Effectiveness of different fertilizer levels in surface and drip fertigation

The growing population has increased the need for food day by day. Therefore, it is necessary to improve the yield of plants per unit area. The increase in crop yield is largely due to the use of chemical fertilizers. This has led to the improper use of fertilizers by farmers. So far, many studies have examined the effect of surface (SF) and drip fertigation (DF) on surface (SC) and drip (DC) irrigation along with traditional fertilization at different levels of fertilizer for crop yield index. But each of these studies has been done under different circumstances. Due to the dispersion of results and the lack of a general conclusion from the published results, meta-analysis is required as a structured method to achieve a single result in relation to the impact of different levels of fertigation on the mentioned indicators. In this study, by performing meta-analysis on 21 studies in the field of fertigation, the effect of different levels of fertilizer was investigated. The results of each of these studies were classified into subgroups of different levels of fertilizer, which include subgroups of more than 100%, 100%, 70 to 100% and 50 to 70% of the recommended plant fertilizer requirements. The highest increase in crop yield was obtained at 100% of the recommended dose and the effect size was 1.25, but there was no significant difference between the fertilizer levels of 100% and 70% to 100%. Based on these results, the most suitable fertilizer level is 70 to 100%. In this subgroup, 30% of fertilizer consumption can be reduced without a significant reduction in crop yield.