## 4 Results
### Irrigation Technique to Evaluate and Compare
#### 4.2.3. Proposed Smart Irrigation  
The proposal uses the daily water balance to determine the amount of water in the root zone and, through irrigation, to modify the amount of water, respecting the limits that must be kept lower than the field capacity (\(Cc\)) and higher than the permanent wilting point \((Pmp)\). The balance is based on the input and output of water in the root zone, and the proposed system in Figure 3 of the first stage is applied to generate the optimal daily demand.  
\begin{table}
\begin{tabular}{c c c c} \hline  & \multicolumn{3}{c}{**Crop: Alfafla**} \\ \hline  & \(K_{c}\) & **Days** & **Z (mm)** \\ \hline Initial & 0.4 & 10 & 100 \\ \hline Development & 1.05 & 20 & 275 \\ \hline Intermediate & 1.2 & 20 & 800 \\ \hline Final & 1.15 & 10 & 800 \\ \hline \end{tabular}
\end{table}
Table 4: Crop Parameters.  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Date**} & \multirow{2}{*}{**Stage**} & \(\mathbf{ET_{o}}\) & \(\mathbf{ET_{c}}\) & \(\mathbf{LT_{c}}\) & \(\mathbf{L_{RAW}}\) & \(\mathbf{Fr\) (days)} & \(\mathbf{N^{\circ}}\) & \(\mathbf{L_{b}\) (mm/}\) & \(\mathbf{tr}\) \\  & & **(mm/day)** & **(mm/day)** & **(mm)** & **(mm)** & **(mm)** & **(mm)** & **(mm)** & **(mm)** \\ \hline
1 July & Initial & 2.336 & 0.4 & 0.9345 & 1.95 & 2.08 & 5 & 2.59 & 1 \\
10 July & Development & 2.336 & 1.05 & 2.45311 & 5.363 & 2.18 & 10 & 7.15 & 3 \\
30 July & Intermediate & 2.5609 & 1.2 & 3.07308 & 15.6 & 4.91 & 8 & 10.05 & 4 \\ \hline
20–29 August & Final & 2.5609 & 1.15 & 2.68895 & 15.6 & 4.91 & 4 & 10.05 & 4 \\ \hline \end{tabular}
\end{table}
Table 5: Technical Irrigation Schedule.  
The initial moisture is taken into account from the date of planting or when the first irrigation performed; the precipitation is the rainfall that occurs per day and the amount of water it brings to the soil; the irrigation is the amount of water that the controller will bring, depending on the initial moisture and limits; the crop evapotranspiration depends on climatic conditions such as wind, solar radiation, average temperature and relative soil moisture to obtain the reference evapotranspiration and, finally, the crop coefficient depends on the stage of development of alfalfa.  
The proposed smart irrigation determines the upper limit or maximum moisture limit, which is the lamina at field capacity \((L_{Cc})\) with Equation (2) and the minimum limit of water content at a suitable threshold (\(Pw\)). In this way, the plant does not suffer water stress and does not reach below the point of permanent wilting lamina \((L_{Pmp})\). These limits depend on the depth of the root until the first cut, then the root maintains its depth, keeping these limits constant. \(R\) is the irrigation required when the initial moisture is less than or equal to \(Pw\).  
Table 6 shows the irrigation schedule applied to the proposed smart irrigation during the first 10 days in the intermediate stage of the crop. From day 31 to day 38 there is no precipitation \((P)\), therefore the system generates irrigation \((R)\).  
The maximum irrigation input is 7.49 mm since a maximum irrigation time of 4 h per day is considered.