Research Article

Nitrogen Availability and Uptake by Sugarbeet in Years Following a Manure Application

Table 6

Treatment and contrast class mean values for soil (0–30 cm) inorganic N concentrations in spring (before and after planting), cumulative net N mineralization, and cumulative available N during the growing season.

TreatmentSoil N 15 Mar.Soil N 25 Apr.Cum. net N mineralized 25 Apr.–27 Sept.Cum. available N 15 Mar.–27 Sept.
mg kg−1

No manure
 NE-Fert8.3b39.0a18.0bc57.0bc
 Control10.9b12.6b14.6c27.1d
 Fert8.9b33.6a19.6bc62.8bc
Manure-1x
 m1-y113.5b31.8a32.8ab64.6b
 m1-y210.0b17.9b23.7bc41.6c
 m1-y38.3b14.1b22.5bc36.7cd
Manure-3x
 m3-y124.1a45.9a41.4a87.3a
 m3-y212.7b27.8ab28.5bc56.3bc
 m3-y313.7b28.7ab29.1b57.8bc

Treatment classes for contrasts

No manure9.428.417.1b49.0b
Manure13.727.729.7a57.4a

Manure-1x10.621.3b26.3b47.6b
Manure-3x16.834.1a32.9a67.1a

Manure y118.838.9a37.1a76.0a
Manure y2 & y311.222.1b26.0b48.1b

Year 2 & 3: m19.2b16.0b23.1b39.2b
Year 2 & 3: m313.2a28.3a28.8a57.1a

NE-Fert: noneroded fertilizer (all other treatments on eroded soil); m1: manure-1x; m3: manure-3x; y1, y2, y3: fall manure applied 1, 2, and 3 years in the past, respectively; manure: m1 + m3; No manure: NEFert + Control + Fert.
For a given yield or quality parameter, treatment means or means for individual orthogonal contrasts followed by the same lower case letter are not significantly different ( ). Not displayed if effect was not significant in the ANOVA.