Gum boots on and plant tissue sample pastures
Spring can be a hectic time of year and this often means some beneficial agronomy activities may be dropped in the rush. But this year, while we wait for paddocks to dry out, there is a window of opportunity to get on farm and take some leaf tissue samples.
by Lee Menhenett - Technical Agronomist
Download this article
Then, when the paddocks dry out and farmers are busy cutting silage and hay, you’ll be one step ahead, ready to help with some recommendations that will help maximise feed growth for the rest of spring.
Why leaf tissue test?
- It will assist with nutrient decisions to drive the dry matter yield of subsequent hay cuts or grazing rotations.
- It will provide some real data on nutrient removal to assist in future nutrient budgeting.
- It will provide nutrient information for next autumn’s fertiliser application (especially with regard to micronutrients and potassium).
Leaf tissue testing can be likened to a blood test. It provides valuable insights into the nutrient status of the specific plant species sampled.
If a nutrient status is found to be low, then rectifying the problem with a fertiliser application following the silage cut can assist with dry matter yield in the subsequent hay cut or grazing rotation.
In addition to refining spring fertiliser applications, a report on leaf tissue nutrient concentrations allows you to calculate nutrient removal.
All you need is the dry matter yield results from the farmer or contractor. (For example: K at 2.5% x 3 t DM/ha = 75 kg/ha of potassium removed.)
This assists with nutrient replacement strategies and also with understanding nutrient redistribution when fed back to stock.
Most autumn fertiliser programs are formulated from a soil test taken over the summer and early autumn. While this is a recommended strategy, we know leaf tissue sampling provides greater accuracy in predicting micronutrient responses.
While plants are actively growing now, in the spring, it’s a great time to take a ‘blood sample’ and see exactly how the plant is feeling, so any micronutrient (or macronutrient) deficiencies can also be addressed next autumn.
Forward thinking, and gathering as much information as possible, is the best way to provide valuable nutrient recommendations.
For more information, give me a call on 0412 565 176. If plant sampling bags are required contact Nutrient Advantage Laboratory Services on 1800 803 453.
Lee Menhenett
Agronomist – grazing systems
Incitec Pivot Fertilisers
Sampling instructions for key plant species
In each leaf tissue sample, 200 grams of plant material is required.
Lucerne
Sample during a period of active growth, before flowering. Take the top 15 cm of the whole plant.
Temperate legumes
Sample in spring to early summer. In white and strawberry clovers, take the green leaves with petioles at pre-flowering stage. For all other varieties, take all the green leaves and stems from 5 to 7 cm above ground at pre-flowering stage.
Ryegrass
Sample during the active growing season, when moisture is adequate for two to three weeks. Take 40 to 50 tillers at random from over the paddock. All growth – cut 3 to 5 cm above the ground after two to five weeks of regrowth.