Final answer:
Bare ground in a test plot between maize and grass can serve to prevent resource competition, reduce disease and pest risk, and act as a buffer for easier farm management and soil conservation.
Step-by-step explanation:
Leaving bare ground between maize and grass species in a test plot can be explained by several agricultural and ecological principles. The practice of leaving bare soil can be part of a strategy to prevent competition for resources such as water, sunlight, and nutrients, ensuring that the maize and grass do not interfere with each other's growth. This can also reduce the risk of disease transmission and pest infestations that might move readily between closely planted crops.
Additionally, the bare ground could be intended to act as a buffer zone to minimize cross-contamination or to facilitate easier access for farming operations. It can also contribute to soil conservation practices. For instance, leaving the ground bare might be a form of fallowing that allows the soil to recover between plantings, or it might be part of a larger rotational farming system that manages soil fertility and crop productivity.
The case of overgrazing leading to bare and devastated land, as seen in satellite photos of Africa in the 1970s, illustrates the importance of careful land and resource management, which applies similarly to the organization of crops and grasses in the test plot.