Soil Nutrient Retention and pH Buffering Capacity Are Enhanced by Calciprill and Sodium Silicate

Abstract

In the tropics, warm temperatures and high rainfall contribute to acidic soil formation because of the significant leaching of base cations (K+, Ca2+, Mg2+, and Na+), followed by the replacement of the base cations with Al3+, Fe2+, and H+ ions at the soil adsorption sites. The pH buffering capacity of highly weathered acid soils is generally low because of their low pH which negatively impacts soil and crop productivity. Thus, there is a need to amend these soils with the right amount of inorganic liming materials which have relatively high neutralizing values and reactivity to overcome the aforementioned problems. Soil leaching and the pH buffering capacity studies were conducted to determine whether the co-application or co-amendment of a calcium carbonate product (Calciprill) and sodium silicate can improve soil nutrient retention and pH buffering capacity of the Bekenu series (Typic Paleudults). A 30 day soil leaching experiment was carried out using a completely randomized design with 16 treatments and 3 replications after which the leached soil samples were used for a pH buffering capacity study. The Calciprill and sodium silicate treatments significantly improved soil pH, exchangeable NH4+, available P, exchangeable base cations, Effective Cation Exchange Capacity (ECEC), and pH buffering capacity in comparison with the untreated soil. The improvements were attributed to the alkalinity of Calciprill and sodium silicate due to their high inherent K+, Ca2+, Mg2+, and Na+ contents. The neutralizing effects of the amendments impeded the hydrolysis of Al3+ (96.5%), Fe2+ (70.4%), and Mn2+ (25.3%) ions resulting in fewer H+ ions being produced. The co-application of Calciprill and sodium silicate reduced the leaching of Ca2+ (58.7%) and NO3− (74.8%) from the amended soils. This was due to the ability of sodium silicate to reduce soil permeability and protect the Calciprill and available NO3− from being leached. This also improved the longevity of Calciprill to enhance the soil pH buffering capacity. However, the amounts of NH4+, P, and base cations leached from the amended soils were higher compared with the un-amended soils. This was due to the high solubility of sodium silicate. The most suitable combination amendment was 7.01 g Calciprill and 9.26 g sodium silicate (C2S5) per kilogram soil. It is possible for farmers to adopt the combined use Calciprill and sodium silicate to regulate soil nutrient retention and improve the soil pH buffering capacity of highly weathered acidic soils. This will enhance soil and crop productivity.

Assessing spatial variability of selected soil properties in Upper Kabete Campus coffee farm, University of Nairobi, Kenya

“…Deficiency of phosphorus could have compromised the uptake of Ca therefore its (phosphorus) remedial fertilization is encouraged to boost Ca uptake. Slightly higher Ca content in the 15–30 cm depth could be a result of leaching in the humid environment, a suggestion consistent with the findings of Ng et al. (2022) that noted the leaching of base cations in the soil as the reason for higher base concentrations in bottom soil depths.…”

“…Magnesium leaching in the soil was also observed in other studies including Zhang et al. (2021) and Ng et al. (2022) .…”

“…Higher Mg content in the lower depth can be attributed to leaching in the humid environment. Magnesium leaching in the soil was also observed in other studies including Zhang et al (2021) and Ng et al (2022).…”

Organic amendment additions to cadmium-contaminated soils for phytostabilization of three bioenergy crops

“…The CEC values of some amended soils, such as SBM, BMVC, BMCM, and BMBM decreased slightly, which could be result of a dilution effect of the amendments 5 . The amendments may also enhance pH buffering capacity, percent base saturation, soil enzymatic activity and nutrient availability (e.g., available P and exchangeable NH 4 + ) 18 . When compared with a commercial soil in a related study, the control soil in this study had higher concentrations of essential nutrients (N, P, K); however, it had lower concentrations of Ca and Mg 14 .…”

Soil pH, Calcium Content and Bacteria as Major Factors Responsible for the Distribution of the Known Fraction of the DNA Bacteriophage Populations in Soils of Luxembourg

“…Indeed, soils with low pH generally display low calcium availability. As high concentrations of hydrogen ions displace calcium concentration from binding sites, it results in the leaching of “free” calcium, particularly in the more porous soils [ 80 , 81 ]. Such soils, such as the ones of Weierbach and Retgenbusch, i.e., low pH and calcium concentration, did display a low microbial diversity among the bacterial and DNA bacteriophage populations characterised in this study.…”