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Item Effect of adding nitrogen in combination with MnO2 on the growth, yield and composition of rice(Kerala Agricultural University, 1981) Harikrishnan Nair, K; Koshy, M MItem Effect of zinc in combination with lime on the composition of and absorption of nutrients by rice(Kerala Agricultural University, 1979) Mariam, K A; Koshy, M MA pot culture experiment was carried out using the Vellayani Kayal soil (Tropaquept) in a randomized block design to study the effect of zinc in combination with lime on the absorption of nutrients by rice. The soil used in the study had a pH of 4.3 and it contained 0.11% N, 0.02% P20S, 0.36% K20r 0.10% CaO, 0.13% MgO and 4.2 ppm available Zn. The levels of zinc used were 0, 10, 20 and 40 Kg ZnS04 7H20/ha and those of lime were 0, 250, 500 and 1009 Kg CaC03/ha. NPK fertilizers (70+35+35 kg/ha) were also applied as per the package of practices. The application of lime did not result in appreciable increase in the pH of the soil under field conditions. The nitrogen content of grain was increased significantly by zinc, but it had no effect on the nitrogen content of straw. Application of lime reduced the nitrogen content of the grain. Zinc tended to decrease and lime tended to increase the P206 content of both grain and straw. But this effect was significant only in the case of grain. The K.,0, CaO and MgO contents of both grain and straw were practically unaffected by the application of zinc and lime. However there was a trend for CaO and MgO to increase in the plant material with increased applications of lime. When the total quantities of nutrients removed per pot was considered there was significant variation only in the case of nitrogen and phosphorus whereas in the case of the other nutrients the treatment effects, were non-significant.Item On increasing the efficiency of superphosphate in slightly acid submerged soils(Kerala Agricultural University, 1979) Kabeerathumma, S; Padmaja, P; Koshy, M MItem Chemical nature of organic complexes in some samples of town compost(Kerala Agricultural University, 1975) Koshy, M MItem Zinc status of Kerala soils(Kerala Agricultural University, 1975) Revi Kumar Praseedom; Koshy, M MTotal zinc in fourteen typical soil profiles of Kerala varied from 3.5-72.0 ppm in the surface horizons, 3.5-560 ppm in the second horizons and from 3 5- 100.0 ppm in the third layers, the averages for the three horizons being 21.9, 20.9 and 21.5 |-pn respectively. The variation in avaUab,e zinc was from 0.3-7.7 ppm in the surface layers, 0.8-7.7 ppm in the second layers and from 1.3-8.0 ppm in (he third horizons, the averages being 3.0, 3.2 and3.7 ppm. respectively There was significant positive correlation between total and available zinc and significant negative correlation between available zinc and nitrogen. The downward distribution of total zinc in ih- profiles was irregular, whereas available zinc increased with depth in ten of the fourteen profiles. On the basis of the threshold value of 0.55 ppm Kerala soils may be generally considered to be satisfactory with respect to available zinc.Item Chemical and mechanical composition of ground dolomitic limestone distributed in Kerala(Kerala Agricultural University, 1975) Koshy, M M; Vasundhara Bai, B; Sushama, GItem Cation exchange capacity in relation to the mechanical composition and organic matter status of some soil profiles of Kerala(Kerala Agricultural University, 1976) Venugopal, V K; Koshy, M MA study was made of the cation exchange capacity of forty soil samples representing fourteen soil profiles of Kerala in relation to the mechanical composition and organic matter status of the soil. The important findings are summarised below: (1) The cation exchange capacity of the different soil groups exhibited wide variations, the sandy soil recording the lowest and the black soil the highest value. With the exception of black, kari and some alluvial soils all other soil groups gave very low values for this property. (2) Correlation between cation exchange capacity and clay for all the samples taken together was positive and highly significant. The same positive relationship was observed when the individual soil groups were considered. (3) The relationship between organic matter and cation exchange capacity for all the samples together was positive but not significant.Item Exchangeable cations of some important soil profiles of Kerala(Kerala Agricultural University, 1976) Venugopal, V K; Koshy, M MA study was made of the exchangeable cations of forty soil samples representing fourteen soil profiles of Kerala. The exchangeable base content of the different soils was generally in the order calcium > magnesium > potassium > sodium. In the case of kari and black soils the exchangeable sodium showed a higher content over potassium. The maximum amounts of exchangeable calcium, magnesium and potassium was observed in the black soil. The heighest value of exchangeable hydrogen was observed in the case of kari soil which also recorded very low values of pH.Item Response of rice variety triveni to graded doses of magnesium silicate(Kerala Agricultural University, 1977) Abraham Thomas; Koshy, M MItem Effect of zinc in combination with nitrogen on the yield and yield attributes of rice var. triveni(Kerala Agricultural University, 1977) Kabeerathumma, S; Sasidhar, V K; Sadanandan, N; Koshy, M M