Study Of Fertigation Technology In Apple Orchard Of Weibei Dry Highland

As the poor coupling effect of water and nutrients and low soil fertility are the limiting factors for the high-quality development of apple orchards in the Weibei dry highland area,and the technology of fertigation can effectively improve the coupling effect of water and fertilizer to achieve the purpose of saving costs and increasing efficiency.This paper took Ruixue and Changfu No.2 apples as the research objects,and set up two fertilization treatments under the condition of the technology of fertigation to study the spatial and temporal distribution,absorption and utilization characteristics of water and nutrients in the soil profile.With a view to the technology of fertigation in apple orchards provided scientific basis and technical support.The main results of the study were as follows:1.The content of soil organic carbon and total nitrogen decreased with increasing soil depth.The depth of distribution of organic carbon content greater than 5.5 g/kg and total nitrogen content greater than 0.55 g/kg decreased with increasing horizontal distance,and the depth of distribution of Changfu No.2 orchard was greater than that of Ruixue orchard.The content of soluble organic carbon and easily oxidizable organic carbon in the soil profile decreased with the increase of soil depth and horizontal distance,and the decomposition ability of soil organic carbon and total nitrogen in the area of Ruixue Orchard in the horizontal direction of 5-45 cm and vertical direction of 0-30 cm increased.To increase the content of soil soluble organic carbon and easily oxidized organic carbon.2.In the early stage,the soil moisture was concentrated directly under the drip irrigation point,the horizontal migration distance was small,and the vertical infiltration depth was large;with the increase of the number of drip irrigation and rainfall,the soil moisture showed obvious deep infiltration.Nitrate nitrogen and water-soluble base ions showed obvious distribution characteristics of moving with water.Nitrate nitrogen was concentrated near the edge of the wet area,and the base ions are distributed along the edge of the drip irrigation area.All of them appeared to move down and enrich in the deep layer.The spatial distribution of water,nitrate nitrogen and water-soluble base ions between different treatments was not obvious,only the content is different.3.The content of available phosphorus and available potassium showed a tendency of increasing first and then decreasing,and both had obvious phenomenon of "surface aggregation",and the moving distance with water was small.Available phosphorus and available potassium were distributed in the arc area surrounded by 0-20 cm in the horizontal direction and 0-40 cm in the vertical direction,and the content of available potassium in the 0-40 cm deep soil layer was kept at a relatively high level.With the increase of nutrient requirements for fruit development,the content of available potassium in the horizontal layer of 20-40 cm deep soil layer of 0-40 cm had a low value area.The spatial distribution characteristics of available phosphorus and available potassium between different treatments were not obvious.4.The content of N,P,and K in apple leaves showed a downward trend with the growth of fruit trees,and the order of content of N,P,and K in different parts of the mature stage was: leaf>autumn tip>spring tip;The content of Fe and Mn in the leaves showed significant accumulation,while the content of Cu and Zn showed a trend of decreasing first and then increasing.The content of Zn varied greatly in the early stage of growth;the order of content of them showed autumn shoots> spring shoots.5.The optimization model can improve the fruit quality and increase the apple yield;the N,P,K and Fe content of the fruit were increased,but the Mn,Cu and Zn contents were reduced.The N,P,and K content of leaves,branches,and fruits all increased,but the decrease of Fe contents of branches and leaves increased in fruits,and Mn,Cu,and Zn showed the opposite rules.In summary,in the Weibei dry highland dwarf apple orchard,the technology of fertigation experiments were conducted.In this mode,the water irrigation volume was high and the infiltration depth was large.It is recommended to control the water infiltration depth to 0-40 cm,And combined with the spatial migration and distribution of nutrients under drip irrigation conditions and the characteristics of root distribution of different varieties,the location of drip irrigation points was adjusted to increase the water and fertilizer utilization efficiency and achieve the purpose of improving quality and efficiency.