## 2 Materials and Methods
### Life Cycle Inventory and Analysis
The  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multicolumn{3}{c}{**Input**} & \multicolumn{3}{c}{**Output**} \\ \hline \multirow{2}{*}{**Process**} & \multicolumn{2}{c}{**Amount**} & \multirow{2}{*}{**Process**} & \multirow{2}{*}{**Emissions (kg)**} & \multirow{2}{*}{**Laser**} & \multirow{2}{*}{**Control**} \\ \cline{2-2} \cline{6-6}  & **Laser** & & & & \\ \hline \multirow{2}{*}{Electricity (kWh)} & \multirow{2}{*}{0.002} & \multirow{2}{*}{/} & **Laser** & CO\({}_{2}\) & \(1.22\times 10^{-4}\) & / \\  & & & **Lraser** & CH\({}_{4}\) & \(5.54\times 10^{-9}\) & / \\  & & & & N\({}_{2}\)O & \(1.76\times 10^{-8}\) & / \\ \hline \multirow{2}{*}{**Maize seeds (kg)**} & \multirow{2}{*}{2.42} & \multirow{2}{*}{2.71} & \multirow{2}{*}{**Field**} & CO\({}_{2}\) & \(1.80\times 10^{1}\) & \(2.01\times 10^{1}\) \\  & & & & N\({}_{2}\)O & \(1.19\times 10^{-5}\) & \(1.33\times 10^{-5}\) \\  & & & & CH\({}_{4}\) & \(1.14\times 10^{-5}\) & \(1.27\times 10^{-5}\) \\  & & & & NOx & \(1.46\times 10^{-2}\) & \(1.63\times 10^{-2}\) \\  & & & & SO\({}_{2}\) & \(2.63\times 10^{-2}\) & \(2.94\times 10^{-2}\) \\ \hline \multirow{2}{*}{**Irrigation (m3)**} & \multirow{2}{*}{19.68} & \multirow{2}{*}{17.58} & \multirow{2}{*}{} & NH\({}_{3}\)-N & \(1.30\times 10^{1}\) & \(1.45\times 10^{1}\) \\  & & & & N\({}_{2}\)O & \(2.78\) & \(3.11\) \\  & & & & NOx & \(1.13\times 10^{-1}\) & \(1.26\times 10^{-1}\) \\  & & & & CO\({}_{2}\) & \(2.18\times 10^{-1}\) & \(2.44\times 10^{-1}\) \\  & & & & PO\({}_{4}\) & \(6.71\times 10^{-3}\) & \(7.51\times 10^{-3}\) \\
**Pesticides/Diazinon** & \multirow{2}{*}{0.85} & \multirow{2}{*}{0.95} & \multirow{2}{*}{**Cultivation**} & SO\({}_{2}\) & \(1.57\times 10^{-2}\) & \(1.76\times 10^{-2}\) \\  & & & & **Process** & CH\({}_{4}\) & \(2.40\) & \(2.68\) \\  & & & & & Cd & \(1.34\times 10^{-3}\) & \(1.50\times 10^{-3}\) \\  & & & & & Cu & \(4.12\times 10^{-3}\) & \(4.61\times 10^{-3}\) \\  & & & & & Zn & \(3.50\times 10^{-2}\) & \(3.91\times 10^{-2}\) \\  & & & & & Pb & \(6.14\times 10^{-3}\) & \(6.87\times 10^{-3}\) \\
**Electricity/irrigation** & \multirow{2}{*}{12.85} & \multirow{2}{*}{14.37} & \multirow{2}{*}{} & Ni & \(3.64\times 10^{-3}\) & \(4.07\times 10^{-3}\) \\  & & & & & Cr & \(1.80\times 10^{-2}\) & \(2.02\times 10^{-2}\) \\ \hline \multirow{2}{*}{**Harvest machine/fuel**} & \multirow{2}{*}{2.71} & \multirow{2}{*}{2.71} & \multirow{2}{*}{**Harvesting**} & CO\({}_{2}\) & \(7.40\) & \(7.40\) \\  & & & & N\({}_{2}\)O & \(4.91\times 10^{-6}\) & \(4.91\times 10^{-6}\) \\  & & & & CH\({}_{4}\) & \(4.69\times 10^{-6}\) & \(4.69\times 10^{-6}\) \\  & & & & NOx & \(6.02\times 10^{-3}\) & \(6.02\times 10^{-3}\) \\  & & & & SO\({}_{2}\) & \(1.08\times 10^{-2}\)following equations were used to calculate the fertilizer-induced discharges of nitrous oxide (N\({}_{2}\)O), ammonia (NH\({}_{3}\)), nitrate (NO\({}^{3-}\)), carbon dioxide (CO\({}_{2}\)), and phosphorus (P):  
Nitrous oxide (N\({}_{2}\)O) emission:  
\[\text{N}_{2}\text{O}=\left(\text{Fsn}+\text{Fcn}+\text{Fcor}+\text{Fsom} \right)\times\text{EF1}\times\frac{44}{28} \tag{1}\]  
Nitrate (NO\({}_{3}\)) emission:  
\[\text{NO}_{3}=\left(\text{Fsn}+\text{Fcn}+\text{Fscm}\right)\times\text{FLEACH} -\left(\text{h}\right)\times\frac{62}{14} \tag{2}\]  
Ammonia (NH\({}_{3}\)) emission:  
\[\text{NH}_{3}=\left(\text{Fsn}+\text{FracGASF}\right)\times\frac{17}{14} \tag{3}\]  
where,  
FSN = the quantity of applied chemical fertilizer, N, to the soil (kg N). FON = the quantity of N in the applied manure to the soil (kg N). FCR = the amount of N in the crop residues (above-ground and below-ground) (kg N). FSOM = the amount of N in the mineral soils that are mineralized (kg N). EF1 = the emission factor for N\({}_{2}\)O emissions from N inputs:  
\[\left(\frac{\text{kg N}_{2}\text{O}-\text{N}}{\text{kg N}_{\text{INPUT}}}\right) \tag{4}\]  
FLEACH-(H) = fraction of all added N lost to leaching. \[\left(\frac{\text{kg N}}{\text{kg of N additions}}\right)\]  
FracGASF = fraction of the fertilizer N that volatilizes as NH\({}_{3}\) and NOx.