It’s Time to Start Monitoring your Alfalfa Fields for %NDF

alfalfa

Ohio has seen on average a cooler spring than in previous years even though there were record and near-record highs last month. Fluctuations in temperature and varying rainfall make it extremely difficult to determine the exact date every year when to harvest alfalfa stands. If managed properly, spring harvests can be one of our most and least digestible harvest of the year. Many growers may base harvest decisions primarily on alfalfa maturity; however, this method can be misleading due to climatic variations affecting the rate of bud and flower development.

Spring changes of alfalfa %NDF can increase about 5 percentage units each week. Therefore, it is imperative for growers to be monitoring their alfalfa for optimal harvest times. Traditional wet chemistry remains the best method to measure %NDF; however, these traditional methods are often too time consuming when a rapid estimation of NDF is needed to make harvest decisions. 

Growers can easily measure %NDF in their fields using a method referred to as PEAQ, Predictive Equations for Alfalfa Quality. This method uses max height and max stage of a pure standing alfalfa crop to determine %NDF. Neutral Detergent Fiber estimations using this method can begin as soon as the alfalfa crop reaches at least 16 inches in height. The protocol for utilizing PEAQ in the fields can be found here and short video describing the method can also be found here.

The PEAQ method was developed for pure alfalfa stands. Using this method to determine %NDF of alfalfa-grass mixtures will be inaccurate.  Cornell University has developed a method to estimate %NDF in both grass and alfalfa-grass mixtures using a smart phone app. More information on this method and where to download the app can be found at forages.org.

Over the next few weeks ANR Educators and State Specialists across Ohio will be reporting %NDF of pure alfalfa stands. Below are NDF estimates from the past week.

Table 1. Alfalfa Average %NDF for Counties Across Ohio

Date

Location (County)

Average Height

Stage

Average %NDF

4/25/22

Adams

17.7

Vegetative

29.7

4/29/22

Adams

18.6

Vegetative

30.7

4/30/22

*Geauga

8

Vegetative

 

5/2/22

Licking

16

Vegetative

28.6

4/29/22

*Putnam

12

Vegetative

 

4/29/22

*Stark

12

Vegetative

 

5/2/22

*Wayne

12

Vegetative

 

* Alfalfa with max height below 16 inches cannot be calculated using PEAQ.

The Hay and Forage Grower recently published a great article on the importance of a timely first cutting alfalfa harvest. This article can be found here.

 

 

 

 

Crop Observation and Recommendation Network

C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.