The performance of variable rate fertilizer (VRF) manage-
ment practice was compared with the current farmers' practice
management (FPM) in experiments conducted on 45 VRF and
15 FPM fields at Icheon in Korea. The FPM fields were man-
aged by 17 growers without any interference from the resear-
cher. In the VRF treatments, the prescription rate for N, P2O5,
and K2O fertilizer was determined based on soil testing. The
importance of sufficient late-season N supply for achieving
higher rice yield has been highlighted in other studies (Bijay-
Singh et al. 2002; Peng and Cassman 1998; Perez et al. 1996). In
VRF experiments, the rate of N top-dressing rate at the panicle
initiation stage was determined from plant growth diagnosis to
optimize N-use efficiency and minimize losses through exces-
sive application.
In VRF fields, N fertilizer use was reduced by 30%, despite
an increase of 13% in K2O fertilizer use. The coefficient of vari-
ation (CV) of tiller and panicle number at VRF was lower than
at FPM. There was no difference in culm length and panicle
number between treatments at grain filling stage, but the coeffi-
cient of variation and the number of panicles per m2 was signifi-
cantly lower in VRF than in FPM fields. Rice yield at VRF was
not different to FPM despite a higher brown rice recovery and
1,000-grain weight in VRF fields. Under VRF management,
head rice yield was higher due to the significant higher head rice
ratio accompanied by low protein content of brown rice and low
variation of quality characteristics than under FPM. Mean milled
rice yield between treatments did not differ, however, head rice
yield was higher by 0.26 t ha-1 due to the greatly improved head
rice ratio at VRF fields. Both CV of head rice yield and protein
content at VRF were low and agronomic efficiency of applied N
increased by about 40% at VRF than at FPM.
The results of this study supported by other site-specific
nutrient management studies (Harmandeep et al. 2007) clearly
show that VRF technology has the potential for quality improve-
ment by reducing growth variability among individual fields,
higher head rice yield, and lower protein content of rice.
Furthermore, the use of VRF technology has the potential for
reducing the amount of fertilizer used on farms resulting in con-
siderable environmental and economic benefits
The performance of variable rate fertilizer (VRF) manage-
ment practice was compared with the current farmers' practice
management (FPM) in experiments conducted on 45 VRF and
15 FPM fields at Icheon in Korea. The FPM fields were man-
aged by 17 growers without any interference from the resear-
cher. In the VRF treatments, the prescription rate for N, P2O5,
and K2O fertilizer was determined based on soil testing. The
importance of sufficient late-season N supply for achieving
higher rice yield has been highlighted in other studies (Bijay-
Singh et al. 2002; Peng and Cassman 1998; Perez et al. 1996). In
VRF experiments, the rate of N top-dressing rate at the panicle
initiation stage was determined from plant growth diagnosis to
optimize N-use efficiency and minimize losses through exces-
sive application.
In VRF fields, N fertilizer use was reduced by 30%, despite
an increase of 13% in K2O fertilizer use. The coefficient of vari-
ation (CV) of tiller and panicle number at VRF was lower than
at FPM. There was no difference in culm length and panicle
number between treatments at grain filling stage, but the coeffi-
cient of variation and the number of panicles per m2 was signifi-
cantly lower in VRF than in FPM fields. Rice yield at VRF was
not different to FPM despite a higher brown rice recovery and
1,000-grain weight in VRF fields. Under VRF management,
head rice yield was higher due to the significant higher head rice
ratio accompanied by low protein content of brown rice and low
variation of quality characteristics than under FPM. Mean milled
rice yield between treatments did not differ, however, head rice
yield was higher by 0.26 t ha-1 due to the greatly improved head
rice ratio at VRF fields. Both CV of head rice yield and protein
content at VRF were low and agronomic efficiency of applied N
increased by about 40% at VRF than at FPM.
The results of this study supported by other site-specific
nutrient management studies (Harmandeep et al. 2007) clearly
show that VRF technology has the potential for quality improve-
ment by reducing growth variability among individual fields,
higher head rice yield, and lower protein content of rice.
Furthermore, the use of VRF technology has the potential for
reducing the amount of fertilizer used on farms resulting in con-
siderable environmental and economic benefits
การแปล กรุณารอสักครู่..