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4 Hydraulic Conductivity, Infiltration Rate and Moisture Content

4 Hydraulic Conductivity, Infiltration Rate and Moisture Content

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water intake and infiltration rate (IR) increased in the order of NT > MT > RB > CT

and in mulching treatment the order was PM > StM > SM > NM. The maximum

mean value of IR (182.4 mm/day) was obtained in case of no tillage and polythene

mulch combination and minimum (122.4 mm/day) was recorded in CT and no

mulch combination.

According to Aikin and Afuakwa (2012) in upper 10 cm soil layer for the 2009

major growing season, tillage treatments showed significant influence in moisture

content from the planting date through the first 5 weeks after planting, and after

harvest. There was no significant difference in moisture content from the sixth to the

eighth week after planting in the 0–10 cm soil layer. In the 0–10 cm soil layer for

the 2010 major growing season, tillage treatments significantly affected moisture

content only on the planting date, the seventh and eighth week after planting, and

after harvest. Tillage treatment caused significant difference in moisture content in

the 10–20 cm soil layer throughout the 2009 major growing season except at 7 and

8 weeks after planting. Tillage treatment did not significantly influence soil moisture content in the 10–20 cm soil layer from the planting date through the first 5

weeks after planting during the 2010 major growing season. Significant differences

in soil moisture content were observed at 6, 7 and 8 weeks after planting, and after

harvest. Plots with disc ploughing followed by disc harrowing tillage had the highest soil moisture contents. The lowest soil moisture contents were located in the no

tillage plots.



5.5



Soil Aeration and Soil Temperature



Plant roots and soil fauna require oxygen, and aerobic microbes are important

decomposers. Air permeability is a measure of how easily air convection occurs

through soil in response to pressure gradients. Pressure gradients can be generated

naturally by air turbulence above the soil surface, and this can lead to air flows

through the tilled layers of soils especially when they contain pores larger than

about 5 mm (Kimball and Lemon 1971).

Temperature is one of the physical states of soil that is rarely analyzed because

of its greater variability in time. Radecki (1986) stated that dark soils show greater

warmth of the surface layer directly after agricultural treatment than when not

treated. Under field conditions the soil temperature can be altered by mulching and

vegetation by acting as buffers and preventing incoming and outgoing radiations. In

arid and semiarid regions or in summers, crop residues left on the soil surface as a

mulch as compared to incorporation, removal or burning are known to be beneficial

for crop production (Dao 1996). If used as mulch, the residue can modify soil temperature and soil temperature is lowered by the plant residues left on the soil surface

in no tillage (Rasmussen 1999).



An Appraisal of Conservation Tillage on the Soil Physical Properties



5.6



17



Soil Erosion



Degradation of agricultural soils as a result of excessive tillage has spurred interest

in no-till cropping systems. These systems help to maintain the physical conditions

of a relatively undisturbed soil. Residue is left on the surface of the soil, making it

less susceptible to wind and water erosion (Baker and Saxton 2007). Tillage accelerates mineralization (breakdown) of crop residue and loss of soil organic matter

(Stubbs et al. 2004). Soil erosion by wind and water occurs in all environments

(Hudson 1995). Low intensity tillage favours consolidation of soil through better

structure thereby imparting resistance to erosion. According to Lal et al. (2007) NT

technologies are very effective in reducing soil and crop residue disturbance, moderating soil evaporation and minimizing erosion losses. The presence of residues at

the soil surface in different types of tillage systems has a tremendous effect on runoff and erosion (Basic 2004). The residues also have an effect on soil temperature,

soil reaction, nutrient distribution and availability, population and activities of soil

fauna, and, therefore, on soil organic matter content. Because of effectiveness in

controlling erosion, no-tillage makes crop production possible on sloping lands that

would under clean tillage result in enormous erosion problems (Lal 1999). No-tillage

systems also ensure significant increases in water conservation. Soil carbon sequestration can be accomplished by management systems that add high amounts of biomass to the soil, cause minimal soil disturbance, conserve soil and water, improve

soil structure, and enhance soil fauna activity.



6



Constraints in the Adoption of Conservation Tillage



Factors for non-adoption of conservation tillage include climate, soil, levels of crop

residue, (mixed) cropping systems etc. Conservation tillage is a function of weather

of a particular region and changes with the type of soils (Lal 1999). A humid temperate climate and political support can be the main reason for lower adoption of

no-tillage (Derpsch et al. 2010; Mader and Berner 2012). Among the disadvantages

are more difficult weed control, specific machinery and cropping systems requirements and soil specificity. For example each crop has specific soil preparation

requirements (for example soil temperature, alleopathic response) and irrigation

needs that create challenges for the universal adoption of conservation tillage. One

of the main obstacles to implementing conservation tillage is furrow or surface irrigation. Crop residues that build up under conservation tillage can cause blockage

impeding the progress of irrigation (Lal 1999). For this reason, maintaining furrows

to supply water is seen as an impediment to the adoption of conservation tillage and

cover cropping practices unless measures are taken to allow efficient irrigation, or

unless water delivery systems are changed to subsurface drip (SDI) or low pressure

overhead sprinklers. Moreover, the increased need for herbicides to control weeds

in conventional tillage under furrow irrigation is potentially an environmental and

economic issue for farmers.



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S.A. Wani et al.



Conclusion



Continuing soil degradation is threatening food security and the livelihood of millions of farm households throughout the world. Soil types and their various reactions to tillage are of paramount importance in determining the superiority of one

practice over the other. There is a need to develop precise objective and quantitative

indices of assessing soil health attributes. Conservation and recycling of nutrients is

a major feature of any organic farming system (National Standard 2005). Issues of

conservation have assumed importance in view of the widespread resource degradation and the need to reduce production costs, increase profitability and make agriculture more competitive. There is considerable evidence that CT can provide a

wide range of benefits to the environment and wildlife, some of these being similar

to that provided by set-aside. Evolution and accelerated adoption of zero tillage is a

significant step paving way for more comprehensive conservation agriculture systems. The new technologies, on one hand, are exciting the farmers to take up new

ways of managing their resources more productively and, on the other and throwing

new challenges to the scientific community to solve emerging problems associated

with new technologies. Future research and development efforts would need to take

a more holistic view of sustainability concerns in developing and promoting technological, policy and institutional options for sustained resource use and profitability

of production systems. CT has the potential to provide some of the benefits while

also allowing farmers to continue cropping, but most will achieve it as part of an

integrated approach to crop management. In addition, by preserving soil and maintaining it in optimum condition, crop yields are sustained thereby reducing the need

to convert remaining natural habitats to agriculture.



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Degraded Soils: Origin, Types

and Management

Muhammad Zia-ur-Rehman, Ghulam Murtaza,

Muhammad Farooq Qayyum, Saifullah, Muhammad Rizwan, Shafaqat Ali,

Fatima Akmal, and Hinnan Khalid



Contents

1



Land Degradation................................................................................................................

1.1 Introduction ................................................................................................................

1.2 Causes of Land Degradation ......................................................................................

1.3 Processes of Land Degradation ..................................................................................

1.3.1 Soil Erosion ....................................................................................................

1.3.2 Soil Salinization .............................................................................................

1.3.3 Water Logging ................................................................................................

1.3.4 Decline in Soil Fertility ..................................................................................

1.4 Types of Land Degradation ........................................................................................

2 Soil Salinity.........................................................................................................................

2.1 Salt Affected Soils......................................................................................................

2.1.1 Saline Soils .....................................................................................................

2.1.2 Saline-Sodic Soils ..........................................................................................

2.1.3 Sodic Soils ......................................................................................................

2.2 Origin of Salt Effected Soils ......................................................................................

2.2.1 Soil Weathering Process .................................................................................

2.2.2 Accumulation on the Surface Due

to Irrigation Under Inadequate Drainage .......................................................

2.2.3 Shallow Water Table.......................................................................................

2.2.4 Fossil Salts......................................................................................................

2.2.5 Seepage from the Upslope Containing Salts ..................................................

2.2.6 Ocean..............................................................................................................

2.2.7 Chemical Fertilizer and Waste Materials .......................................................

2.3 Causes of Salt Affected Soils .....................................................................................

2.3.1 Primary Salinity..............................................................................................

2.3.2 Secondary Salinity..........................................................................................



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M. Zia-ur-Rehman (*) • G. Murtaza • Saifullah • F. Akmal • H. Khalid

Institute of Soil and Environmental Sciences, University of Agriculture Faisalabad,

Faisalabad 38040, Pakistan

e-mail: ziasindhu1399@gmail.com

M.F. Qayyum

Department of Soil Sciences, BZU, Multan, Pakistan

M. Rizwan • S. Ali

Department of Environmental Sciences, GC University, Faisalabad 38040, Pakistan

© Springer International Publishing Switzerland 2016

K.R. Hakeem et al. (eds.), Soil Science: Agricultural and Environmental

Prospectives, DOI 10.1007/978-3-319-34451-5_2



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2.4



Impact of Salt Affected Soil on Plant.........................................................................

2.4.1 Osmotic Deregulation ....................................................................................

2.4.2 Nutrition Imbalance........................................................................................

2.4.3 Structure and Permeability Problem of Salts in the Soil ................................

2.5 Reclamation of Salt-Affected Soils............................................................................

2.5.1 Physical Methods ...........................................................................................

2.5.2 Chemical Process ...........................................................................................

2.5.3 Organic Matter ...............................................................................................

2.5.4 Biological Methods ........................................................................................

2.5.5 Hydro-Technical Method ...............................................................................

2.5.6 Electro-Reclamation Method .........................................................................

2.5.7 Combination of Organic and Chemical Amendments....................................

2.6 Management of Salt Effected Soils............................................................................

2.6.1 Management of Saline Soils...........................................................................

2.6.2 Management of Sodic Soils............................................................................

2.6.3 Management of Saline-Sodic Soils ................................................................

2.6.4 Adaptations of Salt Tolerant Plants ................................................................

3 Soil Erosion.........................................................................................................................

3.1 Types of Soil Erosion .................................................................................................

3.1.1 Water Erosion .................................................................................................

3.1.2 Wind Erosion ..................................................................................................

3.2 Causes of Erosion ......................................................................................................

3.2.1 Soil Structure ..................................................................................................

3.2.2 The Role of Vegetative Cover ........................................................................

3.2.3 Land Topography ...........................................................................................

3.2.4 Disturbances ...................................................................................................

3.3 Assessing Soil Erosion...............................................................................................

3.3.1 Worldwide Cropland ......................................................................................

3.4 Effects of Soil Erosion on Terrestrial Ecosystems .....................................................

3.4.1 Water Availability ...........................................................................................

3.4.2 Nutrient Losses...............................................................................................

3.4.3 Soil Organic Matter ........................................................................................

3.4.4 Soil Depth.......................................................................................................

3.5 Conservation Technologies ........................................................................................

4 Soil Acidity .........................................................................................................................

4.1 Causes of Soil Acidity................................................................................................

4.1.1 Weathering and Leaching ...............................................................................

4.1.2 Organic Matter Decomposition ......................................................................

4.1.3 Acid Rain........................................................................................................

4.1.4 Crop Production and Removal .......................................................................

4.1.5 Application of Acid Forming Fertilizers ........................................................

4.2 Effects of Soil Acidity on Crop Production ...............................................................

4.3 Management of Soil Acidity ......................................................................................

4.3.1 Liming ............................................................................................................

4.3.2 Application of Organic Materials ...................................................................

4.3.3 Use of Acid Tolerant Crops ............................................................................

4.3.4 Agroforestry ...................................................................................................

References .................................................................................................................................



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Degraded Soils: Origin, Types and Management



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Abstract The cultivated lands are continuously degrading and the extent is increasing because of different natural environmental and anthropogenic activities. Soil

degradation due to salinization, erosion, water logging etc. makes environment difficult for plant growth resulting in reduced agricultural production. Soil physical,

chemical and biological properties are affected due to alteration in hydraulic

conductivity, bulk density, osmo-deregulation, poor aeration and specific ion toxicities. A number of management and reclamation technologies are available to counter these problem but the major concern is to optimize the most economical and

eco-friendly technologies. Saline soils can be cultivated growing different halophyte plants and using modern irrigation practices. Conservation and effective and

efficient use of good quality water help proper leaching of soluble salts in saline

soils. Saline-sodic and sodic soils can be rehabilitated with different amendments,

which can provide soluble calcium to replace exchangeable sodium adsorbed on

clay surfaces. Different amendments can provide calcium directly to the soil or

indirectly dissolving native calcium from calcium carbonate already resent in the

soil. The eroded soils can be reclaimed by providing proper soil surface cover either

in the form of mulching or vegetative cover by fodder or wild shrubs. Different studies demonstrate that under adverse conditions where chemical treatments are uneconomical tree plantations provide positive net returns to investment and significant

net benefit and social outcomes from these lands. These findings suggest that there

is great opportunity for capital investment in afforesting abandoned degraded soils

with multipurpose approaches. This chapter covers the introduction to origin, extent

and sources of degraded soils, along with their management and reclamation

options.



Keywords Soil pollution • Salinity stress • Soil erosion • Agroforestry • Soil

management



1

1.1



Land Degradation

Introduction



Degradation means undesirable and unwanted changes brought about by human

activities along with natural phenomenon. Soil degradation is among serious prevailing issues in our modern era. It is badly affecting soil’s natural fertility to

enhance our economic values along with ecological issues. It is being caused due to

natural and anthropogenic activities. The level of degradation depends on degree of

degradative processes; duration of usage of such degraded land and its management.

Land degradation causes exploitation of soil resources, reduces soil productivity

and alters composition of vegetations; thus influencing billions of people around the

globe directly or indirectly (Ravi and D’Odorico 2005).



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Degradation of soils can considerably decrease the soil’s capacity to produce

food and consequently about 66 % of the total world’s population is malnourished

(Pimentel and Burgess 2013; World Health 2000). To feed the ever increasing population of world, food production needs to be enhanced (Haub et al. 2011) It is

important to reverse the land degradation to achieve this modest goal as 99.7 % of

our human diet calories are fulfilled by our land resources and only 0.3 % is being

contributed by aquatic ecosystems (FAO 2004). To overcome our basic food

demands it is most important to maintain productivity and quality of our land.

Generally, soil formation process is 10 to 40 times slower compared to soil lost

(Pimentel and Burgess 2013).

It is pertinent that we should look for alternative means of intensification specially use of sustainable land management techniques (SLM). It is said that utilization of land resources is to use the water, land, plants and animals resources to fulfill

our present day human demands along with enhancing their productive potential

and environmental functions (Quarrie 1992). SLM focus on four land sustaining

techniques, improved irrigation management, rehabilitation of degraded soil,

enhance pasture and grazing processes along with maintenance of our organic soil

all these steps without further degradation of our resources come to meet our present food demands (World Bank 2006). Not only to maintain but also to enhance soil

natural fertility it is important to increase its carbon sequester capacity along with

ability to overcome climate change (FAO 2009; FAO 2010). By using SLM technologies we meet our human food demands without further degradation of our land

and water resources (IFAD 2011; Lal 1997). It is evident that allowing land degradation is expensive because it has long term effects on society as well as on land

owners (Costanza et al. 2014).



1.2



Causes of Land Degradation



The cause of land degradation for a particular area can be one or combined effects

of many. (Geist and Lambin 2004) classified the causes into two categories

• proximate causes (biophysical)

• overlying causes (anthropogenic)

Biophysical have direct effect on all ecosystems like drought, soil salinity, soil

acidity, metal contamination, related to extreme climatic conditions while on the

other hand anthropogenic causes have indirect effect on ecosystem like intensive

cropping, deforestation, overgrazing or poverty, urbanization and industrialization.

Among the proximate causes, agriculture is most contributing source of land

degradation but its effect on land is aggravated by inter-related relations with other

causes. Severe land degradation is observed in combination like the effect of extreme

climatic changes is augmented along with poor man management techniques

(McIntyre and Tongway 2005; Smith et al. 2007). It is widely reported that in



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4 Hydraulic Conductivity, Infiltration Rate and Moisture Content

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