Polysulphate Coffee Trial in Vietnam
11.5
Bao Lam district, Lam Dong Province, Vietnam 2015
11.5
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
Crop
Coffee
Product
Granular Polysulphate
Assessments
Yield, fruit weight, and A-size core
Treatments
This completely randomized block trial comprised 3 replications, each with 3 treatments:
- Traditional practice/control: single application of urea, KCl, and fused Ca, Mg, and P.
- Commercially available compound fertilizers (with S but no Ca or Mg).
- 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/ha | kg/ha | kg/ha | kg/ha | kg/ha | kg/ha | kg/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:
- Traditional practice/control: single application of urea, KCl, and fused Ca, Mg, and P.
- Commercially available compound fertilizers (with S but no Ca or Mg).
- 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/ha | kg/ha | kg/ha | kg/ha | kg/ha | kg/ha | kg/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%.
Bars indicate LSD at 5%.
Source: Petrovietnam Fertilizer and Chemicals Corporation