Polysulphate Sweet Potato Trial in USA
7
Kenly, North Carolina, USA 2019
7
Key Conclusions
Compared with farmers’ fertilization practice, using a blend with Polysulphate increased sweet potato yield by 7%, and increased #1s by 12 bushels/ha.
Objective
To compare the effect on sweet potato (Ipomoea batatas) yield of replacing the farmers’ practice fertilizer blend with a blend which contains Polysulphate, in North Carolina, USA.
Trial Details
Trial station
Kenly, North Carolina, USA
Product
Granular Polysulphate
Assessments
Sweet potato yield
Treatments
Farmers’ practice consisted of a blend of DAP, MOP, and potassium-magnesium sulfate, while the Polysulphate treatment consisted of a blend of DAP, MOP and Polysulphate.
Treatment | N | P2O5 | K2O | S | Mg | Ca |
---|---|---|---|---|---|---|
kg/ha | kg/ha | kg/ha | kg/ha | kg/ha | kg/ha | |
Farmer's blend | 23 | 61 | 225 | 17 | 8 | - |
Blend with Polysulphate | 26 | 65 | 224 | 57 | 10 | 37 |
These blends were applied 2 weeks after setting. Both treatments had liquid UAN (urea ammonium nitrate) side dressed at mid-season.
Treatments
Farmers’ practice consisted of a blend of DAP, MOP, and potassium-magnesium sulfate, while the Polysulphate treatment consisted of a blend of DAP, MOP and Polysulphate.
Treatment | N | P2O5 | K2O | S | Mg | Ca |
---|---|---|---|---|---|---|
kg/ha | kg/ha | kg/ha | kg/ha | kg/ha | kg/ha | |
Farmer's blend | 23 | 61 | 225 | 17 | 8 | - |
Blend with Polysulphate | 26 | 65 | 224 | 57 | 10 | 37 |
These blends were applied 2 weeks after setting. Both treatments had liquid UAN (urea ammonium nitrate) side dressed at mid-season.
Results
- Compared with farmers’ fertilization practice, using a blend with Polysulphate increased sweet potato yield by 7%, and increased #1s by 12 bushels/ha.
- The results showed that with equal amounts of N, P, and K there is a benefit from choosing Polysulphate fertilizer due to the higher rate of plant-available sulfur and calcium. Also, the prolonged availability of the nutrients from Polysulphate may contribute to the enhanced yields.