Application Methods

There are different methods of fertilizer application depending on the kind of fertilizer material, the cropping system and equipment used by the producer.

Broadcasting: A recommended rate of lime or fertilizer is spread over the growing area and left to filter into the soil, or is incorporated into the soil with a cultivator. Broadcasting is the application method generally used for large field areas, when time or labor are limited, or when it is important to obtain a unif distribution of the soil amendment, as with a liming material.

Banding: This method is primarily used to apply small amounts of fertilizer as a plant starter. Starter fertilizer applications may stimulate earl growth and increase yield. This is especially important in no-till cropping s where crop residues or winter covers result in lower soil temperatures and moisture levels that may reduce plant vigor. Narrow bands of fertilizer are gener ally applied in furrows 2 to 3 inches from and 1 to 2 inches deeper (commonly called a 2 X 2 application) than the seeds or plants are planted. Starter materials have also been successfully applied in-furrow (in direct contact with the seed) or in about a 4-inch wide band over the surface of the planted furrow after it is sealed. Careless placement of the fertilizer band too close to the seeds and/or excessive application rate can often reduce germination rate, burn seedling roots and result in loss of stand. It is difficult to make a general statement about tion rate. This depends on the type of fertilizer material, method of placement, s texture and the sensitivity of the crop. Be familiar with what others have succes fully done under soil and environmental conditions similar to those found i farm fields. Get into the program only one step at a time. Try a small area for the first couple of years to be sure that the materials and rates of application do not adversely affect seed germination or yield in your soil type. In-furrow application of starters (in direct contact with the seed) is a less costly but much more risky method than the surface band or 2 X 2 application.

Anhydrous ammonia must be applied as a band injected into the soil either at planting or as a sidedress application. This is simply because of the chemical characteristics of that fertilizer material. Liquid nitrogen materials are often applied in a surface or injected band.

Sidedressing: This term generally refers to those fertilizer materials applied to the soil, (after the crop is up), during the early to mid-growth period of the crop. Sidedressed fertilizer materials can be either broadcast on both sides of the row about 6 to 8 inches from the plants or banded down the row middles. Nitrogen fertilizers are more often sidedressed than phosphorus or potassium materials. This is usually to supplement nitrogen needs, but also to ensure more efficient use under cropping conditions that may favor nitrogen loss (sandy soils, wet soils, irrigated soils)

Fertigation: Nitrogen and potassium are sometimes sidedressed by application in the irrigation water that is applied to crop production systems at intervals during the growing season. This is termed fertigation. Phosphorus is not normally applied in this manner because it forms many insoluble compounds with other elements present in the irrigation water. This tends to clog up the irrigation system unless special care is taken to maintain the water pH at a level where most of these compounds will stay in solution. It is usually best to take care of phosphorus needs (if any exist; many soils contain more than adequate levels of phosphorus for crop production) by a broadcast application of concentrated super phosphate fertilizer prior to crop establishment.

Foliar Feeding: Foliar-applied nutrients are absorbed and used by the plant quite rapidly. Absorption begins within minutes after application and is completed within one to two days with most nutrients. Foliar nutrition can supplement soil nutrition at a critical time for the plant (i.e., to maintain iron nutrition for an established acid-loving plant during the time period of soil pH adjustment with acid-forming fertilizers), but it is not a substitute for soil application. This is especially true for the primary and secondary nutrients. In agronomic cropping systems, University of Tennessee research has shown benefit from foliar application of potassium in some cotton fields. Foliar feeding with potassium is indicated for cotton during the first two years of beginning soil potassium fertilization for those fields testing low in potassium.

Application Methods Potassium

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