Effect of zinc in combination with lime on the composition of and absorption of nutrients by rice

Abstract

A 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.