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Maize Silage Utilization of Fertilizer and Soil Nitrogen on a Hill‐land Ultisol Relative to Tillage Method
Author(s) -
Staley Thomas E.,
Perry H. Douglas
Publication year - 1995
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1995.00021962008700050009x
Subject(s) - silage , loam , ultisol , agronomy , tillage , fertilizer , sowing , alfisol , crop , mathematics , conventional tillage , zoology , environmental science , biology , soil water , soil science
Few studies have compared N utilization by maize ( Zea mays L.) under conventional tillage (CT) and no‐tillage (NT) in the Appalachian region. Silage production (TDM) and fertilizer N and soil N uptake, were investigated in a 3‐yr study on a Gilpin silt loam (fine‐loamy, mixed, mesic Typic Hapludult) in West Virginia previously cropped to pasture. 15 N‐depleted N fertilizer was band‐applied, within‐row, at 0, 56, 112, and 224 kg N ha −1 , 4 wk after planting. Tillage method did not affect silage production, N concentration or total N uptake at any N rate. Maximal silage production under NT (13.2 Mg ha −1 ) was calculated to require just 24 kg ha −1 more fertilizer N than under CT (12.6 Mg ha −1 ). Fertilizer N uptake (kg ha −1 ) was similarly unaffected by tillage method, with annual fertilizer N use efficiencies (% recovery) of 55, 54, and 49% under NT, and 57, 57, and 48% under CT, at application rates of 56, 112, and 224 kg ha −1 , respectively. Similar percentages for cumulative fertilizer N use efficiencies, which account for any labeled N carried over from year to year, suggest that there was little residuum available to the crop, particularly at near‐optimal N rates. Soil N uptake decreased by 17% with N additions below (56 kg ha −1 ) or above (224 kg ha −1 ) the optimum, but was generally unaffected by tillage method. These similarities between NT and CT for maize silage production and N use, despite using a management system contrived to show differences, emphasize the importance of edaphic and climatological factors in predicting N responses under various tillage methods. Nonetheless, these results show that reasonably high levels of silage can be produced without excessive fertilizer N requirements ( ≈ 170 kg N ha −1 ) or losses (< 50%) when pastures are converted to NT maize.