*2.3.1 Multiple index*

Multiple index (D) is the percentage of spacing that are less than or equal to half of the theoretical spacing. D, is an indicator of more than one seed dropped within a desired spacing:

$$\mathbf{D} = \mathbf{N}/n\_1\tag{1}$$

where *N* = total number of observations and *n*<sup>1</sup> = number of spacing's in the region less than or equal to 0.5 times of the theoretical spacing.

*Scaling Mechanization and Profitability in Maize Cultivation through Innovative Maize… DOI: http://dx.doi.org/10.5772/intechopen.111766*

#### *2.3.2 Quality of feed index*

It is the percentage of spacing that are more than half, but not more than 1.5 times the theoretical spacing. Quality of feed index, A, is the measure of how often the seed spacing were close to the theoretical spacing [65]. The quality of feed index is mathematically expressed as follows:

$$\mathbf{A} = \mathbf{N}/\mathfrak{n}\_2\tag{2}$$

where *N* = total number of observations and *n*<sup>2</sup> = number of spacing's between 0.5 times the theoretical spacing and 1.5 times of the theoretical spacing.

#### *2.3.3 Miss index*

It is the percentage of more than 1.5 times the theoretical spacing. Miss index, M, is an indicator of how often a seed skips the desired spacing and expressed as:

$$\mathbf{M} = \mathbf{N}/n\_3 \tag{3}$$

where *N* = total number of observations and *n*<sup>3</sup> = number of spacing in the region more than 1.5 times of the theoretical spacing.

#### *2.3.4 Precision Index*

Precision Index, C, is a measure of the variability in spacing after accounting for variability due to both multiples and skips. The degree of variation is the coefficient of variation of the spacing that are classified as singles, and expressed as:

$$\mathbf{C} = \text{ref}^{\mathbf{f}} \,\mathbf{X}/\mathbf{S}\_2 \tag{4}$$

where, *S*<sup>2</sup> = sample standard deviation of the *n*2 observations and *Xref* = Theoretical spacing.

*Energy input calculations—*The various energy equivalents are shown in **Table 3** and energy indices were calculated using following formulae.


The energy involved in various planters, mechanical weeders, field preparation, combine harvester, biocides, fertilizer, electricity was considered for energy calculations. The various forms of direct and indirect energy were also calculated for row crop planters and other sowing methods.
