Analaysis of the available moisture storage data for 271 profile horizon samples from soils of northwestern, central, eastern, and southwestern Missouri show that for these dominantly silty soils available moisture storage capacity (A.W.C.) decreases with clay and increases with silt content. Coarse silt (0.05 to 0.02 mm.) increases A.W.C. more than fine silt (0.02 to 0.002 mm.). A.W.C. also increases generally with organic matter content but since organic matter increases with coarse silt and decreases with clay the effect can be attributed to textural changes. The siltrich surface is higher in organic matter and A.W.C. than the clay‐rich subsoil (particularly the clay pans). Only in a grouping of samples between 13 and 20% clay is there evidence that organic matter may improve storage, possibly by forming silt sized microaggregates in the clay. This effect is not apparent in soils dominated by fine textural components and relatively low in organic matter.

Tall fescue (Festuca arundinacea Schreb.) is grown primarily for forage on over 162,000 ha in Missouri. Fescue is managed for spring and summer pasture and for both seed and fall forage production. Spring and fall growth is often stockpiled for late fall and winter feed. This study was conducted to determine the effects of rate and time of N applications and forage management on seed yield, and on quality and yield of forage. Plots were layed out on established stands of tall fescue on Gerald, Lebanon and Edina silt loams (Umbric Fragiudalf, Typic Fragiudalf, fine mixed mesic; Typic Argialboll, fine montmorillonite, mesic, respectively.) Nitrogen rates on Gerald and Lebanon soils (Southwest Missouri) were 0, 33, 67, 101, and 134 kg/ha in different time combinations, including December, March, June, and August. Forage management included: (a) removal after seed harvest and again in December, (b) stockpile after seed harvest, harvest in December. Nitrogen rates on Edina silt loam (North Missouri) were 0, 67, and 134 kg/ha in different time combinations, including December, March, July, and August. In addition to the two management systems listed above, forage was round baled at the early head stage and harvested again in December. Effects of treatments were evaluated by seed yield and yield, crude protein, and IVDMD of the forage. Nitrogen for seed production was more efficient when applied in December, while March was a better time to apply N for forage production. One‐hundred‐one kg/ha was the optimum rate for both purposes. Severe lodging was caused by 134 kg/ha N at both locations. Failure to remove plant residue after seed harvest reduced seed yields the following year from 42 to 45%. These residues average 7.0% crude protein and 52% IVDMD. Forage round baled in the early head averaged 10.9% crude protein and 52% IVDMD. August was the best time to apply N for fall forage production and 101 kg/ha was the optimum rate.

The effects of rainfall and temperature on the yield and response of corn (Zea Mays L.) to plant population and nitrogen application rates were estimated from experimental data collected at three Missouri sites over an 8‐year period. The growing season from May through August was divided into 15‐day periods to test for the effect of rainfall and temperature on corn response to several nitrogen and planting rates. Preseason rainfall and total rainfall during the growing season also were included as variables. Both temperature and rainfall variables affected yield significantly with the first half of August being most significant with respect to rainfall and the second half of May with respect to temperature. The economic optimum inputs at the mean rainfall for the growing season were 41,850 plants/ha and 163 kg N/ha. The optimal input of nitrogen was relatively sensitive to the rainfall level with the optimal population level less affected.

Response of corn (Zea Mays L.) yield to nitrogen applications at various planting rates were determined for two soil types over a seven‐year period. Regression analysis was used to determine response surfaces, maximum and economic optimal treatments and yields. Response curves and production surfaces were constructed from the regression data. Significant differences in responses and optimal treatments were found from year to year and between sites. Optimal nitrogen treatments varied from 21.4 to 202.1 kg/ha and optimal planting rates from 12,189 to 54,135 plants/ha. A function from data aggregated over seven years indicated that the optimal rates would be 120 kg/ha of N and 37,787 plants/ha.