TY  - JA
AU  - Singh,B.
AU  - Singh,V.
AU  - Purba,J.
AU  - Sharma,R.K.
AU  - Jat,M.L.
AU  - Singh,Y.
AU  - Thind,H.S.
AU  - Gupta,R.K.
AU  - Chaudhary,O.P.
AU  - Chandna,P.
AU  - Khurana,H.S.
AU  - Kumar,A.
AU  - Singh,J.
AU  - Uppal,H.S.
AU  - Uppal,R.K.
AU  - Vashistha,M.
AU  - Gupta,R.
TI  - Site-specific fertilizer nitrogen management in irrigated transplanted rice (Oryza sativa) using an optical sensor
SN  - 1385-2256
PY  - 2015///
CY  - New York
PB  - Springer
KW  - Rice
KW  - AGROVOC
KW  - Transplanting
KW  - Nitrogen fertilizers
N1  - Peer review
N2  - Blanket fertilizer nitrogen (N) recommendations for large irrigated transplanted rice tracts lead to low N use-efficiency (NUE) due to field-to-field variability in soil N supply and seasonal variability in yield. To achieve high NUE, a fertilizer N management strategy based on visible and near-infrared spectral response from plant canopies using a Green- SeekerTM optical sensor was evaluated. Seven field experiments were conducted during 2005–2007 at two locations in the Indo-Gangetic plains of South Asia to define relationships between in-season sensor measurements at panicle initiation (PI) stage and up to 2 weeks later, and yield of rice. During 2006–2010, seven field experiments were conducted to assess the sensor-based N management strategy and to work out the prescriptive N management to be followed prior to applying sensor-guided fertilizer dose. During 2010 and 2011, the sensorbased N management strategy was evaluated versus farmers’ fertilizer practice at 19 on-farm locations. Relationships with R2 values 0.51 (n = 131), 0.45 (n = 74) and 0.49 (n = 131), respectively, were observed between in-season sensor-based estimates of yield at 42 (PI stage), 49 and 56 days after transplanting of rice and actual grain yield of rice. Applications of 30 kg N ha-1 at transplanting and 45 kg N ha-1 at active tillering stage were found to be the appropriate prescriptive strategy before applying the GreenSeeker-guided dose at PI stage. Sensor-guided N management resulted in similar grain yields as the blanket rate farmer practice, but with reduced N rates, i.e. greater recovery efficiency (by 5.5–21.7 %) and agronomic efficiency [by 4.7–11.7 kg grain (kg N applied)-1]. This study revealed that high yields coupled with high NUE in transplanted rice can be achieved by replacing blanket fertilizer recommendation by an optical sensor-based N management strategy consisting of applying a moderate amount of fertilizerNat transplanting and enough fertilizerNto meet the high N demand during the period between active tillering and PI before applying a sensorguided fertilizer N dose at PI stage of rice
UR  - https://hdl.handle.net/20.500.12665/143
T2  - Precision Agriculture
DO  - https://doi.org/10.1007/s11119-015-9389-6
ER  -