Nutrient absorption and yield of corn and soybeans planted in three row arrangements

The effect of different row arrangements on nutrient absorption and yield of corn and soybeans was investigated in 1972 on a Sequatchie loam soil at the Plant Science Farm, Knoxville, Tennessee. Above ground plant samples taken at different times during the growing season were analyzed for their concentrations of nitrogen, phosphorus, potassium, calcium and magnesium. Generally the nutrient percentages in the above ground corn plants were high early in the season and decreased as the season progressed except for phosphorus which decreased until 77 days after planting, and then increased to day 110. After that time there was a decrease in percent phosphorus to the last sampling date. The nutrient percentages for all row arrangements followed the same pattern and generally no consistant trends were noted, except for the period from the tasseling to the ear filling stage of growth in the 12-24 inch row arrangement. The 12-24 inch row arrangement resulted in a higher percent of nitrogen, phosphorus, potassium, calcium, and magnesium during the tasseling and ear filling stage of growth. Nitrogen, phosphorus, potassium, calcium and magnesium accumulation in pounds per acre increased up to 110 days after planting and then decreased. In soybeans, nitrogen, phosphorus, potassium, calcium, and magnesium percentages were high in the early stages of growth. Percent of nitrogen and phosphorus generally decreased for the first 73 to 81 days after planting and then increased slightly. The percent potassium decreased throughout the season, and calcium and magnesium decreased for the first 73 days after planting and then leveled off. The amount of nitrogen, phosphorus, potassium, calcium and magnesium accumulated in the above ground soybean plant throughout the season. The different row arrangements in corn produced significantly different yields. The 12-24 inch rows had the highest yields with the 12 inch rows next highest and the 36 inch rows the lowest. Irregular soybean plant distribution and a large percent of lodging occurred in the 12 inch and the 12-24 inch row arrangement. This reduced the yield in these treatments and may have accounted for there being no significant differences in yield among the row arrangements in soybeans.