Abstract:  In order to increase the economic benefit of kenaf， the effect of precision drilling and different weeding method of kenaf on production efficiency were studied in rice\|kenaf rotation field. The growth rate of kenaf in the treatment of 150 000 plants·hm-2 and spraying herbicide was the highest， of which the height reached 45523 cm. Besides， the thickness of stems， bark depth， fresh weight per plant and dry weight of leaves， sticks， barks， biological performance of kenaf under this treatment all exhibited significant differences from others. On the dry bark yield， treatment of 270 000 plants·hm-2 and spraying herbicide was the highest （6 77250 g）. At the late stage， efficient plants in blocks followed the trend of spraying herbicide＞manual weeding＞no weeding. Soil available nitrogen （N） and potassium （K） content showed significant differences among treatments， while there was no significant difference in soil organic matter and available phosphorus （P） content. Spraying herbicide was effective for Gramineae grass control， of which the control efficacy was above 77%. The highest yield and the best economic benefit was found in the treatment of 270 000 plants·hm-2 and spraying herbicide.

Key words: rice\, kenaf, precision seeding, weeding method, production efficiency