**Meet the editor**

S.O. Oshunsanya is a senior lecturer in the Department of Agronomy, University of Ibadan, Nigeria. His research focus is primarily on soil and water conservation and soil amendment for sustainable crop cultivation. He has taught soil science related courses at both graduate and postgraduate levels for 10 years, and has been involved in many research and community services as a

consultant in Nigeria and China. He has supervised over 20 postgraduate students and published over 60 articles. He has served the University of Ibadan at various capacities both within and outside and is a member of learned societies at both national and international levels.

Contents

**Preface VII**

Chapter 1 **Introductory Chapter: Relevance of Soil pH to Agriculture 3**

Chapter 3 **Fluoride Adsorption onto Soil Adsorbents: The Role of pH and**

Chapter 4 **Control of Soil pH, Its Ecological and Agronomic Assessment in**

Danute Karcauskiene, Regina Repsiene, Dalia Ambrazaitiene,

Enos Wamalwa Wambu and Audre Jerop Kurui

Regina Skuodiene and Ieva Jokubauskaite

Shinji Matsumoto, Hideki Shimada, Takashi Sasaoka, Ikuo Miyajima,

Chapter 2 **Effects of Acid Soils on Plant Growth and Successful Revegetation in the Case of Mine Site 9**

Ginting J. Kusuma and Rudy S. Gautama

Suarau Odutola Oshunsanya

**Section 2 Soil Fertility and Plant Nutrition 7**

**Section 3 Soil Chemistry and Mineralogy 29**

**an Agroecosystem 47**

**Other Solution Parameters 31**

**Section 1 Introduction 1**

**Section 4 Agro-ecology 45**

## Contents

**Preface XI**



Preface

Kardum.

Soil pH is a measure of a soil solution's acidity and alkalinity, which affects nutrient solubili‐ ty and availability in the soil. Soil pH is affected by the use of nitrogen fertilizers, organic matter decomposition, soil types and land use, rainfall, weathering of minerals, and parent material. Soil pH affects soil productivity by regulating the availability of nutrients for crop plant uptake. Soil pH levels near 7 are optimal for overall nutrient availability, crop tolerance, and soil microorganism activity. Crop productivity starts to decrease when the soil pH falls below 5.5 (CaCl2). Toxic amounts of aluminum and manganese are soluble and released into the soil solution when soil pH falls below 5.0 (CaCl2). Soluble aluminum is toxic to roots of many crop plants and therefore limits their access to soil, water, and nutrients. At a low soil pH, microbial activity decreases and nutrients such as phosphorus, magnesium, calcium, and molybdenum gradually become unavailable to the roots of crops in the soil. At this stage, fertilizers become less effective and agricultural production can be significantly reduced. As the soil becomes acidic, fewer agricultural crops grow. Soil pH can be modified by using soil amendments. Lime or lime compounds (ground limestone, marl, and hydrated lime) are the soil amendments used to raise the soil pH or increase the soil acidity. Sulfur is used to lower soil pH or increase the acidity of the soil. In areas of high total rainfall, calcium and magnesi‐ um could be washed from the soil resulting in an acid soil. Lime can also be used to replace the lost calcium and raise the soil pH to a range preferred by the crop being cultivated.

The editor wishes to place on record the unquantifiable assistance rendered by Ms. Kristina

**S.O. Oshunsanya** B. Agric, M. Sc., PhD Department of Agronomy Faculty of Agriculture University of Ibadan, Nigeria

### Preface

Soil pH is a measure of a soil solution's acidity and alkalinity, which affects nutrient solubili‐ ty and availability in the soil. Soil pH is affected by the use of nitrogen fertilizers, organic matter decomposition, soil types and land use, rainfall, weathering of minerals, and parent material. Soil pH affects soil productivity by regulating the availability of nutrients for crop plant uptake. Soil pH levels near 7 are optimal for overall nutrient availability, crop tolerance, and soil microorganism activity. Crop productivity starts to decrease when the soil pH falls below 5.5 (CaCl2). Toxic amounts of aluminum and manganese are soluble and released into the soil solution when soil pH falls below 5.0 (CaCl2). Soluble aluminum is toxic to roots of many crop plants and therefore limits their access to soil, water, and nutrients. At a low soil pH, microbial activity decreases and nutrients such as phosphorus, magnesium, calcium, and molybdenum gradually become unavailable to the roots of crops in the soil. At this stage, fertilizers become less effective and agricultural production can be significantly reduced. As the soil becomes acidic, fewer agricultural crops grow. Soil pH can be modified by using soil amendments. Lime or lime compounds (ground limestone, marl, and hydrated lime) are the soil amendments used to raise the soil pH or increase the soil acidity. Sulfur is used to lower soil pH or increase the acidity of the soil. In areas of high total rainfall, calcium and magnesi‐ um could be washed from the soil resulting in an acid soil. Lime can also be used to replace the lost calcium and raise the soil pH to a range preferred by the crop being cultivated.

The editor wishes to place on record the unquantifiable assistance rendered by Ms. Kristina Kardum.

> **S.O. Oshunsanya** B. Agric, M. Sc., PhD Department of Agronomy Faculty of Agriculture University of Ibadan, Nigeria

**Section 1**

**Introduction**

**Section 1**
