Cool-season turfgrasses are the dominant grass species used on Indiana golf courses. These species include Kentucky bluegrass, annual bluegrass, perennial ryegrass, tall fescue, fine fescue, and creeping bentgrass. Cool- season turfgrasses benefit enormously from late fall fertilization programs. Some spring nitrogen applications are recommended, but are usually kept to a minimum.
Warm season grasses such as zoysia and bermudagrass are common in southern Indiana. These species benefit from summer applications of nitrogen.
Before designing a fertilization program for your golf course, soil tests should be taken of greens, tees, and fairways. A soil test is instrumental in determining phosphorus and potassium recommendations and also will identify pH problems. Refer to AY-18, "How to Interpret Your Lawn Soil Test Results".
Actual N | ||
Date | lbs/1000 | lbs/A |
September | 1.0 | 43 |
Nov. 1 - Nov. 15* | 1.0-1.5 | 43-65 |
May 15 - June 1 | 1.0 | 43 |
* Apply after last mowing but while grass is still green | ||
Often budgets do not allow for this amount of nitrogen to be applied. If only one application can be made, apply the September treatment. If two applications can be made, apply the September and November treatments.
November fertilizer applications should be of fertilizer that contains 70% or more water soluble nitrogen or a nitrogen source containing isobutyldene diurea(IBDU). This is because the cool fall temperatures reduce microbial activity needed to release nitrogen from ureaformaldehyde(UF) fertilizers, sulfur coated urea(SCU), or natural organic nitrogen sources.
Advantages of the late fall fertilization include a denser turf which reduces weed competition, improved root systems, reduced mowing frequency in the spring, earlier spring greenup, better drought tolerance, and fewer disease problems.
Date | lbs N/1000ft2 |
August | 0. 5 |
September | 1.0 |
November | 1.5 |
May | 0.5 |
June | 0.5 |
This plan, or program, is for fertilizers containing more than 1/3 WIN. Avoid using fertilizers containing less than 1/3 WIN (thereby avoiding buildup of slow release nitrogen in the green). This program should be used as a guide only. Nevertheless, experience of the greens superintendent will determine the final fertilizer applications. As a rule of thumb, color and growth dictate fertilizer needs. If greens are off-color, or are not growing fast enough to recover from wear during the summer, 0.5 lbs. N/1000 ft2 should correct the problem without a large growth flush. Dark green, lush turf should be avoided during the summer because of increased susceptibility to pythium, brown patch, and other diseases. Some superintendents employ a "spoon feeding" program during the summer by applying frequent applications of 1/8 lb N, or less, every other week. This allows maximum control over bentgrass growth.