The Evaluation Of Soil Fertility Quality In The Apple Orchard Of Luochuan County

Luochuan is the only competitive agricultural products (apples) industrial demonstrationcounty in Shaanxi province, which is the Major apple production base in china. Luochuanalso plays a vital role in leading and driving the development of apple industry in Shaanxi.Comprehensively and systematically revealing soil physicochemical properties of appleorchard and scientifically assessing the soil quality of orchard, not only could providescientific evidence to soil management of orchard and promote the quality and benefits ofapple industry, but also has important reference value for soil management in Shaanxi, eventhe national majority of apple orchard.This paper was studied by field investigation, field sampling and laboratory analysis ofsoil physicochemical properties in seventy different type orchards, which from the northern,central, southern part of Luochuan respectively. And the method of classification grading andcomprehensive index had carried on the comprehensive soil quality assessment of appleorchard in Luochuan. The results were as follow:(1) The soil bulk density in topsoil0～20cm was less than1.2g·cm-3, accounting for27.65%of the total samples, and in20～40cm soil layer, there were more than1.5g·cm-3accounting for11.66%of the orchards. The average of soil water content in0～20cm and20～40cm soil layer were only13.24%and13.28%in water deficiency, which were lowerthan60%of water holding capacity of the largest field (13.64%). The average of soil pH was7.99, and there were94.0%orchards of which the pH was more than7.5The average contentof soil organic matter was10.58g·kg-1. And organic matter at deficiency level accounted for67.19%of the total orchards. Average content of total N and were0.52g·kg-1. Total N atdeficiency level accounted for60.41%. Content of total P, K, and available N, P, K, were allover appropriate level. Content of available Fe, Mn, Zn, B below deficiency level accountedfor23.5%,11.8%,17.7%and64.7%. Soil quality assessment of apple orchard were mostly atmedium level or below relatively low level.(2) A downward trend was appeared in soil organic matter and nutrient, while the depthof soil layer was increasing. Content of soil organic matter and total N had a sharply decrease in0～60cm soil layer and slightly decrease below60cm layer. Content of total P, available N,P in the topsoil were significantly higher than the lower layer. Content of available Zn andavailable B decreased sharply from topsoil to40cm soil layer. Content of available Mn had asharply decrease from topsoil to100cm soil layer.(3) The soil bulk density in northern and central part of Luochuan were the same, whichwere both bigger than the southern. Content of soil available N were shown as southern>central> northern. Content of soil available P were shown as southern> northern> central.There were no significant differences among other nutrient items. And there also were nosignificant differences in soil quality assessment among northern, central and southern part ofLuochuan apple orchard. The soil quality in southern part (new producing area) was a littlebetter than the northern and central part, and the central was the worst.(4) Content of soil pH were shown as low-yield orchard>mid-yield orchard> high-yieldorchard, while content of organic matter, total N, P, and available N, P, K were in contrary.The soil quality of mid-yield orchard was better than low-yield orchard, while the high-yieldorchard was the best.(5) Changes in soil pH at different tree ages were stable relatively. With the ages growing,soil organic matter had a little increase. Content of total N, P, K and available N, P, Kincreased from saplings, the first fruits to the flourishing. And there were no differencesbetween the flourishing and the senescence. There were significant differences in differenttree ages. The soil quality in flourishing and senescence orchards was significantly better thansaplings and first fruits orchard.(6) Planting Shamrock could significantly reduce soil pH. The soil quality had somedifferences in different soil management. Planting shamrock could improve soil physical andchemical environment and nutrient status, which the soil quality was better than tillage,inter-tillage and plowing.