Research Information System
in: Climate Challenge on Agrciculture, Murat YILDIRIM,Gökhan ÇAMOĞLU,Arda AKÇAL, Editor, Holistence Publications, Çanakkale, pp.115-125, 2022
Today, the use
of drip irrigation method has become mandatory to protect our water resources,
which are decreasing due to global climate change. In drip irrigation,
irrigation water can be applied automatically by following the soil moisture.
However, it is necessary to measure in the field cover percentage, which is one
of the most important parameters in drip irrigation. This goes against the
logic of automation. Therefore, this study, it is aimed to determine the cover
percentage which is used in the calculation of the amount of irrigation water
to be given in drip irrigation using a spectral reflectance sensor (Decagon
SRS-Nr NDVI) compatible with automation. The study was carried out on pepper
plants in Canakkale in 2017 and 2018. One full irrigation (I-100) and three
water stress (I-25, I-50 and I-75) levels were applied in the research. Before
each irrigation, three representative plants were selected from each plot and
both cover percentage and NDVI measurements were taken on these plants.
According to the results, the highest values in both cover percentage and NDVI
were at the S100 treatment. The cover percentage values in each treatment
increased until a certain growing period in both years, then it started to
decrease. Its highest values were 67% in the first year and 62% in the second
year. In this case, even during the peak vegetation period, approximately 35%
of the area was not irrigated. NDVI values also followed a similar trend to the
cover percentage. The values increased as the plants grew and became more
stable after a certain period. Its highest values were 0.85 in the first year
and 0.80 in the second year. As a result
of the regression analysis, significant relationships (p<0.01) were found
between the cover percentage and NDVI. According to the data from two years,
the coefficient of determination (R2) value was obtained as 0.65. Accordingly,
it can be said that NDVI sensors can be used in both the estimation of the
cover percentage for determining the irrigation amount and the determination of
the water stress level in pepper.