tailieunhanh - Humic Matter in Soil and the Environment: Principles and Controversies - Chapter 8

Nông học TẦM QUAN TRỌNG CỦA VẤN ĐỀ Humic TẦM QUAN TRỌNG trong đất Nó cũng được biết rằng vấn đề đất hữu cơ có tác động tích cực trên các chất hóa học, vật lý, và đặc điểm sinh học của đất. Với những kiến thức tăng lên trong hóa học axit humic, hiệu ứng này là nhận ra được gây ra bởi các thành phần hoạt động của phần vô cơ và chất mùn. | CHAPTER 8 AGRONOMIC IMPORTANCE OF HUMIC MATTER IMPORTANCE IN SOILS It is well known that soil organic matter has a favorable effect on the physical chemical and biological characteristics of soils. With the increased knowledge in humic acid chemistry this effect is now realized to be caused by the active components of the inorganic and humus fraction. EFFECT ON SOIL PHYSICAL PROPERTIES The physical properties of soils are noted to change due to addition of soil organic matter yielding humic substances. These changes are usually interrelated and the change in one physical property will often be followed by changes in other physical properties. Soils high in organic matter usually exhibit high water-holding capacities display well-developed structures have low bulk density values and are often fluffy or friable in consistencies. Although all the physical properties are no doubt very important for the well-being of the soil ecosystem it is perhaps soil structure that Copyright n 2003 by Marcel Dekker Inc. All Rights Reserved. is the most significant in soil formation and soil degradation as well as in plant growth and environmental quality. The formation of soil structure favorable for plant growth is assumed to be caused by the interaction between humic acid and clays and or by complex reactions between humic acid and Al and other metal ions. Since soil structure also infers a mutual arrangement of the three soil phases solid liquid and gas a change in soil structure will affect the balance between these three phases. The liquid and gas phases are especially vulnerable since they are also subject to continuous exchanges with the environment. The effect of humic acid is to create and preserve a stable structure that can provide the proper amounts of pore spaces for the storage of optimum amounts of water and oxygen. The cementation effect of humic acid has long been considered a major factor in formation of soil structure Baver 1963 which is very important .

TÀI LIỆU LIÊN QUAN
TỪ KHÓA LIÊN QUAN
crossorigin="anonymous">
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.