Randomized block design

Figure 4 Randomized block design using four replications having 20 sub-plots each...

Specific exposure concentrations for effluent dilution are often evenly spaced in a linear or geometric series (e.g., 100%, 50%, 25%, 12.5%, and 6.25% effluent). Replicate exposures are required, with test vessels arranged in the incubator in a randomized block design. At the end of the test, statistical calculations of NOECs for survival and reproduction or growth are typically performed as a multiple comparison procedure of effluent-treated groups. The induced effects of effluent pollutants on growth or reproduction and on survival may or may not be equal, suggesting information on the relative... 

Environmental gradients do exist in a laboratory or a field situation. A random block design to take into account such gradients should be used. 

The experimental design for all experiments conducted on the soils was a randomized block design with three replicates. Separate analyses of variance were performed at each sampling time. Mean separations were determined using the Least Significant Difference... 

A randomized block design should be the standard in this case, ensuring that adequate washout times are allowed between treatments. 

Until the early 1990s, nearly all products were laid out in what is now referred to as the conventional layout. In this layout, which is still used for most products, individual test plots (ground boards and concrete slabs) are separated in a grid on 1.5-m centers. Each of ten replications contains a mixture of rates, products, test methods and control plots arranged in a randomized block design (Figure 4). Replications are laid out in two tiers of five replications per tier. The conventional layout utilizes about 0.08 ha. 

At 1-3 day intervals throughout the early growth of the B. napus crop and at ca. 2 week intervals in the mays crop, individual plants, selected by randomized block design, were removed and immediately transferred to the laboratory for determination of 0. Photosynthetic CO2 uptake was measured for attached leaves enclosed in a controlled environment cuvette incorporated into an open gas exchange... 

---