Polysulphate Coffee Trial in Vietnam

11.5

Yield Increase
Supplementing NPK with Polysulphate improved yield (by 11.5%) and quality of coffee crop, increasing net profits by 14%.

Bao Lam district, Lam Dong Province, Vietnam
2015

Trail

11.5

Yield Increase

Key Conclusions

Supplementing NPK with Polysulphate fertilizer increased coffee yield by 11.5%, produced superior quality fruit (indicated by the increased proportion of size A cores), and increased net profit by 14%.

Objective

To evaluate the efficacy of Polysulphate to increase coffee (<em>Coffea robusta</em> yield in Vietnam, and to evaluate the cost-effectiveness of applying fertilizers in split doses compared to the traditional practice of a single application of urea, KCl, and fused Ca, Mg, and P.

Trial Details

Trial station

Bao Lam district, Lam Dong Province, Vietnam

Product

Granular Polysulphate

Assessments

Yield, fruit weight, and A-size core

Treatments

This completely randomized block trial comprised 3 replications, each with 3 treatments:

  1. Traditional practice/control: single application of urea, KCl, and fused Ca, Mg, and P.
  2. Commercially available compound fertilizers (with S but no Ca or Mg).
  3. Same as as the commercially available compound treatment (2. above) but supplemented with Polysulphate.

In the 2 treatments, the total fertilizer dose was split into 4 applications, the first at the beginning of the dry season and the remaining 3 in the early, mid, and late rainy season.

 

Treatment Urea Fused
Ca Mg P
KCl NPKS
16-16-8-13 
NPK
15-15-15
NPKS
15-18-20-10
Polysulphate 
kg/hakg/hakg/hakg/hakg/hakg/hakg/ha
Control 715 1,193 545 
Compound
fertilizers + S
250 200 400 500 500 
Compound
fertilizers + S
with Polysulphate
250 153 400 500 500 200 

Treatments

This completely randomized block trial comprised 3 replications, each with 3 treatments:

  1. Traditional practice/control: single application of urea, KCl, and fused Ca, Mg, and P.
  2. Commercially available compound fertilizers (with S but no Ca or Mg).
  3. Same as as the commercially available compound treatment (2. above) but supplemented with Polysulphate.

In the 2 treatments, the total fertilizer dose was split into 4 applications, the first at the beginning of the dry season and the remaining 3 in the early, mid, and late rainy season.

 

Treatment Urea Fused
Ca Mg P
KCl NPKS
16-16-8-13 
NPK
15-15-15
NPKS
15-18-20-10
Polysulphate 
kg/hakg/hakg/hakg/hakg/hakg/hakg/ha
Control 715 1,193 545 
Compound
fertilizers + S
250 200 400 500 500 
Compound
fertilizers + S
with Polysulphate
250 153 400 500 500 200 

Results

  • Supplementing NPK with Polysulphate resulted in an increase in yield of 11.5% and superior quality produce – more than 22% of the cores were of size A, or larger than 6.3 mm in diameter.
  • Higher yield was due to faster growth, longer fruiting branches, less shedding of immature fruit, and larger and heavier cores.
  • Polysulphate application also increased net profits by 14%.

 

Supplementing NPK with Polysulphate increased coffee yield by 11.5%

Supplementing NPK with Polysulphate increased coffee yield by 11.5%.

 

Polysulphate fertilizer increased coffee fruit weight

Polysulphate fertilizer increased coffee fruit weight.

 

Number of size A coffee cores increased by 22% with Polysulphate

Number of size A coffee cores increased by 22% with Polysulphate.

Bars indicate LSD at 5%.

 

Source: Petrovietnam Fertilizer and Chemicals Corporation

 

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