# Environment- and Genotype-Dependent Irrigation Effect on Soybean Grain Yield and Grain Quality
## 3 Results
### Grain Oil Content and Crude Oil Yield  
The irrigation effect on the grain oil content was significant (\(p\) < 0.01), but it was not affected by the growing season (A), genotype (C) or growing season x genotype (Table 5). On average, the irrigation negatively affected oil accumulation, but the differences between the grain oil contents in the different treatments per year (AB) were not significant (Table 5). On the other hand, the crude oil yield significantly decreased in A1B2 compared with A1B1 (4%) and in A2B3 compared with A2B1 (6.5%), but it significantly increased in A3B2 (28.2%) and A3B3 (43%) compared to A3B1 and in A4B2 (31.3%) and A3B3 (38.8%) compared to A4B1. B3 was significantly higher compared to B2 for the crude oil content in the A2, A3 and A4 growing seasons (Table 6).  
The irrigation effect on the grain oil yield varied among the genotypes, but the differences were not considered significant. Nevertheless, the crude oil yield was significantly higher in B2 and B3 compared with B1 for all of the genotypes, and significant differences  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Growing Season (A)**} & \multicolumn{6}{c}{**Crude Protein Yield (kg ha\({}^{-1}\))**} \\ \cline{2-9}  & \multicolumn{3}{c}{**Irrigation (B)**} & \multirow{2}{*}{**Mean A**} & \multicolumn{3}{c}{**Soybean Genotype (C)**} \\ \cline{2-9}  & **B1** & & & **B2** & **B3** & **C1** & **C2** & **C3** & **C4** \\ \hline A1 & 1386.8 & 1396.2 & 1395.9 & 1392.9 & 1427.6 & 1384.9 & 1401.5 & 1357.9 \\ A2 & 1489.4 & 1627.7 & 1553.1 & 1556.8 & 1298.2 & 1671.2 & 1639.1 & 1618.5 \\ A3 & 1072.5 & 1343.0 & 1490.6 & 1302.1 & 1228.7 & 1332.3 & 1319.5 & 1327.7 \\ A4 & 1109.1 & 1497.2 & 1587.9 & 1398.1 & 1330.7 & 1351.9 & 1455.6 & 1454.0 \\ \hline Mean B & 1264.5 & 1466.0 & 1506.9 & Mean C & 1321.3 & 1435.1 & 1453.9 & 1439.5 \\ \hline  & & & & B1 & 1078.6 & 1252.9 & 1374.0 & 1352.4 \\  & & & & B2 & 1378.8 & 1543.7 & 1475.0 & 1466.6 \\  & & & & B3 & 1506.6 & 1508.7 & 1512.7 & 1499.6 \\ \hline LSD & A & B & C & AB & AC & BC & ABC \\
5\% & 24.97 & 21.63 & 24.97 & 43.26 & 49.95 & 43.26 & 86.51 \\
1\% & 33.06 & 28.63 & 33.06 & 57.26 & 66.11 & 57.26 & 114.51 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Impacts of the environmental conditions in the four growing seasons (A1–A4), three treatments (B1, rain-fed conditions; B2, 60% of the field water capacity, or FWC; B3, 80–100% of the FWC), four genotypes (C1–C4) and their interactions (AB, AC, BC and ABC) on soybean crude protein yield (kg ha\({}^{-1}\)).  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Growing Season (A)**} & \multicolumn{6}{c}{**Grain Protein Content (\% DM)**} \\ \cline{2-9}  & \multicolumn{3}{c}{**Irrigation (B)**} & \multirow{2}{*}{**Mean A**} & \multicolumn{6}{c}{**Soybean Genotype (C)**} \\ \cline{2-9}  & **B1** & & & **B2** & **B3** & **C1** & **C2** & **C3** & **C4** \\ \hline A1 & 40.09 & 40.82 & 40.48 & 40.47 & 40.58 & 40.62 & 40.33 & 40.33 \\ A2 & 36.70 & 38.58 & 39.28 & 38.19 & 37.47 & 38.39 & 38.68 & 38.21 \\ A3 & 35.76 & 35.05 & 3  
were found between B2 and B3 for all of the genotypes except for C4 (Table 6). The highest crude oil yield increase was determined for C1, 22.8% for C1B2 and 32% for C1B3 compared with C1B1. C2 had a 19.5% higher crude oil yield in C2B2 and a 14.6% higher crude oil yield in C2B3 compared to C2B1. The crude oil yield increase was less for C3 and C4 (Table 6).