Effect of chemical fertilizer and humic acid on cabbage leaves' N, P, K and S concentrations (Brassica oleracea var. capitata L.)

A field study was carried out in one of the fields Jdeidet Al-Shatt district is, located 30 km from center Baquba Diyala governorate, during autumnal season 2021-2022 on silty loam soil classified to a level under Typic Torrifluvent according modern American classification know effect adding chemical fertilizer and humic acid availability nitrogen, phosphorus potassium concentrations for cabbage leaves, randomized complete block design (RCBD) by using three replicates. The first factor compound NPK( 20:20:20 ) added at different levels 0, 150 kg ha-1, 300 while second 15 ha-1. Fertilizers were making an incision around plant two stages, when planting 43 days after date batch. results showed that ha-1 led significant differences phosphorous, sulfur elements inner where reached 2.55%,0.34%, 2.95%,1.36% respectively, outer leaves. In contrast, phosphorous 4.00 %, 0.34%, 2.67%, While superiority 2.33%, 0.32%, 2.77%,1.47% leaves 3.80 %,0.31 %,2.49%. Keywords: fertilizer, acid, N,P, K S, cabbage.