A Study On Weed Control And Yeild-improving Effects Of Rice-Duck Farming

In China, there is a long history to breed duck in paddy field, and based on this, rice-duck farmingdeveloped, a paddy field compound farming system. From the perspective of the impacts that rice-duckfarming on quantity and weight of weeds, rice growth and economic efficiency, the current study probesinto the feasibility of rice-duck farming. The results show that:(1) In the first period (after raising ducks in the paddy field for10days) and the second period (afterraising ducks for20days), weed control effects of rice-duck farming is not as good as chemical weedcontrol for chemical herbicide having immediate efficiency and strong short-term weed control ability.However, in the third period (after raising ducks for30days), it is obvious to see that rice-duck farming ismuch better than chemical weed control practices in weed control efficiency, which can be explained bythe fact that the pesticide effect of chemical herbicide is gradually lost and at this moment the duck isgrowing gradually with bigger appetite, thus trampling the weeds more forceful. After raising ducks for30days, there’s57.06%,71.45%and81.25%weed control efficiency in the paddy field with six ducks permu,15ducks per mu and24ducks per mu respectively, while there’s52.01%weed control efficiency inthe field with chemical weed control practices. The quantity of weed is much less in the field with15ducksper mu and24ducks per mu than that with chemical weed control practices (P＜0.05).(2) In the first period, grassy weed control efficiency is better than that of cyperaceae andbroad-leaved weeds. In the third period, broad-leaved weed control efficiency is much better than in thefirst period, and both periods are more efficient than chemical weed control. However, cyperaceae weedcontrol is less efficient than in the first period.(3) After raising ducks for10days, there are13kinds of weeds of10aceaes in the fields that employrice-duck model while there are only9kinds of weeds of7aceaes in the fields that adopt chemical weedcontrol practices; after raising ducks for20days, there are13kinds of weeds of10aceaes in the fieldsadopting rice-duck farming while there are only10kinds of weeds of8aceaes in the fields adoptingchemical weed control practices; after raising ducks for30days, there are13kinds weeds of10aceaes inthe fields adopting paddy-duck farming while there are only10kinds of weeds of8aceaes in the fieldsadopting chemical weed control practices. With the increment of density of duck distribution, the richnessof species (S) is declining. After raising ducks for10d and30d, there are significant differences amongprocess1, process2and process3(P<0.05). After raising ducks for10d and20d, of all the three processes,process2has the biggest Shannon-Wiener index, indicating that a density of15ducks/mu creates the bestrichness. Whittaker is increasing with the increment of density, which shows that there an increasingcorrelation between weed diversity and species richness.(4) In the first period, fresh weight control of chemical weed control area (72.56%) is better thanrice-duck area in all three periods (56.70%,63.51%,68.68%); in the third period, fresh weight control of chemical weed control area (58.32%) is less than rice-duck area (69.52%,76.67%,81.06%) andsignificant differences can be seen (P＜0.05).(5) Both theoretical and practical paddy yield per mu of chemical weed control area are higher thanrice-duck area, and there are significant differences (P＜0.05). Of the three kinds of fields that are raiseddifferent number of ducks, namely6,15and24, the fields with15ducks per mu have the highesttheoretical and practical yields. However, the field with15ducks per mu has the highest actual profit with1542yuan,375yuan higher than chemical weed control area; the actual profit of fields with24ducks permu is280.2yuan lower than that of15ducks per mu. After introducing the new processing technology, thefield with15ducks per mu still has the highest actual profit with5362yuan,2734.8yuan higher thanchemical weed control area; the actual profit of fields with24ducks per mu is558.2yuan lower than thatof15ducks per mu.