Controlled Release Fertilizers for Sustainable Agriculture

By Sabu Thomas

Controlled Release Fertilizers for Sustainable Agriculture provides a comprehensive examination of precision fertilizer applications using the 4-R approach—the right amount of fertilizer at the right time to the right plant at the correct stage of plant growth. This volume consolidates detailed information on each aspect of controlled release fertilizers, including up-to-date literature citations, the current market for controlled release fertilizers and patents. Presenting the tremendous advances in experimental and theoretical studies on sustainable agriculture and related areas, this book provides in-depth insight into state-of-the-art controlled release mechanisms of fertilizers, techniques, and their use in sustainable agriculture.

Conventional release mechanisms have historically meant waste of fertilizers and the adverse effects of that waste on the environment. Controlled release delivery makes significant strides in enhancing fertilizer benefit to the target plant, while protecting the surrounding environment and increasing sustainability.

• Presents cutting-edge interdisciplinary insights specifically focused on the controlled release of fertilizers
• Explores the benefits and challenges of 4-R fertilizer use
• Includes expertise from leading researchers in the fields of agriculture, polymer science, and nanotechnology working in industry, academics, government, and private research institutions across the globe
• Presents the tremendous advances in experimental and theoretical studies on sustainable agriculture and related areas

• Language: English
• Publisher: Academic Press
• Release date: Oct 14, 2020
• ISBN: 9780128226148

Book preview

Controlled Release Fertilizers for Sustainable Agriculture

Editors

F.B. Lewu

Department of Agriculture, Cape Peninsula University of Technology Wellington Campus, Wellington, South Africa

Tatiana Volova

Department of Biotechnology, Siberian Federal University, Krasnoyarsk, Russia

Sabu Thomas

School of Energy Materials; School of Chemical Sciences, International and Inter-University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam, Kerala, India

Rakhimol K.R.

International and Inter-University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam, Kerala, India

Table of Contents

Cover image

Title page

Copyright

Contributors

Chapter 1. Conventional methods of fertilizer release

1. Introduction

2. Classification

3. Mode of application

4. The controlled-release fertilizers

5. Slow- and controlled-release fertilizers

6. Chemicals that affect nitrogen uptake

7. Overfertilization

8. Conclusion

Chapter 2. Fate of the conventional fertilizers in environment

1. Introduction

2. Major components of fertilizer residues

3. Side effects of fertilizer residues

4. Effect on water pollution

5. Effect on soil pollution

6. Effect on air pollution

7. Role of greenhouse gas emission

8. Effect on food quality

9. Fertilizer guidelines

10. Conclusion

Chapter 3. Controlled release of fertilizers—concept, reality, and mechanism

1. Introduction

2. Factors influencing fertilizer release

3. How does it work?

4. Different types of slow or controlled release fertilizers [16]

5. Advantages of CRFs

6. Disadvantages of CRFs

7. Classification of controlled release fertilizers

8. Controlled and slow release fertilizers

9. Mechanisms of control release

10. Factors affecting the nutrient release

11. Mode of nutrient release from CRFs

12. Application of CRFs in agriculture

13. Future aspects

14. Conclusion

Chapter 4. Characteristics and types of slow- and controlled-release fertilizers

1. Introduction

3. Advantages of using CRFs and SRFs

4. Conclusions

Chapter 5. Methods for controlled release of fertilizers

1. Introduction

2. Uncoated nitrogen-based fertilizers

3. Coated nitrogen-based fertilizers

4. Polymer-coated controlled-release fertilizer

5. Commercially available polymer-coated CRF

6. Preparations of CRF formulations

7. Field application methods

8. Biodegradability of CRFs

9. Advantages of controlled release of fertilizers

10. Drawback of controlled-release fertilizers

11. Conclusion

Chapter 6. Manufacturing of slow and controlled release fertilizer

1. Introduction

2. Coated fertilizer manufacture

3. Matrix dispersed fertilizer

4. CRF testing procedure

5. Conclusion

Chapter 7. Controlling factors of slow or controlled-release fertilizers

1. Introduction

2. Fertilizer’s composition and shape

3. Coating composition and physical-chemical properties

4. Soil parameters

5. Conclusion

Chapter 8. Sensors detecting controlled fertilizer release

1. Introduction

2. Nanosensors

3. High-speed stereovision

4. Optical sensors

5. Remote sensing

6. Conclusions

Chapter 9. Trends and technologies behind controlled-release fertilizers

1. Introduction

2. Generalized mechanism of controlled-release fertilizers

3. Compositions of controlled-release fertilizers

4. Failure of release

5. Petroleum-based polymers

6. Nano fertilizers

7. Nanofertilizers are of different types

8. Synthesis of nanoparticle or nanofertilizer

9. Conclusion

Chapter 10. Nanotechnology in controlled-release fertilizers

1. Introduction

2. Designing of nanofertilizer

3. Advantages of nanofertilizers

4. Types of nanofertilizers

5. Nanosensors

6. Methods of fertilizer release

7. Factors affecting the designing of nano-based controlled-release system

8. Nanotoxicity in the fields

9. Conclusion

Chapter 11. Polymer formulations for controlled release of fertilizers

1. Introduction

2. Classification of fertilizers

3. Polymer formulations for controlled release of fertilizers

4. Conclusions

Chapter 12. Chemistry and toxicology behind chemical fertilizers

1. Introduction

2. Types of fertilizers

3. Chemistry of chemical fertilizer

4. Impact of chemical fertilizers on environment

5. Conclusion

Chapter 13. Organic fertilizers as a route to controlled release of nutrients

1. Introduction

2. Natural organic fertilizers

3. Processed organic fertilizers

4. Biofertilizers

5. Controlled release of organic fertilizers

6. Conclusion

Index

Copyright

Academic Press is an imprint of Elsevier

125 London Wall, London EC2Y 5AS, United Kingdom

525 B Street, Suite 1650, San Diego, CA 92101, United States

50 Hampshire Street, 5th Floor, Cambridge, MA 02139, United States

The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, United Kingdom

Copyright © 2021 Elsevier Inc. All rights reserved.

No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions.

This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein).

Notices

Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary.

Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility.

To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein.

Library of Congress Cataloging-in-Publication Data

A catalog record for this book is available from the Library of Congress

British Library Cataloguing-in-Publication Data

A catalogue record for this book is available from the British Library

ISBN: 978-0-12-819555-0

For information on all Academic Press publications visit our website at https://www.elsevier.com/books-and-journals

Publisher: Charlotte Cockle

Acquisitions Editor: Nancy Maragioglio

Editorial Project Manager: Lena Sparks

Production Project Manager: Joy Christel Neumarin Honest Thangiah

Cover Designer: Matthew Limbert

Typeset by TNQ Technologies

Contributors

Ashitha A.,     School of Biosciences, Mahatma Gandhi University, Kottayam, Kerala, India

Soumia Aboulhrouz,     VARENA Center, MAScIR Foundation, Rabat Design, Rabat, Morocco

Aiman E. Al-Rawajfeh,     Department of Chemical Engineering, Tafila Technical University, Tafila, Jordan

Mohammad R. Alrbaihat,     Ministry of Education, Ajman, United Arab Emirates

Ehab M. AlShamaileh,     Department of Chemistry, The University of Jordan, Amman, Ajman, Jordan

Othmane Amadine,     VARENA Center, MAScIR Foundation, Rabat Design, Rabat, Morocco

Subin Balachandran,     School of Biosciences, Mahatma Gandhi University, Kottayam, Kerala, India

Vinaya Chandran,     School of Biosciences, Mahatma Gandhi University, Kottayam, Kerala, India

Karim Danoun,     VARENA Center, MAScIR Foundation, Rabat Design, Rabat, Morocco

Youness Essamlali,     VARENA Center, MAScIR Foundation, Rabat Design, Rabat, Morocco

Ikram Ganetri,     VARENA Center, MAScIR Foundation, Rabat Design, Rabat, Morocco

Jesiya Susan George,     International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam, Kerala, India

Abdul Ghaffar,     Department of Physics, University of Agriculture, Faisalabad, Punjab, Pakistan

Rakhimol K.R.,     International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam, Kerala, India

Jayachandran K.,     School of Biosciences, Mahatma Gandhi University, Kottayam, Kerala, India

Nandakumar Kalarikkal,     International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam, Kerala, India

Jyothis Mathew,     School of Biosciences, Mahatma Gandhi University, Kottayam, Kerala, India

Linu Mathew,     School of Biosciences, Mahatma Gandhi University, Kottayam, Kerala, India

Stalin Nadarajan,     Institute of Plant Science, ARO Volcani Center, Rishon Lezion, Israel

Muhammad Yasin Naz,     Department of Physics, University of Agriculture, Faisalabad, Punjab, Pakistan

Chandra Wahyu Purnomo,     Chemical Engineering Department, Universitas Gadjah Mada, Sleman, Yogyakarta, Indonesia

Maya Rajan,     School of Biosciences, Mahatma Gandhi University, Kottayam, Kerala, India

Hens Saputra,     Agency for the Assessment and Application of Technology, Jakarta, Indonesia

S. Shahena,     School of Biosciences, Mahatma Gandhi University, Kottayam, Kerala, India

Hitha Shaji,     School of Biosciences, Mahatma Gandhi University, Kottayam, Kerala, India

Shazia Shukrullah,     Department of Physics, University of Agriculture, Faisalabad, Punjab, Pakistan

Reshma Soman,     School of Biosciences, Mahatma Gandhi University, Kottayam, Kerala, India

Surya Sukumaran,     School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala, India

Sabu Thomas,     International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam, Kerala, India

Remya V.R.,     International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam, Kerala, India

Mohamed Zahouily

VARENA Center, MAScIR Foundation, Rabat Design, Rabat, Morocco

Laboratoire de Matériaux, Catalyse et Valorisation des Ressources Naturelles, Université Hassan II-Casablanca, Morocco

Chapter 1: Conventional methods of fertilizer release

S. Shahena, Maya Rajan, Vinaya Chandran, and Linu Mathew     School of Biosciences, Mahatma Gandhi University, Kottayam, Kerala, India

Abstract

Any materials that are applied directly to the plant tissue or to the soil to enhance the production and growth of the plants are generally referred to as fertilizers. Nutrient deficiency results in abnormal or stunted growth of crop plants and causes reduction in crop yield. Fertilizers help to ameliorate nutrient deficiency to improve crop yields. The fertilizers are available and applied in solid and liquid form. The methods used for delivering the solid fertilizers are broadcasting, placement, band placement, and pellet application. The liquid fertilizers can be applied as starter solution, foliar application, injection into soil, aerial application, and also by fertigation. The traditional fertilizers can be encapsulated within the shell materials such as sulfur, thermoplastics, ethylene-vinyl acetate, surfactants, etc., to improve their efficiency and also to reduce the environmental contamination. These are called as controlled-release fertilizers. Controlled-release fertilizers, band deep placement, and foliar application can be used to improve or enhance the efficiency and yield of the crop plants and also to minimize phytotoxicity and environmental contamination.

Keywords

Band deep placement; Broadcasting; Controlled-release fertilizer; Fertigation; Fertilizers; Foliar application

1. Introduction

The fertilizer is any kind of material that is applied to soil or to plant tissues to supply one or more plant nutrients essential to the growth of plants. It may be natural or synthetically produced [1].

Management of soil fertility has been a great problem for the farmers for thousands of years. Records showed that Egyptians, Romans, Babylonians, and early Germans were using minerals and manure to enhance the productivity of their farms. The modern science of plant nutrition started in the 19th century with the work of German chemist Justus von Liebig [1].

The Haber process and the Ostwald process developed in the 1910 and 1920s made a great revolution in the fertilizer manufacturing Industry. Ammonia (NH3) is produced from methane (CH4) gas and molecular nitrogen (N2) through the Haber process, which is then converted into nitric acid (HNO3) in the Ostwald process [2].

The nitrogen-based fertilizer production was started with Birkeland–Eyde process, which was one of the most competing industrial processes in the nitrogen-based fertilizer production. In this process, the atmospheric nitrogen (N2) is fixed into nitric acid (HNO3) through nitrogen fixation. The nitric acid was then used as a source of nitrate (NO3 − ) [3].

Nowadays, it has been estimated that almost half the people on the Earth are currently fed as a result of synthetic nitrogen fertilizer. The development of synthetic fertilizer has significantly supported global population growth [4]. In the last 50 years, the use of commercial fertilizers has been increasing steadily; reaching almost 100 million tons of nitrogen per year, and it is estimated that about one-third of the food produced now could not be produced without the addition of fertilizers [5]. The use of phosphate fertilizers has also increased from nine million tons per year in 1960 to 40 million tons per year in 2000. Yara International is the world's largest producer of nitrogen-based fertilizers [6,7].

The supply of nutrients must be optimum for the maximum yield of any crop. The nutrient deficiency will result in stunting of plants and that will gradually reduce the yield by slowing down the progress of the growth cycle, causing late fruiting and delayed maturity. The ability of the crop to absorb the nutrients from the soil depends upon the biological activity. Normally the nutrient deficiency takes place during the growing season and depends on the temperature and moisture content of the soil [8]. Fertilizers enhance plant growth traditionally; either as, being additives that provide nutrients or by enhancing the effectiveness of the soil by modifying its water retention and aeration [9]. Also, an important component of the weed management program is the efficient and appropriate management of fertilizer in terms of evaluation of best source of nutrients, optimum rates of fertilization, proper timing, and suitable fertilizer placement [3,10].

The essential prerequisite for optimizing nutrient application is the detailed knowledge about the addition of nutrients, i e., the absorption of nutrients by the plants. The applied nutrients should satisfy the plant requirements and the method used for the application should minimize the leaching to the environment and thereby control the rate of environmental pollution [11]. The type of fertilizer, timing of fertilizer application, and seasonal trends are the major factors that affect the efficiency of the applied N (nitrogen) to satisfy the N demand of the crops [12,13]. The efficiency of the crops to absorb the N is influenced by the soil type, crop sequence, and the residual and mineralized N [14]. The reduction of nitrogen loss and increase in the N use efficiency can be improved by numerous strategies. For example, the use of N sources, consumption of slow-release fertilizer, proper placement techniques, and also by the use of N inhibitors [15–17].

The plant metabolism is coupled with the availability of the N sources because it has a fundamental role in the plant metabolism. It is necessary to optimize the management of N resources to the cropping system to increase its N use efficiency and thereby improve the productivity [18]. Normally, this can be achieved either by increasing the production of N in the soil or by increasing the accumulation of N compounds in the edible part of the crop [15].

The nutrients required for healthy plant life are classified on the basis of the elements; but these elements are not used directly as fertilizers. The compounds containing these elements are the basis of fertilizers. The macronutrients are consumed in larger quantities by the plants. They are present in plant tissue in quantities from 0.15% to 6.0% on a dry matter (DM) (0% moisture) basis. Plants are made up of four main elements such as hydrogen, oxygen, carbon, and nitrogen. Hydrogen, oxygen, and carbon will be available in the form of water and carbon dioxide. The nitrogen is found in the atmosphere as atmospheric nitrogen which is unavailable to plants. So the nitrogen is considered as the most important fertilizer since nitrogen is present in proteins, DNA, and other components such as chlorophyll. Some bacteria and their host leguminous plants can fix atmospheric nitrogen (N2) by converting it to ammonia. Phosphate is required for the production of DNA and ATP, the main energy carrier in cells, as well as certain lipids.

The fertilizer contains:

• Three main macronutrients:

◦ Nitrogen (N): leaf growth

◦ Phosphorus (P): Development of roots, flowers, seeds, fruit

◦ Potassium (K): Strong stem growth, movement of water in plants, promotion of flowering and fruiting

• Three secondary macronutrients: calcium (Ca), magnesium (Mg), and sulfur (S)

• Micronutrients: copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), zinc (Zn), boron (B). Of occasional significance are silicon (Si), cobalt (Co), and vanadium (V).

Micronutrients are required in smaller quantities, in parts-per-million (ppm) and are present at the active sites of enzymes in the plant tissues that carry out the plant's metabolism [19].

2. Classification

Fertilizers are classified in several ways.

2.1. Based on the nutrient supply

On the basis of the nutrient supply, the fertilizers can be classified into straight fertilizers and complex fertilizers.

2.1.1. Single nutrient or straight fertilizers

As the name indicates, the single nutrient or straight nutrient fertilizers provide a single nutrient to the plants (e.g., K, P, or N). Ammonia or its solutions are the widely used nitrogen-based straight fertilizers. Ammonium nitrate (NH4NO3) and urea are popular sources of nitrogen. Urea is having the advantage that it is solid and nonexplosive, unlike ammonia and ammonium nitrate.

The superphosphates are the main straight phosphate fertilizers. Single superphosphate (SSP) consists of 14%–18% P2O5, again in the forms of Ca(H2PO4)2 and also phosphogypsum (CaSO4·2H2O). The main con-stituents of triple superphosphate (TSP) are 44%–48% of P2O5 and no gypsum. A mixture of single superphosphate and triple superphosphate is called double superphosphate. Most of the (more than 90%) typical superphosphate fertilizer is water-soluble [20].

Muriate of Potash (MOP) is the main potassium-based straight fertilizer. Muriate of Potash consists of 95%–99% KCl, and is typically available as 0-0-60 or 0-0-62 fertilizer [21].

2.1.2. Multinutrient or complex fertilizers

The multinutrient or complex fertilizers provide two or more nutrients (e.g., N and P). The commonly used fertilizers are the complex fertilizers. Since they consist of two or more nutrient components, they are again classified into binary fertilizers and three-component fertilizers or NPK fertilizers [20].

2.1.2.1. Binary (NP, NK, and PK) fertilizers

Since they provide both nitrogen and phosphorus to the plants they are called NP fertilizers, e.g., monoammonium phosphate (MAP) and diammonium phosphate (DAP). The active ingredient in MAP is NH4H2PO4 and the active ingredient in DAP is (NH4)2HPO4. About 85% of MAP and DAP fertilizers are soluble in water.

2.1.2.2. NPK fertilizers

Nitrogen, phosphorus, and potassium containing fertilizers are called three-component fertilizers or NPK fertilizers.

2.2. Based on the presence or absence of carbon

2.2.1. Organic fertilizer

Organic fertilizers are recycled plant- or animal-derived matter.

2.2.2. Inorganic fertilizer

Inorganic fertilizers or synthetic fertilizers are synthesized by various chemical treatments [20].

3. Mode of application

The application rates of fertilizer depend on the soil fertility. The fertility of a soil is usually as measured by a soil test according to the particular crop. The method of applying fertilizers depends on the nature of crop plants, their nutrient needs, and the soil (Table 1.1).

Table 1.1

Figure 1.1 Methods of solid fertilizer application.

Fertilizers are applied to crops both in the form of solids and liquids. Most of the fertilizers are applied in the form of solids (e.g., urea, diammonium phosphate, and potassium chloride). Solid fertilizer is typically used in granulated or powdered form. It is also available in the form of prills or solid globules [22]. Liquid fertilizers comprise anhydrous ammonia, aqueous solutions of ammonia, and aqueous solutions of ammonium nitrate or urea. The concentrated liquid fertilizers can be diluted with water (e.g., UAN). Its more rapid effects and easier coverage are the advantages of liquid fertilizer [9](Fig. 1.1).

3.1. Application of solid fertilizers

3.1.1. Broadcasting

The spreading of fertilizer all over the field in a uniform manner is known as broadcasting. A separate operation in addition to seeding is required in the broadcasting mode of fertilizer application. The fertilizer may be spread on the surface of the soil itself, with or without incorporation into the soil, or it may be placed below the soil surface in closely spaced rows by the use of a fertilizer drill [8].

Normally the fertilizer used for this kind of application is in an insoluble form; especially, insoluble phosphatic fertilizer such as rock phosphate is used for broadcasting mode of application. This method is suitable for crops with dense stand. The plant roots will permeate the whole volume of the soil. Large doses of fertilizers are needed for the application.

There are two methods of broadcasting method of application, namely broadcasting at sowing or planting (basal application) and top dressing.

3.1.1.1. Broadcasting at sowing or planting (basal application)

The main objective of the basal application is the application of fertilizers at sowing time for a uniform distribution. Thus the fertilizer will be spread over the entire field and completely mix with soil.

Boron fertilizers are generally applied by broadcast method. Normally they are incorporated prior to seeding for crops not planted in rows. Boron is applied by broadcast method in plants such as legumes and grasses and broadcast methods are more effective in trees and grape vines and also in the cases of coarser-textured soils [23].

Blackshaw et al. [24] reported that N uptake by green foxtail throughout the growing season was often greater from surface broadcast than from surface pools or point-injected N. To keep abreast of increasing population, the rice production of Asia must be increased up to 2.2%–2.8% annually. The efficiency of fertilizer N can be increased by the improvement of timing and application methods, particularly through the better incorporation of basal fertilizer N without standing water [25].

3.1.1.2. Top dressing

The nitrogenous fertilizers are normally applied closely in crops like paddy and wheat, with the objective of supplying nitrogen in readily available form to growing plants. This kind of application of nitrogen fertilizer is known as top dressing.

To improve rice yield and the nitrogen availability to the plants, top dressing is recommended to the lower soil layer for Japonica rice [26–28], new high yielding rice varieties such as Indica type [29], and large grain type varieties [28,30].

In the case of rice varieties, the timing of top dressing with high nitrogen (HN) to produce high rice yield is not fully understood. Matsushima [26] observed that topdressing at 30   days before heading (30 DBH) resulted in worse plant type and yield reduction due to the elongation of the lower internodes and upper leaves. In a model experiment with Japonica type variety Koshihikari, Matsuba [31] indicated that the topdressing at 30 DBH did not elongate the lower internodes. In the case of Takanari, an Indica variety, the topdressing at 30 DBH did not worsen the plant type but did increase the sink size in high-yielding varieties [26]. Fukushima et al. [28] suggested that the new type rice variety Bekoaoba will increase its sink size and the rice yield by top dressing at 30 DBH or early top dressing leading to short culms and erect leaf.

In Bangladesh, crystal urea is normally applied as top dressing. It decreases yield by misbalancing the yield components. Usually this problem is prevented by the application of super granules of urea (USG); since the USG have the ability to minimize the loss of N from soil, thus effectively increasing up to 20%–25% [32].

Disadvantages of broadcasting: The plants in the field cannot fully utilize the fertilizers as they