• Findings from this growing year showed the capability of cover crops (CC) in weed suppression and in affecting soil health properties. While CC biomass production is crucial towards weed suppression, a mixture of CC is not necessary to produce more biomass than an individual species. • The production of CC biomass was affected by planting date (PD) and the duration of CC growth, thus growers can be advised on the timing of seeding CC into the main crop so that enough time is allowed for biomass production while minimizing competition between CC and the main crop. • Among the CC assessed in this trial, cereal rye/crimson clover, with a record of greater biomass, suppressed weeds the best when considering both the soybean growing period (especially PD-2) and planting them over the fall/winter fallow period (PD-1). In addition, soybean grain yield under the cereal rye/crimson clover was one of the highest demonstrating that the presence of this CC combination treatment does not necessarily out compete grain yields. • It was also observed that the type of CC utilized for interseeding into main crops may affect crop grain yields positvely (cereal rye/crimson clover in this trial) or negatively (wheat in this tiral). • Soil health properties in this trial were significantly affected by the diversity of CC. Notable amongst them included significantly higher amount of a number of macronutrients under the Wheat/Turnip combination treatment while soils with no CC recorded significantly lower measure of a number of soil health properties. • Although there were no significant differences in the PDs for all soil health traits, there was a pattern observed for the following soil health properties where their measured quantities were substantially higher in the PD-1 subplots compared to the other PDs: phosphorous, Bray II P, potassium, organic carbon, and carbon dioxide. This could be indicative of the soil health effect of the CC planted in the fall (PD-1) and terminated in the spring, before soybean planting. The CC biomass production is considered as an attribute in determining how much carbon is sequestered and contributes to increased soil organic concentration. It is expected that as the study continues for the next growing seasons, any consistent effect of the planting dates on the soil health will be detected.

Results of this year showed that turnip and cereal rye/crimson clover cover crops (CC) immensely suppressed weed biomass which corresponded with a higher soybean biomass and soybean grain yield under these two cover crop treatments. On the other hand, the weed dry biomass weight under cereal rye/hairy vetch and wheat was significantly higher than in any other CC-treatments which related with a significantly lower soybean biomass and soybean grain yield. Therefore, US soybean farmers will benefit from growing turnip and cereal rye/crimson clover cover crops for higher soybean yields. Production of cover crop (CC) biomass was affected by planting date and the duration of CC growth. Planting cover crops in October and terminating them a couple of weeks prior to soybean planting in the following year will produce much higher biomass of cover crops than planting cover crops at soybean planting or after soybean planting at V4. Greater biomass of CC will increase the capability of CC in weed suppression and in improving soil health properties. So US soybean farmers will benefit from growing CC in October and terminating it a couple of weeks prior to soybean planting in the following year for weed depression and soil health improvements.