Mombaça Grass Responds to Partial Replacement of K+ by Na+ with Supplemental Ca2+ Addition in Low Fertility Soil

Abstract

Partial replacement of potassium by sodium may be an alternative to reduce the cost of pasture fertilization and reduce the dependence on imported potassium sources. The objective of this study was to evaluate different sources and doses of calcium as enhancers of sodium effect on the partial replacement of potassium by sodium. Here, Mombaça grass (Megathyrsus maximus) was grown on low fertility soil. The experiment was conducted in a factorial (3 × 5) based on a completely randomized design with 4 replications as follow: three sources of Ca ) and two additional treatments (fertilization with 100% of K + without application of Ca 2+ and one control without any fertilization). Potassium was partially replaced (25%) by Na + prior to Ca 2+ additions. Plant height, growth rate, dry weight, Na + , K + , K + /Na + and shoot proline contents were evaluated as well as Na + levels and the electrical conductivity of the soil. The results show that the addition of Ca 2+ provided better plant development when K + was partially replaced by Na + and that the supply of Ca 2+ reduced the absorption of sodium by plants. The partial replacement of K + by Na + did not increase soil salinity or caused stress to the plants.

The Influence of Partial Substitution of Potassium by Sodium on the Growth Effect of Sugarcane

“…Na+ as the replacing positive ion of K+ with the biggest advantage, sodium addition can make the concentration of total positive ions in plants remain stable in the case of potassium deficiency, which can maintain the normal turgor of vacuoles and reduce the adverse effects of osmotic potential changes caused by potassium deficiency (Krishnasamy et al, 2014;Carneiro et al, 2017). The results show that:…”