Supplementing NPK with Polysulphate fertilizer increased coffee yield by 9% and produced superior quality fruit, increasing net profit by 10%.
Location
Di Linh district, Lam Dong Province, Vietnam
Objective
To evaluate the efficacy of Polysulphate to increase coffee 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.
Treatments
This completely randomized block trial comprised three replications, each with three 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 (2) but supplemented with Polysulphate.
In the two treatments, the total fertilizer dose was split into four applications, one at the beginning of the dry season and the remaining three in early, mid, and late rainy season.
Results
- Supplementing NPK with Polysulphate resulted in an increase in yield of 9% 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 10%.
Bars indicate LSD at 5%.
Source: Petrovietnam Fertilizer and Chemicals Corporation