Polysulphate Sweet Potato Trial in USA

7

Yield Increase
Polysulphate fertilizer increased sweet potato yield by 7% compared to the grower standard practice (GSP) in a trial in North Carolina, USA

Kenly, North Carolina, USA
2019

Trail

7

Yield Increase

Key Conclusions

Compared with the GSP, using a blend with Polysulphate increased sweet potato yield by 7% or approximately 4.9 bushels/acre. 

 

Objective

To compare the effect on sweet potato (Ipomoea batatas) yield of replacing the grower standard fertilizer blend with a blend which contains Polysulphate, in North Carolina, USA. 

Trial Details

Trial station

Kenly, North Carolina, USA

Crop

Potato

Product

Polysulphate Granular

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.

 

TreatmentNP2O5K2OSMgCa
kg/ha (lbs/acre) kg/ha (lbs/acre) kg/ha (lbs/acre) kg/ha (lbs/acre) kg/ha (lbs/acre) kg/ha (lbs/acre)
Farmer's blend23 (21)61 (54)225 (201)17 (15)8 (7)-
Blend with Polysulphate26 (23)65 (58)224 (200)57 (51)10 (9)37 (33)

 

These blends were applied two weeks after setting. Both treatments had liquid UAN (urea ammonium nitrate) sidedressed 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.

 

TreatmentNP2O5K2OSMgCa
kg/ha (lbs/acre) kg/ha (lbs/acre) kg/ha (lbs/acre) kg/ha (lbs/acre) kg/ha (lbs/acre) kg/ha (lbs/acre)
Farmer's blend23 (21)61 (54)225 (201)17 (15)8 (7)-
Blend with Polysulphate26 (23)65 (58)224 (200)57 (51)10 (9)37 (33)

 

These blends were applied two weeks after setting. Both treatments had liquid UAN (urea ammonium nitrate) sidedressed at mid-season. 

Results

    • Compared with the GSP, using a blend with Polysulphate increased sweet potato yield by 7% or approximately 12 bushels/ha (approximately 4.9 bushels/acre). 
    • 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. 

 

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Yield Increase