De. Clay et al., CARBON AND NITROGEN MINERALIZATION IN ROW AND INTERROW AREAS OF CHISEL AND RIDGE-TILLAGE SYSTEMS, Soil & tillage research, 35(3), 1995, pp. 167-174
Understanding linkages between C and N cycles will improve our ability
to estimate soil N supplying power. This study investigated temporal
patterns in C and N mineralization at two sampling locations within ri
dge tillage and chisel plow systems. The study was conducted on a Bran
dt silty clay loam (fine-silty over sandy or sandy skeletal, mixed Pac
hic Udic Haploboroll) near Aurora, SD. Maize (Zea mays L.) was planted
at the site in 1992 and 1993. In the chisel plow treatment, net C min
eralization rates in samples from the row and interrow areas were simi
lar. However, in the ridge tillage treatment, net C mineralization rat
es in samples from row areas were higher than those from valley areas
for seven and similar for five, of the 13 sampling dates. In 1992 and
1993, net N mineralization was influenced sampling date but not sampli
ng location. Net N and C mineralization peaks did not occur at the sam
e time. Mineralization peaks occurred during early spring for N and du
ring late spring to mid summer for C. Temporal changes in mineralized
C:N ratios indicate that organic substrate quality changed during the
year. This study shows that C and N mineralization linkages are comple
x and vary in both space and time, and suggest that problems associate
d with relating chemical N mineralization indices to field responses m
ay result from difficulties associated with estimating the effect of t
illage or climatic parameters on microbial activity.