Sugarcane response to polyhalite fertilizer in Brazilian Oxisols

Abstract

Polyhalite (PYH), (K 2 SO 4 ůMgSO 4 ů2CaSO 4 ů2H 2 O), contains four nutrients of great importance to sugarcane (Saccharum spp.), but has lower water solubility than traditional K fertilizers. Two studies were conducted to determine if PYH fertilizer (11.6% K) promoted sugarcane response comparable to other K fertilizers on highly weathered, acidic Oxisol soils in Brazil. A pot study compared PYH with potassium chloride (KCl, 50% K) and potassium sulfate (K 2 SO 4 , 40% K and 17% S), both amended to the same Ca, Mg, and S contents, applied at five rates ranging from 0 to 166 kg K ha −1 in limed and unlimed soil. A field study evaluated PYH with KCl applied in a 5-30-10 blend at planting followed by sidedress applications of K as PYH or KCl in the establishment year and two ratoon crops. In the pot study, there were minimal effects of fertilizer source and application rate on early growth in sugarcane while liming was detrimental. Uptake of K in the biomass was linear and similar among fertilizer sources. PYH increased S uptake and soil tests compared to KCl and K 2 SO 4. In the field study, KCl and PYH had similar sugarcane yield and quality with K uptake in both exceeding K applied and PYH increased S uptake and soil test SO 4-S. These studies confirm nutrient release from PYH to sugarcane was adequate and comparable to KCl and K 2 SO 4 , with some effect of PYH on nutrient uptake and soil test that did not affect sugarcane yield or quality.

Improving potassium use efficiency of sugarcane through the use of polyhalite

“…Despite the critical indicators of low soil fertility in this study such as soil acidity and sandy texture, the use of PHY has the potential to sustainably increase sugarcane DM production and nutrient uptake. Similar results have been reported by Pavinato et al (2020) and Bhatt et al (2021), in acid and sandy soils, respectively. Additionally, Fig.…”

Polyhalite Positively Influences the Growth, Yield and Quality of Sugarcane (Saccharum officinarum L.) in Potassium and Calcium-Deficient Soils in the Semi-Arid Tropics

“…A multi-nutrient fertilizer, "polyhalite" (K 2 Ca 2 Mg(SO 4 ) 4 •2H 2 O) contains potassium (14% K 2 O), calcium (17% CaO), magnesium (6% MgO) and sulfur (48% SO 3 ) [14]. Polyhalite is mined 1200 m below the Earth's surface, in the North Sea, along the northeastern coast of the United Kingdom [15], and has lower environmental impacts than other fertilizers [16]. Polyhalite releases nutrients more slowly than traditional fertilizers [17], which may contribute to increased fertilizer use efficiency [18].…”

Optimizing polyhalite (POLY-4) use in the maize-wheat system: A comparative case study from upper and Trans Indo-Gangetic plains of India

“…Though POLY-4 was used as K equivalent basis and compared with MOP, although, POLY 4 ensures additionally four essential macro-elements to make available to the crops. This helped in the elimination of separate application of different nutrient sources and hence improved the economics [ 5 , 6 , 8 ]. Potassium application through POLY-4 improves the activity of different enzymes; maintains optimum cell pH; influence photosynthesis and transport sugar within plant system [ 2 , 8 ].…”

“…Besides four major nutrients, POLY-4 also contains eight main micronutrients, including boron, copper, iron, manganese, molybdenum, selenium, strontium, and zinc. POLY-4 as a polyhalite is mined from the earth, along the north-eastern coast of the United Kingdom [ 4 ], and has lower environmental impacts than other fertilizers [ 5 ]. It is a raw-processed but not a refined product, therefore involves lesser environmental footprint.…”