Effects Of Agronomic Strategies Or Practices On Weed Composition And Forage Yield Of Oat Field In Bashang Of Northwest Hebei Province

The Bashang area of northwest Hebei is located in the agricultural and pastoral ecotone of North China,which is a typical plateau and semi-arid region;Affected by cold and drought climate and lack of soil and water resources,farmland is a short-season crop once a year.The forage growth season is short,the grass primary productivity level is low,the shortage of forage grass has become one of the main restrictive factors for the rapid development of animal husbandry industry in Bashang area.According to the location advantage of Bashang area,using the same season of rain and heat in June-September,the production of oat forage is developed,the yield and quality of local oat forage are improved,and the stable and high quality forage grass is provided for livestock.Establish high-standard oat hay production base to promote the high-quality development of local animal husbandry.By studying the effects of different tillage measures and different sowing time on weed composition,community characteristics and forage yield in oat field,The innovation of oat green cultivation technology provides technical support for forage oat production in cold and dry areas of northwest Hebei Province.The main findings are as follows:1、Weed composition and community characteristics of oat field with different tillage measures:Farming methods have a significant effect on weed biomass in oat fields,The biomass of weeds in shallow tillage is always at a disadvantage,which is 17.60%～69.67%of the biomass of weeds in no-tillage,41.83%～82.01%of the biomass of weeds in ploughed fallow.The farming method has no effect on the dominant weed species in oat field,The main dominant species of weeds in three kinds of oat fields were oakleaf goosefoot,which accounted for 66.8%,63.1%and 82.1%respectively.2、Changes of forage yield in oat field with different tillage measures:Forage dry weight of ploughed fallow,shallow rotary tillage and no-tillage oat reached maximum at 30d heading,which were 6114.5kg/hm2、7961.8kg/hm2 and 4568.8kg/hm2 respectively.The yield of fresh weight of shallow rotary tillage and tillage oat grass was the highest at 20d after heading,which were 22018.8kg/hm2、15116.7kg/hm2,and the corresponding moisture content was 66.8%and 69.4%respectively.The fresh weight yield of no-tillage oats was the highest at heading stage 11400kg/hm2,but the moisture content was 79.7%,and the moisture content decreased to 65.6%after heading 10d,when the yield of fresh oats was 10912.8kg/hm2.3、Weed composition and community characteristics of oat field at different sowing data:The community structure of weeds in oat field was significantly affected during sowing time,The weeds in the sowing date Ⅰ Yan wheat field are mainly cool-loving oakleaf goosefoot,and the weeds such as amaranth,green bristlegrass,little lovegrass herb and barnyard grass become dominant species.The Shannon diversity index(H’),Pielou uniformity index(J),Simpson diversity index(D),Margalef species richness index(DMG)and so on were lower in the plant communities of Oatmea during sowing data Ⅰ and Ⅲ,sowing on May 24(sowing data Ⅰ)was beneficial to increase forage yield of oats,and the competitive advantage of oats to weeds in the field was obvious.4、Changes of oat forage yield in different sowing date:Oatgrass dry weight of sowing date Ⅰ and Ⅱ reached maximum at 30d heading,which were 7961,8kg/hm2、6307.5kg/hm2,respectively;Sowing data Ⅲ due to late sowing,the yield of hay was 4421.1kg/hm2 at 20d heading,which were55.5%and 65.1%of sowing data Ⅰ and Ⅱ,respectively.The biomass accumulation of fresh oat grass during sowing period Ⅰ and Ⅱshowed "bimodal pattern" in general,The first peak was at heading stage and the second peak was 20d～3 0d after heading.At the second peak(20d after heading)of sowing data Ⅰ,the yield was 22018.4kg/hm2,the yield was 16703kg/hm2 of sowing data Ⅱ(30d after heading),the corresponding moisture content was 69.4%and 62.2%respectively.The yield of fresh oat grass was the highest 20d after heading of sowing data Ⅰ,which was 13067.1kg/hm2,and the moisture content was 66.2%.5、Effect of cutting time on forage quality of oat:The sowing data Ⅰ oat forage can be mowed at 20d and 30d heading,at 20d of heading,although the yield of oat forage can not reach the highest value in the growth period,the quality of oat forage is higher at this time,At 30d of heading,the yield of oat forage reached the highest and met the quality requirement of oat forage;The ADF content was more than 40%before heading 20d,which seriously affected the quality grading of oat forage,The quality grade of oat grass was three levels after heading 20d,and the yield reached the highest value at 40d.Oatgrass of Sowing data Ⅲ can not complete the growth process and yield is low,therefore,the maximum hay yield can be obtained by cutting at 20 d heading,which is 4421.1kg/hm2.