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
EFFECT OF CROP RESIDUES INCORPORATION ON PHYSICO -CHEMICAL PROPERTIES AND YIELD OF GREEN GRAM-SAFFLOWER CROP SEQUENCE UNDER SODIC HAPLUSTERTS.
Purna Valley of Vidarbha region is the unique tract of Vertisols having native sodicity. It is east-west elongated basin with slight convexity to the south and extends from 20 0 45’ to 21 0 15’ N latitude and 75 0 15’ to 77 0 45’E longitude with east-west length about 100-150 km and 10-60 km in width, covering an area about 4.49 lakh ha spread in 894 villages of Amravati, Akola and Buldana districts of Vidarbha (Govt. of Maharashtra, 2001). The development of salinity/sodicity in the basin is the natural and geological phenomenon, where the intensity of salinity/sodicity is comparatively less in surface layer, whereas, it increased with the depth of pedon. The salt affected Vertisols of some part of Purna Valley in Vidarbha having moderate to strong salinity and sodicity. These soils have high clay content, montmorillonitic mineralogy and swell shrink International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 6 Number 9 (2017) pp. 3717-3730 Journal homepage: http://www.ijcmas.com
Investigations on the rôle of organic matter in plant nutrition
1. As the result of decomposition of green manure in a swamp soil, the coarse fractions (including coarse and fine sand) of the surface layer (first 3 inches) decreased by 11·2 per cent. while the fine ones (silt+clay) increased by 9·8 per cent. in the course of 43 days. The effect was less pronounced in the manured soil maintained at 60 per cent. saturation, while no alteration was to be noticed in the case of the unmanured specimens. 2. Treatment with dilute hydrochloric acid prior to dispersion had no appreciable effect on the estimates of mechanical composition obtained in the different cases. Loss in solution was also comparatively small. 3. The silica-sesquioxide ratio increased slightly as the result of decomposition of green manure in swamp soil. The composition of the fine fractions was also altered, the total percentages of the oxides of iron, aluminium and silicon increasing from 90·5 to 99·3 in the course of 71 days. 4. The practical significance of the above and related observations has been discussed.