Influence of fertilizer, fertilizer placement, soil moisture content, and soil type on the emergence of soybeans

Studies are reported on the influence of kind and rate of application of fertilizers, fertilizer placement, soil moisture content, and soil type on the emergence of soybeans. Three analyses of fertilizers applied at six different rates, two methods of placement, two soil moisture levels, and two soil types were used in these studies during the 3-year period of 1939-41, inclusive. Field studies were made on Brookston silty clay loam, and greenhouse studies on Clermont silt loam and Brookston soil. The Dunfield variety of soybeans was used. Fertilizers applied to soybeans under the conditions of these usually inhibited emergence to some extent but not always significantly, irrespective of kind or amount of fertilizer used, placement, soil type, or moisture content of the soil. In general, emergence was inhibited in proportion to the rate of application and kind of fertilizer used when applied in contact with the seed. Applications as large as 375 pounds per acre of 0-20-0 or 0-0-20 or of 125 pounds per acre of 0-20-20 did not significantly reduce emergence in these experiments when applied in contact with the seed on Brookston soil with a high moisture level at the time of planting in either the field or greenhouse. With a low soil moisture content at time of planting, 125 pounds per acre of 0-20-0 or 0-0-20 fertilizer in contact with the seed did not significantly reduce emergence. When applied in bands to the side of and on the same level as the seed, heavy applications of fertilizer, 500 and 750 pounds per acre of 0-20-0, 0-0-20, or 0-20-20, did not significantly reduce emergence compared with unfertilized plots. Fewer plants emerged at the low soil moisture content than at the high soil moisture content when the fertilizer was applied in contact with the seed. In the absence of fertilizer, or when the fertilizer was applied in bands, the difference in emergence due to soil moisture content was not so pronounced except under field conditions. The type of soil used did not appear to have a definite influence on soybean emergence, either in the presence or absence of fertilizers. Soybeans emerged more rapidly in the absence of fertilizer or in the presence of fertilizer applied in bands than when the fertilizer was applied in contact with the seed. Phosphate fertilizer delayed emergence less and reduced final mergence less than potash, in combination these fertilizers gave cumulative deleterious effects on emergence and rapidity of emergence when applied in contact with the seed.