A. Fiegenbaum et al., NITROGEN ACCUMULATION AND NITROGEN RESIDU ES OF FIELD BEANS (VICIA-FABA L) .2. DEVELOPMENT OF THE N-MIN-CONTENT OF THE SOIL AFTER FIELD BEANS, Die Bodenkultur, 45(4), 1994, pp. 319-331
The objective of the investigations was the development of the N-min-c
ontent of the soil after field beans, returning between 70 and 170 kg
N/ha by vegetative residues. Field experiments were conducted in 1990
at one location (Ihinger Hof) and in 1991 at two locations (Ihinger Ho
f, Oberer Lindenhof). Factorial variation included with/without residu
es and with/without soil preparation after harvest. Commencing at the
harvest date at 6 to 8 dates until April/May soil samples (0 to 90 cm)
were taken to analyze the N-min-content. Additionally after harvest s
mall lysimeters containing the 0 to 30 cm soil layer were put in espec
ially choosen plots of the Ihinger Hof - 1991 experiment. Continuously
the percolated water amounts were collected to analyze the NO3-N-cont
ent. Furthermore groups of soil columns (empty set 5 cm) of the 0 to 3
0 cm soil layer were taken and incubated for 16 weeks at 20 degrees C
and 35 degrees C, respectively. At five consecutive dates during this
period the NO3-N-content was analyzed. During autumn in all field expe
riments N-min-contents (0 to 90 cm) increased. Interactions between ye
ars and soil preparation after field bean harvest determined the furth
er development of the N-min-content. In contrary to results of the per
iod investigated in 1990/91, soil preparation seemed to decrease N-min
-levels of field plots and especially of incubated soil columns in 199
1/92. Nevertheless N-min-levels between 30 and 60 kg N/ha and the resu
lts of the lysimeters indicated available NO3-N-amounts and NO3-N-tran
slocation during the investigated period.