1. Key Resource 2002-01-01 Acidification of soil is a natural process with major ramifications on plant growth. As soils become more acid, particularly when the pH drops below 4.5, it becomes increasingly difficult to produce food crops. As soil pH declines, the supply of most plant nutrients decreases while aluminum and a...
  2. 1984-01-01 Excessive soil acidity is a continuing problem in many agricultural areas and is increasingly becoming a yield-limiting factor in other areas. The pH of soils of the dryland wheat-growing area of the Pacific Northwest has dropped an average of one unit in the last 20 years. Similar effects are...
  3. 2004-04-20 Terra preta is very productive soil with long-lasting fertility—unusual in the tropics, where most soils are very weathered, highly acidic, and low in organic matter and essential nutrients. The key to terra preta soils long-term fertility seems to be charcoal; terra preta contains up to 70 times...
  4. ABSTRACT - Journal of Composting Science and Utilization, 2017 Tropical acid soils are highly weathered as they exist under tropical environment with high rainfall and temperature throughout the year, which affects nitrogen availability. Soil organic nitrogen is important in estimating soil...
  5. Key Resource 2009-01-20 All plants need certain mineral elements for proper growth, development, and maintenance. The basic structure of all organisms is built of carbon (C), oxygen (O) and hydrogen (H). Plants obtain these elements from water (H2O) in the soil and carbon dioxide (CO2) in the air, so no input is...
  6. 2017-02-15 This report describes and analyzes the soil distribution and characteristics of the main soil types in Mainland Southeast Asia (MSEA) that comprise the countries of Cambodia, Lao PDR, Myanmar, Thailand, and Vietnam. This article is from ECHO Asia Note #30
  7. 2001-04-20 Soil acidity, or low pH, limits plant growth in many parts of the world. Although low pH can harm plants in many ways, this article will deal only with one of these factors, aluminum (Al) toxicity.Al is the third most abundant element on the earth (after oxygen and silicon), and the most abundant...
  8. 2002-01-20 The conventional view of the relationship between soil nutrients and crop productivity in the tropics is leading to both damaging agricultural policies and inefficient and damaging farm-level practices. There is no need to use the huge quantities of chemical fertilizers that are so often...
  9. Key Resource
    2002-01-01 Acidification of soil is a natural process with major ramifications on plant growth. As soils become more acid, particularly when the pH drops below 4.5, it becomes increasingly difficult to produce food crops. As soil pH declines, the supply of most plant nutrients decreases while aluminum and a...