You probably learned a lot more about individual differences in grade school than you realize. Grade school was the first place where many of us regularly interacted with a relatively large number of human beings. You were able to observe a rich diversity of individual differences, although you probably were not thinking about it in such terms, at the time. Children of the same age can differ in physical traits, such as height, weight, eye color, hair color, and skin color. They can also differ in behavior traits such as coordination, running speed, strength, and stamina. Children can also differ on psychological traits such as anxiety, aggression, extraversion, and impulsivity. Of course, you also probably noticed that grade school students can differ on their success in the classroom.

Soil water occurs in the unsaturated zone and is the only source of water and nutrients for most agricultural crops. Since nutrients, including fertilizers, are dissolved in soil water, it is the only source from which plants can extract them. The objective of irrigation is to maintain enough soil water in the soil. This chapter discusses some rudimentary aspects of this water.

Line and scatter plots, which we described in Chapters 4 and 5, are the bread and butter of scientific visualization. There are, however, many other kinds of graphs used to display and analyze scientific and engineering information. In this chapter, we examine two such kinds of visualization: contour plots and animations of two-dimensional plots and images. Contour plots are a common way of presenting data whose values change based on the location in two-dimensional space.

Irrigation scheduling is a fundamental component of irrigation management and is vital for optimum agricultural production. It varies with the type of crop, soil, climate, method of irrigation, and agricultural practices. There are different methods for irrigation scheduling. This chapter discusses some of the commonly used methods of irrigation scheduling.

A pipe is a closed conduit, and when it runs full its hydraulics is different from the hydraulics of open channels in which the upper surface of flow is exposed to the atmosphere. Pipes or closed conduits are used in sprinkler and drip irrigation systems to carry water from the source of water supply to the individual sprinkler or emitter. Water may be conveyed from a reservoir through a pipeline. These systems are also called pressurized irrigation systems. This chapter reviews the principles of pipeline hydraulics.

In Chapter 6, we looked at the analysis of one-dimensional arrays of data. Along the way, we introduced the for loop and the branching statement. Looping enables us to make some set of calculations repeatedly. Branching enables us to ask questions of our data. In this chapter, we extend our discussion to two-dimensional arrays.

One of the neat features of Python is that it works very well as a “glue” language. That is, it enables us to manage many, if not all, parts of a scientific or engineering workflow, within a single computing environment. In earlier chapters, we saw how Python can be used for reading in data, doing calculations on the data, and making plots of the results. We have also seen that Python can be used to generate “data,” in the form of model or simulation results, which can also be analyzed and graphed. In the past, scientists and engineers used separate programs to work on each of these steps in their workflow, and these separate programs did not communicate with each other except through files.

In the previous chapters, the lists and arrays of data we have looked at have been pretty small. Partly, this is because it is easier to understand small datasets, which helps us when we are learning a new tool. However, what makes using a programming language (as opposed to Excel) a better tool to analyze data is the ease with which a program written in a programming language can be scaled up to handle a large dataset. In Excel, it is not so easy to go from, say, 500 rows of data to 500 million rows of data.

Land surface characteristics, especially slope and highs and lows or irregularities, substantially affect the efficiency of irrigation systems. Indeed, the type of irrigation system to be employed is determined by the land surface itself. Ideally the land surface should be such that the irrigation water moves as uniformly as possible but the natural landscape is not always so. Therefore, the natural landscape or topography is altered, entailing the movement of earth from one place (high) to another (low). Land leveling or smoothing is one of the most important surface irrigation management and design practices. The objective of this chapter is to discuss the methodology for altering the landscape and various aspects thereof.