Effect of Soil Fertility on Comparative Yields and Nutritional Characteristics of Corn and Sorghum Cultivars

Abstract

A field experiment was conducted on plots with different soil fertility to compare yields and nutritional characteristics of KU Hybrid-8501 sorghum, KU-439 sorghum, KU Hybrid-2602 corn and Suwan-1 corn. Sorghum reached maximum grain yield at much lower soil fertility than corn and gave higher grain yields as well as being superior in sustaining fertility of low-fertility soils. At high fertility levels, corn gave much higher grain yields than sorghum which outran slight, if any, nutritional advantages of sorghum. There was no significant difference in grain yields of the two corn cultivars at all fertility levels though KU Hybrid-2602 gave higher stover yields than Suwan-1. KU-8501 sorghum gave higher grain and stover yields than KU-439 sorghum at low fertility levels. Differences in soil fertility depletion between cultivars of each kind of crop were found to be slight, if any. In views of grain yields and sustaining N, P and K status of soils, sorghum cropping was superior to corn cropping on low-fertility soils. On high-fertility soils, the reverse was observed. For medium-fertility soils corn and sorghum were comparable. At all fertility levels, the two corn cultivars were comparable. KU-8501 sorghum was superior to KU-439 sorghum at low soil fertility levels.