eChapters

In the wild (forests) plants grow by their own, but in agriculture because of limited space they don’t have freedom to grow in a much natural way. This can lead to structural irregularities in their growth, and can hamper the overall plant’s development and this will impact the produce or crop yield. To deal with such constraints and to boost the crop production, the methods of thinning and pruning provide efficient ways to train the growth of young plants and maintain the health of grown-up plants.

11.1 Introduction

In agriculture, thinning means the removal of some plants or some parts of plants that show inconsistent growth and or are damaged by some pest or disease, without removing the whole tree or plant. The selective removal of branches, buds or roots is termed as pruning [1]. If the plants are overcrowded in a confined space, the overall health of the crop decreases due to the competitive stress from the neighbouring plants. Thinning and pruning is done to improve the growth rate or health of the plants by decreasing the competitive stress. Thinning and pruning in agriculture is the sensible removal of plant parts such as flowers, shoots, its branches or other parts to correct or maintain that structure of the tree and control be directed growth of the crop. This practice covers the precise removal of the unhealthy and obstructive part of the plant branch, leaves, fruits, buds, fruits, etc. Pruning improves the quality and longevity of the crop, leading to quality produce and increased yield of the field. This also helps in increasing the size of the fruit as it increases the availability of nitrogen required for growing and stimulating growth of the crop. There are several factors that influence the amount of pruning to be done, i.e., age of the plant, condition of the bark and wood, growth characteristics, whether cup crop/plantation is permanent or seasonal [2]. Pruning is done for controlling the size of the plant, controlling the structure makeup of the plant, controlling and improving the light distribution of the plants by the selective removal of leaves to improve the quality of the fruits, removing the diseased parts of the plant and to regulate the fruit crop and increase the life of the tree.

The principle behind thinning and pruning is to admit more sunlight to the branches that bear fruit by the selective removal of the unproductive branches which obstruct the sunlight to fall on the productive branches to increase the productivity white and vitality of the plant to obtain optimum healed of good quality crop [3]. Young trees are pruned so that they acquire the desired shape. In old trees it is done to stimulate flowering. In plants bearing fruits or crops, pruning is done to allow adequate sunlight to fall on fruit bearing branches, so that quality crop is produced. Very old plants heavy pruning is done to restore the vigour of the plant. It is also done so that the loss of nutrients being shared by the diseased peak or shading branches is reduced. The use of robotics and other automated systems can aid in the precise pruning and thinning of the crop. This will also automate the whole process and will save their requirement on the extensive manpower which ultimately saves time.

To cater the increased demand of food, it will be required that farmers are equipped with tools and methods to improve their yields and make informed decisions [1]. Also, with the increase in population, the agricultural land is decreasing by 1 lakh hectares per year and it is required to double the agricultural produce in the next 30 years to sustain the global food requirements.

The improvements in various technological fields like machine learning, navigation, robotics etc. and their applications in agriculture is required to meet this increasing need. One of the factors is to make the farmland ready for sowing the crops, spraying, etc. and this has to be done in a precise and faster manner to address the latter issues. So, the uses of autonomous tractors for such jobs offer accurate, precise and timely preparation of the fields for the cultivation.

12.1 Introduction

Autonomous tractors or driverless tractors are unmanned ground vehicles mainly employed in agriculture for various purpose like preparation of land for the crops, harvesting, spraying, and other agricultural purposes. They are equipped with GPS, autopilot, cameras, lasers (LiDAR), and other wireless technologies navigation and mutual coordination and offer saving of both the manpower and time. These autonomous tractors can be programmed to navigate their paths through the fields and are designed to avoid the obstacles while doing their jobs. These tractors automate various laborious field jobs and also minimize human intervention in the process.

These autonomous machines are regarded to revolutionize the agriculture industry and offer safety, sharing of resources, economical solutions per square area of land, etc. Several industries like Jhon Dheere, AgraBots, EcoRobotix, RowBot, etc.

Harvesting is one of the most labour intensive jobs in agriculture, and by implying the robotics in harvesting, the quantity of the harvested yield can be readily increased, thus saving a lot of time and human resources. This also aids in reducing the farm to market transportation times. The use of robotics can also reduce the seasonal requirement of the manual labour and thus reduce the recurring costs.

13.1 Introduction

The incorporation of robotics in agriculture has proved to be advantages for the farmers and thus for the economy. The automation of various agricultural processes led to the reduction of the operational costs and also in the reduction of the labour required. A possible solution to address the problems of labour availability and scaling up the harvesting of the crop is the incorporation of robotics.

The development of the civilisation humans have tried to domesticate the animals. Initially dogs were known to be the first pet domesticated by humans followed by the domestication of other animals like cattle, horses, sheep etc.

14.1 Introduction

When humans started to domesticate the animal, they have tried several ways to control them. Generally these animals are released in free space to graze and one of the known problems is to prevent them from overgrazing. So building a fence is one of the ways to limit their movement is one viable solution, but building a fence is limited to a smaller area. Since these animals are locked in a large number, so building a bigger fence and moving it every time for grazing is not viable. It can be observed in the history of humankind as that civilisation progressed the use of Shepherd dogs has been one of the widely accepted. Shepherd dogs not only help in shepherding and herding but also prevents these livestock from wolves

The incorporation of robotics will not only automate the process intelligently but also keep a vigil on various aspects of livestock management. In recent years there has been a substantial development in this regard. The development of robotic dogs for shepherding and herding purposes has found a lot of increment developments. SPOT developed by Boston dynamics and SwagBot developed by University of Sydney, are well-known robots developed in recent times for the purpose.

These robots are equipped with multiple sensors like LiDAR, gas and heat sensors, high-resolution cameras etc. The array of sensors are used to capture the data in real-time and is then used for decision-making processes. Also these reports are built to be rugged and can navigate on a variety of terrains.

Smooth gourd or sponge gourd (2n =2x = 26, Luffa cylindrica Roem syn. aegyptiaca, family Cucurbitaceae, monoecious, cross-pollinated but genetically behaving like self-pollinated crop) is not a global crop and is a vegetable crop very much indigenous to India and the adjoining countries. As per estimates, the acreage of this crop in India is about 50,000 ha spread over almost all the states but on a limited scale. However, UP, Bihar and West Bengal are the main states growing sponge gourd.

Origin and Domestication

It is agreed that sponge gourd may have originated from Asian sub-tropical areas, particularly India and India itself should be the centre of domestication as well because global presence of this crop is negligible (Kalloo, 1993). NBPGR, New Delhi publications unanimously mention Indo-Chinese and Hindustani gene centres as primary centres/domestication/secondary centres for Luffa species and in their publications, Luffa aegyptiaca is more commonly used than Luffa cylindrica for sponge gourd (Pandey et al., 2019).

The subject on micrometeorology deals with small scale meteorology of near ground surface with its related elements of both physical and biological processes. When this micrometeorology is integrated for crop production purposes, then it becomes crop micrometeorology, which is very important in the science of agricultural climatology. This crop micrometeorology gets varied with the architecture of the crops grown, available soil moisture, agronomical practices followed, soil texture, topography of the area, the nature of climate and weather that prevails etc. The soil surface heat, exerts a profound frictional effect on wind movements and hence it is different from the air layers at higher levels. These special features constitute the microclimate, which is modified compared to a flat bare surface by factors like topography, nature of soil surface, presence of vegetation and type of vegetative cover. The presence of crop canopy leads to distinct differences in the thermal and humidity regimes of the soil, the air layers immediately above it and the distribution of radiation and wind profiles inside the canopy. The study on the physical exchanges of the transfer of heat, momentum and moisture in the microclimatic region is called as micrometeorology (Venkataraman and Krishnan, 1992).

Radha Krishna Murthy (2002) reported that the micrometeorology is the micro scale of both the physical and meteorological factors that are taking place within the ecosphere. The ecosphere means the area between just above the crop canopy and just below the root zone of a crop. Further he was on the opinion that the microclimate of valley is important as compared to the entire climate of the mountain for the bio-life of valley. For the crops purpose, the microclimate is the climate of the ground surface to top of the crop canopy or otherwise it can be called as crop’s climate, a modified one from the Stevenson’s Screen climate/weather observation.

Potentiometry

Potentiometry is based on measurement of potential of an electrode system

Principle

When a metal electrode is immersed in a solution containing its own ions, the metal atom pass into the solution in the form of metal ions and a potential difference is established between the metal and the solution. This potential is called as electrode potential.

Potential on an electrode depends on the ions present in solution and their concentration which can be determined by using electrochemical cells and expressed by Nernst equation

Determination of size of the food materials

Size is an important physical attribute of foods used in screening solids to separate foreign materials, grading of fruits and vegetables, and evaluating the quality of food materials. Various types of cleaning, grading and separation equipment are designed on the basis of size. The size and shape of the grains are used to determine the size of screen openings, angle of inclination, vibration amplitude and frequency of screen in designing an air screen grain cleaner and conveying characteristics of the solid materials.

Theory

Texture testing is a well-established technique for evaluating the mechanical properties of raw materials, food structure, pre- and post- harvest quality control checks. The texture testing has many applications across wide range of foods including cereals, fruits, vegetables, meat, poultry, fish, baked foods, confectionaries, snacks, dairy, gelatins, pasta, etc. Food texture analysis of foods can highlight the quality improvement throughout the supply chain. At research and development stage, new or alternative ingredients can be compared with existing ingredients.

Texture profile parameters

The texture profile parameters including hardness, firmness, crispiness, rupture strength springiness, chewiness, cohesiveness, gumminess, gel strength, adhesiveness, consistency, crunchiness, elasticity, extensibility, fracturability, stiffness, stringiness, toughness, work to cut, penetrate and shear can be measured by the mechanical food texture analyzer.

Aim

To study the numerical problems on grain moisture content and equilibrium moisture content.

Problem 1

Five hundred kilograms of paddy at 22% moisture content (wb) is dried to 14% moisture content (wb) for milling. Calculate the amount of moisture removed in drying.

Aim

To study the determination of drying rate of agricultural products

Problem

In a drying experiment on paddy at an air temperature of 60ºC, the following data were obtained. Prepare a drying rate curve for the experiment. Initial weight of the sample is 1250 gm and initial moisture content is 35% (d.b).

Aim

To draw the drying characteristic curve for given grain by thin layer drying.

To determine the drying constant, heat utilization factor and coefficient of performance.

Aim

To design a bucket elevator

Theory

The bucket elevator’s capacity mainly depends on bucket size, conveying speed, bucket design and spacing, the way of loading and unloading, the bucket and the characteristic of bulk material.

Bucket elevators with a belt carrier can be used at fairly speeds of 2.5 to 4 m/s. The speed of the belt depends on the head pulley.

If the belt speed is too low, the discharge of the grains become more difficult, with too high speed the buckets are not fed well.

Aim

To design a belt conveying system

Theory

The design of belt conveying system is based on available space, horizontal conveying length, conveying lift, characteristics of the materials to be conveyed and capacity requirement.

On the basis of overall requirement and information, the belt width, belt speed, required horsepower, maximum belt tension and breaking strength of the belt, diameter of the pulleys and idlers and quantity of belt (thickness) are determined to design a belt conveyor (Fig.32.1).

Greenhouse selection

Selection of greenhouse to be constructed is important as each type has its own merits and demerits. There are two common types of commercial greenhouses namely; (i) Freestanding (single span) and (ii) Ridge and furrow (gutter connected or multi-span). Multi-span structure permits economy in construction, heating and cooling but the single span gives flexibility as far as microclimate inside the greenhouse in concerned. The freestanding Quonset type is usually accommodates many growing situations but there height restrictions near the side walls. Another freestanding type is single gable greenhouse and its many variations. The ridge and furrow or gutter connected greenhouse are joined at the eave by a common gutter.

Aim

To measure horizontal distance on the level ground using chain

Materials required

Chain

Ranging rods

Chain pins

Field note book

Theory

Area computation is an important part of surveying. The term ‘Area’ is meant the projected area on a horizontal plane. The area is computed from the following methods: (i) Graphical method (ii) Instrumental method and (iii) Use of formulae. In graphical method, the area can be computed by dividing the whole area either into triangles or squares. The area of individual triangle is computed from base and the altitude and summation of individual area gives the total area. A tracing paper is divided into number of small squares is placed over the plan. The number of complete squares within the boundary is counted. The squares more than half are counted as full squares and those less than half are neglected. The total number of squares multiplied by the area of each square gives the total area of the field. In instrumental method, the planimeter is used to measure the area of a plotted plan. In use of formulae, computation of area by formulae depends on the shape of the field.

Aim

To identify different parts of prismatic compass and to know their functions.

To practice of taking the angular measurement.

Compass survey principle

Compass surveying is a branch of surveying in which directions of survey lines are determined with a compass and the lengths of the lines are measured with a chain or tape. In practice, the compass is generally used to run a traverse. In compass surveying, a traverse consists of a series of straight lines connected together to form an open or closed polygon as shown in Fig.44.1. The points A, B, C, D and E defining the ends of the traverse lines are called traverse station or traverse points. The lengths of the traverse lines are measured with a chain or tape. At each traverse station, where the traverse lines meet, the angle is measured with a compass.

Aim

To determine the area of the field by intersection method using a prismatic compass.

To determine the included angle of the closed polygon.

Materials required

Prismatic Compass

Tripod

Measuring tape

Arrows

Ranging Rods

Aim

To determine the reduced level of various points

To find out difference of elevations of two points

Materials required

Dumpy level

Levelling staff

Aim

To determine the reduced levels on various points on the road

To plot the profile of the road

Materials required

Dumpy level

Levelling staff

Theory

Profile leveling is the process of leveling along a fixed line to determine the elevations of the ground surface along that line. The fixed line is generally the centre line of a highway, railway, canal, sewer, etc. The profile leveling is done to determine the undulations of the ground surface. Cross-sectioning is required to determine the levels across the line along which profile leveling is done. Profile leveling should be commenced from a bench mark and should end at a bench mark, as far as possible. When the ground surface does not have many undulations, the intermediate points are fixed at a uniform interval. If the ground surface is irregular and there are abrupt changes in the ground surface, the interval may be non-uniform.

Aim

To measure the irrigation water by using weirs

a) Weirs

A weir is a notch or opening of some definite shape installed on a channel or a stream through which waterfalls (Fig.59.1). Materials like wood, concrete, mild steel, rigid PVC etc. can be used for construction of a weir. Mainly a cut on a sheet metal is used for fabrication of weirs, to be installed at various locations in a channel. Advantages of weirs are (i) capable of accurately measuring a wide range of flows (ii) easy to construct, portable and adjustable (iii) tends to provide more accurate discharge rating than flumes and orifices.

Aim

To measure the irrigation water flowing through a pipe by using Venturimeter

Theory

A venturimeter is a device used to measure the rate of flow of a fluid through a pipe and is often fixed permanently at different sections of the pipeline to know the discharge there. Venturimeter consists of three parts: (i) a short converging part (ii) a throat (iii) a diverging part (Fig.62.1). In the venturimeter, the fluid is accelerated through a converging cone of angle 15-20° and the pressure difference between the upstream side of the cone and the throat is measured, and provides the signal for the rate of flow. Due to the constriction there is an increase in the flow velocity and hence an increase in the kinetic energy. The fluid slows down in a cone with smaller angle (5-7°) where most of the kinetic energy is converted back to pressure energy. Because of the cone and the gradual reduction in the area there is no “vena contracta”. The flow area is at minimum at the throat.