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|Title:||Effect of Liquid Manure on Corn and Soybean Growth, Nitrogen Uptake, and Yields|
|Author(s):||Schmitt, Michael Allan|
|Department / Program:||Agronomy|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||The injection of liquid manure into soils, at rates that should provide sufficient quantities of nitrogen (N), phosphorus (P), and potassium (K) for corn, has resulted in uneven growth and reduced grain yields. Field studies were conducted at Pearl City, Illinois, in 1983 and 1984 to evaluate the effects of manure rate, nitrification inhibitors, methods of manure application, and supplemental inorganic N on corn and soybean growth, N uptake, and yield.
Liquid manure (6% solids) was applied at rates of 28050 and 42075 l/ha in 1983 and at 37400 l/ha in 1984. The nitrification inhibitors used were nitrapyrin, applied at a rate of 1.12 kg/ha as N-Serve 24E, and dicyandiamide, applied at a rate equal to 5% of the predicted available N in the manure. Supplemental N was applied at a rate of 179 kg/ha as NH(,4)NO(,3).
The manure application methods evaluated in this study were knife injection--resulting in a vertical band of manure, sweep injection--resulting in a horizontal band of manure, and broadcast applications with subsequent tillage to mix the manure into the soil. Corn was planted at 12.7-cm intervals from the manure zone to determine the influence of distance from the manure zone on N concentration in the plants. Soil samples were collected at 12.7-cm intervals from the manure zone and were analyzed for No(,3)('-)-N and NH(,4)('+)-N.
Supplemental N generally increased plant N concentrations early in the growing season but did not increase ear leaf N concentrations consistently. Yields were increased by supplemental N in 1983. The use of either nitrification inhibitor increased plant N concentrations consistently at all stages of growth and also increased yields, although the increases were not always significant. Manure rates did not affect any of the variables studied.
The lowest yields were usually associated with vertical injection of the manure. In 1984, the use of horizontal manure injection resulted in consistently higher yields than vertical injection. Broadcast application of manure resulted in the highest yield of any manure treatment. The control treatment, which did not receive manure but did receive supplemental N, had the highest N concentrations in the plant for most years and stages of growth. In 1984, the highest yields--which were 14.4 g/ha higher than yields obtained when manure was applied with injector knives--were from this treatment.
Increasing the distance between the corn plants and the manure zone resulted in lower plant N concentrations early in the growing season, but this effect dissipated with time. Soil inorganic N was concentrated generally near the manure when it was applied in a vertical zone, but was distributed in a horizontal pattern when applied in a horizontal zone.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1985.
|Date Available in IDEALS:||2014-12-16|