Effect Of No Tillage And Delayed Irrigation At Jointing Stage On Lodging Resistance Of Winter Wheat Under Wide-precision Planting Pattern

With the increasing of winter wheat yield,the contradiction between lodging and high yield is more and more obvious,lodging has become an important factor restricting the yield and quality of winter wheat,stem lodging is the most common production process of winter wheat lodging types,in order to increase the yield of winter wheat,improving winter wheat stalk quality and enhancing stem bending resistance are beneficial to improve the stem lodging.The North China Plain is an important winter wheat producing area in China areas,it is also a serious shortage of water resources in the area.Jointing stage is the most important period of irrigation of winter wheat,delayed irrigation at jointing stage can significantly improve irrigation water use efficiency,and increase grain yield.No tillage as a protective tillage,can increase water conservation,and water use efficiency,increase crop yield,but because of no tillage soil has high mechanical resistance and poor permeability,will cause the seedling weak,lead to stem lodging easily.Setting the different farming model and jointing water irrigation time,researching on realization of winter wheat lodging resistance and high yield in order to provide theoretical basis and technical support for stable and high yield of Winter Wheat in North China plain.The study area was located at the Agronomy Experimental Station of the Shandong Agricultural University during the winter wheat growing seasons of 2015-2016.The experiment adopted a split plot design arranged in randomized blocks with three replications.Main plots were two kinds of tillage models: no tillage(N)and conventional tillage(T),subplots consisted of jointing water irrigation time: normal irrigation(I1)and delayed 10 days irrigation(I2).Plant height,gravity of center height,fresh mass,stem diameter,wall thickness,fresh density,bending strength,flexural modulus,flexural rigidity,lodging resistance index at the key growing stages and the creep characteristics of filling stage,studying the lodging resistance properties of winter wheat.The main results are as follows:No-tillage had no significant effect on winter wheat plant height,gravity center height and fresh mass,compared to the normal irrigation at jointing stage,delayed 10 days irrigation at jointing stage had a significant effect on winter wheat plant height,,gravity center height and fresh mass: at the heading period,delayed 10 days irrigation at jointingstage significantly increased plant height,gravity center height and fresh mass,at the filling stage,delayed 10 days irrigation at jointing stage significantly decreased plant height and fresh mass.Conventional tillage with normal irrigation at jointing stage(TI1)compared to the other coupling could significantly increase the gravity center height and fresh mass at filling stage,conventional tillage with delayed 10 days irrigation at jointing stage(TI2)compared to the other coupling could significantly decrease the gravity center height and fresh mass at filling stage.No-tillage had no significant effect on the diameter of the last second stems.Compared with the normal irrigation at jointing stage,delayed 10 days irrigation at jointing stage significantly decreased the diameter of the r the last second stems at heading filling stage.Conventional tillage with normal irrigation at jointing stage(TI1)had the maximum diameter of the last second stems at every key growing stage.No-tillage significantly increased the wall thickness but significantly decreased the fresh density of the last second stem at dough stage.Delayed 10 days irrigation at jointing stage significantly increased the wall thickness but significantly decreased the fresh density of the last second stem at filling stage.No-tillage with delayed 10 days irrigation at jointing stage(NI2)significantly decreased the bending strength and flexural rigidity at filling stage bur significantly increased the bending strength and flexural rigidity at dough stage;normal irrigation at jointing stage(TI1)under conventional tillage pattern was significantly increased the bending strength at filling stage.Conventional tillage with delayed 10 days irrigation at jointing stage(TI2)significantly decreased the bending strength at heading and filling stages,significantly increased flexural modulus at filling stage and significantly increased flexural rigidity at filling and dough stages.Compared to conventional tillage with normal irrigation at jointing stage(TI1),notillage with normal irrigation at jointing stage(NI1)could increase the lodging resistance index at heading and filling stages but decreased it significantly at dough stage.No-tillage with delayed 10 days irrigation at jointing stage(NI2),compared to no-tillage with normal irrigation at jointing stage(NI1),it significantly increased the lodging resistance index at dough stage and decreased it at heading and filling stages,compared to conventional tillage delayed 10 days delayed 10 days irrigation at jointing stage(TI2),it decreased the lodging resistance index at filling and dough stages,lodging index,what's more,the lodging resistance index of conventional tillage delayed 10 days delayed 10 days irrigation at jointing stage(TI2)was higher than conventional tillage with normal irrigation at jointingstage(TI1),therefore conventional tillage with delayed 10 days irrigation at jointing stage(TI2)could increase the lodging resistance index at filling stage and ripening stage,and improved the lodging resistance ability of winter wheat.Combining the yield factors,conventional tillage with delayed 10 days irrigation at jointing stage(TI2)which could significantly improve the winter wheat lodging resistance ability at filling and dough stages,and also obtained the highest yield,is a good lodging resistance and water saving and high yield cultivation and irrigation pattern.Four element Burgers model could be used to describe the creep characteristics of the last second stems of filling stage,and the relational expression between the deformation and time of the four element model of Burgers was the creep constitutive equation of winter wheat.Under constant force,conventional tillage with delayed 10 days irrigation at jointing stage(TI2)which had a small creep strain,big the elastic coefficient and viscosity coefficient of Maxwell and Kelvin model,small delayed time,strong ability to resist bending deformation,could improve the lodging resistance ability of stem at filling stage.