S678 : The study of effective factors on the heterogeneity of spatial distribution of winter wheat yield using geostatistic and remote sensing methods
Thesis > Central Library of Shahrood University > Agricultural Engineering > MSc > 2019
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Abstarct: Geostatistical and remote sensing techniques were used to describe some factors affecting spatial distribution variability of wheat yield on a winter wheat field located in Faculty of Agriculture, Shahrood University of Technology in 2017-2018 growing season. Different wheat traits such as density, height, chlorophyll content (spad number), biological and grain yield, weed density and biomass were measured at 110 points of field baxsed on a 8× 8 m grid. Some soil properties such as soil microbial respiration, total nitrogen, available potassium and phosphorus, electrical conductivity (Ec) and pH also were measured at the same places of wheat traits on a 16× 16 m grid. Also, in order to investigation of biological and grain yield of wheat using remote sensing, an aerial image was taken by a quadcopter from 120 m and then numerical values of aerial image pixels extracted and analyzed. Results showed that, different traits of wheat such as density, height, chlorophyll content (spad number), biological and grain yield and weed density and biomass had a patchy distribution pattern. Soil properties also showed heterogeneous spatial patterns on the field. Cross-semivariograms showed a moderate spatial dependence between wheat biological yield with plant density, plant height and grain yield. Grain yield showed poor and moderate spatial continuity with density and height of wheat respectively. Weed density and biomass showed negative spatial correlation of 75.89 to 62.50% with wheat biological yield and negative spatial correlation of 91.9 and 56.25 with grain yield of wheat respectively. Results showed that wheat biological distribution patterns had a strong spatial continuity with available potassium and phosphorus, electrical conductivity (Ec) and pH and while it had a negative poor correlation with microbial respiration and nitrogen. Grain yield patterns also showed a weak to strong (19.22 to 98%) with available potassium and phosphorus, electrical conductivity (Ec) and pH and a moderate negative correlation of 60.76 and 53.49% with microbial respiration and nitrogen respectively. Remote sensing data showed a strong correlation of 88.23 and 78.12% with biological and grain yield of wheat respectively. Remote sensing data also showed strong correlation with available potassium and phosphorus and pH. High spatial dependence was observed between the maps of biological and grain yield of wheat. Also weed density and biomass patterns on the maps of weeds were similar to patterns of wheat biological and grain yield on the maps. baxse on this experiment results, different wheat traits such as density, height, chlorophyll content (spad number), biological and grain yield, weed density and biomass and soil properties such as soil microbial respiration, total nitrogen, available potassium and phosphorus, electrical conductivity (Ec) and pH had a patchy distribution and so they can, depending on their degree of impact affect the growth and yield patterns of wheat in a non-uniform manner.
Keywords:
#Spatial distribution #Soil properties #Geostatistics #Weeds #Growth heterogeneity # Keeping place: Central Library of Shahrood University
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