The productivity of Dickson, Waynesboro and Huntington soils for corn at selected levels of nitrogen and plant population

The need for more information about the yield of various crops under defined levels of management inputs has been recognized for several years. If this information were available for all soils, the probability of making better decisions involving the use of farm land, labor and capital would be greatly enhanced. To obtain the yields of various crops under defined levels of management for all soils would be an impractical task at this time. Therefore, some representative soil types with high, average and low productive capacities in respect to a given crop have been selected for study. An intensive study of these representative soil types will help in predicting responses from different levels of inputs on these soil types and others with similar characteristics. This study and preliminary studies by Graves (1958-59) and Peace (1960) were conducted on Huntington, Waynesboro and Dickson soils in Putnam County, Tennessee. The 1958 study of the productivity of these soils showed that they have different productive capacities for corn at low to moderate levels of management and do not respond alike to given inputs, thus requiring different management practices for optimum corn production. Research in 1960 showed that the productive capacities of these soils were brought closer together under high levels of management, fertility and adequate moisture. The response to added fertilizer increased as the level of fertility decreased. The objectives of the 1961 study were: (1) to determine the productive capacity of these soils for corn at selected levels of nitrogen and plant population; (2) to determine the residual effects of fertilizer applied in I960 on these soils when no additional fertilizer was applied in 1961; and (3) to determine the effects of fertilizer applied in I960 on these soils when an additional one thousand pounds per acre of 10-20-20 fertilizer was broadcast prior to planting in 1961.