Moisture content is one of the most important variables — and challenges — the high quality hay producer must face. Baling at proper Moisture levels is critical to the hay grower’s objective — to bale and store hay in a manner to reduce mold development and at the same time preserve leaves, color, and feed value. Using a Moisture Tester is the only way a farmer can be sure that his hay is being baled at the ideal Moisture levels.

Most probe-type meters operate on the principle of electrical resistance, utilizing the relationship between the Moisture content of the material and its conductivity. This relation is possible because Moisture is an effective conductor of electricity and hay acts as an effective insulator. The "reading" is made between the two metal contacts at the tip of the probe.

Traditionally, the recommended Moisture content for baling hay without a preservative is between 18-20%.

If using a preservative, follow the instructions set forth by each particular preservative manufacturer. Smart use of a Moisture Tester in combination with preservatives and drying agents allows hay to be baled at higher than traditionally recommended Moisture levels.

In either case, do not attempt to bale hay before it is at an acceptable Moisture level, even when using a preservative.

In The Windrow

• Collect hay from the windrow and place it in a five or ten gallon container. Apply a multi-pin prod to the hay and press down on the handle. Take a reading. Mix the hay and repeat this procedure no less than three times.
  Then from the same area of the windrow, select up to five large, slower-drying stems and place one at a time across two adjacent points on the multi-pin prod and take readings. The average of these stem readings should be about two to five points higher than actual Moisture content.
• Repeat these steps in different parts of the field and pay special attention to the areas where the hay is heaviest. Your decision to start baling should consider the amount of variation found among windrow readings as well as the average stem Moisture.

In The Bale

• Since the interior of most bales is seldom uniform with regard to density and leaf/stem ratio, and it is impossible to obtain a truly "representative" sample, it is important to take a number of readings from various parts of a bale and average them. Pay close attention to the range of readings and the high readings. Drive the prod across the bale slices to obtain firmer, more uniform contact.

Random spoilage of baled hay can occur due to fluctuating field conditions, i.e. windrow size, soil Moisture, stand density, low spots, and shade. Therefore, it is imperative to check bales at several locations in the field.

In The Bale Chamber

• The hay producer can install a micro-controller based Moisture Meter in the tractor cab and connect it to a sensor in the bale chamber to monitor Moisture while baling, without leaving the cab.
• The microcomputer collects and processes eight readings that are accumulated every four seconds. The meter then displays the average and highest reading. This cycle is repeated every four seconds.

A microprocessor-based continuous monitor is an easy and reliable way to give the operator clear guidelines and a little less to worry about. Even though this method provides reliable information, we recommend that you take readings in several bales, especially at the beginning of baling, and as you see conditions change. The FX-2000 can be used for on-the-go Moisture monitoring or as a portable meter.

Besides Moisture content, factors which affect meter readings most are: Moisture distribution, crop variety, temperature of the hay, crop maturity, sample density, cutting, and the overall climatic conditions present. Cloud cover and high relative humidity result in more variable Moisture readings than a sunny, dry day with light breezes.

Because field conditions can change rapidly, accuracy guidelines must be considered in terms of "ranges", not specific points. Claims of accuracy should be taken with caution, because it is unlikely that such claims can be consistent. Expert evaluations of the same meter may yield different results, mainly dependent on the technician’s sampling procedure, conditioning and uniformity of the samples, difference in crop, and differences in oven test procedure. For optimum results, carefully read the owners manual provided with each meter.

The primary or electrical calibration of the tester can easily be checked by the built-in calibration checkpoint feature or by using an optional Moisture content standard.

Delmhorst Moisture Meters are well known for their ruggedness and ability to withstand years of rough handling. Like any testing instrument, a little care goes a long way toward trouble-free service:

• Store the meter in clean, dry place
• Change batteries and pins as needed
• Keep the meter and electrode clean by using any biodegradable cleanser sparingly on external parts only.