Evaluation of Three Soil Measurements, Impacts of Four Seedbed Surfaces and Corressponding Impacts On Germination Rates and Plant Growth of a Specific Corn Variety.

Soil moisture and soil temperature conditions in the seedbed zone (top 5 cm) can encourage or delay seed germination and plant emergence.  Surface residue cover can affect soil temperature by insulating the soil surface and impeding soil drying, while a crust layer can delay or prevent seedling emergence. Therefore, the objective of this study was to evaluate soil moisture, soil temperature, and soil density and their effects on four seedbed surfaces and corresponding impacts on germination rates and plant growth to the 7^th leaf stage of selected corn variety.  A randomized block design consisting of 4 treatments and 4 replications was used and included 1) flat surface (FLT), 2) crusted surface (CRU), 3) ridge surface (RDG), and 4) residue surface (RES). Measurements collected were soil moisture, soil temperature and soil density at 1.3, 5.0, and 15 cm depths.  Other parameters which were recorded include above ground biomass, root biomass, leaf number and leaf length. Data were analyzed using Excel spread sheet.

Results indicated that soil temperatures varied from 18 to 28, 20 to 27, 20 to 26, and 22 to 27 ^OC for FLT, CRU, RES, and RDG treatments, respectively. Soil moisture (%) varied from 0.4 to 7.2 for FLT, 0.3 to 6.8 for CRU, 0.8 to 7.7 for RES, and 0.3 to 6.3 for RDG treatments with higher percentages being recorded at the 15 cm depth.  At the 1.3 and 5 cm depths, densities were 0 kPa, however,  at the 15 cm depth, soil density varied from 1.3 to 34 kPa for all treatments, except CRU, which ranged from 26 to 52 kPa. Germination rates were determined one week after planting. Results showed that germination percentages were 51, 30, 19, and 57 % for FLT, CRU, RES, and RDG, respectively.

An analysis of average values per treatment using dry weights above ground biomass data indicated that FLT was significantly higher than the other treatments and the roots data indicated the RDG was significantly lower as compared to the CRU treatment with the highest weight, though not statistically higher than the mean (alpha = 0.05). Mean dry weights for root biomass were 0.18, 0.16, 0.17, and 0.14 kg for CRU, RES, FLT, and RDG, respectively. Mean dry weights for above ground biomass were 0.58, 0.67, 0.73, and 0.58, respectively for CRU, RES, FLT, and RDG treatments.