Answer: The Reconstruction Era lasted from the end of the Civil War in 1865 to 1877. Its main focus was on bringing the southern states back into full political participation in the Union, guaranteeing rights to former slaves and defining new relationships between African Americans and whites and nation:
<span>Producers must consider the advantage and disadvantages of a tillage system before changing systems. The most important advantage of conservation tillage systems is significantly less soil erosion due to wind and water. Other advantages include reduced fuel and labor requirements. However, increased reliance may be placed on herbicides with some conservation tillage systems. The herbicide labels do not change the recommended rates based on tillage system, but tillage may not be an option for weed control in some tillage systems.</span>
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Answer:To Prevent Bias which may arise from a major difference from personal characteristics.
Explanation: Sampling is a part of a population that is to be used for a research or experiment.
Variables are factors or members of a sample or Population that are can be altered (Dependent variables) in order to create an effect on another variables.
Independent variables are variables that are consistent and are not affected by other variables.
To Prevent BIAS,proper Sampling or inducing independent variables it must include all the factors necessary in an experiment or research.