eChapters

A seed consists of a plant embryo, stored food material surrounded by a seed coat. Seeds of cereals and grasses consist of embryo or germ, endosperm and the pericarp.

Seeds of legumes contain no endosperm, the bulk of the seed being made up of the two cotyledons. The cotyledons constitute the food storage portion.

The embryo of the grass seed is made of epicotyl, hypocotyl and scutellum- the single cotyledon of monocots, the epicotyl gives rise to the shoot and the hypocotyl produces the roots.

Tillage is the physical manipulation of the soil with tools and implements which, results in good tilth for better germination and subsequent growth of crops.

Tilth is the physical condition of the soil resulting from tillage. Soil is said to be in good tilth when it is mellow, friable and adequately aerated. Tilth is dynamic. Mechanical forces may change the roughness of the soil surface, the total porosity and bulk density of the tilled layer and the aggregate or clod size. Heavy rainfall and high velocity wind or water destroys the tilth. The action of wetting and drying, freezing and thawing regenerates desirable tilth. The roughness of the soil surface is an index of the amount of water that can be stored in soil depressions and may also be related to the resistance of the soil surface to sealing. Roughness may be related to rate of evaporation, transfer of heat and air between the soil and atmosphere.

Soil fertility is the ability of the soil to supply all the essential nutrients in optimum amount in balanced proportion in a form readily available to plants under conditions favourable for plant growth and should be free from toxic substances.

Soil productivity: Soil productivity is defined as the capability of soil for producing a specified crop or sequence of crops under defined set of management practices. It is measured in terms of outputs or harvests in relation to the inputs of production factors for specific kinds of soils under a physically defined system of management according to USDA (1957).

The word soil is derived from the Latin word ‘Solum’ means soil. In general the top 15-20 cm cultivated layer is referred as soil. It is a loose and unconsolidated outer layer of the earth crust that is crumbly and powdery in nature. Soil below the plough layer is called subsoil.

Soil is formed by weathering of rocks. Weathering may be physical or chemical or both. Factors of soil formation are parent material, climate, living things-plants, animals and microorganisms, topography and time. Soil formation is a function of parent material (P), climate (C), topography (T_o), life (L) and time (T) which is represented by f(P C To L T).

Field Crops: Refers to the crops grown on a vast scale. They are classified in the following ways

1. According to the place of origin

2. Botanical classification

3. Commercial classification

4. Economic classification

5. Seasonal classification

6. Classification according to ontogeny

7. Agronomic classification

8. Classification based on leaf morphology

9. Classification based on serving special purpose

Crop growth is influenced by internal factors and external factors. Internal factors are controlled by the genes and hereditary. External factors are climate, edaphic, biotic, physiographic and anthropic.

Genetic Factors

Genetic factors are controlled by the genes. Plant height, yield, size and color of the grains or fruit etc. The productivity and quality of the crop can be improved by breeding through conventional methods or by biotechnological approaches.

Environmental factors Climate

Precipitation occurs in the form of rainfall, snow, hail and fog.

Fog: Consists of water droplets so small that their fall velocity is negligible. Fog particles contact vegetation and may adhere, coalesce with other droplets and eventually form a drop which is large enough to fall to ground.

The term agriculture is derived from the Latin words ager or agri meaning soils and cultura means cultivation. Agriculture is the art, science and business of crop production. It encompasses all aspects of crop production, livestock farming, fishery and forestry. Agriculture is the conversion of solar energy into the chemical energy. Crop production is the conversion of environmental inputs like solar energy, carbon dioxide, water and nutrients in soil to economic products in the form of human or animal food or industrial raw materials.

Agriculture is a science, an art and business of crop production

Agriculture is a science of farming. Scientific principles are employed to find ways of making it as efficient as possible. Through scientific principles plants and animals are transformed genetically and most favorable environment is provided to harvest higher yields of good quality with least expense of energy. The scientific principles of various branches viz. soil science, genetics and plant breeding, entomology, plant pathology, microbiology, agricultural engineering etc. were employed in agriculture. Agriculture like any other science is a body of truths synthesized and systematized and arranged in such a way as to show the operation of general laws and principles.

Agriculture is an art which embraces knowledge of the way to perform the operation of a farm in a skillful manner. The physical and mental skills are involved in agriculture. The skills may be acquired through years of experience viz. ploughing, stacking hay bundles, handling animals, sowing seeds, transplanting, driving a tractor etc. Mental skills are those involved in decision making for example when to plough the land, selection of appropriate crops, seed selection etc.

Agriculture is a business which is no longer a way of living or subsistence agriculture, where production is intended to meet the home requirements. Agriculture is intended to earn more income. Land, labour, capital are judiciously used. Like in any industry the farming industry should forecast the demand, tailor the production with demand to earn more profits. It involves processing, value addition, transportation, packing and storage in scientific way. Knowledge of employee and employer relationship or human resource management, export and imports, taxation, customs, tariffs and trade are required. All these aspects demand business knowledge in addition to the production and managerial skills. Traditional agriculture is no longer relevant for success in agriculture. Commercial agriculture or corporate farming, agribusiness development corporations demand entrepreneurs in agriculture rather than technologists alone.

Fig 8.1: A scheme for fertigation program working with automation

In modern farming with fertigation machines (NutriCare) and automated drip irrigation systems, fertigation set up schemes like the above are put into practice. This scheme will stream line the installation, operation and monitoring of the entire process. An informed grower would be able to control crop performance more precisely and achieve his objectives.

The crop growing environment, both soil/media and aerial are controlled in green house. Therefore, the movement of water (liquid and vapour) and minerals (nutrient ions) follow a different pattern altogether. This factor should be considered while preparing the fertigation program. This becomes all the more different if soil-less rooting media is used.

Table 7.1: Differences in Nutrient uptake in open field and Protected (GH) conditions.

There is a lot of confusion and lack of understanding when it comes to scheduling of fertigation. Even crop specialists prepare a fertigation dosage by dividing the total fertilizer quantity by the number of days of crop growth. This is highly erroneous. A scientifically prepared fertigation plan allows coordination of nutrient supply with changing demands of the growing crops which changes with the physiological shifts in the crop. Fertigation planner requires following information to prepare this schedule- which, when and how much plan:

Organic Fertilizers and Manures

Farmers have been using organic waste as fertilizers for a very long time. As previously mentioned, the application of O.M. to a soil can have number of beneficial effects on soil structure, C.E.C. and microbial activity. However, organic manures mainly originate from the waste products of animal and plant production and although rich in carbon compounds, they are usually relatively poor in available plant nutrients.

The nutrient content of organic manures varies widely depending on their source and moisture content. Farm yard manure (F.Y.M.) is one of the most common organic fertilizers used. Others are concentrated animal manures, and crop residues such as straw.

Although the application of fertilizer to even fairly fertile soils can give a great increase in crop yield, soil fertility is not simply a matter of nutrient content. It is dependent on a number of complex of issues:

Soil depth

The volume of soil from which the crop draws its nutrition varies according to the rooting depth of the crop. However hard or rocky layers can restrict natural root development; this is particularly the case with micro irrigation systems.

Soil structure

Particle size and soil aggregate size and distribution, effect the size and distribution of pores and therefore the availability of air and water to the roots.

Only a very brief mention of various basic aspects of plant nutrition is given here. Associates wanting to know more details should refer to any one of the standard Plant Nutrition publication (PRINCIPLES OF PLANT NUTRITION by K. Mengel and E.A. Kirkby).

Increased production of food and cash crops is the need of our times; as land and irrigation water are limited and beyond any means of expansion. Crop yields per unit input should increase. Crop yield under natural production systems is limited by the availability of nutrients in the soil. Unless the supply of nutrients can be enhanced yields cannot be high.

What is that the grower wants to achieve while he nourishes the crop with costly fertilizer inputs? He would like to get maximum output (yield and quality) of the produce; and for the maximization of out-put the fertilizer input should be utilized by the crop to its maximum potential. Thus it is not higher fertilizer dose that decides the highest yield; but the highest efficiency in crop’s use of those fertilizers. The efficiency, yield/unit fertilizer can be enhanced by the following factors;

a) Plant roots absorbing (in-take) total quanta of applied fertilizer and minimizing the loss of applied nutrients by not having spare quantities lying around the soil profile. This is possible only if the quantum of application matches with the quantum of need.

b) Plants utilizing the absorbed nutrients for metabolic activities concurrent to absorption. This is possible only if the fertilizers are applied in times of need of the plants and not before or after. This compels the grower to know the physiological need of the nutrient during each developmental stages; which nutrient required when.

Here the grower must have a powerful tool or method to provide nutrients to the plants strictly following the above two factors. Fertigation offers an opportunity to practice nutrient inputs based on the above two factors: the grower is able to correctly decide the dose, type and time of providing the correct nutrient at precise quantity and at the required stage of plant/ crop development.

Thus the purpose of Agriculture, to maximize yield and quality of crops and minimize the costs of production while maintaining sustainability can be put into practice by fertigation. Two most important prerequisites to achieve all of these are the optimal and balanced supply of water and nutrients. Tuning of plant nutrient supply with the uptake and utilization rates by crops is essentially an art and is made doable by fertigation technology.

Introduction

Almost every test of reasoning contains questions on coding. In such questions, generally one word and its code are given, and the students are required to find the code for the other word. The student is required to apply the same logic, as was applied in the given words.

Let’s discuss some of the commonly asked questions based on coding : Some of the major types of coding logics are

We must know our family, its members and their relationships. Let us first look at basic relationships which often figure in the questions. If you are conversant with the given items in the table below, half of your battle is already won. It is not required to mug-up these names, but instead make a clear picture in your mind as you go through each one of them. This will go a long way in retaining the details of these given shortcut tricks for solving Blood relations problems for logical and analytical reasoning. Read the following thoroughly before moving on

Questions related to analogy ae simple to answer with application of little aptitude. Analogy means ‘similar items’. There is three types of Analogy, 1. Number Analogy, 2. Letter Analogy and 3. Word Analogy. In questions based on analogy, a pair of numbers/letters/words is given that have certain relationship between them. This pair is followed by a third numbers/letters/ words. The candidate is required to identify the relationship between the pair of numbers/letters/words given and find out the fourth numbers/letters/words such that the relationship between the third and the fourth numbers/letters/ words is similar to the relationship that exists between the first and the second numbers/letters/words. Similarly some figures are also given in questions and the next pattern of the figures is to be guessed. It requires candidate’s concentration and common wisdom. Therefore the candidates should be very attentive to answer these type of questions.

In mathematics, we use different type of digits called numbers. These numbers may be real, natural, rational, irrational, composite and complex, imaginary, perfect, positive and negative integers, whole number, prime and co prime numbers and even-odd numbers and make students confused. Therefore the concept of numbers should be very clear to the students so that they may answer the questions easily.

The number system mainly into classified into 8 types.

The questions related to different series like perfect squares, perfect cubes, geometric, arithmetic, two stage types etc. are given to quantify the aptitude of the students. These series have a definite pattern and require to stressed upon the basic knowledge and aptitude of the candidates to find out the proper answer. The series may follow different pattern either additive, deductive or multiple based on earlier values given in the series. Some of the tips are given below for better understanding of the students and also these tips will help you to solve some of the ticklish questions.