The Wisconsin Forage Council exists for the purpose of learning better management skills for forage production and use. For this reason the Wisconsin Forage Council recommends coordinated demonstrations to local councils. By conducting demonstrations in similar manner across the state, results can be compared and new information provided to farmer members.
In addition to the four coordinated demonstrations outlined below, the Forage Council is recommending that all locals participate in the scissors clip program. Measurements can be taken either by clipping or with a forage quality stick (protocols at http://www.uwex.edu/ces/forage/wfc/scissor.htm) and entered into the scissors clip website (http://cf.uwex.edu/ces/ag/scissorsclip/springclip.cfm) for all to use. This is a strong tool many have used to harvest high quality forage in the spring.
Purpose: to determine if manure application to alfalfa affects alfalfa fermentation after ensiling and resulting forage quality.
(1) Apply manure to a portion of an alfalfa field immediately after cutting. Record amount and type of manure applied.
(2) Harvest each portion of the alfalfa field into a silo tube marking the outside to indicate where each treatment occurs.
(3) Four weeks or more after ensiling, take a sample of the forage from each portion of the silo tube and send to Dairyland Laboratories in Acradia, WI. Request a fermentation analysis (pH, acetic acid, butyric acid, isobutyric acid, propionic acid and lactic acid) for $12 in addition to the standard forage analysis.
Purpose: to determine if wheel traffic from harvesting alfalfa affects soil compaction and alfalfa regrowth.
(1) Mow/Harvest with two wheel traffic densities – harvest a portion of the field by cutting 8 to 9 foot swath and baling or chopping each windrow individually. Harvest another portion of the field by taking full cutter width and merging windrows before harvesting. The first should have harvesting wheel traffic very 8 to 9 feet and the latter should have harvesting wheel traffic every 24 ft (if 12 foot mower-conditioner).
(2) Estimate yield of succeeding cutting by weighing portion harvested from 1 acre or more of each treatment or by counting small bales. One acre can be calculated as the length of windrow times the cutter bar width to equal one acre. Note: harvesting of both treatments must occur on same day so that wheel traffic of harvesting is not confounded with alfalfa regrowth.
Demonstration 3: AM/PM Cutting Alfalfa
Purpose: to determine if PM cut alfalfa has higher sugars in harvested material. This has been shown to increase palatability and intake of western hays.
(1) Cut portions of same alfalfa field in morning (8 to 10 am) and in mid afternoon (3 to 5 pm. Condition and handle as normal. Cuttings may both occur on same day or be PM of one day and AM of next.
(2) Take a sample of freshly cut alfalfa within 15 minutes of cutting and freeze.
(3) Bale or chop alfalfa when at appropriate moisture for storage.
(4) Record times of mowing and harvesting. Also record drying conditions: Sunshine, temperature, humidity, wind speed.
(5) Sample stored alfalfa approximately 3 weeks after harvesting. This can be done easily from bales or silage put into a tube that was marked on the outside with spray paint to indicated location of AM and PM cut alfalfa. Send samples to John Peters at UW Marshfield Soil and Forage Analysis Laboratory and request sugar and starch analysis in addition to standard forage analysis.
Demonstration 4: Alfalfa Sulfur Response Trial
Purpose: to determine sulfur fertilizer needs of alfalfa
(1) Choose a site with strong alfalfa stand— If doing more than one site in your area, it is useful to have at least one of them that has not received manure in the last 3 years. Field should have been seeded last year or no more than 2 years ago and should not have received any S fertilizer. We would hope to keep the plots for at least 2 to 3 years.
(2) Layout plots — When small plot clipping or a plot harvester is used, plots may be as small as 5 ft x 10 to 15 ft; however, if field equipment or windrow measurements are used, then plots may be one to two spreader widths wide in strips across the whole field. Treatments should be replicated three to five times.
(3) Take pre-trial soil samples — Three cores should be taken by 6-inch increments to 3 feet and composited. These samples should be sent to Kelling/Speth for analysis.
(4) Apply sulfur treatments — These treatments can be applied after first cutting or after the other harvests if that timing works better. Applications in subsequent years should be made at the same time. We suggest that gypsum (CaSO4) be used as the S source and that a uniform rate of K2O be applied across the whole field. The rate to be applied is 25 lb/acre once per year as sulfate sulfur. A second rate of 50 or 100 lb S/acre/year can also be included as a third treatment.
(5) Harvest each cutting by some method that allows for the determination of quantity of dry matter produced per acre— Possible approaches include:
Whole plot harvest
Small plot harvester
Windrow section weight
Whatever method is chosen, the data that needs to be collected include:
Wet weight of harvested material
Area from which the wet weight material was collected
Collect a subsample so that the moisture content at the time of wet weight measurement can be determined, and the tissue nutrient concentrations can be measured
(6) Send about 1000 g of harvested tissue from each plot to Kelling/Speth for processing and analysis — Sample should be placed in sealed plastic bag to avoid moisture loss. Sample can be delivered, mailed, or sent by a carrier such as UPS.
(7) Fill out site information sheet — Some of the information only needs to be provided once. Other parts (those relating to harvest) must be done at each harvest, for each replication.
(8) Collect 0- to 6-inch depth soil samples (eight to ten cores per plot) following the late-August cutting each year.