Comparison of Trifolium alexandrinum L. and Parthenium hysterophorus L. Green Manures in Rice–Wheat Cropping System

A pot experiment was conducted to study the comparative effect of Trifolium alexandrinum L. green manure and Parthenium hysterophorus L. green manure on growth in rice ( Oryza sativa L.) and wheat ( Triticum aestivum L.). Soil treatment of green manure covered the range 1-4% for Trifolium green manure (TGM) and Parthenium green manure (PGM). In July 2006, rice was planted and, after harvest, wheat was sown in the same pots in November 2006. Prior to the sowing of wheat, no additional amendments were made to any of the pots. The treatments 4% TGM and 3% PGM proved to be the most effective for root and shoot growth of rice, respectively. There were 40% & 15%, and 50% & 7% increases in shoot and root phytomass over the control under 4% TGM and 3% PGM treatments, respectively. For wheat, the highest increases of 29% and 67% in shoot phytomass over the control were observed in 2% TGM and PGM, respectively. Similarly, 3% and 2% TGM and PGM resulted in maximum increments of 147% and 209% in root phytomass of wheat over the control, respectively. Key Words: green manure, Parthenium hysterophorus, Trifolium alexandrinum, rice, wheat