eChapters

1. INTRODUCTION

The agricultural paradigm in the developing world including Iran will have to be recast to take advantage of knowledge availability to achieve multiple goals of income, food, jobs, etc. Although, many farming communities in developing countries need timely expert advices to make them more productive and competitive, they are still facing a multitude of problems to maximize agricultural productivity. In spite of successful and promising researches conducted on new agricultural practices, majority of the farmers are not getting upper-bound yield due to several reasons. One of them is that scientific agricultural advice is not reaching the farming community in a timely manner. A wide information gap exists between research and practice.

To cope with this problem different countries have taken various measures. What is common in the extension systems of developing countries is that in a backdrop of rapid organizational and social changes in agriculture, new hardware and software devices have to be applied for better responsiveness to increasing farmers demand for timely and accurate information. At the pace of recent progress in ICT, within a decade it will be possible to provide instantaneous connectivity to millions of people, enabling mass customization and personalized services (Reddy and Ankaiah, 2005). Data mining technology can be used to extract useful knowledge from huge database and simulation technology can be used to predict in to the future (Wiederhold, 2002).

1. Introduction

Iran, with an area of 1648 thousand sq.kms.,  is situated in the eastern portion of the northern hemisphere, in the south west of Asia, and is considered as one of the Middle East countries. Iran is a mountainous country with a variety of climates. The average temperature and rainfall for the whole country are quoted as 18ºC and 240 mm respectively (CAPES, 1996). The country is also organized into 28 provinces. Over the past two decades, rapid rate of population growth has been a major source of concern in Islamic Republic of Iran. The population of the country passed the 60 million figures in 1993 and is projected to reach 86 million by the year 2010. In fact, the Iranian population has doubled in this period (CAPES, 1996). For example, according to the 1991 census, the female population of 15 years and above was 15 million (Anonymous, 1998). However, thanks to considerable investments and well-organized and directed national population planning program, population growth rate is now 1.5 percent in the urban and two percent in the rural areas. At the national level, the figure is 1.65 percent (CAPES, 1996).

1. INTRODUCTION

There is increasing recognition that information and knowledge are now at the heart of socio-economic development. Information and Communication Technology (ICT) and broadband are enabling tools and infrastructures for accessing, developing, using and sharing information and knowledge. Accordingly, Irish Government policy has focused on promoting the adoption and use of ICT in the home, in education and in the workplace.

There have been significant increases in levels of engagement with ICT in Ireland in recent years. Almost two-thirds of all adults now have access to the internet, compared with only 1 in 20 in 1996, while four out of every five adults own a mobile phone. This chapter critiques the level of adoption of ICTs among the farming community and compares this with levels of adoption by the general population. It analyses the use of ICTs by the government and by public and private extension agencies in Ireland and identifies constraints to their adoption.

The Ministry of Agriculture has been among the most enthusiastic supporters of the Government of Ireland’s policy by promoting the adoption and use of ICTs among its clients. It sought to facilitate easier transmission of information to clients, to minimise the collection of new data by using existing electronic information and to integrate with clients’ own systems. These projects are described in this chapter.

The use of ICTs by the public extension system is also critiqued; it has been innovative in using ICTs to disseminate information to its clients and the use of mobile telephony has been particularly effective. Internet based services to deliver online training and advisory information have also been developed and are critiqued.

A family of about 66 genera and over 2,244 species, Iridaceae are distributed in both tropical and temperate regions with the chief centres of distribution in tropical America and South Africa. Chief areas of distribution in India are Kashmir, and Kumanon hills. Common species cultivated in Indian gardens include Belamcanda chinensis, Crocus sativus, C. biflorus, C. speciosa, Gladiolus primulinus, G. colvillei, Freesia refracta, Iris kumaonensis, I. germanica and I. foetidissima. Iridaceae are cultivated throughout the world for their beautiful flowers.
Gladiolus ‘the queen of bulbous flowers’ is one of the most important bulbous ornamentals grown commercially in all parts of the world for its attractive flowers. It is very much liked for its majestic spikes containing attractive,
elegant and delicate florets which open in sequence over a long duration and hence, has good keeping quality of cut spikes. These are extensively employed as cut flower in herbaceous borders, individual beds in the gardens, for exhibition, as pot plants for various kinds of interior decoration and for making bouquets. North American Gladiolus Council, Boston established in 1910 (www.gladworld.org), and New England Gladiolus Society (www.britglad. com), came into existence during post war era (1945-55), are actively involved in popularization and improvement of gladiolus in tune with flourishing cut flower trade in western countries.

INTRODUCTION

Irises are among the easiest of perennials to grow, providing an abundance of beauty with minimum care. Iris means ‘rainbow’ because they come in various colours. These are herbs with sword like leaves and roots are generally rhizomatous, although in a few species they are bulbous. The majority of garden irises are hybrid, often complex ones, whose parentage is obscene. Bulbous irises are more important in commercial horticulture, with over 50 cultivars, but dominated almost equally by two i.e. Ideal and Professor Blaauw which together account for over 70% of the area grown in the Netherlands. Regular irises make great cut flowers with their tall, sturdy stalks. Dwarf varieties are suited for flower beds and rock gardens.

Certain irises were at one time widely used in the manufacture of perfume, also has been widely used in folk medicine, mostly because of the fragrance of its dried roots which are used in the preparation of face powder and dentifrices. Commercially, the powder is known as Orris-root or Orris. The rhizomes of certain irises also have edible value.

Iron Toxic Soils

Lowland rice is being cultivated on approximately 128 million hectares of either irrigated or rainfed land out of which 100 million hectares suffer due to nutrient deficiency or toxicities. Among the toxicities, iron toxicity is well recognized as a nutritional disorder in low land rice production. Iron toxicity is a syndrome of disorder associated with high concentration of Fe²⁺ in soil solution. A wide range of soil types show iron toxicity problem including acid sulphate soils, acid clay soils, peat soil and valley bottom soil. During monsoon rains in the wet season, soluble iron (Fe²⁺) migrate to the surface and its iron content increases to subtoxic or toxic levels.

In rolling topography and with heavy monsoon downpour there is considerable lateral flow of iron containing water from the adjacent uplands to mid – and low lands. This increases the iron content to toxic levels. Poorly drained sandy soils in valleys receiving interflow water from adjacent uplands with laterite horizon (Plinthudults) showed iron toxicity in Srilanka and Kerala and Odisha in India. These soil groups come under the taxonomic orders Alfisols, Ultisols and Oxisols occurring in association with Entisols and Inceptisols. The iron concentration (Fe²⁺) in soil solution that affect low land rice yield ranges from 10 to > 2000 mg L^-1 Iron toxicity induced yield reduction which is associated with poor nutrients . status (deficiency of P, K and Zn) and H₂S toxicities.

9.1. INTRODUCTION

Iron (Fe) is important component of a plant’s energy-power house chlorophyll. It also interacts with all the major enzymes and proteins at higher concentration in the soil, and it is toxic to plants. Fe-toxicity creates a range of nutrient disorders and deficiencies of P, K, Ca, Mg, Mn and Zn in plants. These elements were reported to play decisive roles in manifesting toxicity symptoms in rice (Sahu, 1968; Ottow et al., 1983; Yamauchi, 1989; Sahrawat et al., 1996). Excess absorption and translocation of Fe in the rice plants led to toxicity, which has been a major limiting factor in wetland rice. Average yield loss due to Fe-toxicity accounts to 50% and in fact ranges from 10-100% (Brigit et al., 1993).

Water is indispensable for human, animal and plant life. Water is essential part of protoplasm. It is essential for photosynthesis. About 400 to 500 litres of water is necessary for the production of  a kilo of plant dry matter.
 
Irrigation

It is the human manipulation of hydrological cycle to improve crop production and quality and to decrease the economic effects of drought. Israelsen and Hansen (1962) defined irrigation as the artificial application of water for the purpose of supplying moisture to plant growth.

A. Precision irrigation

The prevalent flood irrigation in crops would be the thing of past because of limited water resources, waste of water in leaching and evaporation and cumbersome management resulting in considerable loss of water. The micro irrigation (sprinkler and drip- irrigation) are preferred depending on the field topography. Undulated fields are better irrigated by sprinkler and laser levelled field by drip irrigation. There are precise tools to deliver only required amount of water at different stages of growth of crops with the help of sensors. Irrigation water volume release is mechanised and automated. Efforts of using microirrigation methods such as sprinkler and drip irrigation have been made in last three decades in many parts of the world. There is no ideal irrigation method available which may be suitable for all weather conditions, soil structure and variety of crops cultures.

Precision irrigation is worldwide accepted concept in irrigation. Precision irrigation involves the accurate and precise application of water to meet the specific requirements of individual plants or management units and minimize adverse environmental impact. Commonly accepted definition of precision irrigation is sustainable management of water resources which involves application of water to the crop at the right time, right amount, right place and right manner thereby helping to manage the field variability of water in turn increasing the crop productivity and water use efficiency along with reduction in energy cost on irrigation. It utilizes a systems approach to achieve ’differential irrigation’ treatment of field variation (spatial and temporal) as opposed to the ’uniform irrigation’ treatment that underlies traditional management systems. Precise and regulated application of irrigation water and plant nutrients at low pressure and frequent intervals through drippers/emitters directly into the root zone of plant with the help of close network of pipes is known as drip irrigation system.

In the field of agriculture/horticulture, various irrigation systems are being employed to fulfil the water requirement for better growth and development of the tree. Since, cashew is hardy plant which can sustain in rainfed conditions of warm and humid region; it has very good potential to produced higher nut yield. Of the various irrigation methods, drip irrigation system is best method in the areas where natural resources of water is limiting factor. It is well known fact that this system has many advantages.

During the first year after planting, protective irrigation is recommended at 15 days interval during winter and at 8 days interval during summer season. At each irrigation, 25 litres of water to be given per graft. The studies on mulching and irrigation were under taken with a view to determine fruit retention. It was observed that black polythene mulch with irrigation @ 60 liter of water per tree at 15 days interval showed beneficial effect on increasing fruit retention (66.15%) over control. Cashew is grown under rainfed conditions. However, supplementary irrigation during summer months, especially during January-March at fortnightly intervals @ 200 litres/plant proved to double the yield. This is evident from the research results obtained at NRC-Cashew, Puttur (Karnataka).

Water is one of the most critical resources in horticultural production, directly influencing plant growth, flowering, fruit development, and quality. This chapter introduces principles of irrigation scheduling, water requirements, soil–water relationships, and efficient water application. Surface, sprinkler, drip, micro-irrigation, fertigation, and other modern systems are discussed in relation to crop type and environmental conditions. The chapter emphasizes irrigation efficiency, root-zone moisture management, water quality, salinity, drainage, and conservation. Proper irrigation scheduling reduces water losses and prevents both drought stress and excessive wetness. Modern technologies such as sensors, automated irrigation, and precision fertigation are also considered important tools for sustainable horticultural water management.

1.1 Introduction

Like animals, plants are living beings and so require water and air for their survival. In addition, they need water for preparation of food by the process of photosynthesis. Majority of this water requirement of the crops is met from different forms of precipitation. However, when the water requirement is not fully met from precipitation, then growth of the crops is affected. This results in reduction of yield of the crops. The reduction in yield depends on the amount of scarcity of water requirement of the crops. It also depends on the stage of crop growth and also depends on the types of the crops. Generally all the crops are sensitive to water stress during reproductive stage. Water requirement of crops depend on many factors. It depends on the type of crops, irrigation schedules practiced, soil texture, position of groundwater table below effective root zone of the crop and management practice followed in crop cultivation. The pulses, oilseeds, vegetables etc. which are also otherwise termed as dry land crops need less water compared to rice which is a water loving crops and perennial crops like sugarcane, banana etc.

Water requirement of crops is partly met by the upward flux of groundwater. The capillary rise of shallow water table in the form of upward flux helps in meeting the water requirement of crops to some extent. The upward flux depends on the type of the soil, effective root zone depth of the crop, depth of water table below effective root zone depth of the crop and potential gradient of soil moisture suction. If the soil is heavy like clay, effective root zone depth of the crop is more (deep rooted crop) and position of ground water table is near to ground level (shallow water table), then the upward flux is more.

An efficient irrigation system implies effective transfer of water from the source to the filled with minimum possible loss. The objective of the efficiency concept is to identify the nature of water loss and to decide the type of improvements in the system.

Evaluation of performance in terms of efficiency is prerequisite for proper use of irrigation water.

3.1 Introduction
Irrigation efficiency evaluates how effectively the water has been distributed for the purpose of crop production. Water is conveyed to crop field through canal water courses and channels. During this process considerable amounts of water get lost through run off, deep percolation, evaporation, etc. The losses of water greatly depend on the skill of the irrigator, degree of land preparation, and design and planning of the system. The extent of water losses starting to diversion of water from its source to crop field though conveyance and ultimate application and distribution of water in crop field which can be estimated separately. The estimation of these efficiencies enables one to identify the step(s) where improvement is required. The method of measurement and evaluation for its efficiency is prerequisite for proper use of water. Irrigation efficiency in developing countries in general is poor particularly in gravity irrigation methods. However, water is become more and more scarce. Due to pressing need of it judicious and efficient management is one of the vital issues to be solved on priority basis.

3. 1 Introduction

Irrigation efficiency evaluates how effectively the water has been distributed for the purpose of crop production. Water is conveyed to crop field through canal water courses and channels. During this process considerable amounts of water get lost through run off, deep percolation, evaporation, etc. The losses of water greatly depend on the skill of the irrigator, degree of land preparation, and design and planning of the system. The extent of water losses starting to diversion of water from its source to crop field though conveyance and ultimate application and distribution of water in crop field which can be estimated separately. The estimation of these efficiencies enables one to identify the step(s) where improvement is required. The method of measurement and evaluation for its efficiency is prerequisite for proper use of water. Irrigation efficiency in developing countries in general is poor particularly in gravity irrigation methods. However, water is become more and more scarce. Due to pressing need of it judicious and efficient management is one of the vital issues to be solved on priority basis.

Q. 1 When flow parameters change with time but remain constant with space the flow is called as:-
(A) Unsteady uniform flow       (B) Steady uniform flow
(C) Steady non-uniform flow   (D) Unsteady non-uniform flow

Water is one of the most vital components for the successful growth and development of crops. It influences most of the plant metabolic activities, namely photosynthesis, respiration, absorption, translocation utilization of mineral nutrients, etc. Its stress or in excess affects the growth and development of a plant directly and consequently its yield and quality.

Role of water: Water plays an important role in plant growth and development in many ways.

• It is the chief constituent of protoplasm.
• It provides aqueous medium for various biochemical (metabolic) reactions.
• It serves as a temperature stabilizer and helps in maintaining a stable metabolic rate.
• It is an essential input for photosynthesis.
• It helps to maintain turgidity of cells and plant organs.
• It is an excellent solvent for various organic materials of cells.

1. Introduction

1.1 Background

The historical backdrop of irrigation is rich and diverse, reflecting the ingenuity of civilizations in adapting to their environments to meet the basic human need for sustenance. Ancient cultures such as the Sumerians, Egyptians, and Chinese were pioneers in developing rudimentary irrigation systems, channeling water from rivers, and constructing canals to nourish their crops. These early practices laid the foundation for the evolution of irrigation, marking a significant transition from relying solely on rainfall to actively controlling water distribution.