Effect of adding vermicompost, ammonium sulfate and fertilizer batches on the absorbed amounts of some nutrients and the yield and quality of summer squash

A field experiment was conducted at one of the research stations of the College of Agricultural Engineering Sciences / University of Baghdad in the Al-Jadiriyah region for the autumn season of 2021, located within latitude 33.27 north and longitude 44.39 east in Silty Loam soil with a split -split plot design with three replicates. To study the effect of adding vermicompost and ammonium sulfate fertilizers and batches on the yield and quality of summer squash, nitrogen fertilizer was added at three levels (100%, 0, 50%) from the fertilizer recommendation (0, 80, 160) kg N ha-1 (N0, N1, N2). ), using ammonium sulfate fertilizer containing (21% N) and organic fertilizer (vermicompost) were added at three levels (0, 5, 10) Mg ha-1 (V0, V1, V2) respectively, fertilizers were added in two batches after (10, 20) days of planting and three batches after (10,20 and 40) days of planting. The first batch was added after 10 days of planting. The concentration (N and P) in the fruits were measured, the amount of the total yield, the percentage of protein, the percentage of total soluble solids (TSS) and fruit hardness. The results showed the significant effect of adding vermicompost and ammonium sulfate fertilizers, the number of batches on the amount of nitrogen and phosphorous absorbed in the fruits, the total yield, the percentage of protein in the fruits, the percentage of total soluble solids (TSS) and the hardness of the fruits. The treatment P2V2N1 excelled and gave the highest amount of nitrogen absorbed in the fruits, which was 1995 kg N ha-1. Phosphorous absorbed in the fruits amounted to 172.10 kg P ha-1 and the highest total yield reached 21.53 Mg ha-1 . The percentage of protein in the fruits amounted to 36.63%, the percentage of total soluble solids TSS amounted to 4.90%, and the hardness of the fruits amounted to 10.27 B. From this, we conclude that by adding nitrogen fertilizer at the first level (N1) (80 kg N ha-1 ) and organic fertilizer (V2) (10 Mg ha-1 ) and in two batches (P2) we got the highest yield and the highest qualitative traits of hardness, protein percentage and TSS. Thus, we conclude that the organic fertilizer improved the qualitative traits, gave the highest yield and compensated for a part of the mineral fertilizer. The organic fertilizer has a role in raising the absorption efficiency of (N and P). Keywords: vermicompost fertilizer, ammonium sulfate fertilizer, summer squash.