With the arrival of October, the year of 2016 is seeping away towards its end. No-one likes to feel that anything - whether that’s a resource or even time itself - has been wasted. We can’t stop time slipping by but we can help farmers to stop
sulphate seeping away beyond their crop roots’ reach.
Cutting losses
Leaching of sulphate in the soil is something that’s preventable. Leaching is the loss of plant nutrients from the root zone. Preventing sulphate leaching has several benefits:
- Retains sulphates within roots’ reach
- Boosts crop growth
- Avoids pollution of groundwater
- Saves the farmer money
So far, many farmers and their advisors would agree, that all makes good sense. The important question is how does Polysulphate perform? Does the sulphate it contains stay in roots’ reach? How long?
An investigation into the rate of sulphate release from Polysulphate provides the answers to these questions.
Learning about leaching
To learn about leaching takes time and careful technique. An experiment to compare the rate of release of sulphate from Polysulphate compared with other fertilizers was set up at the University of Nottingham in the United Kingdom. It took the form of a soil
column test where a series of tall glass tubes were filled with a soil sample - or microfield.
Each soil sample, a depth or column of loam soil, had previously been leached of soil nutrients. Then four different fertilizers - Polysulphate, ammonium sulphate, sulphate of potash and kieserite - were added to the tops of the soil. The fertilizers each contained
equivalent rates of sulphur.
Then it rained. By rain, we mean that the researchers flushed the soils daily with de-ionised water and then measured the sulphate contents of the leachates - the water containing water soluble nutrients that drain out the bottom of the soil samples.
The results are significant.
|
