The Relationship Between Agrogeology Condition And Apple Qualities In Weibei Dryland

The Weibei region in Shaanxi province is famous for its apple production, the uniqueclimate and the soil condition is the key point to its success. Developing the fruit industry willhelp farmers increase their income. Then blossoming the relative production area. Anddeveloping the fruit planting will distribute a lot for the landform of this region. With theupdating of the fruit industry, there are some urgent scientific problems which are in need ofstudying and solving, such as rot, early-falling, chlorosis. And the trees are growing weak, thefull period are shorter than before, senility are coming earlier in apple trees, the apples’storability degenerated. The primary causes of those diseases are lack of the knowledge ofchoosing orchards site by considering its condition. And these problems also are caused bythe unreasonable planting management, using chemical fertilizers improper and the lack of thedetails in orchards management. This study based on the agro geology knowledge system, andstarted from researching the construct of soil profiles and the topography and geomorphology,aimed for understanding the distribution of chemical elements which never changed byfertilization in soil. The conclusions will be the crucial scientific information for evaluatingthe best orchards and will provide a proper direction for precise management in orchards.The apple planting zones distribute on the region that Loess plateau gully belt of Weibeiin Xunyi in north Xianyang in Midwest Shaanxi. The terrain of this field area is complex,with the addition of the contribution of the climate, geomorphology, soil profile structure andmanagement so that there are many pieces of land are bad for planting apple trees. Thisphenomenon is a threaten for trees growing health and also will harm for apple qualitycultivate. This study followed the basic theories of agro geology science, and closed differenttypes of soil profiles, terrain types and sites, different planting-year of orchards as theexperiment fields, analyzed several soil qualities and main apple fruit’s quality indexes indifferent orchards in the experiment field. The treatment of the study includes soil profiles,micro topography, planting-year, production model. The conclusions list below:1. The soil type of Weibei Dryland is dark loessial soil, which was developed from loessand formed an special soil profile, dark loessial layer. From the whole perspective, soilavailable Mn decreased as the depth of soil layer increased in this type of soil profile. The depth of dark loessial layer in soil profile is the key to the amount of Mn and Ca in trees andalso affects the apple’s quality and the trees’ disease resistance. The apple’s qualities whichinfluenced by the depth of dark loessial layer includes fruit size index, fruit density, fleshfirmness, soluble solid, sugar-acid ratio. When the dark loessial layer was higher, the amountof soil Mn was higher and caused the rough bark, it’s the bed for microorganism todecomposing the trees. It’s the prof that the dark loessial soil is not suitable for plangtingapple.2. Loess plateau own a unique landform loess broken plateau area, and the brokenplateau incline. The amount of S was influenced by the surface flow and soil flow. Thedifferent of the special distribution of soil available S was great within25km of horizontaldistance. The amount of soil available S decreased as the depth of soil layer increased,especially60cm below the S accumulated remarkable. Meanwhile, the amount of soilavailable S raised as the altitude becoming lower. The different of soil S amount in horizontalscale and vertical scale influenced the apple fruits’ quality, and also caused the uppertableland in short of S, while soil available S accumulated in lower tableland. The spatialdifferent of soil available S affected the apple quality indexes in orchards on the tableland.3. The soil Ca degeneration in orchards in Weibei is remarkable. The soil Ca saturationdecreased as the planting-year of orchards increased, and the soil Ca saturation in orchardswere lower than80%, which is the lowest standard value for health soil. Most of the numbersof soil Ca saturation were in the range of65%~75%, and several figure of soil Ca saturationin soil layers lower than65%, becoming the unhealthy level. The change of soil Ca saturationwas not easy to detect by people for this is a typical soil covert degradation. Because of thesoil Ca degradation, the fruit total Ca decreased rapidly as the planting-year increased, so thatthe flesh firmness decreased, it’s harmful for keeping apple fruits.4. There is a orchards practicing stereoscopic agriculture, the chickens are raised inorchards day by day. And as the result, the soil surface became acidification and sub-layerbecame alkalization. Additionally, the soil surface layer became eutrophication. Keepingchickens in orchards caused the amount of soil CO32-decreased in0~50cm, and the practicepromoted the decreasing of soil CaCO3. The decrement of soil CaCO3increased more17.75kg CaCO3m-2than CK. The water-soluble Ca of chicken-orchards was higher than CK,because of soil CaCO3was dissolved. With the amount of soil water-soluble Ca increased, thesoil provided abundant Ca to trees, so that the apple quality was developed by keepingchickens in the orchards. Keeping chickens have made a positive effection in improving fruitqualities currently. However, according to the loss rate of the soil calcium, it must beconcerned greatly about the potential danger in the healthy and sustainability of fruit industry. In conclusion, the amount of soil available Mn and its distribution affected the amount ofCa in apple fruits and leaves, caused the degeneration of fruit quality. The altitude influencedthe amount of soil available S, while decreased the Ca in fruits and leaves, while differentterrain changed fruit quality significantly. As the planting-year raise, the fruit quality declined,and practicing stereoscopic agriculture will affect soil and fruit quality. This affection need along-term monitoring and control. Although Weibei is one of the best regions for growingapple trees, not every pieces of land in this region are really good for apple planting.