亚洲一区欧美在线,日韩欧美视频免费观看,色戒的三场床戏分别是在几段,欧美日韩国产在线人成

In the double cropping area of North China Plain, the straw amount is huge as a result of the tremendous grain production, therefore, the maize straw needs proper handling during wheat seeding for the good of soil health and wheat grown. In order to address this issue, a field experiment was conducted in the experimental station at Zhuozhou, Hebei Province in 2016—2018, the effects of straw returning position on the seedbed physical properties of soil moisture content, soil temperature, soil aggregate size distribution, percentage emergence and yield of winter wheat were studied. Four treatments were investigated, including straw mixture (SM), half straw mixture (HSM), straw cover (SC) and controlled check of no straw returning (CK). Experiment results showed that straw return could: increase seedbed soil moisture content at 0~30cm, SC and HSM had significant increasing effect while SM had not, which was even lower than CK at 0~10cm depth in 2016;increase seedbed soil water stable macroaggregates, SM, HSM, SC all showed significant effect and macroaggregates were increased by 6.3, 4.9 and 4.8 percentage points, respectively;mitigate soil temperature change, soil temperature of CK at noon was significantly higher than the straw returning treatments, indicating that straw return could lead to slower warm up of soil which was not good for wheat growth;increase percentage emergence of winter wheat, the order from high to low was HSM, SC, SM and CK, and percentage emergence was increased by 40.1%, 34.1%, 14.8%, respectively, however, only HSM showed significant effect, besides SM was significantly lower than HSM in 2016;increase winter wheat yield by 17.2%, 10.9% and 2.9% of SC, HSM and SM, respectively. It could be concluded that straw returning, although impacted soil temperature, it could increase soil water content, improve soil structure and soil health, thus ultimately increasing winter wheat yield. Among the three straw returning treatments, SC obtained the highest yield, then HSM of half straw mixture. SM of straw mixture obtained the highest water stable macroaggregates, but nonetheless the soil moisture and percentage emergence of it was the least, besides it had a certain impact on soil temperature, thus leading to the lowest yield of the three treatments, therefore straw returning positions of SC and HCM were more recommended.