Polyhalite alters the uptake and partitioning of mineral nutrients in corn

[摘要] Modern corn (Zea mays L.) hybrids coupled with advanced agronomic practices have led to an increased yield potential on many US corn acres, but to realize these higher yields requires a better understanding of crop nutrition. Polyhalite is a multi-nutrient fertilizer that supplies four key plant nutrients potassium, calcium, magnesium, and sulfur. Sirius Minerals, a company formed to develop and market the new fertilizer, has started to commercially produce a granulated version of polyhalite with the trade name POLY4 (0-0-14-10Ca-4Mg-19S). The granulated version of polyhalite has several unique chemical characteristics that allow for a synchronized release of each nutrient in a season-long fashion. The slow-release delivery of POLY4 is the result of the fertilizer’s physical characteristics, specifically its relatively low water solubility of 27 g L-1 (25 ℃). Until recently, polyhalite based fertilizers have not been widely offered as a commercially available products due to limited mineral supply; however, there is renewed interest in polyhalite as a broad acre fertilizer due to the recent discovery of a vast Zechstein deposit in the North Sea basin on the coast of the United Kingdom. The objective of this study was to document the pattern of uptake, partitioning, and remobilization of nutrientsby corn plants fertilized with POLY4 compared to muriate of potash (MOP;0-0-60). Field studies were conducted in 2017 and 2018 comparing pre-plant applications of 75 lb acre-1 of K2O as MOP, 75 lb acre-1 of K2O as POLY4, and 75 lb acre-1 of K2O as a 75:25 blend of POLY4:MOP to an untreated control. Plants were sampled above ground at the V6, V10, V14, R2, R4, and R6 growth stages, and separated into four fractions for dry weight and nutrient determination, with grain yield also measured at physiological maturity. All of the potassium fertilization treatments resulted in significantly greater above ground dry weight accumulation compared to the unfertilized control, but season-long plant accumulations of potassium and sulfur were greater in response to all treatments containing POLY4. Corn grain yield production was greatest for plants fertilized with POLY4 and POLY4:MOP; both of which resulted in a 6 bu acre-1 yield increase over plants fertilized with MOP and a 7 bu acre-1 yield increase compared those that did not receive any potassium fertilizer. Corn that did not receive any potassium fertilizer had a two-year average grain yield of 254 bu acre-1. Differences in crop growth and productivity (grain yield and dry weight accumulation) among the potassium fertilizer treatments was the result of alterations in seasonal nutrient accumulation as plants fertilized with POLY4 and/or POLY4:MOP appeared to be supplied with optimal crop nutrition compared to plants fertilized with MOP and/or those that did not receive potassium fertilizer. These results, in addition to the new discovery of a vast Zechstein deposit potentially keeping product cost low, suggest that polyhalite – in the form of POLY4 – may be an efficient and effective premium fertilizer source for corn growers in central Illinois.

[效力级别] Polyhalite

[关键词] Corn;Polyhalite;Nutrient Uptake;Maize;Potassium;Calcium;Magnesium;Sulfur;Yield;Illinois;United States;Fertility;POLY4;Nutrient;Uptake;Partitioning;Remobilization;Nutrient Accumulation