Issue 5 2017
 
Peanut yield given a push with Polysulphate
Experimental site at Binh Dinh Province, Vietnam. Photo by G. Kalyan.
Peanut research proves power of Polysulphate
If someone asked you to pick the number of countries where peanuts are a crop, what would you say? If your answer was close to a hundred you would be close. In fact 112 countries grow the peanut crop and that’s why news from Vietnam of the power of polyhalite to increase yield and improve quality is so interesting.
 
Peanut potential
Push up the productivity of the peanut crop and farm incomes could potentially go up in parallel. Moreover peanuts, as a legume, are an important part of the traditional rotation in the central coast region of Vietnam. Not to mention their contribution to the local and regional diet.
 
Investigating the power of polyhalite
With those three reasons in mind the research team, supported but the International Potash Institute (IPI), began their research to evaluate the effects of K and polyhalite. They also hoped to develop fertilizer recommendations for the Central Coast of Vietnam.

Crop development was monitored closely from germination to harvest. Soil examinations were carried out before and after harvest to measure the texture, pH, organic matter and residual levels of nutrients.

The full methodology and the results are published and available to download from the IPI website by clicking this link .

Proving how peanuts and soils benefit
The results of the work in peanut plots are positive. They show that giving optimum K (60 kg/hectare) and polyhalite (214 kg/hectare) doses in two applications gave rise to 24% increase in yield and 98% increase in net benefit to the farmer. In addition it was found that using polyhalite created a balanced N-P-K-S management leading to enhanced soil fertility and a sustainable cropping system.
Effects of fertilization treatments on peanut net yields and harvest index. Different letters indicate statistically differences in net yields at P <0.05. Polysulphate was applied to treatments NP-K30-S1, NP-K60-S2, and NP-K90-S3 at doses of 25, 50 and 75 kg/ha S (corresponding to 107, 214, and 321 kg/ha Polysulphate), respectively.
Polysulphate improved profitability
The highest profit to the farmer occurred at treatment NP-K60-S2 (214 kg/ha of Polysulphate), with benefit rate of 0.57, twice as high as that of FP (farmers' practice).  
Effects of fertilization treatments on net income and benefit rate from peanut production in 2016 at Cat Hai commune, Phu Cat district, Binh Dinh province, Vietnam. Polysulphate was applied to treatments NP-K30-S1, NP-K60-S2, and NP-K90-S3 at doses of 25, 50 and 75 kg/ha S (corresponding to 107, 214, and 321 kg/ha Polysulphate), respectively.
Putting Polysulphate at the heart of sustainable cropping
It is another example to add to the portfolio of proof of the power of polyhalite - both as a source of key plant nutrients itself and for its synergistic effect on the uptake of other nutrients.
 
To improve yield and crop quality is a valid goal in itself, but combine that with cost-effectiveness, the boost to farm incomes and the considerable contribution to soil health and sustainable systems and you are left with a whole basket full of reasons to advocate the use of polyhalite as fertilizer.
Overview of the trial plots at Binh Dinh Province, Vietnam. Photo by G. Kalyan.
 
Mined in the UK, ICL is the first – and only - producer in the world to mine polyhalite, marketed as Polysulphate™