Garden Care
Organic fertilizers
Animal manure is a secret ingredient which many home gardeners overlook. Manure offers many benefits, the most notable being increased available soil phosphorus and enhanced water infiltration rates. Chemical reactions with soil-and-water calcium alter the phosphorus to forms that are not available or only slowly available to plants. When manure decays, organic phosphates are released and the total phosphorus level available to plants increases. Organic phosphates may persist for many years after manure applications have stopped. The organic phosphorus also moves much deeper into the soil than do inorganic forms of phosphorus fertilizers.
Manure application also increases water infiltration dramatically compared to non-manured plots. In fact, studies indicate that manured plots can be properly irrigated five times faster than non-manured plots. Manure also keeps soils from sealing tightly while crops are growing.
There are three problems which can cause manure to be more of a problem than an asset. A cheap source of manure may be hard to find with so many gardeners scouring the countryside.
Secondly, one must consider the source of the manure because undigested weed seeds cause problems in a garden. Thirdly, large amounts of salts in the manure can kill garden plants if large quantities are used. Salt content is a major problem in using sewage sludge (too many water softeners polluting a potentially excellent manure source). Saline plant toxicity can also be a problem when using feedlot manure if cattle are fed high salt rations.
How much manure should be added to a garden? Bag instructions recommend 40 pounds per 100 square feet of garden area. That is a good, safe recommendation; however, some very successful gardeners apply the manure at 80 pounds per 100 square feet (8 pounds per tomato plant located 3 feet apart). Actually, the type of manure determines the rate which can be safely used. Barnyard manure can be used in greater quantities because it does not contain as much ammonia. Vapors of ammonia in fresh manure, especially rabbit or poultry manure, can severely damage plants. Thoroughly incorporate all fresh manure into the soil several weeks before planting.
Certain tomato varieties, such as Merced and Surefire, and most peppers respond well to heavy manure applications. However, adding excessive amounts of manure on a yearly basis is not encouraged since nutrient release occurs over a period of time and nutrient toxicity could eventually occur.
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Add organic material when preparing your soil
Once the best location has been selected, begin soil preparation. If you have an established garden area, usually weeds and grass are not present. If tenacious grass such as bermuda is present, it must be removed. Till the area to a 1 inch depth and remove all soil and grass stubble. Do no think that such grasses can be tilled into the soil and disposed of; they will return more vigorous than before. If the grass is dormant, contact herbicides such as glyphosate are not effective.
Till or spade soil when it is moist but not wet. Working soil when too wet can cause large clods and a rough planting surface.
Adding liberal amounts of organic material to all types of garden soils is a highly recommended practice. Hay, compost, rotted grass clippings or leaves applied 2 to 3 inches deep to the garden surface and tilled or worked into the soil greatly improves sands or clays.
Heavy clay soils, which are sticky when wet and hard as a brick when dry, can be modified if large quantities of organic matter and a washed, coarse sand are added. Use a washed sand to insure removal of calcium carbonate, which makes alkaline soils even more alkaline. If only sand and clay soil are mixed the result will be a hard adobe! Quantities of organic matter and sand must be added together to compose a garden mix which is one-third sand, one-third soil and one-third organic matter. For instance, add 3 inches of sand and 3 inches of organic matter to the garden surface if the soil is to be tilled to a 10-inch depth.
Gypsum (calcium sulfate) added to a "sticky" soil makes it more friable. Gypsum is a neutral product which does not increase or decrease the soil's alkalinity. Not only is it a good soil conditioner, but it also furnishes certain amounts of calcium, which may prevent such minor element disorders as blossom-end-rot of tomatoes. Never add lime or wood ashes to alkaline soils.
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Understanding fertilizers and their uses
Once the garden soil has been tilled with the organic material and sand incorporated consider fertilization.
Fertilizer increases plant growth only if it is a limiting factor. Plants grown in poorly drained soils, in excessive shade or in competition with tree roots do not respond to fertilizer.
Fertilizer is organic or inorganic. Organic fertilizers are manures, bone meal, cotton seed or other naturally occurring materials. Inorganic fertilizers contain manmade products.
The three numbers shown on fertilizer containers are the fertilizer analysis. They indicate the percent of nitrogen, phosphorus and potassium present in the fertilizer. These figures are always listed in the same order. So, a 100-pound sack of 10-20-10 fertilizer contains 10 pounds of nitrogen, 20 pounds of phosphorus and 10 pounds of potassium. That equals 40 pounds of nutrients. The rest of the fertilizer is simply carrier or filler, such as sand, perlite or rice hulls. A complete fertilizer is one with all three elements. A general recommendation for gardens and flower beds is 2-3 pounds of a slow-release, complete fertilizer such as 19-5-9 per 100 square (10' X 10') feet of planting area.
Just as people need nourishment, plants must have nutrients to grow and flourish. Plants need a balanced diet with all of the necessary nutrients readily available for their use. Plants will grow at optimum rates if nutrition is furnished on a "as needed" basis. If you incorporate the knowledge that plants need a continuous source of nutrition with the realization that the major pollutant of ground water is nitrates which can come from plant fertilizer applications, then the idea of using slow release fertilizers to feed plants small portions of the nutrition they need makes sense. Fertilizers which gradually feed plants rather than deluging them with excessive nitrogen are not only environmentally-sensible, but they also enable plants to grow at optimum rates. This is why slow release formulations are recommended for all plants, whether they are vegetables, flowers, trees, shrubs, groundcovers or lawns.
When fertilizing gardens, use a product containing slow-release fertilizer such as sulfur-coated or plastic-covered urea. When choosing a slow release fertilizer, it is important to note that the higher the percentage content of sulfur-coated or plastic-covered urea, the better.
The chance of groundwater contamination from excessive nitrates washing through the soil is lessened when greater amounts of slow release, sulfur-coated or plastic-coated urea are present. Of course, the more slow-release fertilizer present, the more expensive the product, but safeguarding the environment is certainly worth the cost difference!
Some of the better fertilizers will have at least 50 percent of the total nitrogen content of the bag as sulfur-coated or plastic-coated urea. This information can be determined by reading the Guaranteed Analysis found on each bag of fertilizer. Remember, the higher the percentage or units of sulfur-coated or plastic-coated urea, the more you and the environment benefit. To insure you have the best product, not only look for the "slow release" nomenclature on the bag, but you should also examine the Guaranteed Analysis which indicates what percent of nitrogen (the first number on the bag) is derived from sulfur-coated or plastic-coated urea.
Slow-release fertilizer in your gardens has the following advantages:
* Makes more nitrogen slowly available as a nutrient to the plant.
* Resists leaching or washing through the soil into the water supply.
* Deceases risk of fertilizer burn associated with heavy applications of conventional fertilizers.
* Releases independently of microbial and bacterial action.
* Offers controlled-release feeding for 10 weeks.
* Stimulates a more drought-tolerant plant.
Fertilize properly
After deciding on the types and amounts of fertilizer to use then decide how to apply it. How fertilizer is applied may make the difference between a super productive garden and an "average" garden.
Fertilizers are applied four ways:
Broadcast before planting. The proper amount of fertilizer is spread evenly over the garden and mixed well with the soil to a depth of 3 to 4 inches before making beds for planting. This method is least likely to cause plant damage and is used by most gardeners.
Band or bed applications. The fertilizer is applied in a strip to the side of the row before planting. This method requires care to prevent plant damage from roots which may come into contact with the fertilizer band.
Starter solution. This is used mainly on transplants such as tomatoes and peppers. Mix 2 tablespoons of garden fertilizer with 1 gallon of water and stir well. Pour 1 cup of the mixture into the hole and let it soak in before transplanting.
Side dressing. The term side dressing simply denotes an application of fertilizer, usually one containing nitrogen only, alongside the rows or in a circle around growing plants. This insures a nitrogen supply as plants grow and develop. Side dressing is particularly beneficial in sandy soils or in seasons of abundant rainfall as nitrogen has a bad habit of being washed or leached out of the root zone.
One heavy fertilizer application in early spring is not enough; it's much better to apply a moderate amount before planting with supplemental side dressings during the growing season.
Side dressing offers three very important advantages. Properly used, it helps prevent delayed fruit set caused by excessive nitrogen too early in the season, it significantly increases yields and it results in healthier, stronger plants with fewer pest problems.
Information concerning the best time to sidedress specific crops is outlined below.
Whenever sidedressing, avoid getting the fertilizer particles on the plant foliage and always water thoroughly after application.* Onions - when 5 to 6 leaves have formed.
* Tomatoes and peppers - when first fruits are small, apply 1 level tablespoon per plant. Repeat every 4 weeks.
* Squash - when vines are 1 foot long at a rate of 1 level tablespoon per plant.
* Herbs - when about half grown and after first harvest.
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