POLY4 increases yield
Here is a breakdown of the polyhalite products yield performance against compared treatments and crop groups.
Here is a breakdown of the polyhalite products yield performance against compared treatments and crop groups.
Statisticians analysed replicated field trials and estimated yield gains from POLY4 fertiliser programmes vs. standard NPK programmes:
* - Mann, K. K., Fields, R., Welham, S., Storer, K. E., Roques, S. E., Berry, P., Wade, B. R., Kindred, D., & Pienaar, C. (2025). Meta-analysis of polyhalite's yield performance across diverse soil, crop, and environmental conditions. Agronomy Journal, 117, e70259. https://doi.org/10.1002/agj2.70259
+1.3%
Corn (112 trials)
+2.3%
Wheat (69 trials)
+3.0%
Barley (15 trials)
+3.7%
Rice (45 trials)
+2.0%
Legumes (69 trials)
+10.0%
Sugarcane (17 trials)
+3.6%
Tree crops (60 trials)
+6.2%
Vegetables (57 trials)
Comparison table showing POLY4 vs. standard treatments and a breakdown of results by crops.
Treatment comparison | Yield increase estimate* | Yield increase estimate* | No. of trials |
POLY4 vs. NP | 6.6% | 12.2% | 649 |
POLY4 vs. NPK | 3.2% | 4.8% | 586 |
POLY4 vs. NPKS | 1.7% | 2.5% | 526 |
POLY4 vs. NPKSMg | 0.5% | 1.0% | 259 |
By crop | Yield enhancement | Yield enhancement | Yield enhancement | No. of trials |
Barley | 6.3% | 3.0% | 1.2% | 24 |
Corn | 4.5% | 1.3% | 1.3% | 117 |
Cotton | 6.1% | 1.4% | -1.7% | 21 |
Forage | 8.6% | 3.1% | 2.1% | 21 |
Legume | 3.8% | 2.0% | 2.1% | 72 |
Oilseed | 7.6% | 4.6 | 1.6% | 55 |
Potato | 9.5% | 0.7% | 1.7% | 38 |
Rice | 8.3% | 3.7% | 0.1% | 42 |
Sugarcane | 16.3% | 10.0% | 6.3% | 23 |
Tree crop | 7.5% | 3.6% | 5.2% | 87 |
Vegetable | 12.5% | 6.2% | 1.6% | 61 |
Wheat | 4.6% | 2.3% | 1.0% | 85 |
Results shown are taken from Meta-analysis of polyhalite's yield performance across diverse soil, crop, and environmental conditions (https://acsess.onlinelibrary.wiley.com/doi/full/10.1002/agj2.70259).
Estimates of percentage increase in yield due to fertiliser programs based on polyhalite compared with different control treatments for all trials. *Meta-analysis estimates are optimistic (no outliers removed), intermediate (trials with stdres > 3.0 removed), or conservative (trials with stdres > 2.0 removed). Trials classified as “responsive” had a significant improvement (P<0.1) in yield with K or S fertiliser applications.
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