SOIL EROSION ISSUES IN AGRICULTURE Edited by Danilo Godone and Silvia Stanchi Soil Erosion Issues in Agriculture Edited by Danilo Godone and Silvia Stanchi Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2011 InTech All chapters are Open Access articles distributed under the Creative Commons Non Commercial Share Alike Attribution 3.0 license, which permits to copy, distribute, transmit, and adapt the work in any medium, so long as the original work is properly cited. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published articles. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book. Publishing Process Manager Silvia Vlase Technical Editor Teodora Smiljanic Cover Designer Jan Hyrat Image Copyright Sandra Cunningham, 2010. Used under license from Shutterstock.com First published September, 2011 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechweb.org Soil Erosion Issues in Agriculture, Edited by Danilo Godone and Silvia Stanchi p. cm. ISBN 978-953-307-435-1 free online editions of InTech Books and Journals can be found at www.intechopen.com Contents Preface IX Part 1 Case Studies 1 Chapter 1 Soil Degradation 3 Rajendra Hegde, A. Natarajan, L G K Naidu and Dipak Sarkar Chapter 2 Water Erosion from Agricultural Land Under Atlantic Climate 41 Montserrat Valcárcel, Antonio Paz González, Jorge Dafonte, José Manuel Mirás-Avalos, Jorge Paz-Ferreiro, Ildegardis Bertol and Eva Vidal Vázquez Chapter 3 Micro-Topographic Characteristics in Coordinate with Surface Erosion 59 Qingfeng Zhang, Longshan Zhao, Faqi Wu and Jian Wang Chapter 4 Losses of Soil and Nutrients from a Purplish Soil on Slopping Lands as Affected by Rain Intensity and Farming Practices 71 Chaowen Lin, Chunyan Luo, Liangyu Pang and Shihua Tu Part 2 Vineyards 87 Chapter 5 Soil Erosion Aspects in Agricultural Ecosystem 89 Elena Comino, Paolo Marengo and Valentina Rolli Chapter 6 Evaluation of Erosion Intensity and Some of Its Consequences in Vineyards from Two Hilly Environments Under a Mediterranean Type of Climate, Italy 113 Giuseppe Corti, Eugenio Cavallo, Stefania Cocco, Marcella Biddoccu, Giorgia Brecciaroli and Alberto Agnelli VI Contents Part 3 Dry Environments 161 Chapter 7 Hydrological Effects of Different Soil Management Practices in Mediterranean Areas 163 Giuseppe Bombino, Vincenzo Tamburino, Demetrio Antonio Zema and Santo Marcello Zimbone Chapter 8 Planting System on Permanent Beds; A Conservation Agriculture Alternative for Crop Production in the Mexican Plateau 183 Agustin Limon-Ortega Chapter 9 The Significance of Soil Erosion on Soil Fertility Under Different Tillage Systems and Granitic Sandy Soils in Semi-Arid Zimbabwe: A Comparison of Nutrient Losses Due to Sheet Erosion, Leaching and Plant Uptake 207 Adelaide Munodawafa Chapter 10 Effect of Slope Position and Land-Use Changes to Bio- Physical Soil Properties in Nakasongola Pastoral Rangeland Areas, Central Uganda 241 M. Buyinza and M. Nabalegwa Part 4 Erosion Control 255 Chapter 11 Pastoral Hill Slope Erosion in New Zealand and the Role of Poplar and Willow Trees in Its Reduction 257 Ian McIvor, Grant Douglas, John Dymond, Garth Eyles and Michael Marden Chapter 12 Erosion Control in Furrow Irrigation Using Polyacrylamide 279 Carlos Chávez, Carlos Fuentes and Fernando Brambila Chapter 13 Soil Erosion Control on Arable Lands from North-East Romania 295 Bucur Daniel, Jitareanu Gerard and Ailincai Costica Chapter 14 Terracing as a Measure of Soil Erosion Control and Its Effect on Improvement of Infiltration in Eroded Environment 315 Marcin K. Widomski Preface Erosion is a natural process among soil dynamics concerning the movement of soil portions and their deposition in a different location. The intensity of particles removal is variable and leads to different environmental impacts. Soil formation rate is highly slower than any erosion phenomena, this fact suggest that erosion control and mitigation practices should be adopted in order to preserve soil as a crucial environmental resource. Several natural events as water or atmospheric phenomena trigger erosion processes. Moreover anthropic activities, like inappropriate agricultural practices, deforestation, overgrazing, forest fires and construction activities, may exert a remarkable impact on erosion processes. The lack of appropriate knowledge of agricultural best practices or their disregarding, frequently due to the need of providing food in overpopulated areas, leads to the endangering of soil equilibrium. This aspect, also historically proven, is worsened in developing countries by critical socio-economical conditions and unfavourable climatic conditions. More generally, unsustainable land management policies, not only concerning agricultural sector, are key factors in soil endangering. Moreover, in the current climate change scenario, weather related variables are increasing their impact on soil erosion; directly, by the amplification of their intensity (severe rainfalls, strong winds…), or indirectly, by worsening environmental conditions (droughts, heat waves…) thus leading to replace spoiled crops by the exploitation of marginal areas or forcing large human settlements to move towards more hospitable areas and available resources; in the worst case this migrations aim to settle in natural areas in order to acquire more space for moving population and for increasing cultivable land surface. This practice causes the reduction of natural areas such as forests, shrubland and consequently the simplification of landscape structure; moreover it influences water cycle and availability in the colonized area. Soil erosion is a continuous process in Earth cycle and, if not properly faced, may conduct to extreme environmental consequences, like soil degradation o soil loss, threatening human activities and safety. In mountain and hillside areas soil erosion is X Preface an instability factor which may cause slope failures that can put in danger human settlements and infrastructures, from the agricultural point of view, extreme soil erosion may reduce nutrient availability thus reducing crop yield and causing land abandonment. Excessively impoverished soil, instead of evolving in other vegetation covers, could be involved in desertification processes. This book, in its fourteen chapters, deals with several aspects of soil erosion, focusing on its connection with the agricultural world. Chapters’ topics are various, ranging from irrigation practices to soil nutrient, land use changes or tillage methodologies. The book is subdivided into four sections grouping different facets of the topic. In the first one several case studies are presented with the aim of introducing soil erosion issue in the world; in fact, chapters come from India, Spain and China. Each one present soil erosion features in a different geographical and climatic context, and various study approaches. The other three sections focus on a detail among the vast topic. Section number two covers a typical cultivation, vineyard. An agricultural practice limited to a confined geographical milieu but characterized by a remarkable economic impact. The correct agronomical management of vineyards is a key factor in soil erosion reduction, in hilly environments, allowing, contemporarily, to obtain profitable yields from vines, as quality production is required by market, instead of mass production. The two chapters describe experimental approaches applied to vineyards located in Italy. The third section theme is a geoclimatic one, since it concerns dry environments and their relationship with soil erosion theme management. The section includes chapters coming from different areas such as Africa (Uganda and Zimbabwe), South America (Mexico) and Europe (Italy) covering Arid, Semiarid and Mediterranean environments. In the last section the erosion control matter is investigated. Chapters from various countries evaluate erosion control practices like the employment of afforestation to reduce grazing impact or the role of terracing, tillage and irrigation practice in soil erosion control, in cultivated areas. In conclusion, this book approaches the soil erosion theme, concentrated on agriculture world. Certainly, due to the extent of the subject, the book is not a comprehensive collection of soil erosion studies, but it aims to supply a sound set of scientific works, concerning the topic. It analyzes different facets of the issue, with various methodologies, and offers a wide series of case studies, solutions, practices, or [...]... Compaction in the surface layer is dynamic and changes significantly over the cropping season, increasing with increasing machinery passes 20 Soil Erosion Issues in Agriculture over the field and decreasing again with primary tillage for seed bed preparation for the following season Adequate tillage effectively reduces soil compaction in the surface layer and its effects Sub -soil compaction affects soils... machinery Swelling-shrinking, freezing-thawing and biological activities can alleviate compaction to a certain extent Sub-soiling using specially designed equipment can in some cases alleviate sub -soil compaction, but is very energy demanding some times, soils become more dense than it was before sub-soiling because of the destabilization of the soil caused by the mechanical energy input from the sub-soiling... high rainfall in Kerala state (Southern India) makes the soil most vulnerable for severe erosion losses Gullies and ravines are also commonly seen in these areas Wind erosion is dominant in the western regions of the country and to some extent in the coastal areas It causes loss of topsoil, terrain deformation, over blowing and shifting of sand dunes It is estimated that more than 45 per cent of India's... latest estimate indicates that soil erosion, salinity and alkalinity, water logging and declining soil fertility has affected about 57 per cent (187.8 m ha) of the land resources in the country, threatening the sustainability of the resource base(Table 1) Land resource includes soil, water, bio-diversity, climate etc Soil is the most important component among all, as any effect on it, directly influences... sustaining production 'indefinitely' This word implies that it is the rate at which soil is renewed by rock weathering The latter has not often been measured, but studies of rates of natural erosion show these to be more typically 1t ha-1 per year, and it is reasonable to assume that weathering keeps pace with erosion It may be that 'tolerable' erosion rates will sustain 14 Soil Erosion Issues in Agriculture. .. Therefore, a structured soil is heterogeneous; where a degraded, structure less soil is homogeneous Soil structure significantly influences all processes that take place in the soil It influences water infiltration (and hence runoff), the movement of water within the soil and the amount of water that can be stored in the soil Soil structure also determines aeration levels in the soil, which are essential... (extrinsic processes)(Antony Young 1998) Intrinsic processes Degradation of the Physical fertility Compaction Crusting Structural degradation Soil loss: Water and Wind erosion Mining Urbanization of agricultural lands Land movements by civil engineering for infrastructure projects Excess water/waterlogging Degradation of Chemical fertility Loss of nutrient: Leaching Extraction by plants (nutrient mining)... (ginger in place of paddy): a cause for soil degradation Animals R resources but cause for degradation Fig 5 Uncontrolled grazing by livestock: a cause for degradation 12 Soil Erosion Issues in Agriculture accelerating erosion rates, usually by reducing or eliminating plant and residue cover However, once productive agricultural soils have been formed over periods of thousands or millions of years, erosion. .. success 22 Soil Erosion Issues in Agriculture 3.8 Causes and effects of soil physical degradation The main causes of soil physical degradation are inappropriate land use and soil management practices All exploitative practices will ultimately lead to degradation and hence reduce soil productivity In the developing world, land not suitable for cultivation, such as dry lands or steep terrain, is increasingly... Alkalinity Addition of salt to soils increases the concentration of Na in the soil solution more than those of Ca and Mg and alters the composition of the exchange phase in favor of Na, because the Na salts are the most soluble salts in nature Fig 17 Providing sub-surface drainage to manage soil salinity/alkalinity This increase in exchangeable Na (Nax) is called sodification and soils degraded in this . Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechweb.org Soil Erosion Issues in Agriculture, . SOIL EROSION ISSUES IN AGRICULTURE Edited by Danilo Godone and Silvia Stanchi Soil Erosion Issues in Agriculture Edited by Danilo. related variables are increasing their impact on soil erosion; directly, by the amplification of their intensity (severe rainfalls, strong winds…), or indirectly, by worsening environmental conditions