First year and residual effects of municipal solid waste (MSW) compost application on corn (Zea mays L.) grain yield were evaluated on a Verndale sandy loam (coarse-loamy, mixed, Udic Argiboroll) at Staples, MN, and on a Hubbard loamy sand (sandy, mixed, Udorthentic Haplaboroll) at Becker, MN. At both locations, compost 'A' was applied at 0, 20, 40, and 80 dry tons/acre in 1992, and two other composts, 'B' at Staples and 'C' at Becker, were applied at 40 tons/acre in the same year. The N fertilizer treatments were 0 or 220 lb N/acre applied each growing year. With the low C:N ratio mature composts 'B' and 'C', yield was equal to or greater than that of the nonamended control at 220 lb N/acre during the first growing season. Based on the difference between N uptake due to compost and N uptake in nonamended control, about 8% of the total compost N was available from the low C:N ratio composts 'B' and 'C' the first year while compost 'A', which had a high C:N ratio, reduced stand count and induced N immobilization at Staples. At Becker, there was no response in grain yield with compost 'A' without N fertilizer in the first year, however, there was a negative response in grain yield with compost 'A' when N fertilizer was applied. In residual years, grain yield with all composts was greater than or equal to that of the nonamended control without N fertilizer. Nitrogen availability from compost 2 to 3 yr after application ranged from 3 to 10% of the total compost N per year and depended on the rate of compost application. The first year, fall soil nitrate N concentrations were elevated with compost 'B' and 'C', especially with the addition of 220 lb N/acre. In subsequent years, fall soil nitrate N concentrations increased with compost in combination with N fertilizer.
ASJC Scopus subject areas
- Plant Science