Penetrometer kỹ thuật trong quan hệ để nén chặt đất và tăng trưởng gốc Đất độ cứng là điện trở của đất biến dạng, có thể là của một gốc cây, lưỡi cày một, hoặc đầu penetrometer một. Đất cứng là một vấn đề lớn trong nông nghiệp trên toàn thế giới, hạn chế tăng trưởng gốc và sự xuất cây giống, làm tăng chi phí năng lượng của đất canh tác, và áp đặt các hạn chế về chế độ quản lý đất đai có thể được sử dụng. Penetrometers được sử dụng phổ biến để đo lường sức mạnh. | 10 Penetrometer Techniques in Relation to Soil Compaction and Root Growth A. Glyn Bengough Scottish Crop Research Institute Dundee Scotland Donald J. Campbell and Michael F. O Sullivan Scottish Agricultural College Edinburgh Scotland I. INTRODUCTION Soil hardness is the resistance of the soil to deformation be it by a plant root the blade of a plow or the tip of a penetrometer. Hard soils are a major problem in agriculture worldwide they restrict root growth and seedling emergence increase the energy costs of tillage and impose restrictions on the soil management regimes that can be used. Penetrometers are used commonly to measure soil strength. If a standard probe and testing procedure is used penetrometers give an empirical measure of soil strength that enables comparisons between different soils. A penetrometer consists typically of a cylindrical shaft with a conical tip at one end and a device for measuring force at the other Fig. 1 . Penetration resistance is the force required to push the cone into the soil divided by the cross-sectional area of its base . a pressure . The American Association of Agricultural Engineers specified a standard penetrometer design that gives a measurement called the cone index ASAE 1969 . This standard has been adopted widely but many nonstandard penetrometers are in use. Nonstandard penetrometers and testing procedures are more appropriate for some applications as long as comparisons are made using the same procedure. The principles behind the testing procedure must be understood so that the results can be interpreted sensibly. In this chapter we describe the theory behind the measurement of penetration resistance and how penetration resistance is related to other soil properties. Copyright 2000 Marcel Dekker Inc. Force applied by hand or loading frame to drive cone into soil force transducer shaft _cone soil surface Fig. 1 Schematic diagram of a penetrometer showing cone shaft and force transducer. We then consider the .
