studies on integrated nutrient management through vermicomposting in direct seeded rice wheat sequence

Abstract

This investigation was carried to find out the suitable level of vermicompost in direct seeded rice-wheat sequence at the experimental farm of Department of Agronomy, CSK HPKV, Palampur during Kharif 2003 and Kharif 2004, Rabi 2003-04 and Rabi 2004-05. Other objectives of the study were to find out the effect of vermicompost with different levels of NPK fertilizers in direct seeded rice-wheat crop sequence and to study the economics of various treatments under investigation. The field experiment consisted of 13 treatment combinations of 4 vermicompost levels viz., no vermicompost, vermicompost at 2 t/ha, vermicompost at 4 t/ha and vermicompost at 6 t/ha and three levels of chemical fertilizers viz., 1/3rd of recommended NPK, 2/3rd of recommended NPK and recommended NPK and one absolute control. These treatments were applied to paddy crop and its residual effect was studied in wheat crop. Wheat crop was raised by applying 50% of recommended N fertilizer. It has been concluded from this investigation that application of vermicompost at 6 t/ha proved to be sufficient in direct seeded rice-wheat sequence. With the increase in level of vermicompost from no vermicompost to vermicompost at 6 t/ha, the grain yield of paddy increased from 1766, 1979 kg/ha (1st year, 2nd year) to 2446, 2797 (1st year, 2nd year), respectively with an increase of 27.8, 29.2% over no vermicompost during both the crop seasons. Application of recommended dose of fertilizers resulted in 12.9 and 17.6% increase in grain yield over 1/3rd and 2/3rd recommended NPK levels. Application of vermicompost at 6 t/ha to paddy crop in direct seeded rice-wheat sequence and application of recommended dose of NPK fertilizer resulted in higher gross and net returns and net returns per rupee invested. Application of 6 t/ha of vermicompost to paddy resulted in significantly higher residual effect on wheat grain yield, straw yield and NPK uptake. Fertilizer levels did not showed any residual effect on grain and straw yield of wheat during both the years of study. Application of 6 t/ha of vermicompost alongwith 2/3rd of recommended NPK was found to be most suitable and a saving of 33% of chemical fertilizers can be obtained.