbs./ton dry material) |
|
Buckwheat |
Summer |
75 |
Nonlegume |
14 |
|
Crimson clover |
Winter |
15 |
Legume |
45 |
|
Rye |
Winter |
75 |
Nonlegume |
21 |
|
Southernpea |
Summer |
90 |
Legume |
60 |
|
Soybean |
Summer |
75 |
Legume |
46 |
|
Sudan grass |
Summer |
25 |
Nonlegume |
28 |
|
Vetch |
Winter |
30-50 |
Legume |
62 |
|
Wheat |
Winter |
75 |
Nonlegume |
20 |
|
Nightshade Family |
Legumes |
Cucurbits |
Cole |
|
Eggplant |
English pea |
Cantaloupe |
Broccoli |
| Light Feeders | Medium Feeders | Heavy Feeders |
| Southernpeas | Asparagus Beans, all Beets Broccoli Cantaloupes Carrot Cauliflower Corn Cucumbers Eggplant Greens (kale, mustard, turnip, collards) Herbs Okra Peas, English Peppers Pumpkin Radish Squash Sweet potato Swiss chard Watermelon |
Cabbage Lettuce Onions Potatoes, Irish Tomatoes |
|
Crop |
Hardiness |
Days to Maturity |
|
Asparagus |
Perennial, winter tolerant |
Second Season |
|
Bean, bush |
Tender |
50-60 |
|
Bean, pole |
Tender |
65-75 |
|
Bean, lima |
Tender |
65-75 |
|
Beet |
Half-hardy |
55-65 |
|
Broccoli |
Hardy |
60-80 |
|
Cabbage |
Hardy |
65-80 |
|
Cantaloupe |
Very tender |
80-90 |
|
Carrot |
Half-hardy |
70-80 |
|
Cauliflower |
Half-hardy |
55-60 |
|
Collard |
Hardy |
55-70 |
|
Corn |
Tender |
80-100 |
|
Cucumber |
Very tender |
60-65 |
|
Eggplant |
Very tender |
75-90 |
|
Kale |
Hardy |
50-70 |
|
Lettuce |
Half-hardy |
60-85 |
|
Mustard |
Hardy |
40-50 |
|
Okra |
Very tender |
55-60 |
|
Onion |
Hardy |
100-120 |
|
Peas, garden |
Hardy |
60-80 |
|
Pepper |
Very tender |
65-80 |
|
Potato, Irish |
Half-hardy |
70-90 |
|
Radish |
Hardy |
25-30 |
|
Southernpea |
Tender |
60-70 |
|
Spinach |
Hardy |
40-45 |
|
Squash, summer |
Very tender |
50-55 |
|
Squash, winter |
Tender |
85-120 |
|
Sweet potato |
Very tender |
90-150 |
|
Tomato |
Tender |
70-85 |
|
Turnip |
Hardy |
45-65 |
|
Watermelon |
Very tender |
80-90 |
|
Crop |
Recommended Varieties |
|
Asparagus |
Jersey Gem, Mary Washington, Viking |
|
Beans, bush |
Strike, Bush Blue Lake 274, Provider |
|
Beans, half-runner |
State, White Half-Runner |
|
Beans, pole snap |
Kentucky Wonder 191, Stringless Blue Lake |
|
Beets |
Detroit Dark Red, Ruby Queen |
|
Broccoli |
Green Comet, Green Duke, Premium Crop |
|
Cabbage |
|
|
Head Start |
|
Market Prize, Gourmet |
|
Rio Verde |
|
Red Acre |
|
Cantaloupe |
Planter's Jumbo, Edisto 45 |
|
Carrots |
Scarlet Nantes, Chantenay Red Core |
|
Collards |
Georgia, Vates, Carolina |
|
Corn |
|
|
Hybrid Truckers Favorite |
|
Silver Queen |
|
Seneca Chief, Bonanza, Golden Queen, Merit |
|
Cucumber |
|
|
Ashley, Marketmore 76, Dasher II, Poinsett 76 |
|
Chipper, Carolina |
|
Eggplant |
|
|
Ichiban, Dusky |
|
Black Beauty, Florida Market |
|
Kale |
Siberian Curled, Vates |
|
Lettuce |
|
|
Great Lakes |
|
Grand Rapids |
|
Lima, bush |
|
|
Fordhook 242 |
|
Henderson’s Bush, Nemagreen, Jackson Wonder (speckled) |
|
Lima, pole |
Sieva |
|
Mustard |
Florida Broadleaf, Tendergreen II (hybrid) |
|
Okra |
|
|
Emerald |
|
Clemson Spineless 80 |
|
Onions |
|
|
Crystal Wax, Granex |
|
Crystal Wax, White Portugal |
|
Southport Red Globe |
|
Peas, English or garden |
|
|
Sugar Snap |
|
Alaska, Little Marvel, Laxton Progress #9 |
|
Southernpeas |
California Blackeye #5, Worthmore, White Acre, Mississippi Silver, Zipper Cream |
|
Peppers |
|
|
Sweet Banana |
|
Yolo Wonder L, Keystone Resistant Giant |
|
Large Red Hot |
|
Long Thin Cayenne, TAM Jalapeno |
|
Truhart Perfection |
|
Potatoes, Irish |
Kennebec, Red Pontiac |
|
Pumpkin |
Big Max (large), Connecticut Field (medium), Jack O’Lantern (small) |
|
Radish |
Cherry Belle, Scarlet Globe |
|
Spinach |
Bloomsdale Long Standing, Melody |
|
Squash, summer |
|
|
Early Prolific Straight Neck, Early Summer Crookneck, Dixie (hybrid), Multipik |
|
Seneca, Zucchini Select |
| Squash, winter |
Early Butternut, Table King, Spaghetti |
|
Sweet potato |
Centennial, Georgia Red, Red Jewel, Georgia Jet |
|
Tomato |
|
|
Mountain Pride, Celebrity, Big Set |
|
Better Boy, Monte Carlo |
|
Roma |
|
Turnip |
Purple Top, Shogoin, Just Right |
|
Watermelon |
AU-Producer, Jubilee, Crimson Sweet |
|
Materials |
Percent1 |
Availability |
||
|
N |
P2O5 |
K2O |
||
|
Bone meal (steamed) |
0.7 to 4 |
18 to 34 |
0 |
Slow medium |
|
Castor pomace |
5 |
1.8 |
1 |
Slow |
|
Cocoa shell meal |
2.5 |
1 |
2.5 |
Slow |
|
Compost (not fortified) |
1.5 to 3.5 |
.5 to 1 |
1 to 2 |
Slow |
|
Cottonseed meal (dry) |
6 |
2.5 |
1.7 |
Slow medium |
|
Dried blood (dry) |
12 |
1.5 |
.6 |
Medium rapid |
|
Fertrell-Blue Label |
1 |
1 |
1 |
Slow |
|
Fertrell-Gold Label |
2 |
2 |
2 |
Slow |
|
Fertrell-Super |
3 |
2 |
3 |
Slow |
|
Fertrell-Super "N" |
4 |
3 |
4 |
Slow |
|
Fish meal (dry) |
10 |
4 |
0 |
Slow |
|
Fish scrap (dry) |
3.5 to 12 |
1 to 12 |
.08 to 1.6 |
Slow |
|
Garbage tankage(dry) |
2.7 |
3 |
1 |
Very slow |
|
Guano (bat) |
5.7 |
8.6 |
2 |
Medium |
|
Guano (Peru) |
12.5 |
11.2 |
2.4 |
Medium |
|
Kelp2 |
0.9 |
0.5 |
4 to 13 |
Slow |
|
Manure3 (fresh) |
||||
|
.25 |
.15 |
.25 |
Medium |
|
0.3 |
.15 |
0.5 |
Medium |
|
0.6 |
.33 |
.75 |
Medium |
|
0.3 |
0.3 |
0.3 |
Medium |
|
1.5 |
1 |
0.5 |
Medium rapid |
|
2 |
2 |
1 |
Medium rapid |
|
3 |
2.5 |
1.5 |
Medium rapid |
|
6 |
4 |
3 |
Medium rapid |
|
Marl |
0 |
2 |
4.5 |
Very slow |
|
Milorganite (dry) |
5 |
2 to 5 |
2 |
Medium |
|
Mushroom compost |
0.4 to 0.7 |
.57 to .62 |
0.5 to 1.5 |
Slow |
|
Peat and muck |
1.5 to 3 |
.25 to 0.5 |
0.5 to 1 |
Very slow |
|
Sawdust |
0.2 |
0.1 |
0.2 |
Very slow |
|
Sewage sludge (active dry) |
2 to 6 |
3 to 7 |
0 to 1 |
Medium |
|
Sewage sludge (digested) |
1 to 3 |
0.5 to 4 |
0 to 0.5 |
Slow |
|
Soybean meal (dry) |
6.7 |
1.6 |
2.3 |
Slow medium |
|
Tanbark4 |
0 |
1.5 |
2 |
Very slow |
|
Tobacco stems(dry) |
2 |
0.7 |
6 |
Slow |
|
Urea5 |
42 to 46 |
0 |
0 |
Rapid |
|
Wood ashes6 |
0 |
1 to 2 |
3 to 7 |
Rapid |
Some of the materials may not be available because of restricted sources.
1
The percentage of plant nutrients is highly variable; with some materials, average
percentages are listed.
2 Contains common salt, sodium carbonate, sodium, and potassium sulfates.
3 Plant nutrients available during year of application. Varies with
amount of straw and method of storage.
4 Contains calcium.
5 Urea is an organic compound, but manufactured sources are synthetic,
and it is doubtful that most organic gardeners would consider it acceptable.
6 Potash content
depends on the tree species burned. Wood ashes are alkaline, containing approximately
32 percent CaO.
The University of Georgia and Ft. Valley State University, the U.S. Department of Agriculture and counties of the state cooperating. The Cooperative Extension Service, the University of Georgia College of Agricultural and Environmental Sciences offers educational programs, assistance and materials to all people without regard to race, color, national origin, age, sex or disability.
An Equal Opportunity Employer/Affirmative Action Organization Committed to a Diverse Work Force
Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, The University of Georgia College of Agricultural and Environmental Sciences and the U.S. Department of Agriculture cooperating.