Author
![]() |
CLARK, J - University Of Minnesota |
![]() |
Veum, Kristen |
![]() |
FERNANDEZ, F - University Of Minnesota |
![]() |
CAMBERATO, J - Purdue University |
![]() |
CARTER, P - Dupont Pioneer Hi-Bred |
![]() |
FERGUSON, R - University Of Nebraska |
![]() |
FRANZEN, D - North Dakota State University |
![]() |
Kitchen, Newell |
![]() |
LABOSKI, C.A.M. - University Of Wisconsin |
![]() |
NAFZIGER, E - University Of Illinois |
![]() |
SAWYER, J - Iowa State University |
![]() |
SHANAHAN, J - Dupont Pioneer Hi-Bred |
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 8/30/2016 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Correctly estimating the amount of mineralizable nitrogen (N) can enhance nitrogen use efficiency. The anaerobic potentially mineralizable nitrogen (PMNAn) test is a tool that may help improve predictions of N uptake, grain yield, and the economical optimum nitrogen rate (EONR) of corn (Zea mays L.). A 30 site-year study across eight US Midwestern states was conducted to quantify PMNAn across various soils and regions and to determine the influence of soil sampling timing, N fertilizer, and laboratory incubation lengths (7, 14, and 28 days) on improving the PMNAn correlation with N uptake, grain yield, and EONR. Soil was sampled from 0-30 cm before planting and N fertilizer application (PPNT) or at the V5 leaf stage where 0 (V50) or 179 kg-N/ha (V5-179) were applied at planting. Overall, PMNAn ranged from 0.19 to 136 mg/kg with a mean of 36 mg/kg. Mean PMNAn for coarse, medium and fine textured soils were 22, 34, and 45 mg/kg, respectively. This indicates greater potential for mineralization with finer textured soils, which in general had greater organic matter content. There was no consistent pattern in PMNAn with time of sampling. The PMNAn was larger in ten site-years at PPNT and nine site-years at V50, with no difference in the other eleven site-years. There was also no consistent pattern in response to the addition of N fertilizer. The V5-179 PMNAn was lower than the V50 in ten site-years, greater in one site-year, and no different in 19 site-years. All sites increased in PMNAn as laboratory incubation length increased. Preliminary results for the PPNT 7 day incubation indicate that for each 1 mg/kg increase in PMNAn the EONR was reduced 1 kg-N/ha. Additional results of the correlations between PMNAn and N uptake, grain yield, and EONR will also be discussed. |