Study On The Control Effect Of Chemical Herbicide And Different Agricultural Measurement To The Farmland Weeds Of Qinghai Highland

Weed is the worldwide pest of farmland, as the widely using of chemical herbicide, the side-effect become more and more evidence, such as resistance, environment pollution, the harm of herbicide to crops, the alternation of weed community, so some new measurement should be developed.This paper mainly discuss on the weed alternation, distribution and harm of Qinghai province farmland. In order to decrease the dosage and increase control effect, the effect of controlling weed and increasing yield by different highland-barley planting density, different herbicide dosage and different apply fertilizer in Qinghai highland area are studied; the effect of shallow tillage to controlling wild oat in the area around Qinghai Lake are studied too: the wild oat seed produced in the same year distributed in the different soil layer of shallow and deep tillage fields are studied; the quantity of wild oat seed fallen on the soil surface after harvest in the shallow and deep tillage fields were measured in the 3 years continuously, the soil moisture in the soil layers of 0-10cm, 10-20cm and 20-30cm were measured before seeding in the 3 years continuously. The chemical herbicide of Benazolin-ethyl Quizalofp-p-ethyl 14EC is firstly used at Hippophae rhamnoides L. seedling nursery. Test spots are located on new reclaiming farm in highland area and plain area in ledu county, test were conducted in the farm of Tanggermu of Qinghai, the farm of Qinghai Triangle Town and plain area of ledu county respectively.The result showed that: 1. in the past decades, the weed community of Qinghai farmland changes obviously due to the singleness use of herbicide, singleness control method or ignoring weed control in some area. The Broad-leaf weeds have been increased due to always use the some herbicide- triallate, the tolerance weeds such as Galium aparine L., Sonchus brachyotus DC, Hypecoum leptocarpum Hook, Cephalanopllos setosum Kita, Convolvulus arvensis also increased due to use 2,4-D for long period. The perennial weeds increased due to resistance to 2,4-D and the change of tillage system.2.At the condition of use 2,4-D, higher density of highland-barley could control the Broad-leaf weeds quantity and fresh weight obviously, At the condition of use triallate,...