Growth and K Nutrition of Sesame (Sesamum indicum L.) Seedlings as Affected by Balancing Soil Exchangeable Cations Ca, Mg, and K of Continuously Monocropped Soil from Upland Fields Converted Paddy

Abstract

Growth of sesame is known to be limited by poor K nutrition as a result of imbalance in soil exchangeable cations that cause a competitive ion effect in continuous monocropping from upland fields converted paddy. We hypothesized that balancing soil exchangeable cations will improve the K nutrition and growth of sesame plants. Therefore, the specific objectives of this study were to determine the effect of balancing soil exchangeable cations Ca, Mg, and K of continuously monocropped soils on the growth and cation uptake of sesame seedlings and also identify a suitable source of nutrients for improving K nutrition. A pot experiment was conducted under greenhouse condition in a 3 × 3 factorial design consisting of three levels of balancing treatments i.e. inorganic fertilizer for Ca, Mg, and K, rice husk biochar to increase K content, and the three durations of continuous monocropping soils of one year, two years, and four years from upland fields converted paddy. Balancing soil exchangeable cations was aimed at achieving optimal base saturations (CaO, 75%; MgO, 25%; and K2O, 10%). Results showed that balancing exchangeable cations did not significantly affect growth and cation uptake in the one and two-year soils but significant effect was observed in the four-year soil. Overall, plant height and dry weight increased for the balancing treatments of inorganic fertilizer K and rice husk biochar. Balancing exchangeable cations with biochar was more beneficial than with inorganic fertilizers. The four-year soil’s growth increase was attributed to an increase in K concentration and uptake due to the decrease in the soil Ca/K and Mg/K ratios to that of acceptable levels, which eliminated competitive ion effect as the soil K saturation increased above 5.0%, enhancing sesame growth. Therefore, a balanced soil exchangeable Ca, Mg, and K that eliminates a competitive ion effect will improve sesame growth and K nutrition although future research should focus on ensuring balanced cation rations under field conditions in continuous monocropping.

Effects of Balancing Exchangeable Cations Ca, Mg, and K on the Growth of Tomato Seedlings (Solanum lycopersicum L.) Based on Increased Soil Cation Exchange Capacity

“…It has been reported that the content of Ca and Mg in soils is higher than K, which would cause an ionic competition effect between them. Ca and Mg would replace K on the soil colloid, resulting in a K nutrient deficiency in soils [33,34]. As observed in our study, the imbalance of exchangeable cations in soils requires fertilizer dosage calculation based on ideal Ca, Mg, and K saturation ratios, which are in turn based on soil diagnostic results and precise supplementation of Ca, Mg, and K nutrients to successfully mitigate the cation competition effect.…”

Application of Steel Slag for Degraded Land Remediation

“…However, as can be seen in the figure, samples with fertiliser had lower Ca values. This lower concentration of Ca could be due to the larger quantities of other cations, such as K competing with Ca and Mg cations [60]. Nevertheless, this is not the case for the pots with 0-20 mm slag since amendments E25 and E50 had extremely high levels of calcium both with and without fertiliser.…”

Yield Variability in Oil Palm Plantations in Tropical India Is Influenced by Surface and Sub-Surface Soil Fertility and Leaf Mineral Nutrient Contents

“…The availability and stoichiometry of N and sulfur (S) in soil influence N and S uptake and thus the N/S ratio in crop plant tissues [20][21][22]. Wacal et al [23] reported the influence of soil Ca, Mg, and K and their ratios (Ca/K and Mg/K) on the K nutrition of sesame. Similarly, the mobility of Mg in soil and plants is affected by the soil Ca, K, and NH 4 + [24].…”