Polysulphate Wheat Trial
16
León Province, Spain 2022
16
Key Conclusions
Using Polysulphate instead of the usual practice of DAP and iron sulfate increased wheat yield by 16%, and increased the protein content of the wheat by 22%. Overall, the net income from the wheat crop rose by 149% when Polysulphate was used.
Objective
To investigate the efficiency of Polysulphate as a potassium source which also includes sulfur, and to compare it with the farmers’ practice which requires iron sulfate as an additional source of sulfur for wheat.
Trial Details
Trial station
León Province, Spain
Crop
Wheat
Product
Granular Polysulphate
Assessments
NDVI, yield, protein content in grain, and grain specific weight
Treatments
This field experiment on Wheat (Triticum durum, cv. Solindo R1) was conducted in a randomized complete block design with two replicates. The experiment tested three treatments: farmers’ practice without sulfur application, farmers’ practice including an application of iron sulfate at a dose of 200 kg/ha, and Polysulphate applied at 300 kg/ha. The Polysulphate provided all the potassium (42 kg K2O/ha) and the sulfur (58 kg S/ha) as sulfate.
In all three treatments, the nitrogen and phosphorus applications were maintained at 198 kg N/ha and 92 kg P2O5/ha by applying calcium ammonium nitrate and DAP. Potassium was applied at 42 kg K2O/ha, as KCl in the two farmers’ practice treatments and as Polysulphate in the 3rd treatment. All fertilizers were incorporated before sowing, except calcium ammonium nitrate which was applied as top dressing.
Treatments
This field experiment on Wheat (Triticum durum, cv. Solindo R1) was conducted in a randomized complete block design with two replicates. The experiment tested three treatments: farmers’ practice without sulfur application, farmers’ practice including an application of iron sulfate at a dose of 200 kg/ha, and Polysulphate applied at 300 kg/ha. The Polysulphate provided all the potassium (42 kg K2O/ha) and the sulfur (58 kg S/ha) as sulfate.
In all three treatments, the nitrogen and phosphorus applications were maintained at 198 kg N/ha and 92 kg P2O5/ha by applying calcium ammonium nitrate and DAP. Potassium was applied at 42 kg K2O/ha, as KCl in the two farmers’ practice treatments and as Polysulphate in the 3rd treatment. All fertilizers were incorporated before sowing, except calcium ammonium nitrate which was applied as top dressing.
Results
- Polysulphate improved the biomass, measured by NDVI, at the tillering and flowering stages.
- Wheat yield was 16% higher with Polysulphate compared to iron sulfate.
- Protein content of wheat fertilized with Polysulphate was 0.8% higher (an 8% increase) compared with iron sulfate, and up by 2.2% (a 22% increase) compared with the farmers’ practice.
- Polysulphate increased the grain specific weight by 1.7% compared with iron sulfate and 2.1% compared with the farmers’ practice.
- Polysulphate increased the net income from the wheat crop by 149% compared with iron sulfate.