Meta-Analysis of Surface and Drip Fertigation Effectiveness on Crop Yield, Fertilizer, and Water Productivity

The explosive growth of science and the dissemination of various results have confused researchers in various fields. Simple surveys and reviews of results collected in a specific area seem necessary. Meta-analysis as a structured method and using statistical methods aggregate the results of studies on a subject. In this study, in order to assess the surface and drip fertigation based on crop yield and water and fertilizer productivity, a meta-analysis approach was used. For this purpose, studies of eight databases were recruited, and, after reviewing them, 21 studies had the conditions to enter the meta-analysis. Combined results showed that both surface and drip fertigation methods significantly increased the indicators of crop yield and water and fertilizer productivity. Measuring the effect size of the results for crop yield in surface and drip fertigation methods compared to surface irrigation with traditional fertilization method was equal to 1.32 and 1.25, respectively. The effect size of water productivity for surface and drip fertigation compared to surface irrigation with traditional fertilization methods was 1.24 and 1.74. These values were 2.12 and 1.43, respectively, in terms of fertilizer productivity. Therefore, both surface and drip fertigation methods increase crop yield and water and fertilizer productivity. The results of this study are derived from the quantitative data of preliminary studies, to achieve higher accuracy, it is suggested that further studies be examined by meta-analysis.