eChapters

For plant analysis to be meaningful, collection of particular plant part(tissue) at the right stage of growth is very important. A research worker in soil fertility is generally interested in finding out the nutrient uptake by crop at different stages. The stage at which nutrient uptake is to be studied will vary with different crops. One may also be interested in collecting a plant sample when some abnormality is observed in the plants and a nutrient deficiency or toxicity is suspected. In such cases no time should be lost in collecting the sample otherwise secondary reactions that often take place in the mineral content of plants will conceal the real cause of deficiency or toxicity. In such cases only the affected plants are to be sampled as compared to general sampling technique described below.

For research projects each plot receiving differential fertilizer or some other treatment is to be sampled separately. For general advisory purposes one sample would be good enough for the entire field (not exceeding 2 hectares). One should, however, take care that the sample comes from a field or a part there of having a uniform stand. If a field is patchy and differences in stand and plant growth are obvious, each such area should be sampled separately.

Introduction

Plant analysis can be defined as the quantitative determination of the concentration of an element or extractable fraction of an element in a sample from a particular part or portion of a crop. From the nutritional standpoint, plant analysis is based on the principle that the concentration of a nutrient within the plant is an integral value of all the factors that have interacted to it. Plant analysis is used as an index of available nutrient element supply. Plant growth or yield are compared with the elemental concentrations contained in the dry matter of the entire plant or plant structures such as leaves, petioles, fruit or grain sampled at different times during their development. Plant analysis gives the overall picture of the nutrient levels within the plant at the time the nutrient was taken. The use of plant analysis is based on the principle that the nutrient level present is as a result of all factors affecting the growth of the plant.

Plant analysis involves the determination of nutrient concentration in diagnostic plant part(s) sampled at recommended growth stage(s) of the crop. In a way plant analysis complements soil analysis. There are reliable sampling criteria and procedures for most of the world’s commercial crops.

Importance

Plant analysis assesses nutrient uptake while soil testing predicts nutrient availability. The two tests are complementary to each other as crop management tools. Plant analysis will detect unseen hidden hunger and confirm visual deficiency symptoms. Toxic levels may also be detected. If it is done early, plant analysis will allow a corrective fertilizer application in the same season.

Abstract

The recent earth movements and the related seismicities in the Southern part of the Indian Peninsula has been a matter of enigma for a century and more. While one school was strongly holding the opinion that the southern Indian Peninsula is free from recent earth movements as it is a shield area, the other school has narrated the possibilities for the ongoing earth movements. Under these circumstances, the various anomalies observed from satellite data and ground based information on geomorphology, subsurface lithology, geophysics, hydrogeology, geochemistry etc. have suggested a possible Pleistocene / Holocene graben along Pondicherry in the northeast and Cumbum Valley in the southwest in the southern tip of the Indian Peninsula.

Abstract

The tectonics of the geological past from Archaeozoic to early part of Cenozoic era has been studied due to their penetrative documentation in the form of folds and faults. But the tectonic history of the latter part of the Cenozoic era (i.e Pleistocene period) has remained a matter of conjecture owing to the poor response of the rocks to Pleistocene movements. In the present study the authors presented a model for the Pleistocene earth movements of South India through the study of river migration, coast line changes and lineament fabric derived from the space borne photographs.

In the area of study, the northerly migration of Paleru and Pennar and southerly shift of Palar, Ponnaiyar and Cauvery rivers, marine regressions restricted within this segment and the closely spaced crest line fractures suggest a lineament controlled E-W trending Quaternary upwarping along Mangalore-Madras alignment. Similar E-W cymatogeny is inferred in the southern tip of the Peninsular India on the basis of once again such observations. Such E-W trending Pleistocene arching phenomenon suggests a N-S oriented regional compression which could be related to the collision of Indian plate with Tibetan plate.

14.1 Changes in policy and strategy

14.1.1 Policy changes

In the discussion on land use planning we suggested that the ideal pattern of development is to establish a long-term national or regional policy, which leads to medium-term strategies, and short-term tactical operations. In the real world a curious situation is arising in that the adoption of the new land husbandry approach is growing so fast that the practitioners have moved ahead of the politicians and opinion formers, with the result that the implementation of strategies by Non-Government Organisations, aid agencies, and senior field officers, is helping to shape new policies.

There is always the problem that national policies ought to be long term, but are created by politicians usually working within a short time frame to the next election. Fortunately, the land husbandry approach allows planners at all levels from farmers to governments to appreciate the long-term issues.

The new approach was mentioned in section 9.2.1 in connection with land use planning. It is summed up in the slogan From soil conservation to land husbandry, and two reviews using that title list the main points as the need for:

Drought, a sporadic yet impactful event, presents a significant challenge to agricultural systems and economies globally. A notable observation in this context is the tendency of policymakers to readily claim success for their governance during years of favorable weather, while conversely attributing agricultural failures in drought years primarily to natural causes. This inclination often masks an underlying lack of consistent focus and investment in proactive drought-proofing measures. This international comparison examines the contrasting approaches to drought management between developed and developing nations, highlighting how this lack of focus, coupled with varying capacities and resources, shapes their respective policy responses. Understanding these disparities is crucial for fostering more effective and equitable drought resilience measures worldwide, moving beyond the simplistic attribution of agricultural successes to policy and failures solely to weather

Introduction

Environment pollution is a burning topic of the day. Air, water and soil are being polluted alike. Soil being a “universal sink” bears the greatest burden of environmental pollution. It is getting polluted in a number of ways. There is importance in controlling the soil pollution in order to preserve the soil fertility and increase the productivity. Pollution may be defined as an undesirable change in the physical, chemical and biological characteristics of air, water and soil which affect human life, lives of other useful living plants and animals, industrial progress, living conditions and cultural resources. A pollutant is something which harmfully interferes with health, comfort and environment of the people. Most pollutants are introduced in the environment by waste, accidental discharge, sewage or else. They are by-products or residues from the production of something useful. Due to this our valuable natural resources like air, water and soil are getting polluted. The basis of agriculture is Soil. All crops for human food and animal feed depend upon it. We are losing this important natural resource by the accelerated erosion to some extent. In addition to this the huge quantities of man-made waste products, sludge and other product from new waste treatment plants, and even polluted water are also causing or leading to soil pollution. In order to preserve the fertility and the productivity of the soil.

ABSORPTION (of light): A process by which light is taken-up by another material. Examples include soot consisting of tiny black particles, which absorb all visible light; and nitrogen dioxide, a pollutant mostly from diesel and gasoline engines, that absorbs blue light resulting in air with a brown tint.

7.1. Introduction

The integrated farming system (IFS) is becoming increasingly important for effective farm resource management in order to increase farm productivity, reduce environmental degradation, improve the quality of life for resource-poor farmers, and ensure sustainability. Integration happens when one production sub-system's outputs (typically by-products) are used as inputs in another within the farm unit (Radhammani et al., 2003; Lightfoot and Minnick, 1991). IFS are a mixed farming system made up of at least two distinct but logically linked components of crop and animal enterprises. The integrated farming system is effective in reducing risk, increasing productivity and revenues, and improving the use of organic waste and agricultural leftovers.

Abstract

Quality of water is a matter of serious concern for arid and semi arid region like Rajasthan. The study area chosen is extreme western arid part of Rajasthan state where water quality and quantity both are very important issues. Due to absence of any perennial river, scanty rainfall and scarcity of surface water resources, ground water is very deep and saline. The groundwater potability assessment was based on 1119 wells water quality data. The purposes of this investigation were (1) to provide an overview of present groundwater quality and (2) to determine spatial distribution of groundwater quality parameters which affect water potability and (3) to map groundwater potability in the study area by using GIS and Geostatistics techniques. Arc GIS 9.3 and Arc GIS Geostatistical Analyst were used for generation of various thematic maps and Arc GIS Spatial Analyst to produce the final groundwater potability map.

Potassium is the third important essential nutrient element after nitrogen (N) and phosphorus (P) required by all living organisms, including plants and animals. Potassium is essential for many metabolic activities like carbohydrate metabolism, nitrogen metabolism. It is required for the activation of over 60 enzymes in plants. It controls/regulates the activities of various essential nutrients. It is vital to photosynthesis, and synthesis of carbohydrates, starch and proteins in plants. It plays vital role in controlling the opening and closing of stomata in photosynthesis. It also helps in controlling water use by plants by regulating the osmotic pressure of guard cells during transpiration. It plays a major role in transport of water and nutrients throughout the plant in xylem. Potassium improves crop yield and quality of flowers, fruits, vegetables and other field crops in terms of size, shape, colour, taste, shelf-life, and fibre quality. Potassium stimulates the growth of strong stems and provides strength to the plant against some disease by promoting thickness of the outer cell walls. It is required for translocation of assimilates. Under reduced K supply, translocation of NO₃^-, PO₄^3-, Ca²⁺, Mg²⁺ and amino acids is hampered. It also imparts resistance against environmental stresses such as drought, cold and frost. Adequate K can reduce moisture loss from growing plants, thereby giving some drought resistance. It reduces lodging of crops and enhances their winter-hardiness.

It is taken up by the plants as K⁺. Being a basic element, it takes part in neutralization of the acidity in plants caused by several organic acids produced. It does not form organic compounds in the plant system. It is the most mobile element in the plant. Thus, it can move through all the plant system due to osmotic pressure. When any plant sample is dipped into water, some K comes out. This shows that it is highly mobile.

Potassium is also required for animal nutrition and human beings. Potassium is essential for many metabolic functions. It maintains salt balance between cells and body fluids. Adequate K is essential for nerve function and preventing muscle cramps. It is routinely added to many animal feeds. Since K⁺ is not stored in the human body, dietary replacement is required on a regular basis. Government agencies state that diets containing foods that are good sources of K and low in Na may reduce the risk of high blood pressure and stroke.

16.1. Forms of Soil K

Ignoring potassium (K) in soil organism, total K in soil may be classified as (i) water soluble K, (ii) readily exchangeable K (exchangeable K), (iii) slowly exchangeable K (non- exchangeable or fixed K) and (iv) mineral or lattice K. The different forms are in dynamic equilibrium with one another.

Potassium is an important plant nutrient that influences water relations, carbohydrate and nitrogen metabolism, crop quality and resistance to environmental stresses. This chapter examines potassium behaviour and management in irrigated soils. It begins with the functions of potassium and explains the different forms in which potassium occurs in soil, including relatively unavailable, slowly available and readily available forms. Potassium fixation and release are discussed in relation to soil colloids, temperature, drying, soil pH and aeration. These processes determine the amount of potassium available for plant uptake and are particularly important in intensively cultivated irrigated soils. The chapter also considers luxury consumption and interactions between potassium and other elements. Potassium management is discussed through appropriate rates and methods of application and selection of suitable potassic fertilizers. The effects of potassium nutrition on plant behaviour, water utilization, carbohydrate and nitrogen metabolism, crop quality, disease resistance and low-temperature injury are highlighted. The chapter therefore provides a framework for maintaining potassium availability and preventing nutrient depletion in productive irrigated

Potassium (K) is among the most important essential macronutrients for plant growth. About 98% of the potassium in the earth’s crust exists in insoluble forms as rocks and silicate minerals, resulting in very low concentrations of soluble potassium in the soil for plant growth and development. Potassium is never incorporated in any organic compound and even in the plant system it remains as K⁺ ion. It does not form any gas that could be lost to the atmosphere. It does not cause eutrophication. When left in the ecosystem as such, it is not at all toxic.Potassium activates enzymes, maintains cell turgor, enhances photosynthesis, reduces respiration, helps in transport of sugars and starches, and is essential for protein synthesis. In addition to plant metabolism, potassium improves crop quality because it helps in grain filling and kernel weight, strengthens straw, increases disease resistance and helps the plant better to withstand stress.

Potassium in Soils

Soils usually contain potassium in larger amounts than any other nutrients. Total K content in soil is 30,000- 50,000 kg/ha in top layer of the soil. Nearly 98 % of K bound in the mineral form and 2 % is in soil solution. Generally, potassium in soils exist in four forms (often called fractions), their availability to crop roots is considerably different.

Glauber J. R. (1604–1670) in Netherlands first proposed that the salt peter (KNO₃) was the principle of vegetation. He obtained large increases in crop yield by addition of salt peter.

Mineral soils contain 0.04–3.0% K. Total potassium content of soils range from 3000 to 100000 kg per ha in the upper 0.2 m of soil profile. Of this total potassium approximately 98 percent is bound in mineral form whereas 2% in soil solution and exchangeable phases.

ROLE OF POTASSIUM

It is Involved in activating the enzymes (as many as 80) responsible for carbon dioxide reduction and required for synthesis of adenosine triphosphate. Hence deficiency of potassium reduces crop growth and yields.

Theoritical aspects of design has been discussed in chapter 1. Discharging capacity of canal is

 computed by Manning Equation (1)and continuity Equation (2) (Para 1.4).

 In the Manning's equation  V  =   R2/3  S1/2 / N (Eq. 1, Para 1.4);  N and R play most important role.

 The effect of  R has been discussed in para 1.4.1, Chapter 1. In this chapter the complexities of Manning's n (or N, also known as Manning's rougosity coefficient

 or simply rougosity coefficient) and some practical aspects of composite sections and velocity in best

 Mehboob, trapezoidal or rectangular sectioned channels are discussed.

2.0 Manning's Rugosity Coefficient (n)

Value of N depends upon a number of factors such as , surface roughness, vegetation, obstructions, type of lining, age of lining, erosion and damages in lining, curves, discharging capacity , perimeters, depth of flow, velocity etc. These are discussed below and commonly adopted values of n are given in tables 2.1 to 2.3.

Precipitation indices convert rainfall data into standardized measures of wetness, dryness, intensity and duration. They allow climatic conditions to be compared across locations and time scales despite differences in normal rainfall. This chapter introduces major indices such as the Standardized Precipitation Index, Standardized Precipitation Evapotranspiration Index, Percent of Normal and percentile-based measures. It discusses data requirements, calculation, interpretation, strengths and limitations. These indices support meteorological, agricultural and hydrological drought assessment, wet-spell analysis, crop planning and water-resource management. By identifying the severity and persistence of rainfall deficits or surpluses, precipitation indices strengthen early warning, drought preparedness and climate-risk management in agriculture.

3.1 INTRODUCTION

The chemistry of the soil is much more complex than can be represented simply by precipitation, adsorption, or exchange processes. The complexity arises from the time scale of soil chemical reactions in which the structure and dimensions, the extent and distribution of pores, and the content and mobility of water in them, interact immensely with the reaction chemistry. The fourth process adding to this complexity is the dissolution of native and reprecipitated soil constituents by percolating water containing solutes accumulated by natural processes or added by man. The fifth complicating factor compounding the time scale is that very often the resultants of soil chemical reactions are large complex molecules, occasionally polymeric, made up of several constituent groups or atoms. It is by no means clear which of the four processes participate in a chemical reaction and in which order. That a process reoccurs during a prolonged reaction is very likely.

Such complexities explain why no single model related rigorously to the retention and release of cations and anions, can provide a basis for a laboratory procedure to test and compare the chemical properties of soils. In this chapter, some of the soil reactions that are important to plant nutrition and pedological processes are discussed, principally those leading to relatively simple compounds accumulating in soil.

1. Land Degradation- Type, Factors, Distribution, Processes, and Impacts on Soil Productivity

A. Types of Land Degradation

1. Soil Erosion: Soil erosion, a pervasive form of land degradation, manifests through the detachment and transportation of soil particles by various agents like wind and water. Wind erosion is common in arid regions, where dry, loose soil is susceptible to being carried away by the wind. Water erosion, on the other hand, occurs through surface runoff and can lead to gully formation and the loss of fertile topsoil. This loss of topsoil directly impacts agricultural productivity by reducing nutrient availability and water retention capacity.

Abstract

The social and economic development of any state is interlaced with the manner of its natural resource management. The unplanned use and overexploitation of resources are results in various kinds of land degradation, biomass deterioration and siltation of tanks. In addition, the low per capita availability of land, erratic and uneven distribution of rains, undulating topography, improper management, traditional cropping programmes and recurrence of droughts having cumulative effect leading to low productivity and high risk particularly in dryland farming. Further, developing dry land agriculture through sectoral approach did not bring in the desired results, as the efforts were not integrated. However, in nature all the resources are inter-linked and thus, the integrated developmental approach is the best solution for optimal development of any area. Further, development based on administrative units such as district, taluk, block and village have resulted in imbalance and sometimes, no overall development in some areas. Considering this, natural resources management through Geo- informatics tools like, remote sensing, GIS, GPS and other sensor based techniques are the possible ways for making agriculture sustainable. The paper mainly highlights theimportance of application of latest technologies in agriculture along with some field level case studies.

Keywords: Remote sensing, GIS, Watershed, CAPE, Precision agriculture