Development of prescription-based liquid fertilizer application in the system of rice intensification
Uniform-based fertilizer application is still being normally used in nutrient management of System of Rice Intensification (SRI) with very less consideration of Precision Farming (PF). The overall study was to develop a precise prescription-based liquid fertilizer formula...
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Format: | Thesis |
Language: | English |
Published: |
2020
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Subjects: | |
Online Access: | http://psasir.upm.edu.my/id/eprint/85689/1/FK%202020%2069%20-%20ir.pdf |
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Summary: | Uniform-based fertilizer application is still being normally used in nutrient management of System
of Rice Intensification (SRI) with very less consideration of Precision Farming (PF).
The overall study was to develop a precise prescription-based liquid fertilizer
formulation for the SRI field by using Unmanned Aerial Vehicle (UAV). The aerial images of the SRI
field were captured using a digital camera mounted on a UAV flying at low altitude (< 50 m). The
precise amount of nitrogen (N) was then determined by using vegetation indices of IPCA-RGB model
and prescribed according to the actual requirement of the rice plant. A laboratory-scale
experiment in the greenhouse was performed to establish fertilizer formulation and found
that an additional foliar fertilization needs to be conducted during the grain formation
stage. A study on the performance of the UAV flying parameters and spraying requirements was
performed to establish the operating procedure of aerial fertilizer spraying. Results showed that
the droplet pattern and droplet deposition density (59.08 L/min) was higher with a lower
coefficient of variations (CV) of droplet uniformity (3.59%) when the UAV flying speed was
maintained at 2 m/s and spraying rate of 3.00 L/min at a constant height of 2 m above the rice
canopy compared to the higher-flying speeds (4 & 6 m/s) and lower spraying rates (0.75,
1.5, & 2.25 L/min). Twenty plots were set up according to 2 types of liquid fertilizer (organic and
inorganic) and 2 methods fertilizer based-rate (uniform and prescription) with 5 replications for
each of the treatments. Fertilizer spraying was 5 times during 15 Days After Transplanting (DAT),
35 DAT, 55 DAT, 65 DAT, 75 DAT and harvested at 110 DAT. Aerial image acquisition of the SRI field
with the IPCA-RGB model showed a positive result in determining N content for
precise fertilizer application. The IPCA-RGB model had a close relationship with SPAD chlorophyll
meter in the assessment of chlorophyll content at the rice leaf canopy scale during all the five
times fertilization periods. In terms of crop growth and yield performances, results
showed that treatment uniform-based rate with inorganic fertilizer had higher plant
heights (107.43cm) compared to other treatments. However, the treatment of
prescription-based with organic fertilizer showed higher performances for the number of tillers
(34a), the number of panicles (19a), and spikelet per hill (46a) compared to other treatments at p = 0.05. Moreover, prescription-based with organic fertilizer
treatment showed higher values for yield performances compared to other treatments namely; grain
yield (g) (771.35a), net grain yield (g) in 1m2 Crop Cutting Test (CCT) (614.13a), and effective
tillers in 1m2 CCT (309a) at p = 0.05. Thus, prescription-based treatment with organic fertilizer
shows the lowest moisture content (18.67%) compared to other treatments for the grain moisture
comparison. While, for the UAV performance of aerial spraying, treatments that spray prescribed
liquid fertilizer had a faster time to complete the spraying cycle and refilling process compared
to treatments of uniform- based rate. In terms of cost analysis, prescription-based treatment with
organic fertilizer had higher in total revenue (RM 9,405), net profit (RM 3,707.16), and
return of investment (ROI) (65.06%) compared to other treatments. However, organic-based
treatment either for uniform (RM 5,714.38) or prescription-based (RM 5,697.84) showed a higher
amount of production cost compared to inorganic-based treatment either for uniform (RM 5,669.54)
or prescription-based (RM 5,589.04). Overall, a prescription- based fertilizer application was
feasible to be applied to the rice plant with better yield performances and saving in
fertilizer amounts compared to uniform-based rate treatment. Thus, results from this
study can provide technical procedure, and theoretical basis for the application of precise
liquid fertilizer through the prescription-based
method and usage of UAV for liquid fertilizer spraying within the SRI farming. |
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