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Copy link Polysulphate Alfalfa Trial in France
12
Yield increase
Polysulphate increased alfalfa yield, improved alfalfa quality parameters, and reduced the carbon footprint of the crop.
Vésigneul-sur-Marne, France 2020
12
Key Conclusions
Throughout the experiment, the Polysulphate fertilizer alfalfa yielded more than the control plot, increasing alfalfa yield by 12%.
Objective
To evaluate Polysulphate, in combination with KCl, as a K and secondary macronutrients source for rainfed alfalfa, and to examine the response of both yield and quality to increasing proportions of Polysulphate.
Trial Details
Trial station
Vésigneul-sur-Marne, France
Crop
Alfalfa
Product
Granular Polysulphate
Assessments
Yield, feed quality parameters, and carbon footprint
Treatments
- This alfalfa trial consisted of 3 replications, on a randomized complete block design.
- Four different treatments were established with combinations of 2 different sources of potassium, potassium chloride (KCl) and Polysulphate, at a similar K dose of 300 kg K2O/ha, with 4 different proportions: all K from KCl, and 10%, 20% and 40% of the K from Polysulphate.
- A control was established which received no additional nutrient supply.
- The alfalfa was harvest in 6 cuts: 25 May 2019, 1 July 2019, 23 August 2019, 13 May 2020, 3 July 2020, and 20 August 2020.
| Treatment | Fertilizer quantity | Amount of nutrients | |||||
|---|---|---|---|---|---|---|---|
| MOP (KCl) | Polyhalite | K2O | MgO | SO3 | CaO | ||
| kg/ha | kg/ha | kg/ha | kg/ha | kg/ha | kg/ha | ||
| Controls | 0 | 0 | 0 | 0 | 0 | 0 | |
| KCl | 500 | 0 | 300 | 0 | 0 | 0 | |
| Polysulphate 200 | 450 | 200 (granular) | 300 | 12 | 96 | 32 | |
| Polysulphate 405 | 405 | 405 (granular) | 300 | 24 | 194 | 65 | |
| Polysulphate 800 | 310 | 800 (powder) | 300 | 48 | 384 | 128 | |
Treatments
- This alfalfa trial consisted of 3 replications, on a randomized complete block design.
- Four different treatments were established with combinations of 2 different sources of potassium, potassium chloride (KCl) and Polysulphate, at a similar K dose of 300 kg K2O/ha, with 4 different proportions: all K from KCl, and 10%, 20% and 40% of the K from Polysulphate.
- A control was established which received no additional nutrient supply.
- The alfalfa was harvest in 6 cuts: 25 May 2019, 1 July 2019, 23 August 2019, 13 May 2020, 3 July 2020, and 20 August 2020.
| Treatment | Fertilizer quantity | Amount of nutrients | |||||
|---|---|---|---|---|---|---|---|
| MOP (KCl) | Polyhalite | K2O | MgO | SO3 | CaO | ||
| kg/ha | kg/ha | kg/ha | kg/ha | kg/ha | kg/ha | ||
| Controls | 0 | 0 | 0 | 0 | 0 | 0 | |
| KCl | 500 | 0 | 300 | 0 | 0 | 0 | |
| Polysulphate 200 | 450 | 200 (granular) | 300 | 12 | 96 | 32 | |
| Polysulphate 405 | 405 | 405 (granular) | 300 | 24 | 194 | 65 | |
| Polysulphate 800 | 310 | 800 (powder) | 300 | 48 | 384 | 128 | |
Results
- Over the whole duration of the experiment, the alfalfa fertilized with Polysulphate and KCl yielded 1.6 ton/ha more than the crop fertilized only with MOP, and 3.1 ton/ha more than the K0 control.
- A clear trend was observed in all cuts – especially in the second year – with improvements in the quality parameters (protein contents) of the alfalfa fertilized with Polysulphate.
- Polysulphate slightly reduced the carbon footprint of the crop (CO2 emissions calculated with the Cool Farm Tool).
Polysulphate fertilizer increased alfalfa yield by 12% compared to the control.
Different letters indicate significant differences at p < 0.05. Error bars are SD.
* From research funded by the International Potash Institute www.ipipotash.org
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