Effect of gypsum and calcium carbonate on plant yield and chemical composition and calcium availability in a non-saline sodic soil
SummaryThe availability of Ca from different levels of gypsum and calcium carbonate in a non-saline sodic soil has been investigated. Different levels of tagged gypsum (Ca45SO4.2H2O) and calcium carbonate (Ca45CO3) (i.e. 0, 25, 50, 75, and 100 per cent of gypsum requirement) were mixed thoroughly in 3.5 Kg of a non-saline alkali soil (ESP, 48.4; ECe, 2.68 millimhos/cm). Dhaincha (Sesbania aculeata) — a legume and barley (Hordeum vulgare L.) — a cereal were taken as test crops. Increasing levels of gypsum caused a gradual increase in the yield of dry matter, content of Ca and K in the plant tops and Ca:Na and (Ca+Mg):(Na+K) ratios in both the crops. Application of calcium carbonate caused a slight increase in the dry matter yield, content of Ca and Mg and Ca:Na and (Ca+Mg):(Na+K) ratios in barley, however, in case of dhaincha there was no such effect. Gypsum application caused a gradual decrease in the content of Na and P in both the crops. Total uptake of Ca, Mg, K, N and P per pot increased in response to gypsum application. The effect of calcium carbonate application on the total uptake of these elements was much smaller on dhaincha, but in barley there was some increasing trend.Increasing application of tagged gypsum and calcium carbonate caused a gradual increase in the concentration and per cent contribution of source Ca in both the crops, although, the rate of increase was considerably more in dhaincha. The availability of Ca from applied gypsum was considerably more than that from applied calcium carbonate. Efficiency of dhaincha to utilize Ca from applied sources was considerably more (i.e. about five times) than that of barley
A Floristic Study of the Vascular Plants of the Gypsum Hills and Redbed Plains Area of Southwestern Oklahoma
The vascular floras of gypsum and redbed soils in southwestern Oklahoma were collected and studied during the growing season (April-October) of 1975. A total of 359 taxa and 230 genera and 63 families were included in the study. Thirteen taxa are considered to be gypsophiles and indicators of gypsum soils in Oklahoma. Nine taxa are considered calicoles occurring only on gypsum and limestone derived soils. Two introduced species, Bromus catharticus Vahl (syn. = Bromus willdenowii) and Caesalpinia gilliesii, are believed to be new additions to Oklahoma’s flora. Editor’s note: The abstract and a brief summary of this thesis was published as “Floristic Components of the Gypsum Hills and Redbed Plains Area of Southwestern Oklahoma” in The Southwestern Naturalist 24(3):431- 437 September 15, 1979 and is included here by permission.
Advances in Chemical and Colorimetric Methods
and total hardness of water by simple tit rations, and the calculation of magnesium hardness by difference. These methods, published in the last four years, are of impressive simplicity and accuracy, but the interferences are not all known and accounted for and some work remains to be done. Nevertheless, the methods appear susceptible of refinement, and there seems little doubt that in a relatively short time they will replace the present methods for the routine determination of the