10 15 20 25

3.5

4.0

4.5

5.0

10 15 20 255 15 25

10

20

30

40

50

5 10 15 20 25

Introduction

Polyhalite has potential to be a multi-nutrient fertilizer for maize

production. However, little information is available for the

response of maize to polyhalite. This study was conducted for

two consecutive seasons (2013 and 2014) to compare effects of

polyhalite (POLY), to muriate of potash (MOP), sulfate of

potash (SOP) and sulfate of potash magnesia (SOPM), on maize

grown in a sandy soil in greenhouse and in open field excluding

SOPM.

Materials and Methods

For both studies, treatments were arranged in a complete

randomized design with three and four replicates for the

greenhouse and the open field respectively. Fertilizers were

applied at the rates of 50, 100, 200, and 300 K2O Kg ha-1, for the

greenhouse and 50, 100, 150, and 250 K2O Kg ha-1 for the open

field. Soil used in both studies was the Ankona sandy soil

(Sandy, siliceous, hyperthermic, ortstein Arenic Ultic Alaquods).

All treatments received 200 N kg ha-1 as urea and 125 P2O5 kg

ha-1 as triple super phosphate (TSP). POLY was provided by

Sirius Minerals Plc, Scarborough, UK and MOP, SOP, SOP-M,

urea and TSP were acquired from a local fertilizer dealer.

Evaluated variables

Soil analysis before planting and after harvest, plants height,

plants basal stem diameter, kernel size, grain yields, leaves

greenness, elemental concentration in leaves and in grains at 30

and 100 days after planting respectively were analyzed for both

studies. For the greenhouse study, the germination rate and

number of leaves were also assessed. Treatments effects over

variables were quantified using analysis of variance (α >0.05)

and marginal means were separated using Student’s LSD or

Tukey’s HSD.

Results

Germination rate from seeds in pots receiving MOP at 300 K2O

kg ha-1 was 33% and 42% for the 2013 and 2014 season,

respectively while other treatments had 75%-100% germination

rates. MOP effect over seeds germination was not observed in

the open field study at the rate of 250 K2O kg ha-1, the highest

rate used in that study. Maize responded well to polyhalite

under greenhouse and field conditions. POLY does not affect

maize seed germination nor kernel size.

Using Polyhalite As a Multi-Nutritional Fertilizer for Corn

Number of leaves and basal stem diameter for plants receiving POLY were similar to those receiving MOP, SOP and SOPM. Plants receiving POLY were taller than those receiving SOPM

and MOP. Leaves were greener for plants receiving SOP and POLY than those receiving SOPM and MOP. Total fresh and dry weight from those plants receiving POLY were similar to

those receiving SOP, but greater than the ones receiving SOPM and MOP. K uptake by leaves from those plants receiving POLY was similar to SOP but greater than SOPM and MOP. Ca

uptake by leaves from those plants receiving POLY was greater than those receiving MOP, SOP or SOPM. Mg uptake by leaves and grains from those plants receiving POLY was similar

to those receiving SOPM, but greater than those receiving SOP or MOP. K and Ca uptake by grains from those plants receiving POLY was greater than SOP, SOPM and MOP. After

harvest, more available Ca and SO4 were found in the soil treated with POLY than those treated with MOP and SOP.

SOP-M SOP POLY MOPGreenhouse in g plant-1 Open field in Mg ha-1

Ca

in soil

after

harvest

Correlation

between

Grain yield

and

K concentration

in leaves

Marcel Barbier, Yuncong Li, Guodong Liu, Zhenli He, Rao Mylavarapu, Shouan Zhang

Tropical Research and Education Center & Indian River Research and Education Center

Conclusions:

This study demonstrated that POLY is an alternative source of K, Ca, Mg and S and can meet the nutritional

requirements of maize plants for healthy growth and production.

Acknowledgements:

We want to thank Sirius Minerals Plc. for the

support and sponsor of this study.

Gra

ins

g p

lan

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2013 2014

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2014

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2014

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2013

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2014

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2014

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2013

100K2O ha-1

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Greenhouse Open field

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