# Maize Replacement for Controlling Invasive _Eupatorium adenophorum_
## 3 Results and Discussion
### Implications for Agriculture
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Code** & \(\mathbf{M_{stem}}\) **(g)** & \(\mathbf{M_{core}}\) **(g)** & \(\mathbf{M_{grain}}\) **(g)** & **TSM (g)** & \(\mathbf{M_{resh}}\) **(g)** & **Yields (kg/hm\({}^{2}\))** & **Income (yuan/hm\({}^{2}\))** \\ \hline CK & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ CS & 0 & 0 & 0 & 0 & 0 & 0 \\ M1 & \(740.42\pm 80.32\) a & \(65.75\pm 6.88\) a & \(129.16\pm 14.69\) a & \(281.45\pm 30.21\) a & \(3771.64\pm 386.65\) c & \(7271.85\pm 757.11\) c & \(145.873.76\) c \\ M3 & \(732.11\pm 77.68\) a & \(62.84\pm 5.52\) a & \(126.05\pm 14.35\) a & \(283.26\pm 29.98\) a & \(5526.00\pm 498.33\) b & \(8874.12\pm 911.82\) b & \(1774.824\) b \\ M4 & \(728.0073.61\) a & \(60.34\pm 5.39\) a & \(125.23\pm 15.28\) a & \(278.72\pm 29.61\) a & \(7308.56\pm 559.27\) a & \(10,136.75\pm 1173.87\) a & \(20,273.50\) a \\ \hline \hline \end{tabular} Note: Different letters in the same column indicate significant difference (\(p<0.05\)).  
\end{table} 
Table 7: The parameters, yield and economic benefit of maize in 2017. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Code** & \(\mathbf{M_{stem}}\) **(g)** & \(\mathbf{M_{core}}\) **(g)** & \(\mathbf{M_{grain}}\) **(g)** & **TSM (g)** & \(\mathbf{M_{resh}}\) **(g)** & **Yields (kg/hm\({}^{2}\))** & **Income (yuan/hm\({}^{2}\))** \\ \hline CK & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ CS & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ M1 & \(740.42\pm 80.32\) a & \(65.75\pm 6.88\) a & \(129.16\pm 14.69\) a & \(281.45\pm 30.21\) a & \(3771.64\pm 386.65\) c & \(7271.85\pm 757.11\) c & \(145.873.76\) c \\ M3 & \(732.11\pm 77.68\) a & \(62.84\pm 5.52\) a & \(126.05\pm 14.35\) a & \(283.26\pm 29.98\) a & \(5526.00\pm 498.33\) b & \(8874.12\pm 911.82\) b & \(1774.824\) b \\ M4 & \(728.0073.61\) a & \(60.34\pm 5.39\) a & \(125.23\pm 15.28\) a & \(278.72\pm 29.61\) a & \(7308.56\pm 559.27\) a & \(10,136.75\pm 1173.87\) a & \(20,273.50\) a \\ \hline \hline \end{tabular} Note: Different letters in the same column indicate significant difference (\(p<0.05\)).  
\end{table} 
Table 8: The parameters, yield and economic benefit of maize in 2018.  
assisted in effectively occupying the niche. Based on the rule of positive succession, replacement control strategy, using plants to replace weeds, could enhance ecological and economic value. The area formerly occupied by the weeds then recovered to form a healthy ecological system with an appropriate structure, function and self-sustaining ability [27; 39]. It is important to select suitable substitute plants in this process. Maize is the most popular grain crop in China because it is drought resistant and simple to grow. Liangshan Prefecture of Sichuan has an arid, hot climate with a rainy season from June to September and a dry season from November to April (Figure 2b). The climate is suitable for the cultivation of maize, and the method of maize replacement for controlling _E. adenophorum_ has sustainability. _E. adenophorum_ seeds are fully mature in mid-April and then disperse via wind, water and traffic to land on soil surfaces. The niche overlap between _E. adenophorum_ and maize could lead to effective inhibition of weed seed germination and vegetative growth. Maize replacement could reduce the resource consumption of _E. adenophorum_ to a negligible level (Tables 5 and 6). In addition, maize replacement increased income by 20,273.50 and 23,633.22 yuan/hm\({}^{2}\) simply by selling corn in 2017 and 2018, and rational close planting could generate greater economic benefit. In addition, the maize stalk and corncob core could also be used as silage. In this study, the weight of fresh straw in 2017 and 2018 (Tables 7 and 8) were 37.72-73.09 ton/hm\({}^{2}\) (3771.64-7308.56 g/m\({}^{2}\)) and 40.63-77.66 ton/hm\({}^{2}\) (4063.58-7766.97 g/m\({}^{2}\)), respectively. If the price was 100 yuan/ton, maize silage could produce income of 3772-7309 yuan/hm\({}^{2}\) and 4064-7767 yuan/hm\({}^{2}\), respectively. Therefore, replacement planting could achieve an ecological weed control effect, and it also increased farmers' income.