Potassium Fertilization for Fresh Market Potato Production in Tropical Soils

Abstract

Potassium (K) is the most taken up and removed nutrient by potato (Solanum tuberosum L.), and has a great influence on tuber yield and quality. This study was performed to evaluate the effects of three rates (100, 200, and 400 kg K2O ha−1) and two timings of application of K (single application at planting furrow and split application of 50% at planting furrow plus 50% at hilling), as potassium chloride, as well as a control (without K application) on the plant nutrition and tuber yield and quality of potato ‘Agata’ grown in tropical clay soils. The split application of K fertilizer had little influence on plant nutrition and tuber yield and quality. The influence of K fertilization on increasing K and reducing Ca and Mg concentrations in the leaf was more significant in soil with low exchangeable K. In this soil, the maximum tuber yield (33.6 Mg ha−1; 107% higher than the control) was obtained with an estimated rate of 325 kg K2O ha−1, while in the soils with medium and high exchangeable K, the tuber yield was increased between 22 and 34% and only up to a rate of 200 kg K2O ha−1. The critical leaf K concentration to reach 95% of the maximum yield was 29.3 g K kg−1, but there was an extreme increase in the tuber yield even with K rates that provided leaf K concentrations above this limit. Potassium fertilization increased the firmness and reduced soluble solids and protein in tubers. Core Ideas K is the nutrient that is most taken up and removed by the potato crop. In clay soils, the splitting of K fertilization has little influence on potato tuber yield and quality. K fertilization increases tuber yield more, and up to higher rates in soil with low K concentration. K fertilization increases the tuber firmness, but reduces the soluble solids and protein concentration.

Critical Value of Soil Potassium for Potato Crops in Volcanic Soils

“…Potatoes (Solanum tuberosum L) are an important staple crop in most parts of the world. They have high nutrient requirements, among which potassium (K) is required in higher concentrations than both nitrogen and phosphorus (Fernandes et al 2017;Job et al 2019). Fernandes et al (2017), when comparing five potato cultivars under different phosphorus supplies, showed that the N, P and K in the whole plant dry matter varied between 1.58-2.16, 0.18-0.26 and 2.93-3.78%, respectively.…”

“…Therefore, a high amount of K fertilizers is usually required to obtain high potato crop yields probably due to the low nutrient uptake efficiency of potato crops due to their small root systems (Iwama 2008;Sandaña 2016). However, tuber yield responses to K fertilization depend on the initial level of soil K availability (Birch et al 1967;Allison et al 2001;Li et al 2015;Job et al 2019). Nonetheless, farmers did not know how much K should be applied due to the lack of information regarding the critical level of soil K for potato crops (Li et al 2015).…”

Potassium: A Vital Macronutrient in Potato Production—A Review

“…Nonetheless, rates higher than those reported by Abdelgadir et al [72] are commonly applied by potato farmers/producers. Furthermore, Job et al [89] reported that the maximum tuber yield was obtained with an estimated fertilization rate of 325 kg of K2O ha −1 in a soil with low exchangeable K (27 mg kg −1 ), while the tuber yield increased only up to the rate of 200 kg K2O ha −1 in the soils with 62 and 144 mg kg −1 exchangeable soil K. In this regard, several researchers revealed that most vegetative parameters, as well as Sharma and Sud [79] conducted studies on acidic and alluvial soils and showed that K 2 SO 4 was superior to KCl in increasing tuber dry matter, ascorbic acid, and starch content. Indeed, K 2 SO 4 is a readily plant-available form of K [80] and this could explain the faster translocation of photosynthates from leaves and stems to tubers under fertilization with K 2 SO 4 compared to KCl [69].…”

“…Nonetheless, rates higher than those reported by Abdelgadir et al [72] are commonly applied by potato farmers/producers. Furthermore, Job et al [89] reported that the maximum tuber yield was obtained with an estimated fertilization rate of 325 kg of K 2 O ha −1 in a soil with low exchangeable K (27 mg kg −1 ), while the tuber yield increased only up to the rate of 200 kg K 2 O ha −1 in the soils with 62 and 144 mg kg −1 exchangeable soil K. In this regard, several researchers revealed that most vegetative parameters, as well as yield and its components, increased significantly when K fertilization rates increased from 120 to 240 kg K 2 O ha −1 [28,64]. Singh and Singh [90] observed a noteworthy increase in plant height and shoot biomass of potato as K fertilization rates increased from 50 to 200 kg K 2 O ha −1 .…”

Fertirrigação potássica por gotejamento no cultivo da batata

“…Estudos prévios com fracionamento da fertilização em diversas culturas mostraram que uma parte do nutriente deve ser aplicado no plantio para maximizar a produtividade (CORRÊA et al, 2018;LUO;LI, 2018;MAROUELLI et al, 2015). No entanto, a fertilização de K feita somente no plantio pode causar salinização e prejudicar a absorção de outros nutrientes (JOB et al, 2019). Neste estudo não foi adotado fertilização de K totalmente no plantio.…”